include/linux/pinctrl/pinmux.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 /*
   3  * Interface the pinmux subsystem
   4  *
   5  * Copyright (C) 2011 ST-Ericsson SA
   6  * Written on behalf of Linaro for ST-Ericsson
   7  * Based on bits of regulator core, gpio core and clk core
   8  *
   9  * Author: Linus Walleij <linus.walleij@linaro.org>
  10  */
  11 #ifndef __LINUX_PINCTRL_PINMUX_H
  12 #define __LINUX_PINCTRL_PINMUX_H
  13
  14 #include <linux/types.h>
  15
  16 struct pinctrl_dev;
  17 struct pinctrl_gpio_range;
  18
  19 /**
  20  * struct pinmux_ops - pinmux operations, to be implemented by pin controller
  21  * drivers that support pinmuxing
  22  * @request: called by the core to see if a certain pin can be made
  23  *      available for muxing. This is called by the core to acquire the pins
  24  *      before selecting any actual mux setting across a function. The driver
  25  *      is allowed to answer "no" by returning a negative error code
  26  * @free: the reverse function of the request() callback, frees a pin after
  27  *      being requested
  28  * @get_functions_count: returns number of selectable named functions available
  29  *      in this pinmux driver
  30  * @get_function_name: return the function name of the muxing selector,
  31  *      called by the core to figure out which mux setting it shall map a
  32  *      certain device to
  33  * @get_function_groups: return an array of groups names (in turn
  34  *      referencing pins) connected to a certain function selector. The group
  35  *      name can be used with the generic @pinctrl_ops to retrieve the
  36  *      actual pins affected. The applicable groups will be returned in
  37  *      @groups and the number of groups in @num_groups
  38  * @set_mux: enable a certain muxing function with a certain pin group. The
  39  *      driver does not need to figure out whether enabling this function
  40  *      conflicts some other use of the pins in that group, such collisions
  41  *      are handled by the pinmux subsystem. The @func_selector selects a
  42  *      certain function whereas @group_selector selects a certain set of pins
  43  *      to be used. On simple controllers the latter argument may be ignored
  44  * @gpio_request_enable: requests and enables GPIO on a certain pin.
  45  *      Implement this only if you can mux every pin individually as GPIO. The
  46  *      affected GPIO range is passed along with an offset(pin number) into that
  47  *      specific GPIO range - function selectors and pin groups are orthogonal
  48  *      to this, the core will however make sure the pins do not collide.
  49  * @gpio_disable_free: free up GPIO muxing on a certain pin, the reverse of
  50  *      @gpio_request_enable
  51  * @gpio_set_direction: Since controllers may need different configurations
  52  *      depending on whether the GPIO is configured as input or output,
  53  *      a direction selector function may be implemented as a backing
  54  *      to the GPIO controllers that need pin muxing.
  55  * @strict: do not allow simultaneous use of the same pin for GPIO and another
  56  *      function. Check both gpio_owner and mux_owner strictly before approving
  57  *      the pin request.
  58  */
  59 struct pinmux_ops {
  60         int (*request) (struct pinctrl_dev *pctldev, unsigned int offset);
  61         int (*free) (struct pinctrl_dev *pctldev, unsigned int offset);
  62         int (*get_functions_count) (struct pinctrl_dev *pctldev);
  63         const char *(*get_function_name) (struct pinctrl_dev *pctldev,
  64                                           unsigned int selector);
  65         int (*get_function_groups) (struct pinctrl_dev *pctldev,
  66                                     unsigned int selector,
  67                                     const char * const **groups,
  68                                     unsigned int *num_groups);
  69         int (*set_mux) (struct pinctrl_dev *pctldev, unsigned int func_selector,
  70                         unsigned int group_selector);
  71         int (*gpio_request_enable) (struct pinctrl_dev *pctldev,
  72                                     struct pinctrl_gpio_range *range,
  73                                     unsigned int offset);
  74         void (*gpio_disable_free) (struct pinctrl_dev *pctldev,
  75                                    struct pinctrl_gpio_range *range,
  76                                    unsigned int offset);
  77         int (*gpio_set_direction) (struct pinctrl_dev *pctldev,
  78                                    struct pinctrl_gpio_range *range,
  79                                    unsigned int offset,
  80                                    bool input);
  81         bool strict;
  82 };
  83
  84 #endif /* __LINUX_PINCTRL_PINMUX_H */