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
16struct pinctrl_dev;
17struct 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 * @function_is_gpio: determine if the indicated function selector passed
39 *	corresponds to the GPIO function which is used by the accelerated GPIO
40 *	functions @gpio_request_enable, @gpio_disable_free and
41 *	@gpio_set_direction. When the pin control core can properly determine
42 *	if a function is a GPIO function, it is easier to use the @strict mode
43 *	on the pin controller. Since a single function is passed, this is
44 *	only useful on pin controllers that use a specific function for GPIO,
45 *	and that usually presupposes that a one-group-per-pin approach is
46 *	used, so that a single function can be set on a single pin to turn
47 *	it to GPIO mode.
48 * @set_mux: enable a certain muxing function with a certain pin group. The
49 *	driver does not need to figure out whether enabling this function
50 *	conflicts some other use of the pins in that group, such collisions
51 *	are handled by the pinmux subsystem. The @func_selector selects a
52 *	certain function whereas @group_selector selects a certain set of pins
53 *	to be used. On simple controllers the latter argument may be ignored
54 * @gpio_request_enable: requests and enables GPIO on a certain pin.
55 *	Implement this only if you can mux every pin individually as GPIO. The
56 *	affected GPIO range is passed along with an offset(pin number) into that
57 *	specific GPIO range - function selectors and pin groups are orthogonal
58 *	to this, the core will however make sure the pins do not collide.
59 * @gpio_disable_free: free up GPIO muxing on a certain pin, the reverse of
60 *	@gpio_request_enable
61 * @gpio_set_direction: Since controllers may need different configurations
62 *	depending on whether the GPIO is configured as input or output,
63 *	a direction selector function may be implemented as a backing
64 *	to the GPIO controllers that need pin muxing.
65 * @strict: do not allow simultaneous use of the same pin for GPIO and another
66 *	function. Check both gpio_owner and mux_owner strictly before approving
67 *	the pin request.
68 */
69struct pinmux_ops {
70	int (*request) (struct pinctrl_dev *pctldev, unsigned int offset);
71	int (*free) (struct pinctrl_dev *pctldev, unsigned int offset);
72	int (*get_functions_count) (struct pinctrl_dev *pctldev);
73	const char *(*get_function_name) (struct pinctrl_dev *pctldev,
74					  unsigned int selector);
75	int (*get_function_groups) (struct pinctrl_dev *pctldev,
76				    unsigned int selector,
77				    const char * const **groups,
78				    unsigned int *num_groups);
79	bool (*function_is_gpio) (struct pinctrl_dev *pctldev,
80				  unsigned int selector);
81	int (*set_mux) (struct pinctrl_dev *pctldev, unsigned int func_selector,
82			unsigned int group_selector);
83	int (*gpio_request_enable) (struct pinctrl_dev *pctldev,
84				    struct pinctrl_gpio_range *range,
85				    unsigned int offset);
86	void (*gpio_disable_free) (struct pinctrl_dev *pctldev,
87				   struct pinctrl_gpio_range *range,
88				   unsigned int offset);
89	int (*gpio_set_direction) (struct pinctrl_dev *pctldev,
90				   struct pinctrl_gpio_range *range,
91				   unsigned int offset,
92				   bool input);
93	bool strict;
94};
95
96#endif /* __LINUX_PINCTRL_PINMUX_H */