linux-hardened/include/linux/pinctrl/pinconf-generic.h
Heiko Stübner 7970cb770d pinctrl: add pinconf-generic define for a pin-default pull
There exist controllers that don't support to set the pull to up or down
separately but instead automatically set the pull direction based on
embedded knowledge inside the controller, for example depending on the
selected mux function of the pin.

Therefore this patch adds another config option to use this default
pull-state for a pin where it is not possible to know or decide if the
pin will be pulled up or down.

Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-06-16 11:56:51 +02:00

138 lines
6 KiB
C

/*
* 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 disabled.
* @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 disabled.
* @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
* on embedded knowledge of the controller, like current mux function.
* If the argument is != 0 pull up/down is enabled, if it is 0,
* the pull is disabled.
* @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_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 on a custom format. 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 in output, use argument
* 1 to indicate high level, argument 0 to indicate low level.
* @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_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);
}
#endif /* CONFIG_GENERIC_PINCONF */
#endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */