pinconf-generic.h
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/*
* Interface the generic pinconfig portions of 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_PINCONF_GENERIC_H
#define __LINUX_PINCTRL_PINCONF_GENERIC_H
/*
* You shouldn't even be able to compile with these enums etc unless you're
* using generic pin config. That is why this is defined out.
*/
#ifdef CONFIG_GENERIC_PINCONF
/**
* enum pin_config_param - possible pin configuration parameters
* @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
* transition from say pull-up to pull-down implies that you disable
* pull-up in the process, this setting disables all biasing.
* @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
* mode, also know as "third-state" (tristate) or "high-Z" or "floating".
* On output pins this effectively disconnects the pin, which is useful
* if for example some other pin is going to drive the signal connected
* to it for a while. Pins used for input are usually always high
* impedance.
* @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it
* weakly drives the last value on a tristate bus, also known as a "bus
* holder", "bus keeper" or "repeater". This allows another device on the
* bus to change the value by driving the bus high or low and switching to
* tristate. The argument is ignored.
* @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
* impedance to VDD). If the argument is != 0 pull-up is enabled,
* if it is 0, pull-up is total, i.e. the pin is connected to VDD.
* @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
* impedance to GROUND). If the argument is != 0 pull-down is enabled,
* if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
* @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
* on embedded knowledge of the controller hardware, like current mux
* function. The pull direction and possibly strength too will normally
* be decided completely inside the hardware block and not be readable
* from the kernel side.
* If the argument is != 0 pull up/down is enabled, if it is 0, the
* configuration is ignored. The proper way to disable it is to use
* @PIN_CONFIG_BIAS_DISABLE.
* @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
* low, this is the most typical case and is typically achieved with two
* active transistors on the output. Setting this config will enable
* push-pull mode, the argument is ignored.
* @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
* collector) which means it is usually wired with other output ports
* which are then pulled up with an external resistor. Setting this
* config will enable open drain mode, the argument is ignored.
* @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
* (open emitter). Setting this config will enable open drain mode, the
* argument is ignored.
* @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
* passed as argument. The argument is in mA.
* @PIN_CONFIG_INPUT_ENABLE: enable the pin's input. Note that this does not
* affect the pin's ability to drive output. 1 enables input, 0 disables
* input.
* @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
* If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
* schmitt-trigger mode is disabled.
* @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
* schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
* the threshold value is given on a custom format as argument when
* setting pins to this mode.
* @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
* which means it will wait for signals to settle when reading inputs. The
* argument gives the debounce time in usecs. Setting the
* argument to zero turns debouncing off.
* @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
* supplies, the argument to this parameter (on a custom format) tells
* the driver which alternative power source to use.
* @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
* this parameter (on a custom format) tells the driver which alternative
* slew rate to use.
* @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
* operation, if several modes of operation are supported these can be
* passed in the argument on a custom form, else just use argument 1
* to indicate low power mode, argument 0 turns low power mode off.
* @PIN_CONFIG_OUTPUT: this will configure the pin as an output. Use argument
* 1 to indicate high level, argument 0 to indicate low level. (Please
* see Documentation/pinctrl.txt, section "GPIO mode pitfalls" for a
* discussion around this parameter.)
* @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
* you need to pass in custom configurations to the pin controller, use
* PIN_CONFIG_END+1 as the base offset.
*/
enum pin_config_param {
PIN_CONFIG_BIAS_DISABLE,
PIN_CONFIG_BIAS_HIGH_IMPEDANCE,
PIN_CONFIG_BIAS_BUS_HOLD,
PIN_CONFIG_BIAS_PULL_UP,
PIN_CONFIG_BIAS_PULL_DOWN,
PIN_CONFIG_BIAS_PULL_PIN_DEFAULT,
PIN_CONFIG_DRIVE_PUSH_PULL,
PIN_CONFIG_DRIVE_OPEN_DRAIN,
PIN_CONFIG_DRIVE_OPEN_SOURCE,
PIN_CONFIG_DRIVE_STRENGTH,
PIN_CONFIG_INPUT_ENABLE,
PIN_CONFIG_INPUT_SCHMITT_ENABLE,
PIN_CONFIG_INPUT_SCHMITT,
PIN_CONFIG_INPUT_DEBOUNCE,
PIN_CONFIG_POWER_SOURCE,
PIN_CONFIG_SLEW_RATE,
PIN_CONFIG_LOW_POWER_MODE,
PIN_CONFIG_OUTPUT,
PIN_CONFIG_END = 0x7FFF,
};
/*
* Helpful configuration macro to be used in tables etc.
*/
#define PIN_CONF_PACKED(p, a) ((a << 16) | ((unsigned long) p & 0xffffUL))
/*
* The following inlines stuffs a configuration parameter and data value
* into and out of an unsigned long argument, as used by the generic pin config
* system. We put the parameter in the lower 16 bits and the argument in the
* upper 16 bits.
*/
static inline enum pin_config_param pinconf_to_config_param(unsigned long config)
{
return (enum pin_config_param) (config & 0xffffUL);
}
static inline u16 pinconf_to_config_argument(unsigned long config)
{
return (enum pin_config_param) ((config >> 16) & 0xffffUL);
}
static inline unsigned long pinconf_to_config_packed(enum pin_config_param param,
u16 argument)
{
return PIN_CONF_PACKED(param, argument);
}
#ifdef CONFIG_OF
#include <linux/device.h>
#include <linux/pinctrl/machine.h>
struct pinctrl_dev;
struct pinctrl_map;
int pinconf_generic_dt_subnode_to_map(struct pinctrl_dev *pctldev,
struct device_node *np, struct pinctrl_map **map,
unsigned *reserved_maps, unsigned *num_maps,
enum pinctrl_map_type type);
int pinconf_generic_dt_node_to_map(struct pinctrl_dev *pctldev,
struct device_node *np_config, struct pinctrl_map **map,
unsigned *num_maps, enum pinctrl_map_type type);
static inline int pinconf_generic_dt_node_to_map_group(
struct pinctrl_dev *pctldev, struct device_node *np_config,
struct pinctrl_map **map, unsigned *num_maps)
{
return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
PIN_MAP_TYPE_CONFIGS_GROUP);
}
static inline int pinconf_generic_dt_node_to_map_pin(
struct pinctrl_dev *pctldev, struct device_node *np_config,
struct pinctrl_map **map, unsigned *num_maps)
{
return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps,
PIN_MAP_TYPE_CONFIGS_PIN);
}
#endif
#endif /* CONFIG_GENERIC_PINCONF */
#endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */