diff options
Diffstat (limited to 'include/linux/pinctrl/pinconf-generic.h')
| -rw-r--r-- | include/linux/pinctrl/pinconf-generic.h | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h new file mode 100644 index 00000000000..4f0abb9f1c0 --- /dev/null +++ b/include/linux/pinctrl/pinconf-generic.h @@ -0,0 +1,114 @@ +/* + * 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_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_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. Sending this config will enabale + * 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. Sending this + * config will enabale open drain mode, the argument is ignored. + * @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source + * (open emitter). Sending this config will enabale open drain mode, the + * argument is ignored. + * @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. The argument zero turns the schmitt trigger + * off. + * @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_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_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_PULL_UP, + PIN_CONFIG_BIAS_PULL_DOWN, + PIN_CONFIG_DRIVE_PUSH_PULL, + PIN_CONFIG_DRIVE_OPEN_DRAIN, + PIN_CONFIG_DRIVE_OPEN_SOURCE, + PIN_CONFIG_INPUT_SCHMITT, + PIN_CONFIG_INPUT_DEBOUNCE, + PIN_CONFIG_POWER_SOURCE, + PIN_CONFIG_LOW_POWER_MODE, + 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 */ |