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/list.h>
15 #include <linux/seq_file.h>
16 #include <linux/pinctrl/pinctrl.h>
17 
18 struct pinctrl_dev;
19 
20 /**
21  * struct pinmux_ops - pinmux operations, to be implemented by pin controller
22  * drivers that support pinmuxing
23  * @request: called by the core to see if a certain pin can be made
24  *	available for muxing. This is called by the core to acquire the pins
25  *	before selecting any actual mux setting across a function. The driver
26  *	is allowed to answer "no" by returning a negative error code
27  * @free: the reverse function of the request() callback, frees a pin after
28  *	being requested
29  * @get_functions_count: returns number of selectable named functions available
30  *	in this pinmux driver
31  * @get_function_name: return the function name of the muxing selector,
32  *	called by the core to figure out which mux setting it shall map a
33  *	certain device to
34  * @get_function_groups: return an array of groups names (in turn
35  *	referencing pins) connected to a certain function selector. The group
36  *	name can be used with the generic @pinctrl_ops to retrieve the
37  *	actual pins affected. The applicable groups will be returned in
38  *	@groups and the number of groups in @num_groups
39  * @set_mux: enable a certain muxing function with a certain pin group. The
40  *	driver does not need to figure out whether enabling this function
41  *	conflicts some other use of the pins in that group, such collisions
42  *	are handled by the pinmux subsystem. The @func_selector selects a
43  *	certain function whereas @group_selector selects a certain set of pins
44  *	to be used. On simple controllers the latter argument may be ignored
45  * @gpio_request_enable: requests and enables GPIO on a certain pin.
46  *	Implement this only if you can mux every pin individually as GPIO. The
47  *	affected GPIO range is passed along with an offset(pin number) into that
48  *	specific GPIO range - function selectors and pin groups are orthogonal
49  *	to this, the core will however make sure the pins do not collide.
50  * @gpio_disable_free: free up GPIO muxing on a certain pin, the reverse of
51  *	@gpio_request_enable
52  * @gpio_set_direction: Since controllers may need different configurations
53  *	depending on whether the GPIO is configured as input or output,
54  *	a direction selector function may be implemented as a backing
55  *	to the GPIO controllers that need pin muxing.
56  * @strict: do not allow simultaneous use of the same pin for GPIO and another
57  *	function. Check both gpio_owner and mux_owner strictly before approving
58  *	the pin request.
59  */
60 struct pinmux_ops {
61 	int (*request) (struct pinctrl_dev *pctldev, unsigned offset);
62 	int (*free) (struct pinctrl_dev *pctldev, unsigned offset);
63 	int (*get_functions_count) (struct pinctrl_dev *pctldev);
64 	const char *(*get_function_name) (struct pinctrl_dev *pctldev,
65 					  unsigned selector);
66 	int (*get_function_groups) (struct pinctrl_dev *pctldev,
67 				  unsigned selector,
68 				  const char * const **groups,
69 				  unsigned *num_groups);
70 	int (*set_mux) (struct pinctrl_dev *pctldev, unsigned func_selector,
71 			unsigned group_selector);
72 	int (*gpio_request_enable) (struct pinctrl_dev *pctldev,
73 				    struct pinctrl_gpio_range *range,
74 				    unsigned offset);
75 	void (*gpio_disable_free) (struct pinctrl_dev *pctldev,
76 				   struct pinctrl_gpio_range *range,
77 				   unsigned offset);
78 	int (*gpio_set_direction) (struct pinctrl_dev *pctldev,
79 				   struct pinctrl_gpio_range *range,
80 				   unsigned offset,
81 				   bool input);
82 	bool strict;
83 };
84 
85 #endif /* __LINUX_PINCTRL_PINMUX_H */
86