xref: /linux-6.15/include/linux/pinctrl/pinmux.h (revision db4e8395)
1 /*
2  * Interface the pinmux subsystem
3  *
4  * Copyright (C) 2011 ST-Ericsson SA
5  * Written on behalf of Linaro for ST-Ericsson
6  * Based on bits of regulator core, gpio core and clk core
7  *
8  * Author: Linus Walleij <[email protected]>
9  *
10  * License terms: GNU General Public License (GPL) version 2
11  */
12 #ifndef __LINUX_PINCTRL_PINMUX_H
13 #define __LINUX_PINCTRL_PINMUX_H
14 
15 #include <linux/list.h>
16 #include <linux/seq_file.h>
17 #include "pinctrl.h"
18 
19 /* This struct is private to the core and should be regarded as a cookie */
20 struct pinmux;
21 
22 #ifdef CONFIG_PINMUX
23 
24 struct pinctrl_dev;
25 
26 /**
27  * struct pinmux_ops - pinmux operations, to be implemented by pin controller
28  * drivers that support pinmuxing
29  * @request: called by the core to see if a certain pin can be made available
30  *	available for muxing. This is called by the core to acquire the pins
31  *	before selecting any actual mux setting across a function. The driver
32  *	is allowed to answer "no" by returning a negative error code
33  * @free: the reverse function of the request() callback, frees a pin after
34  *	being requested
35  * @list_functions: list the number of selectable named functions available
36  *	in this pinmux driver, the core will begin on 0 and call this
37  *	repeatedly as long as it returns >= 0 to enumerate mux settings
38  * @get_function_name: return the function name of the muxing selector,
39  *	called by the core to figure out which mux setting it shall map a
40  *	certain device to
41  * @get_function_groups: return an array of groups names (in turn
42  *	referencing pins) connected to a certain function selector. The group
43  *	name can be used with the generic @pinctrl_ops to retrieve the
44  *	actual pins affected. The applicable groups will be returned in
45  *	@groups and the number of groups in @num_groups
46  * @enable: enable a certain muxing function with a certain pin group. The
47  *	driver does not need to figure out whether enabling this function
48  *	conflicts some other use of the pins in that group, such collisions
49  *	are handled by the pinmux subsystem. The @func_selector selects a
50  *	certain function whereas @group_selector selects a certain set of pins
51  *	to be used. On simple controllers the latter argument may be ignored
52  * @disable: disable a certain muxing selector with a certain pin group
53  * @gpio_request_enable: requests and enables GPIO on a certain pin.
54  *	Implement this only if you can mux every pin individually as GPIO. The
55  *	affected GPIO range is passed along with an offset into that
56  *	specific GPIO range - function selectors and pin groups are orthogonal
57  *	to this, the core will however make sure the pins do not collide
58  */
59 struct pinmux_ops {
60 	int (*request) (struct pinctrl_dev *pctldev, unsigned offset);
61 	int (*free) (struct pinctrl_dev *pctldev, unsigned offset);
62 	int (*list_functions) (struct pinctrl_dev *pctldev, unsigned selector);
63 	const char *(*get_function_name) (struct pinctrl_dev *pctldev,
64 					  unsigned selector);
65 	int (*get_function_groups) (struct pinctrl_dev *pctldev,
66 				  unsigned selector,
67 				  const char * const **groups,
68 				  unsigned * const num_groups);
69 	int (*enable) (struct pinctrl_dev *pctldev, unsigned func_selector,
70 		       unsigned group_selector);
71 	void (*disable) (struct pinctrl_dev *pctldev, unsigned func_selector,
72 			 unsigned group_selector);
73 	int (*gpio_request_enable) (struct pinctrl_dev *pctldev,
74 				    struct pinctrl_gpio_range *range,
75 				    unsigned offset);
76 };
77 
78 /* External interface to pinmux */
79 extern int pinmux_request_gpio(unsigned gpio);
80 extern void pinmux_free_gpio(unsigned gpio);
81 extern struct pinmux * __must_check pinmux_get(struct device *dev, const char *name);
82 extern void pinmux_put(struct pinmux *pmx);
83 extern int pinmux_enable(struct pinmux *pmx);
84 extern void pinmux_disable(struct pinmux *pmx);
85 
86 #else /* !CONFIG_PINMUX */
87 
88 static inline int pinmux_request_gpio(unsigned gpio)
89 {
90 	return 0;
91 }
92 
93 static inline void pinmux_free_gpio(unsigned gpio)
94 {
95 }
96 
97 static inline struct pinmux * __must_check pinmux_get(struct device *dev, const char *name)
98 {
99 	return NULL;
100 }
101 
102 static inline void pinmux_put(struct pinmux *pmx)
103 {
104 }
105 
106 static inline int pinmux_enable(struct pinmux *pmx)
107 {
108 	return 0;
109 }
110 
111 static inline void pinmux_disable(struct pinmux *pmx)
112 {
113 }
114 
115 #endif /* CONFIG_PINMUX */
116 
117 #endif /* __LINUX_PINCTRL_PINMUX_H */
118