include/linux/pinctrl/pinmux.h

root/include/linux/pinctrl/pinmux.h
/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Interface the pinmux subsystem
 *
 * Copyright (C) 2011 ST-Ericsson SA
 * Written on behalf of Linaro for ST-Ericsson
 * Based on bits of regulator core, gpio core and clk core
 *
 * Author: Linus Walleij <linus.walleij@linaro.org>
 */
#ifndef __LINUX_PINCTRL_PINMUX_H
#define __LINUX_PINCTRL_PINMUX_H

#include <linux/types.h>

struct pinctrl_dev;
struct pinctrl_gpio_range;

/**
 * struct pinmux_ops - pinmux operations, to be implemented by pin controller
 * drivers that support pinmuxing
 * @request: called by the core to see if a certain pin can be made
 *      available for muxing. This is called by the core to acquire the pins
 *      before selecting any actual mux setting across a function. The driver
 *      is allowed to answer "no" by returning a negative error code
 * @free: the reverse function of the request() callback, frees a pin after
 *      being requested
 * @get_functions_count: returns number of selectable named functions available
 *      in this pinmux driver
 * @get_function_name: return the function name of the muxing selector,
 *      called by the core to figure out which mux setting it shall map a
 *      certain device to
 * @get_function_groups: return an array of groups names (in turn
 *      referencing pins) connected to a certain function selector. The group
 *      name can be used with the generic @pinctrl_ops to retrieve the
 *      actual pins affected. The applicable groups will be returned in
 *      @groups and the number of groups in @num_groups
 * @function_is_gpio: determine if the indicated function selector passed
 *      corresponds to the GPIO function which is used by the accelerated GPIO
 *      functions @gpio_request_enable, @gpio_disable_free and
 *      @gpio_set_direction. When the pin control core can properly determine
 *      if a function is a GPIO function, it is easier to use the @strict mode
 *      on the pin controller. Since a single function is passed, this is
 *      only useful on pin controllers that use a specific function for GPIO,
 *      and that usually presupposes that a one-group-per-pin approach is
 *      used, so that a single function can be set on a single pin to turn
 *      it to GPIO mode.
 * @set_mux: enable a certain muxing function with a certain pin group. The
 *      driver does not need to figure out whether enabling this function
 *      conflicts some other use of the pins in that group, such collisions
 *      are handled by the pinmux subsystem. The @func_selector selects a
 *      certain function whereas @group_selector selects a certain set of pins
 *      to be used. On simple controllers the latter argument may be ignored
 * @gpio_request_enable: requests and enables GPIO on a certain pin.
 *      Implement this only if you can mux every pin individually as GPIO. The
 *      affected GPIO range is passed along with an offset(pin number) into that
 *      specific GPIO range - function selectors and pin groups are orthogonal
 *      to this, the core will however make sure the pins do not collide.
 * @gpio_disable_free: free up GPIO muxing on a certain pin, the reverse of
 *      @gpio_request_enable
 * @gpio_set_direction: Since controllers may need different configurations
 *      depending on whether the GPIO is configured as input or output,
 *      a direction selector function may be implemented as a backing
 *      to the GPIO controllers that need pin muxing.
 * @strict: do not allow simultaneous use of the same pin for GPIO and another
 *      function. Check both gpio_owner and mux_owner strictly before approving
 *      the pin request.
 */
struct pinmux_ops {
        int (*request) (struct pinctrl_dev *pctldev, unsigned int offset);
        int (*free) (struct pinctrl_dev *pctldev, unsigned int offset);
        int (*get_functions_count) (struct pinctrl_dev *pctldev);
        const char *(*get_function_name) (struct pinctrl_dev *pctldev,
                                          unsigned int selector);
        int (*get_function_groups) (struct pinctrl_dev *pctldev,
                                    unsigned int selector,
                                    const char * const **groups,
                                    unsigned int *num_groups);
        bool (*function_is_gpio) (struct pinctrl_dev *pctldev,
                                  unsigned int selector);
        int (*set_mux) (struct pinctrl_dev *pctldev, unsigned int func_selector,
                        unsigned int group_selector);
        int (*gpio_request_enable) (struct pinctrl_dev *pctldev,
                                    struct pinctrl_gpio_range *range,
                                    unsigned int offset);
        void (*gpio_disable_free) (struct pinctrl_dev *pctldev,
                                   struct pinctrl_gpio_range *range,
                                   unsigned int offset);
        int (*gpio_set_direction) (struct pinctrl_dev *pctldev,
                                   struct pinctrl_gpio_range *range,
                                   unsigned int offset,
                                   bool input);
        bool strict;
};

#endif /* __LINUX_PINCTRL_PINMUX_H */
Linux
