Commit Graph

67 Commits

Author SHA1 Message Date
Sachin Kamat 2917e8338c pinctrl: core: Make pinctrl_release static
'pinctrl_release' is used only in this file. Hence make it static.

Without this patch we get the following sparse error:
drivers/pinctrl/core.c:815:6: warning:
symbol 'pinctrl_release' was not declared. Should it be static?

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-30 11:00:58 +01:00
Linus Walleij ab78029ecc drivers/pinctrl: grab default handles from device core
This makes the device core auto-grab the pinctrl handle and set
the "default" (PINCTRL_STATE_DEFAULT) state for every device
that is present in the device model right before probe. This will
account for the lion's share of embedded silicon devcies.

A modification of the semantics for pinctrl_get() is also done:
previously if the pinctrl handle for a certain device was already
taken, the pinctrl core would return an error. Now, since the
core may have already default-grabbed the handle and set its
state to "default", if the handle was already taken, this will
be disregarded and the located, previously instanitated handle
will be returned to the caller.

This way all code in drivers explicitly requesting their pinctrl
handlers will still be functional, and drivers that want to
explicitly retrieve and switch their handles can still do that.
But if the desired functionality is just boilerplate of this
type in the probe() function:

struct pinctrl  *p;

p = devm_pinctrl_get_select_default(&dev);
if (IS_ERR(p)) {
   if (PTR_ERR(p) == -EPROBE_DEFER)
        return -EPROBE_DEFER;
        dev_warn(&dev, "no pinctrl handle\n");
}

The discussion began with the addition of such boilerplate
to the omap4 keypad driver:
http://marc.info/?l=linux-input&m=135091157719300&w=2

A previous approach using notifiers was discussed:
http://marc.info/?l=linux-kernel&m=135263661110528&w=2
This failed because it could not handle deferred probes.

This patch alone does not solve the entire dilemma faced:
whether code should be distributed into the drivers or
if it should be centralized to e.g. a PM domain. But it
solves the immediate issue of the addition of boilerplate
to a lot of drivers that just want to grab the default
state. As mentioned, they can later explicitly retrieve
the handle and set different states, and this could as
well be done by e.g. PM domains as it is only related
to a certain struct device * pointer.

ChangeLog v4->v5 (Stephen):
- Simplified the devicecore grab code.
- Deleted a piece of documentation recommending that pins
  be mapped to a device rather than hogged.
ChangeLog v3->v4 (Linus):
- Drop overzealous NULL checks.
- Move kref initialization to pinctrl_create().
- Seeking Tested-by from Stephen Warren so we do not disturb
  the Tegra platform.
- Seeking ACK on this from Greg (and others who like it) so I
  can merge it through the pinctrl subsystem.
ChangeLog v2->v3 (Linus):
- Abstain from using IS_ERR_OR_NULL() in the driver core,
  Russell recently sent a patch to remove it. Handle the
  NULL case explicitly even though it's a bogus case.
- Make sure we handle probe deferral correctly in the device
  core file. devm_kfree() the container on error so we don't
  waste memory for devices without pinctrl handles.
- Introduce reference counting into the pinctrl core using
  <linux/kref.h> so that we don't release pinctrl handles
  that have been obtained for two or more places.
ChangeLog v1->v2 (Linus):
- Only store a pointer in the device struct, and only allocate
  this if it's really used by the device.

Cc: Felipe Balbi <balbi@ti.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Mitch Bradley <wmb@firmworks.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Rickard Andersson <rickard.andersson@stericsson.com>
Cc: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
[swarren: fixed and simplified error-handling in pinctrl_bind_pins(), to
correctly handle deferred probe. Removed admonition from docs not to use
pinctrl hogs for devices]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-23 16:39:51 +01:00
Haojian Zhuang d6e99abb42 pinctrl: core: get devname from pinctrl_dev
Add new function to get devname from pinctrl_dev. pinctrl_dev_get_name()
can only get pinctrl description name. If we want to use gpio driver to
find pinctrl device node, we need to fetch the pinctrl device name.

Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-21 15:14:39 +01:00
Julien Delacou 840a47ba43 pinctrl: add sleep mode management for hogs
This fix allows handling sleep mode for hogged
pins in pinctrl. It provides functions to set pins
to sleep/default configurations according to their
current state.

Signed-off-by: Julien Delacou <julien.delacou@stericsson.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-11 21:48:05 +01:00
Linus Walleij 89216494ae pinctrl: skip deferral of hogs
Up until now, as hogs were always taken at the end of the
pin control device registration, it didn't cause any problem.
But when starting to hog pins from the device core it will
cause deferral of the pin controller device itself since the
default pin fetch is done *before* the device probes, so
let's fix this annoyance (which is also aesthetically ugly).

Also take some care to make sure that if any one map entry
results in a deferral rather than a failure, then that
deferral will take precedence.

Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-01-11 21:48:05 +01:00
Linus Walleij b0666ba474 pinctrl: fix comment mistake
This variable pertains to pinctrl handles not muxes
specifically.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-12-26 01:59:52 +01:00
Linus Walleij 9afbefb227 pinctrl: add function to retrieve range from pin
This adds a function to the pinctrl core to retrieve the GPIO
range associated with a certain pin for a certain controller.
This is needed when a pinctrl driver want to look up the
corresponding struct gpio_chip for a certain pin. As the
GPIO drivers can now create these ranges themselves, the
pinctrl driver no longer knows about all its associated GPIO
chips.

Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-21 08:55:12 +01:00
Linus Walleij dfa9751548 pinctrl: make range registration defer properly
This makes the pinctrl_find_and_add_gpio_range() return
-EPROBE_DEFER if the range hosting pin controller cannot be
located. We may assume that the common case for why adding a
range fails is that the targe pin controller device has not
probed yet.

Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-21 08:55:10 +01:00
Linus Walleij 192c369c61 gpiolib: rename find_pinctrl_*
Rename the function find_pinctrl_and_add_gpio_range()
to pinctrl_find_and_add_gpio_range() so as to be consistent
with the rest of the functions.

Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-21 08:55:10 +01:00
Shiraz Hashim f23f1516b6 gpiolib: provide provision to register pin ranges
pinctrl subsystem needs gpio chip base to prepare set of gpio
pin ranges, which a given pinctrl driver can handle. This is
important to handle pinctrl gpio request calls in order to
program a given pin properly for gpio operation.

As gpio base is allocated dynamically during gpiochip
registration, presently there exists no clean way to pass this
information to the pinctrl subsystem.

After few discussions from [1], it was concluded that may be
gpio controller reporting the pin range it supports, is a
better way than pinctrl subsystem directly registering it.

[1] http://comments.gmane.org/gmane.linux.ports.arm.kernel/184816

Cc: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Shiraz Hashim <shiraz.hashim@st.com>
[Edited documentation a bit]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11 19:06:00 +01:00
Viresh Kumar 7e10ee68f8 Revert "pinctrl: remove pinctrl_remove_gpio_range"
This reverts earlier commit which removed
pinctrl_remove_gpio_range(), because at that time there
weren't any more users of that routine. It was removed as the
removal of ranges was done in unregister of pinctrl.

But as we are now registering stuff from gpiolib, we may
remove and insert a gpio module multiple times. So, we
need this routine again.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11 19:05:59 +01:00
Linus Walleij 1a78958dc2 pinctrl: reserve pins when states are activated
This switches the way that pins are reserved for multiplexing:

We used to do this when the map was parsed, at the creation of
the settings inside the pinctrl handle, in pinmux_map_to_setting().

However this does not work for us, because we want to use the
same set of pins with different devices at different times: the
current code assumes that the pin groups in a pinmux state will
only be used with one single device, albeit different groups can
be active at different times. For example if a single I2C driver
block is used to drive two different busses located on two
pin groups A and B, then the pins for all possible states of a
function are reserved when fetching the pinctrl handle: the
I2C bus can choose either set A or set B by a mux state at
runtime, but all pins in both group A and B (the superset) are
effectively reserved for that I2C function and mapped to the
device. Another device can never get in and use the pins in
group A, even if the device/function is using group B at the
moment.

Instead: let use reserve the pins when the state is activated
and drop them when the state is disabled, i.e. when we move to
another state. This way different devices/functions can use the
same pins at different times.

We know that this is an odd way of doing things, but we really
need to switch e.g. an SD-card slot to become a tracing output
sink at runtime: we plug in a special "tracing card" then mux
the pins that used to be an SD slot around to the tracing
unit and push out tracing data there instead of SD-card
traffic.

As a side effect pinmux_free_setting() is unused but the stubs
are kept for future additions of code.

Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Loic Pallardy <loic.pallardy@st.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Jean Nicolas Graux <jean-nicolas.graux@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-11-11 19:05:56 +01:00
Wei Yongjun b4dd784ba8 pinctrl: fix missing unlock on error in pinctrl_groups_show()
Add the missing unlock on the error handle path in function
pinctrl_groups_show().

Cc: stable@kernel.org
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-10-23 10:35:10 +02:00
Sachin Kamat eb26cc9c71 pinctrl: Fix potential memory leak in pinctrl_register_one_pin()
'pindesc' was not freed when returning from an error induced
exit path.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-09-27 13:43:14 +02:00
Richard Genoud d599bfb324 trivial: pinctrl core: remove extraneous code lines
In function pinctrl_get_locked, pointer p is returned on
error, and also return on no_error.
So, we just return it with no error test.

It's pretty the same in function pinctrl_lookup_state_locked:
state is returned in every case, so we drop the error test
and just return state.

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
2012-08-17 11:09:58 +02:00
Dong Aisheng 3e5e00b654 pinctrl: add pinctrl_add_gpio_ranges function
Often GPIO ranges are added in batch, so create a special
function for that.

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-07-03 21:51:08 +02:00
Dong Aisheng 5d589b092a pinctrl: remove pinctrl_remove_gpio_range
The gpio ranges will be automatically removed when the pinctrl
driver is unregistered.

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-07-03 21:51:07 +02:00
Devendra Naga da9aecb02d pinctrl/pinctrl-core: cleanup pinctrl_register
lots of places the ret is used just for non zero cases
with out that also we can check the status of the function
calls.

Signed-off-by: Devendra Naga <devendra.aaru@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-07-03 21:51:07 +02:00
Guennadi Liakhovetski bc66468cee pinctrl: fix a minor harmless typo
The way the for_each_maps() macro is currently used, using "i" instead of
"_i_" works and is harmless. Still, this is a bug, that can trigger any
time, if the code around that macro changes. Better fix it now.

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-06-04 09:52:52 +02:00
Dong Aisheng 4650b7cbea pinctrl: support gpio request deferred probing
As pinctrl handles, it may be possible the pinctrl gpio ranges
are still not got registered when user call pinctrl_gpio_request.
Thus, add defer support for it too.

Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-05-02 01:14:20 +02:00
Dong Aisheng 5b3aa5f7c6 pinctrl: add pinctrl_provide_dummies interface for platforms to use
Add a interface pinctrl_provide_dummies for platform to indicate
whether it needs use pinctrl dummy state.

ChangeLog v3->v4:
* remove dummy gpio support in pinctrl subsystem.
  Let gpio driver decide whether it wants to use pinctrl gpio mux
  function.
ChangeLog v2->v3:
* Also changed the missed pinctrl gpio APIs in v1.
ChangeLog v1->v2:
* Based on sascha's suggestion, drop using kconfig since it will hide
  pinctrl errors on all other boards.
  See: https://lkml.org/lkml/2012/4/18/282
  It seemed both Linus and Stephen agreed with this way, so i'm ok
  with it too.
* Add dummy gpio support.
  pinctrl gpio in the same situation as state.
* Patch name changed.
  Original is pinctrl: handle dummy state in core.
* Split removing old dt dummy interface into a separate patch

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-26 23:31:04 +02:00
John Crispin ad6e1107ba pinctrl: enhance reporting of errors when loading from DT
There are a few places in the api where the code simply returns -EINVAL when
it finds an error. An example is pinmux_map_to_setting() which now reports an
error if we try to match a group with a function that it does not support.

