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linux-sg2042/include/linux/pinctrl/pinctrl.h

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drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
/*
* Interface the pinctrl subsystem
*
* Copyright (C) 2011 ST-Ericsson SA
* Written on behalf of Linaro for ST-Ericsson
* This interface is used in the core to keep track of pins.
*
* Author: Linus Walleij <linus.walleij@linaro.org>
*
* License terms: GNU General Public License (GPL) version 2
*/
#ifndef __LINUX_PINCTRL_PINCTRL_H
#define __LINUX_PINCTRL_PINCTRL_H
#ifdef CONFIG_PINCTRL
#include <linux/radix-tree.h>
#include <linux/list.h>
#include <linux/seq_file.h>
pinctrl: split pincontrol states into its own header Move the pin control state defines into its own header file, since it is used both by machine.h which is facing the platform and by consumer.h which is facing the drivers, and pinctrl.h which is pinctrl-driver internal, let's not have each and every .h file include all others, then isolation is moot. Acked-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-07 04:15:51 +08:00
#include "pinctrl-state.h"
pinctrl: introduce PINCTRL_STATE_DEFAULT, define hogs as that state This provides a single centralized name for the default state. Update PIN_MAP_* macros to use this state name, instead of requiring the user to pass a state name in. With this change, hog entries in the mapping table are defined as those with state name PINCTRL_STATE_DEFAULT, i.e. all entries have the same name. This interacts badly with the nested iteration over mapping table entries in pinctrl_hog_maps() and pinctrl_hog_map() which would now attempt to claim each hog mapping table entry multiple times. Replacing the custom hog code with a simple pinctrl_get()/pinctrl_enable(). Update documentation and mapping tables to use this. Signed-off-by: Stephen Warren <swarren@nvidia.com> Acked-by: Dong Aisheng <dong.aisheng@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-02 09:48:32 +08:00
pinctrl: forward-declare struct device Add a dummy declaration of struct device to avoid the following warning: In file included from include/linux/pinctrl/machine.h:15:0, from arch/arm/mach-tegra/board-pinmux.h:18, from arch/arm/mach-tegra/board-trimslice-pinmux.c:20: include/linux/pinctrl/pinctrl.h:115:12: warning: 'struct device' declared inside parameter list [enabled by default] include/linux/pinctrl/pinctrl.h:115:12: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default] Signed-off-by: Stephen Warren <swarren@wwwdotorg.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-07 03:12:12 +08:00
struct device;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
struct pinctrl_dev;
struct pinmux_ops;
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-20 00:14:33 +08:00
struct pinconf_ops;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
struct gpio_chip;
/**
* struct pinctrl_pin_desc - boards/machines provide information on their
* pins, pads or other muxable units in this struct
* @number: unique pin number from the global pin number space
* @name: a name for this pin
*/
struct pinctrl_pin_desc {
unsigned number;
const char *name;
};
/* Convenience macro to define a single named or anonymous pin descriptor */
#define PINCTRL_PIN(a, b) { .number = a, .name = b }
#define PINCTRL_PIN_ANON(a) { .number = a }
/**
* struct pinctrl_gpio_range - each pin controller can provide subranges of
* the GPIO number space to be handled by the controller
* @node: list node for internal use
* @name: a name for the chip in this range
* @id: an ID number for the chip in this range
* @base: base offset of the GPIO range
