228 lines
9.7 KiB
C
228 lines
9.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Interface the generic pinconfig portions of the pinctrl subsystem
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*
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* Copyright (C) 2011 ST-Ericsson SA
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* Written on behalf of Linaro for ST-Ericsson
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* This interface is used in the core to keep track of pins.
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*
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* Author: Linus Walleij <linus.walleij@linaro.org>
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*/
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#ifndef __LINUX_PINCTRL_PINCONF_GENERIC_H
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#define __LINUX_PINCTRL_PINCONF_GENERIC_H
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#include <linux/device.h>
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#include <linux/pinctrl/machine.h>
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struct pinctrl_dev;
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struct pinctrl_map;
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/**
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* enum pin_config_param - possible pin configuration parameters
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* @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it
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* weakly drives the last value on a tristate bus, also known as a "bus
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* holder", "bus keeper" or "repeater". This allows another device on the
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* bus to change the value by driving the bus high or low and switching to
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* tristate. The argument is ignored.
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* @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
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* transition from say pull-up to pull-down implies that you disable
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* pull-up in the process, this setting disables all biasing.
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* @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
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* mode, also know as "third-state" (tristate) or "high-Z" or "floating".
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* On output pins this effectively disconnects the pin, which is useful
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* if for example some other pin is going to drive the signal connected
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* to it for a while. Pins used for input are usually always high
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* impedance.
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* @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
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* impedance to GROUND). If the argument is != 0 pull-down is enabled,
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* if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
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* @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
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* on embedded knowledge of the controller hardware, like current mux
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* function. The pull direction and possibly strength too will normally
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* be decided completely inside the hardware block and not be readable
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* from the kernel side.
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* If the argument is != 0 pull up/down is enabled, if it is 0, the
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* configuration is ignored. The proper way to disable it is to use
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* @PIN_CONFIG_BIAS_DISABLE.
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* @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
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* impedance to VDD). If the argument is != 0 pull-up is enabled,
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* if it is 0, pull-up is total, i.e. the pin is connected to VDD.
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* @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
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* collector) which means it is usually wired with other output ports
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* which are then pulled up with an external resistor. Setting this
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* config will enable open drain mode, the argument is ignored.
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* @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
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* (open emitter). Setting this config will enable open source mode, the
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* argument is ignored.
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* @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
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* low, this is the most typical case and is typically achieved with two
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* active transistors on the output. Setting this config will enable
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* push-pull mode, the argument is ignored.
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* @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
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* passed as argument. The argument is in mA.
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* @PIN_CONFIG_DRIVE_STRENGTH_UA: the pin will sink or source at most the current
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* passed as argument. The argument is in uA.
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* @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
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* which means it will wait for signals to settle when reading inputs. The
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* argument gives the debounce time in usecs. Setting the
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* argument to zero turns debouncing off.
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* @PIN_CONFIG_INPUT_ENABLE: enable the pin's input. Note that this does not
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* affect the pin's ability to drive output. 1 enables input, 0 disables
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* input.
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* @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
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* schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
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* the threshold value is given on a custom format as argument when
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* setting pins to this mode.
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* @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
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* If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
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* schmitt-trigger mode is disabled.
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* @PIN_CONFIG_MODE_LOW_POWER: this will configure the pin for low power
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* operation, if several modes of operation are supported these can be
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* passed in the argument on a custom form, else just use argument 1
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* to indicate low power mode, argument 0 turns low power mode off.
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* @PIN_CONFIG_MODE_PWM: this will configure the pin for PWM
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* @PIN_CONFIG_OUTPUT: this will configure the pin as an output and drive a
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* value on the line. Use argument 1 to indicate high level, argument 0 to
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* indicate low level. (Please see Documentation/driver-api/pin-control.rst,
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* section "GPIO mode pitfalls" for a discussion around this parameter.)
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* @PIN_CONFIG_OUTPUT_ENABLE: this will enable the pin's output mode
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* without driving a value there. For most platforms this reduces to
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* enable the output buffers and then let the pin controller current
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* configuration (eg. the currently selected mux function) drive values on
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* the line. Use argument 1 to enable output mode, argument 0 to disable
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* it.
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* @PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS: this will configure the output impedance
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* of the pin with the value passed as argument. The argument is in ohms.
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* @PIN_CONFIG_PERSIST_STATE: retain pin state across sleep or controller reset
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* @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
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* supplies, the argument to this parameter (on a custom format) tells
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* the driver which alternative power source to use.
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* @PIN_CONFIG_SKEW_DELAY: if the pin has programmable skew rate (on inputs)
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* or latch delay (on outputs) this parameter (in a custom format)
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* specifies the clock skew or latch delay. It typically controls how
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* many double inverters are put in front of the line.