The reporting of errors in pinconf_check_ops and pinmux_check_ops now has the
same style and is located inside the according functions and not the calling
code.

When the map is found in the DT but the default state can not be selected we
get an error to know that the code at least tried.

The patch also removes a stray word from one comment and a "->" from another
for the sake of consistency.

Finally we replace a few pr_err/debug() calls with dev_err/dbg().

Thanks go to Stephen Warren for reviewing the patch and enhancing the reporting
inside pinmux_map_to_setting().

Signed-off-by: John Crispin <blogic@openwrt.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-26 23:11:04 +02:00
Stephen Warren fde04f419a pinctrl: propagate map validation errors
pinctrl_register_map() was returning early if pinmux_validate_map() or
pinconf_validate_map() failed, but was not actually returning the error
code.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-26 10:49:28 +02:00
Dong Aisheng dcb5dbc305 pinctrl: show pin name for pingroups in sysfs
Pin name is more useful to users.

After change, when cat pingroups in sysfs, it becomes:
root@freescale /sys/kernel/debug/pinctrl/20e0000.iomuxc$ cat pingroups
registered pin groups:
group: uart4grp-1
pin 219 (MX6Q_PAD_KEY_ROW0)
pin 218 (MX6Q_PAD_KEY_COL0)

group: usdhc4grp-1
pin 305 (MX6Q_PAD_SD4_CMD)
pin 306 (MX6Q_PAD_SD4_CLK)
pin 315 (MX6Q_PAD_SD4_DAT0)
pin 316 (MX6Q_PAD_SD4_DAT1)
pin 317 (MX6Q_PAD_SD4_DAT2)
pin 318 (MX6Q_PAD_SD4_DAT3)
pin 319 (MX6Q_PAD_SD4_DAT4)
pin 320 (MX6Q_PAD_SD4_DAT5)
pin 321 (MX6Q_PAD_SD4_DAT6)
pin 322 (MX6Q_PAD_SD4_DAT7)

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18 13:53:13 +02:00
Stephen Warren 6d4ca1fb46 pinctrl: implement devm_pinctrl_get()/put()
These functions allow the driver core to automatically clean up any
allocations made by drivers, thus leading to simplified drivers.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18 13:53:13 +02:00
Linus Walleij c05127c4e2 pinctrl: implement pinctrl deferred probing
If drivers try to obtain pinctrl handles for a pin controller that
has not yet registered to the subsystem, we need to be able to
back out and retry with deferred probing. So let's return
-EPROBE_DEFER whenever this location fails. Also downgrade the
errors to info, maybe we will even set them to debug once the
deferred probing is commonplace.

Cc: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18 13:53:11 +02:00
Viresh Kumar d1e90e9e74 pinctrl: replace list_*() with get_*_count()
Most of the SoC drivers implement list_groups() and list_functions()
routines for pinctrl and pinmux. These routines continue returning
zero until the selector argument is greater than total count of
available groups or functions.

This patch replaces these list_*() routines with get_*_count()
routines, which returns the number of available selection for SoC
driver. pinctrl layer will use this value to check the range it can
choose.

This patch fixes all user drivers for this change. There are other
routines in user drivers, which have checks to check validity of
selector passed to them. It is also no more required and hence
removed.

Documentation updated as well.

Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
[Folded in fix and fixed a minor merge artifact manually]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18 13:53:10 +02:00
Stephen Warren 57291ce295 pinctrl: core device tree mapping table parsing support
During pinctrl_get(), if the client device has a device tree node, look
for the common pinctrl properties there. If found, parse the referenced
device tree nodes, with the help of the pinctrl drivers, and generate
mapping table entries from them.