pinctrl: add a pin_base for sparse gpio-ranges This patch enables mapping a base offset of gpio ranges with a pin offset even if does'nt matched. A base of pinctrl_gpio_range means a base offset of gpio. However, we cannot convert gpio to pin number for sparse gpio ranges just only using a gpio base offset. We can convert a gpio to real pin number(even if not matched) using a new pin_base which means a base pin offset of requested gpio range. Now, the pin control subsystem passes the pin base offset to the pinmux driver. For example, let's assume below two gpio ranges in the system. static struct pinctrl_gpio_range gpio_range_a = { .name = "chip a", .id = 0, .base = 32, .pin_base = 32, .npins = 16, .gc = &chip_a; }; static struct pinctrl_gpio_range gpio_range_b = { .name = "chip b", .id = 0, .base = 48, .pin_base = 64, .npins = 8, .gc = &chip_b; }; We can calucalate a exact pin ranges even if doesn't matched with gpio ranges. chip a: gpio-range : [32 .. 47] pin-range : [32 .. 47] chip b: gpio-range : [48 .. 55] pin-range : [64 .. 71] Signed-off-by: Chanho Park <chanho61.park@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-11-11 17:47:58 +08:00
* @pin_base: base pin number of the GPIO range
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
* @npins: number of pins in the GPIO range, including the base number
* @gc: an optional pointer to a gpio_chip
*/
struct pinctrl_gpio_range {
struct list_head node;
const char *name;
unsigned int id;
unsigned int base;
pinctrl: add a pin_base for sparse gpio-ranges This patch enables mapping a base offset of gpio ranges with a pin offset even if does'nt matched. A base of pinctrl_gpio_range means a base offset of gpio. However, we cannot convert gpio to pin number for sparse gpio ranges just only using a gpio base offset. We can convert a gpio to real pin number(even if not matched) using a new pin_base which means a base pin offset of requested gpio range. Now, the pin control subsystem passes the pin base offset to the pinmux driver. For example, let's assume below two gpio ranges in the system. static struct pinctrl_gpio_range gpio_range_a = { .name = "chip a", .id = 0, .base = 32, .pin_base = 32, .npins = 16, .gc = &chip_a; }; static struct pinctrl_gpio_range gpio_range_b = { .name = "chip b", .id = 0, .base = 48, .pin_base = 64, .npins = 8, .gc = &chip_b; }; We can calucalate a exact pin ranges even if doesn't matched with gpio ranges. chip a: gpio-range : [32 .. 47] pin-range : [32 .. 47] chip b: gpio-range : [48 .. 55] pin-range : [64 .. 71] Signed-off-by: Chanho Park <chanho61.park@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-11-11 17:47:58 +08:00
unsigned int pin_base;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
unsigned int npins;
struct gpio_chip *gc;
};
/**
* struct pinctrl_ops - global pin control operations, to be implemented by
* pin controller drivers.
* @list_groups: list the number of selectable named groups available
* in this pinmux driver, the core will begin on 0 and call this
* repeatedly as long as it returns >= 0 to enumerate the groups
* @get_group_name: return the group name of the pin group
* @get_group_pins: return an array of pins corresponding to a certain
* group selector @pins, and the size of the array in @num_pins
* @pin_dbg_show: optional debugfs display hook that will provide per-device
* info for a certain pin in debugfs
*/
struct pinctrl_ops {
int (*list_groups) (struct pinctrl_dev *pctldev, unsigned selector);
const char *(*get_group_name) (struct pinctrl_dev *pctldev,
unsigned selector);
int (*get_group_pins) (struct pinctrl_dev *pctldev,
unsigned selector,
pinctrl: get_group_pins() const fixes get_group_pins() "returns" a pointer to an array of const objects, through a pointer parameter. Fix the prototype so what's pointed at by the returned pointer is const, rather than the function parameter being const. This also allows the removal of a cast in each of the two current pinmux drivers. Signed-off-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-20 06:19:25 +08:00
const unsigned **pins,
unsigned *num_pins);
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
void (*pin_dbg_show) (struct pinctrl_dev *pctldev, struct seq_file *s,
unsigned offset);
};
/**
* struct pinctrl_desc - pin controller descriptor, register this to pin
* control subsystem
* @name: name for the pin controller
* @pins: an array of pin descriptors describing all the pins handled by
* this pin controller
* @npins: number of descriptors in the array, usually just ARRAY_SIZE()
* of the pins field above
* @pctlops: pin control operation vtable, to support global concepts like
* grouping of pins, this is optional.
