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Diffstat (limited to 'include/linux/pinctrl/pinconf-generic.h')
| -rw-r--r-- | include/linux/pinctrl/pinconf-generic.h | 232 |
1 files changed, 232 insertions, 0 deletions
diff --git a/include/linux/pinctrl/pinconf-generic.h b/include/linux/pinctrl/pinconf-generic.h new file mode 100644 index 000000000..d74b7a4ea --- /dev/null +++ b/include/linux/pinctrl/pinconf-generic.h @@ -0,0 +1,232 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * 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> + */ +#ifndef __LINUX_PINCTRL_PINCONF_GENERIC_H +#define __LINUX_PINCTRL_PINCONF_GENERIC_H + +#include <linux/types.h> + +#include <linux/pinctrl/machine.h> + +struct device_node; + +struct pinctrl_dev; +struct pinctrl_map; + +/** + * enum pin_config_param - possible pin configuration parameters + * @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_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_DOWN: the pin will be pulled down (usually with high + * impedance to GROUND). If the argument is != 0 pull-down is enabled, + * the value is interpreted by the driver and can be custom or an SI unit + * such as Ohms. + * @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_BIAS_PULL_UP: the pin will be pulled up (usually with high + * impedance to VDD). If the argument is != 0 pull-up is enabled, + * the value is interpreted by the driver and can be custom or an SI unit + * such as Ohms. + * @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 source mode, the + * argument is ignored. + * @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_STRENGTH: the pin will sink or source at most the current + * passed as argument. The argument is in mA. + * @PIN_CONFIG_DRIVE_STRENGTH_UA: the pin will sink or source at most the current + * passed as argument. The argument is in uA. + * @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_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: 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_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_MODE_LOW_POWER: 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_MODE_PWM: this will configure the pin for PWM + * @PIN_CONFIG_OUTPUT: this will configure the pin as an output and drive a + * value on the line. Use argument 1 to indicate high level, argument 0 to + * indicate low level. (Please see Documentation/driver-api/pin-control.rst, + * section "GPIO mode pitfalls" for a discussion around this parameter.) + * @PIN_CONFIG_OUTPUT_ENABLE: this will enable the pin's output mode + * without driving a value there. For most platforms this reduces to + * enable the output buffers and then let the pin controller current + * configuration (eg. the currently selected mux function) drive values on + * the line. Use argument 1 to enable output mode, argument 0 to disable + * it. + * @PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS: this will configure the output impedance + * of the pin with the value passed as argument. The argument is in ohms. + * @PIN_CONFIG_PERSIST_STATE: retain pin state across sleep or controller reset + * @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_SKEW_DELAY: if the pin has programmable skew rate (on inputs) + * or latch delay (on outputs) this parameter (in a custom format) + * specifies the clock skew or latch delay. It typically controls how + * many double inverters are put in front of the line. + * @PIN_CONFIG_SLEEP_HARDWARE_STATE: indicate this is sleep related state. + * @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_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. + * @PIN_CONFIG_MAX: this is the maximum configuration value that can be + * presented using the packed format. + */ +enum pin_config_param { + PIN_CONFIG_BIAS_BUS_HOLD, + PIN_CONFIG_BIAS_DISABLE, + PIN_CONFIG_BIAS_HIGH_IMPEDANCE, + PIN_CONFIG_BIAS_PULL_DOWN, + PIN_CONFIG_BIAS_PULL_PIN_DEFAULT, + PIN_CONFIG_BIAS_PULL_UP, + PIN_CONFIG_DRIVE_OPEN_DRAIN, + PIN_CONFIG_DRIVE_OPEN_SOURCE, + PIN_CONFIG_DRIVE_PUSH_PULL, + PIN_CONFIG_DRIVE_STRENGTH, + PIN_CONFIG_DRIVE_STRENGTH_UA, + PIN_CONFIG_INPUT_DEBOUNCE, + PIN_CONFIG_INPUT_ENABLE, + PIN_CONFIG_INPUT_SCHMITT, + PIN_CONFIG_INPUT_SCHMITT_ENABLE, + PIN_CONFIG_MODE_LOW_POWER, + PIN_CONFIG_MODE_PWM, + PIN_CONFIG_OUTPUT, + PIN_CONFIG_OUTPUT_ENABLE, + PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS, + PIN_CONFIG_PERSIST_STATE, + PIN_CONFIG_POWER_SOURCE, + PIN_CONFIG_SKEW_DELAY, + PIN_CONFIG_SLEEP_HARDWARE_STATE, + PIN_CONFIG_SLEW_RATE, + PIN_CONFIG_END = 0x7F, + PIN_CONFIG_MAX = 0xFF, +}; + +/* + * Helpful configuration macro to be used in tables etc. + */ +#define PIN_CONF_PACKED(p, a) ((a << 8) | ((unsigned long) p & 0xffUL)) + +/* + * 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 8 bits and the argument in the + * upper 24 bits. + */ + +static inline enum pin_config_param pinconf_to_config_param(unsigned long config) +{ + return (enum pin_config_param) (config & 0xffUL); +} + +static inline u32 pinconf_to_config_argument(unsigned long config) +{ + return (u32) ((config >> 8) & 0xffffffUL); +} + +static inline unsigned long pinconf_to_config_packed(enum pin_config_param param, + u32 argument) +{ + return PIN_CONF_PACKED(param, argument); +} + +#define PCONFDUMP(a, b, c, d) { \ + .param = a, .display = b, .format = c, .has_arg = d \ + } + +struct pin_config_item { + const enum pin_config_param param; + const char * const display; + const char * const format; + bool has_arg; +}; + +struct pinconf_generic_params { + const char * const property; + enum pin_config_param param; + u32 default_value; +}; + +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); +void pinconf_generic_dt_free_map(struct pinctrl_dev *pctldev, + struct pinctrl_map *map, unsigned num_maps); + +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); +} + +static inline int pinconf_generic_dt_node_to_map_all(struct pinctrl_dev *pctldev, + struct device_node *np_config, struct pinctrl_map **map, + unsigned *num_maps) +{ + /* + * passing the type as PIN_MAP_TYPE_INVALID causes the underlying parser + * to infer the map type from the DT properties used. + */ + return pinconf_generic_dt_node_to_map(pctldev, np_config, map, num_maps, + PIN_MAP_TYPE_INVALID); +} + +#endif /* __LINUX_PINCTRL_PINCONF_GENERIC_H */ |