During pinctrl_put(), free any results of device tree parsing.

Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18 13:53:10 +02:00
Stephen Warren d26bc49fa4 pinctrl: implement pinctrl_check_ops
Most code assumes that the pinctrl ops are present. Validate this when
registering a pinctrl driver. Remove the one place in the code that
was checking whether one of these non-optional ops was present.

Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-04-18 13:53:10 +02:00
Stephen Warren 1e2082b520 pinctrl: enhance mapping table to support pin config operations
The pinctrl mapping table can now contain entries to:
* Set the mux function of a pin group
* Apply a set of pin config options to a pin or a group

This allows pinctrl_select_state() to apply pin configs settings as well
as mux settings.

v3: Fix find_pinctrl() to iterate over the correct list.
   s/_MUX_CONFIGS_/_CONFIGS_/ in mapping table macros.
   Fix documentation to use correct mapping table macro.
v2: Added numerous extra PIN_MAP_*() special-case macros.
   Fixed kerneldoc typo. Delete pinctrl_get_pin_id() and
   replace it with pin_get_from_name(). Various minor fixes.
   Updates due to rebase.

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>
2012-03-05 11:25:11 +01:00
Stephen Warren 6e5e959dde pinctrl: API changes to support multiple states per device
The API model is changed from:

p = pinctrl_get(dev, "state1");
pinctrl_enable(p);
...
pinctrl_disable(p);
pinctrl_put(p);
p = pinctrl_get(dev, "state2");
pinctrl_enable(p);
...
pinctrl_disable(p);
pinctrl_put(p);

to this:

p = pinctrl_get(dev);
s1 = pinctrl_lookup_state(p, "state1");
s2 = pinctrl_lookup_state(p, "state2");
pinctrl_select_state(p, s1);
...
pinctrl_select_state(p, s2);
...
pinctrl_put(p);

This allows devices to directly transition between states without
disabling the pin controller programming and put()/get()ing the
configuration data each time. This model will also better suit pinconf
programming, which doesn't have a concept of "disable".

The special-case hogging feature of pin controllers is re-written to use
the regular APIs instead of special-case code. Hence, the pinmux-hogs
debugfs file is removed; see the top-level pinctrl-handles files for
equivalent data.

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>
2012-03-05 11:22:59 +01:00
Stephen Warren 7ecdb16fe6 pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c
This change separates two aspects of struct pinctrl:

a) The data representation of the parsed mapping table, into:

   1) The top-level struct pinctrl object, a single entity returned
      by pinctrl_get().

   2) The parsed version of each mapping table entry, struct
      pinctrl_setting, of which there is one per mapping table entry.

b) The code that handles this; the code for (1) above is in core.c, and
   the code to parse/execute each entry in (2) above is in pinmux.c, while
   the iteration over multiple settings is lifted to core.c.

This will allow the following future changes:

1) pinctrl_get() API rework, so that struct pinctrl represents all states
   for the device, and the device can select between them without calling
   put()/get() again.

2) To support that, a struct pinctrl_state object will be inserted into
   the data model between the struct pinctrl and struct pinctrl_setting.

3) The mapping table will be extended to allow specification of pin config
   settings too. To support this, struct pinctrl_setting will be enhanced
   to store either mux settings or config settings, and functions will be
   added to pinconf.c to parse/execute pin configuration settings.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-05 11:20:50 +01:00
Stephen Warren 57b676f9c1 pinctrl: fix and simplify locking
There are many problems with the current pinctrl locking:

struct pinctrl_dev's gpio_ranges_lock isn't effective;
pinctrl_match_gpio_range() only holds this lock while searching for a gpio
range, but the found range is return and manipulated after releading the
lock. This could allow pinctrl_remove_gpio_range() for that range while it
is in use, and the caller may very well delete the range after removing it,
causing pinctrl code to touch the now-free range object.

Solving this requires the introduction of a higher-level lock, at least
a lock per pin controller, which both gpio range registration and
pinctrl_get()/put() will acquire.

There is missing locking on HW programming; pin controllers may pack the
configuration for different pins/groups/config options/... into one
register, and hence have to read-modify-write the register. This needs to
be protected, but currently isn't. Related, a future change will add a
"complete" op to the pin controller drivers, the idea being that each
state's programming will be programmed into the pinctrl driver followed
by the "complete" call, which may e.g. flush a register cache to HW. For
this to work, it must not be possible to interleave the pinctrl driver
calls for different devices.

As above, solving this requires the introduction of a higher-level lock,
at least a lock per pin controller, which will be held for the duration
of any pinctrl_enable()/disable() call.

However, each pinctrl mapping table entry may affect a different pin
controller if necessary. Hence, with a per-pin-controller lock, almost
any pinctrl API may need to acquire multiple locks, one per controller.
To avoid deadlock, these would need to be acquired in the same order in
all cases. This is extremely difficult to implement in the case of
pinctrl_get(), which doesn't know which pin controllers to lock until it
has parsed the entire mapping table, since it contains somewhat arbitrary
data.

The simplest solution here is to introduce a single lock that covers all
pin controllers at once. This will be acquired by all pinctrl APIs.

This then makes struct pinctrl's mutex irrelevant, since that single lock
will always be held whenever this mutex is currently held.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-03-05 11:19:49 +01:00
Stephen Warren 110e4ec5a1 pinctrl: assume map table entries can't have a NULL name field
pinctrl_register_mappings() already requires that every mapping table
entry have a non-NULL name field.

Logically, this makes sense too; drivers should always request a specific
named state so they know what they're getting. Relying on getting the
first mentioned state in the mapping table is error-prone, and a nasty
special case to implement, given that a given the mapping table may define
multiple states for a device.

Remove a small part of the documentation that talked about optionally
requesting a specific state; it's mandatory now.

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 16:20:54 +01:00
Stephen Warren 46919ae63d 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 16:18:24 +01:00
Stephen Warren 3eedb43723 pinctrl: move pinctrl-maps debugfs file to top-level
The debugfs file pinctrl-maps is a system-wide file, not specific to any
pin controller, so place it in the top-level directory.

Also, move the code implementing the file to keep the order of all the
functions matching the order they're created in pinctrl_init_*debugfs().
The only non-obvious change here is no private data is passed to
debugfs_create_file() or single_open().

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>
2012-02-29 19:10:56 +01:00
Stephen Warren 2304b4737f pinctrl: remove pin and hogs locks from struct pinctrl_dev
struct pinctrl_dev's pin_desc_tree_lock and pinctrl_hogs_lock aren't
useful; the data they protect is read-only except when registering or
unregistering a pinctrl_dev, and at those times, it doesn't make sense to
protect one part of the structure independently from the rest.

Move pinctrl_init_device_debugfs() to the end of pinctrl_register() so
that debugfs can't access the struct pinctrl_dev until it's fully
initialized, i.e. after the hogs are set up.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-24 06:30:50 +01:00
Stephen Warren 02f5b98951 pinctrl: allocate sizeof(*p) instead of sizeof(struct foo)
This hopefully makes it harder to take the sizeof the wrong type.

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>
2012-02-24 06:28:56 +01:00
Stephen Warren 95dcd4aea5 pinctrl: use dev_*() instead of pr_*(), add some msgs, minor cleanups
e.g. dev_err instead of pr_err prints messages in a slightly more
standardized format.

Also, add a few more error messages to track down errors.

Also, some small cleanups of messages.

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>
2012-02-24 06:26:58 +01:00
Stephen Warren 1681f5ae4c pinctrl: disallow map table entries with NULL dev_name field
Hog entries are mapping table entries with .ctrl_dev_name == .dev_name.
All other mapping table entries need .dev_name set so that they will
match some pinctrl_get() call. All extant PIN_MAP*() macros set
.dev_name.