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-20 00:14:33 +08:00
* @pmxops: pinmux operations vtable, if you support pinmuxing in your driver
* @confops: pin config operations vtable, if you support pin configuration in
* your driver
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
* @owner: module providing the pin controller, used for refcounting
*/
struct pinctrl_desc {
const char *name;
struct pinctrl_pin_desc const *pins;
unsigned int npins;
struct pinctrl_ops *pctlops;
struct pinmux_ops *pmxops;
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-20 00:14:33 +08:00
struct pinconf_ops *confops;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
struct module *owner;
};
/* External interface to pin controller */
extern struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
struct device *dev, void *driver_data);
extern void pinctrl_unregister(struct pinctrl_dev *pctldev);
extern bool pin_is_valid(struct pinctrl_dev *pctldev, int pin);
extern void pinctrl_add_gpio_range(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range);
extern void pinctrl_remove_gpio_range(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range);
extern const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev);
extern void *pinctrl_dev_get_drvdata(struct pinctrl_dev *pctldev);
#else
pinctrl: fix "warning: 'struct pinctrl_dev' declared inside parameter list" when pinctl subsystem is not selected, when compiling drivers including the include/linux/pinctrl/pinctrl.h, we will get the warning as below: In file included from include/linux/pinctrl/pinmux.h:17, from drivers/tty/serial/sirfsoc_uart.c:25: include/linux/pinctrl/pinctrl.h:126: warning: 'struct pinctrl_dev' declared inside parameter list include/linux/pinctrl/pinctrl.h:126: warning: its scope is only this definition or declaration, which is probably not what you want Signed-off-by: Barry Song <Baohua.Song@csr.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-28 11:38:24 +08:00
struct pinctrl_dev;
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
pinctrl: add a pin config interface This add per-pin and per-group pin config interfaces for biasing, driving and other such electronic properties. The details of passed configurations are passed in an opaque unsigned long which may be dereferences to integer types, structs or lists on either side of the configuration interface. ChangeLog v1->v2: - Clear split of terminology: we now have pin controllers, and those may support two interfaces using vtables: pin multiplexing and pin configuration. - Break out pin configuration to its own C file, controllers may implement only config without mux, and vice versa, so keep each sub-functionality of pin controllers separate. Introduce CONFIG_PINCONF in Kconfig. - Implement some core logic around pin configuration in the pinconf.c file. - Remove UNKNOWN config states, these were just surplus baggage. - Remove FLOAT config state - HIGH_IMPEDANCE should be enough for everyone. - PIN_CONFIG_POWER_SOURCE added to handle switching the power supply for the pin logic between different sources - Explicit DISABLE config enums to turn schmitt-trigger, wakeup etc OFF. - Update documentation to reflect all the recent reasoning. ChangeLog v2->v3: - Twist API around to pass around arrays of config tuples instead of (param, value) pairs everywhere. - Explicit drive strength semantics for push/pull and similar drive modes, this shall be the number of drive stages vs nominal load impedance, which should match the actual electronics used in push/pull CMOS or TTY totempoles. - Drop load capacitance configuration - I probably don't know what I'm doing here so leave it out. - Drop PIN_CONFIG_INPUT_SCHMITT_OFF, instead the argument zero to PIN_CONFIG_INPUT_SCHMITT turns schmitt trigger off. - Drop PIN_CONFIG_NORMAL_POWER_MODE and have a well defined argument to PIN_CONFIG_LOW_POWER_MODE to get out of it instead. - Drop PIN_CONFIG_WAKEUP_ENABLE/DISABLE and just use PIN_CONFIG_WAKEUP with defined value zero to turn wakeup off. - Add PIN_CONFIG_INPUT_DEBOUNCE for configuring debounce time on input lines. - Fix a bug when we tried to configure pins for pin controllers without pinconf support. - Initialized debugfs properly so it works. - Initialize the mutex properly and lock around config tampering sections. - Check the return value from get_initial_config() properly. ChangeLog v3->v4: - Export the pin_config_get(), pin_config_set() and pin_config_group() functions. - Drop the entire concept of just getting initial config and keeping track of pin states internally, instead ask the pins what state they are in. Previous idea was plain wrong, if the device cannot keep track of its state, the driver should do it. - Drop the generic configuration layout, it seems this impose too much restriction on some pin controllers, so let them do things the way they want and split off support for generic config as an optional add-on. ChangeLog v4->v5: - Introduce two symmetric driver calls for group configuration, .pin_config_group_[get|set] and corresponding external calls. - Remove generic semantic meanings of return values from config calls, these belong in the generic config patch. Just pass the return value through instead. - Add a debugfs entry "pinconf-groups" to read status from group configuration only, also slam in a per-group debug callback in the pinconf_ops so custom drivers can display something meaningful for their pins. - Fix some dangling newline. - Drop dangling #else clause. - Update documentation to match the above. ChangeLog v5->v6: - Change to using a pin name as parameter for the [get|set]_config() functions, as suggested by Stephen Warren. This is more natural as names will be what a developer has access to in written documentation etc. ChangeLog v6->v7: - Refactor out by-pin and by-name get/set functions, only expose the by-name functions externally, expose the by-pin functions internally. - Show supported pin control functionality in the debugfs pinctrl-devices file. Acked-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-10-20 00:14:33 +08:00