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* @PIN_CONFIG_SLEEP_HARDWARE_STATE: indicate this is sleep related state.
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* @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
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* this parameter (on a custom format) tells the driver which alternative
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* slew rate to use.
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* @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
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* you need to pass in custom configurations to the pin controller, use
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* PIN_CONFIG_END+1 as the base offset.
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* @PIN_CONFIG_MAX: this is the maximum configuration value that can be
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* presented using the packed format.
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*/
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enum pin_config_param {
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PIN_CONFIG_BIAS_BUS_HOLD,
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PIN_CONFIG_BIAS_DISABLE,
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PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
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PIN_CONFIG_BIAS_PULL_DOWN,
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PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
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PIN_CONFIG_BIAS_PULL_UP,
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PIN_CONFIG_DRIVE_OPEN_DRAIN,
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PIN_CONFIG_DRIVE_OPEN_SOURCE,
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PIN_CONFIG_DRIVE_PUSH_PULL,
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PIN_CONFIG_DRIVE_STRENGTH,
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PIN_CONFIG_DRIVE_STRENGTH_UA,
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PIN_CONFIG_INPUT_DEBOUNCE,
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PIN_CONFIG_INPUT_ENABLE,
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PIN_CONFIG_INPUT_SCHMITT,
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PIN_CONFIG_INPUT_SCHMITT_ENABLE,
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PIN_CONFIG_MODE_LOW_POWER,
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PIN_CONFIG_MODE_PWM,
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PIN_CONFIG_OUTPUT,
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PIN_CONFIG_OUTPUT_ENABLE,
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PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS,
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PIN_CONFIG_PERSIST_STATE,
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PIN_CONFIG_POWER_SOURCE,
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PIN_CONFIG_SKEW_DELAY,
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PIN_CONFIG_SLEEP_HARDWARE_STATE,
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PIN_CONFIG_SLEW_RATE,
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PIN_CONFIG_END = 0x7F,
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PIN_CONFIG_MAX = 0xFF,
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};
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/*
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* Helpful configuration macro to be used in tables etc.
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*/
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#define PIN_CONF_PACKED(p, a) ((a << 8) | ((unsigned long) p & 0xffUL))
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/*
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* The following inlines stuffs a configuration parameter and data value
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* into and out of an unsigned long argument, as used by the generic pin config
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* system. We put the parameter in the lower 8 bits and the argument in the
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* upper 24 bits.
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*/
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static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
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{
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return (enum pin_config_param) (config & 0xffUL);
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}
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static inline u32 pinconf_to_config_argument(unsigned long config)
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{
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return (u32) ((config >> 8) & 0xffffffUL);
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}
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static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
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u32 argument)
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{
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return PIN_CONF_PACKED(param, argument);
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}
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#define PCONFDUMP(a, b, c, d) { \
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.param = a, .display = b, .format = c, .has_arg = d \
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}
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struct pin_config_item {
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const enum pin_config_param param;
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const char * const display;
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const char * const format;
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bool has_arg;
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};
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struct pinconf_generic_params {
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const char * const property;
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enum pin_config_param param;
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u32 default_value;
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};
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int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
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struct device_node *np, struct pinctrl_map **map,
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unsigned *reserved_maps, unsigned *num_maps,
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enum pinctrl_map_type type);
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int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
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struct device_node *np_config, struct pinctrl_map **map,
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unsigned *num_maps, enum pinctrl_map_type type);
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void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev,
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struct pinctrl_map *map, unsigned num_maps);
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static inline int pinconf_generic_dt_node_to_map_group(
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struct pinctrl_dev *pctldev, struct device_node *np_config,
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struct pinctrl_map **map, unsigned *num_maps)
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{
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return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
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PIN_MAP_TYPE_CONFIGS_GROUP);
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}
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static inline int pinconf_generic_dt_node_to_map_pin(
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struct pinctrl_dev *pctldev, struct device_node *np_config,
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struct pinctrl_map **map, unsigned *num_maps)
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{
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return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
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PIN_MAP_TYPE_CONFIGS_PIN);
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}
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static inline int pinconf_generic_dt_node_to_map_all(
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struct pinctrl_dev *pctldev, struct device_node *np_config,
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struct pinctrl_map **map, unsigned *num_maps)
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{
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/*
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* passing the type as PIN_MAP_TYPE_INVALID causes the underlying parser
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* to infer the map type from the DT properties used.
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*/
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return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
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PIN_MAP_TYPE_INVALID);
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}
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#endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */
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