So, there is no reason to allow mapping table entries without .dev_name
set. Update the code and documentation to disallow 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>
2012-02-24 06:24:52 +01:00
Stephen Warren b1eed4ece7 pinctrl: error if mapping table's control dev can't be found
This is a serious error, and the pin control system will not function
correctly if it ends up not programing the mapping table entries into
the HW. Instead of just ignoring this, error out.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
[rebased to fit the applied patch series, cast error to pointer]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-22 17:59:34 +01:00
Stephen Warren f026fe3d10 pinctrl: downgrade pinctrl_get warning when no maps are found
This may be perfectly legitimate. An IP block may get re-used
across SoCs. Not all of those SoCs may need pinmux settings for the
IP block, e.g. if one SoC dedicates pins to that function but
another doesn't. The driver won't know this, and will always
attempt to set up the pinmux. The mapping table defines whether any
HW programming is actually needed.

Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
[rebased to fit the applied patch series]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-22 17:59:34 +01:00
Stephen Warren 9891d98c7a pinctrl: assume map table entries can't have a NULL ctrl_dev_name field
These are already disallowed. Clean up some code that doesn't assume this.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-22 17:59:33 +01:00
Stephen Warren 4ecce45dd6 pinctrl: core.c/h cleanups
* Make all functions internal to core.c static. Remove any of these from
  core.h.
* Add any missing EXPORT_SYMBOL_GPL().

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-22 17:59:33 +01:00
Stephen Warren b2b3e66e40 pinctrl: Store mapping table as a list of chunks
Instead of storing a single array of mapping table entries, which
requires realloc()ing that array each time it's extended and copying
the new data, simply store a list of pointers to the individual chunks.
This also removes the need to copy the mapping table at all; a pointer
is maintained to the original table, this saving memory.

A macro for_each_maps() is introduced to hide the additional complexity
of iterating over the map entries.

This change will also simplify removing chunks of entries from the mapping
table. This isn't important right now, but will be in the future, when
mapping table entries are dynamically added when parsing them from the
device tree, and removed when drivers no longer need to interact with
pinctrl.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-22 17:59:31 +01:00
Stephen Warren 8b9c139f16 pinctrl: use list_add_tail instead of list_add
This mostly makes debugfs files print things in the order that they
were added or acquired, which just feels a little more consistent.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-22 17:59:31 +01:00
Stephen Warren 13398a4b90 pinctrl: pinctrl_register_mappings() shouldn't be __init
It may be common for pinctrl_register_mappings() to be used from __init
context, but there's no reason that additional mappings shouldn't be
added at a later point, e.g. if loading modules that add pin controllers
and their mapping tables.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-22 17:59:30 +01:00
Stephen Warren 449d16b025 pinctrl: make "hog" mapping table entries work
Commit 77a5988 "pinctrl: changes hog mechanism to be self-referential"
modified the way "hog" entries were represented in the mapping table.
However, the new representation failed some error checks in
pinctrl_hog_map(). Remove the now-bogus error-check, and fix the code
to solve the issue the error-check used to avoid.

Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-22 17:59:30 +01:00
Linus Walleij 77a5988355 pinctrl: changes hog mechanism to be self-referential
Instead of a specific boolean field to indicate if a map entry shall
be hogged, treat self-reference as an indication of desired hogging.
This drops one field off the map struct and has a nice Douglas R.
Hofstadter-feel to it.

Acked-by: Dong Aisheng <dong.aisheng@linaro.org>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-10 21:33:10 +01:00
Linus Walleij befe5bdfbb pinctrl: factor pin control handles over to the core
This moves the per-devices struct pinctrl handles and device map
over from the pinmux part of the subsystem to the core pinctrl part.
This makes the device handles core infrastructure with the goal of
using these handles also for pin configuration, so that device
drivers (or boards etc) will need one and only one handle to the
pin control core.

Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2012-02-10 21:33:06 +01:00