/* Sufficiently stupid default functions when pinctrl is not in use */
drivers: create a pin control subsystem This creates a subsystem for handling of pin control devices. These are devices that control different aspects of package pins. Currently it handles pinmuxing, i.e. assigning electronic functions to groups of pins on primarily PGA and BGA type of chip packages which are common in embedded systems. The plan is to also handle other I/O pin control aspects such as biasing, driving, input properties such as schmitt-triggering, load capacitance etc within this subsystem, to remove a lot of ARM arch code as well as feature-creepy GPIO drivers which are implementing the same thing over and over again. This is being done to depopulate the arch/arm/* directory of such custom drivers and try to abstract the infrastructure they all need. See the Documentation/pinctrl.txt file that is part of this patch for more details. ChangeLog v1->v2: - Various minor fixes from Joe's and Stephens review comments - Added a pinmux_config() that can invoke custom configuration with arbitrary data passed in or out to/from the pinmux driver ChangeLog v2->v3: - Renamed subsystem folder to "pinctrl" since we will likely want to keep other pin control such as biasing in this subsystem too, so let us keep to something generic even though we're mainly doing pinmux now. - As a consequence, register pins as an abstract entity separate from the pinmux. The muxing functions will claim pins out of the pin pool and make sure they do not collide. Pins can now be named by the pinctrl core. - Converted the pin lookup from a static array into a radix tree, I agreed with Grant Likely to try to avoid any static allocation (which is crap for device tree stuff) so I just rewrote this to be dynamic, just like irq number descriptors. The platform-wide definition of number of pins goes away - this is now just the sum total of the pins registered to the subsystem. - Make sure mappings with only a function name and no device works properly. ChangeLog v3->v4: - Define a number space per controller instead of globally, Stephen and Grant requested the same thing so now maps need to define target controller, and the radix tree of pin descriptors is a property on each pin controller device. - Add a compulsory pinctrl device entry to the pinctrl mapping table. This must match the pinctrl device, like "pinctrl.0" - Split the file core.c in two: core.c and pinmux.c where the latter carry all pinmux stuff, the core is for generic pin control, and use local headers to access functionality between files. It is now possible to implement a "blank" pin controller without pinmux capabilities. This split will make new additions like pindrive.c, pinbias.c etc possible for combined drivers and chunks of functionality which is a GoodThing(TM). - Rewrite the interaction with the GPIO subsystem - the pin controller descriptor now handles this by defining an offset into the GPIO numberspace for its handled pin range. This is used to look up the apropriate pin controller for a GPIO pin. Then that specific GPIO range is matched 1-1 for the target controller instance. - Fixed a number of review comments from Joe Perches. - Broke out a header file pinctrl.h for the core pin handling stuff that will be reused by other stuff than pinmux. - Fixed some erroneous EXPORT() stuff. - Remove mispatched U300 Kconfig and Makefile entries - Fixed a number of review comments from Stephen Warren, not all of them - still WIP. But I think the new mapping that will specify which function goes to which pin mux controller address 50% of your concerns (else beat me up). ChangeLog v4->v5: - Defined a "position" for each function, so the pin controller now tracks a function in a certain position, and the pinmux maps define what position you want the function in. (Feedback from Stephen Warren and Sascha Hauer). - Since we now need to request a combined function+position from the machine mapping table that connect mux settings to drivers, it was extended with a position field and a name field. The name field is now used if you e.g. need to switch between two mux map settings at runtime. - Switched from a class device to using struct bus_type for this subsystem. Verified sysfs functionality: seems to work fine. (Feedback from Arnd Bergmann and Greg Kroah-Hartman) - Define a per pincontroller list of GPIO ranges from the GPIO pin space that can be handled by the pin controller. These can be added one by one at runtime. (Feedback from Barry Song) - Expanded documentation of regulator_[get|enable|disable|put] semantics. - Fixed a number of review comments from Barry Song. (Thanks!) ChangeLog v5->v6: - Create an abstract pin group concept that can sort pins into named and enumerated groups no matter what the use of these groups may be, one possible usecase is a group of pins being muxed in or so. The intention is however to also use these groups for other pin control activities. - Make it compulsory for pinmux functions to associate with at least one group, so the abstract pin group concept is used to define the groups of pins affected by a pinmux function. The pinmux driver interface has been altered so as to enforce a function to list applicable groups per function. - Provide an optional .group entry in the pinmux machine map so the map can select beteween different available groups to be used with a certain function. - Consequent changes all over the place so that e.g. debugfs present reasonable information about the world. - Drop the per-pin mux (*config) function in the pinmux_ops struct - I was afraid that this would start to be used for things totally unrelated to muxing, we can introduce that to the generic struct pinctrl_ops if needed. I want to keep muxing orthogonal to other pin control subjects and not mix these things up. ChangeLog v6->v7: - Make it possible to have several map entries matching the same device, pin controller and function, but using a different group, and alter the semantics so that pinmux_get() will pick all matching map entries, and store the associated groups in a list. The list will then be iterated over at pinmux_enable()/pinmux_disable() and corresponding driver functions called for each defined group. Notice that you're only allowed to map multiple *groups* to the same { device, pin controller, function } triplet, attempts to map the same device to multiple pin controllers will for example fail. This is hopefully the crucial feature requested by Stephen Warren. - Add a pinmux hogging field to the pinmux mapping entries, and enable the pinmux core to hog pinmux map entries. This currently only works for pinmuxes without assigned devices as it looks now, but with device trees we can look up the corresponding struct device * entries when we register the pinmux driver, and have it hog each pinmux map in turn, for a simple approach to non-dynamic pin muxing. This addresses an issue from Grant Likely that the machine should take care of as much of the pinmux setup as possible, not the devices. By supplying a list of hogs, it can now instruct the core to take care of any static mappings. - Switch pinmux group retrieveal function to grab an array of strings representing the groups rather than an array of unsigned and rewrite accordingly. - Alter debugfs to show the grouplist handled by each pinmux. Also add a list of hogs. - Dynamically allocate a struct pinmux at pinmux_get() and free it at pinmux_put(), then add these to the global list of pinmuxes active as we go along. - Go over the list of pinmux maps at pinmux_get() time and repeatedly apply matches. - Retrieve applicable groups per function from the driver as a string array rather than a unsigned array, then lookup the enumerators. - Make the device to pinmux map a singleton - only allow the mapping table to be registered once and even tag the registration function with __init so it surely won't be abused. - Create a separate debugfs file to view the pinmux map at runtime. - Introduce a spin lock to the pin descriptor struct, lock it when modifying pin status entries. Reported by Stijn Devriendt. - Fix up the documentation after review from Stephen Warren. - Let the GPIO ranges give names as const char * instead of some fixed-length string. - add a function to unregister GPIO ranges to mirror the registration function. - Privatized the struct pinctrl_device and removed it from the <linux/pinctrl/pinctrl.h> API, the drivers do not need to know the members of this struct. It is now in the local header "core.h". - Rename the concept of "anonymous" mux maps to "system" muxes and add convenience macros and documentation. ChangeLog v7->v8: - Delete the leftover pinmux_config() function from the <linux/pinctrl/pinmux.h> header. - Fix a race condition found by Stijn Devriendt in pin_request() ChangeLog v8->v9: - Drop the bus_type and the sysfs attributes and all, we're not on the clear about how this should be used for e.g. userspace interfaces so let us save this for the future. - Use the right name in MAINTAINERS, PIN CONTROL rather than PINMUX - Don't kfree() the device state holder, let the .remove() callback handle this. - Fix up numerous kerneldoc headers to have one line for the function description and more verbose documentation below the parameters ChangeLog v9->v10: - pinctrl: EXPORT_SYMBOL needs export.h, folded in a patch from Steven Rothwell - fix pinctrl_register error handling, folded in a patch from Axel Lin - Various fixes to documentation text so that it's consistent. - Removed pointless comment from drivers/Kconfig - Removed dependency on SYSFS since we removed the bus in v9. - Renamed hopelessly abbreviated pctldev_* functions to the more verbose pinctrl_dev_* - Drop mutex properly when looking up GPIO ranges - Return NULL instead of ERR_PTR() errors on registration of pin controllers, using cast pointers is fragile. We can live without the detailed error codes for sure. Cc: Stijn Devriendt <highguy@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Grant Likely <grant.likely@secretlab.ca> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Barry Song <21cnbao@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2011-05-03 02:50:54 +08:00
static inline bool pin_is_valid(struct pinctrl_dev *pctldev, int pin)
{
return pin >= 0;
}
#endif /* !CONFIG_PINCTRL */
#endif /* __LINUX_PINCTRL_PINCTRL_H */