1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* |
3 | * Copyright 2008 Openmoko, Inc. |
4 | * Copyright 2008 Simtec Electronics |
5 | * http://armlinux.simtec.co.uk/ |
6 | * Ben Dooks <ben@simtec.co.uk> |
7 | * |
8 | * S3C Platform - GPIO pin configuration |
9 | */ |
10 | |
11 | /* This file contains the necessary definitions to get the basic gpio |
12 | * pin configuration done such as setting a pin to input or output or |
13 | * changing the pull-{up,down} configurations. |
14 | */ |
15 | |
16 | /* Note, this interface is being added to the s3c64xx arch first and will |
17 | * be added to the s3c24xx systems later. |
18 | */ |
19 | |
20 | #ifndef __PLAT_GPIO_CFG_H |
21 | #define __PLAT_GPIO_CFG_H __FILE__ |
22 | |
23 | #include <linux/types.h> |
24 | |
25 | typedef unsigned int __bitwise samsung_gpio_pull_t; |
26 | |
27 | /* forward declaration if gpio-core.h hasn't been included */ |
28 | struct samsung_gpio_chip; |
29 | |
30 | /** |
31 | * struct samsung_gpio_cfg GPIO configuration |
32 | * @cfg_eint: Configuration setting when used for external interrupt source |
33 | * @get_pull: Read the current pull configuration for the GPIO |
34 | * @set_pull: Set the current pull configuration for the GPIO |
35 | * @set_config: Set the current configuration for the GPIO |
36 | * @get_config: Read the current configuration for the GPIO |
37 | * |
38 | * Each chip can have more than one type of GPIO bank available and some |
39 | * have different capabilites even when they have the same control register |
40 | * layouts. Provide an point to vector control routine and provide any |
41 | * per-bank configuration information that other systems such as the |
42 | * external interrupt code will need. |
43 | * |
44 | * @sa samsung_gpio_cfgpin |
45 | * @sa s3c_gpio_getcfg |
46 | * @sa s3c_gpio_setpull |
47 | * @sa s3c_gpio_getpull |
48 | */ |
49 | struct samsung_gpio_cfg { |
50 | unsigned int cfg_eint; |
51 | |
52 | samsung_gpio_pull_t (*get_pull)(struct samsung_gpio_chip *chip, unsigned offs); |
53 | int (*set_pull)(struct samsung_gpio_chip *chip, unsigned offs, |
54 | samsung_gpio_pull_t pull); |
55 | |
56 | unsigned (*get_config)(struct samsung_gpio_chip *chip, unsigned offs); |
57 | int (*set_config)(struct samsung_gpio_chip *chip, unsigned offs, |
58 | unsigned config); |
59 | }; |
60 | |
61 | #define S3C_GPIO_SPECIAL_MARK (0xfffffff0) |
62 | #define S3C_GPIO_SPECIAL(x) (S3C_GPIO_SPECIAL_MARK | (x)) |
63 | |
64 | /* Defines for generic pin configurations */ |
65 | #define S3C_GPIO_INPUT (S3C_GPIO_SPECIAL(0)) |
66 | #define S3C_GPIO_OUTPUT (S3C_GPIO_SPECIAL(1)) |
67 | #define S3C_GPIO_SFN(x) (S3C_GPIO_SPECIAL(x)) |
68 | |
69 | #define samsung_gpio_is_cfg_special(_cfg) \ |
70 | (((_cfg) & S3C_GPIO_SPECIAL_MARK) == S3C_GPIO_SPECIAL_MARK) |
71 | |
72 | /** |
73 | * s3c_gpio_cfgpin() - Change the GPIO function of a pin. |
74 | * @pin pin The pin number to configure. |
75 | * @to to The configuration for the pin's function. |
76 | * |
77 | * Configure which function is actually connected to the external |
78 | * pin, such as an gpio input, output or some form of special function |
79 | * connected to an internal peripheral block. |
80 | * |
81 | * The @to parameter can be one of the generic S3C_GPIO_INPUT, S3C_GPIO_OUTPUT |
82 | * or S3C_GPIO_SFN() to indicate one of the possible values that the helper |
83 | * will then generate the correct bit mask and shift for the configuration. |
84 | * |
85 | * If a bank of GPIOs all needs to be set to special-function 2, then |
86 | * the following code will work: |
87 | * |
88 | * for (gpio = start; gpio < end; gpio++) |
89 | * s3c_gpio_cfgpin(gpio, S3C_GPIO_SFN(2)); |
90 | * |
91 | * The @to parameter can also be a specific value already shifted to the |
92 | * correct position in the control register, although these are discouraged |
93 | * in newer kernels and are only being kept for compatibility. |
94 | */ |
95 | extern int s3c_gpio_cfgpin(unsigned int pin, unsigned int to); |
96 | |
97 | /** |
98 | * s3c_gpio_cfgpin_range() - Change the GPIO function for configuring pin range |
99 | * @start: The pin number to start at |
100 | * @nr: The number of pins to configure from @start. |
101 | * @cfg: The configuration for the pin's function |
102 | * |
103 | * Call s3c_gpio_cfgpin() for the @nr pins starting at @start. |
104 | * |
105 | * @sa s3c_gpio_cfgpin. |
106 | */ |
107 | extern int s3c_gpio_cfgpin_range(unsigned int start, unsigned int nr, |
108 | unsigned int cfg); |
109 | |
110 | /* Define values for the pull-{up,down} available for each gpio pin. |
111 | * |
112 | * These values control the state of the weak pull-{up,down} resistors |
113 | * available on most pins on the S3C series. Not all chips support both |
114 | * up or down settings, and it may be dependent on the chip that is being |
115 | * used to whether the particular mode is available. |
116 | */ |
117 | #define S3C_GPIO_PULL_NONE ((__force samsung_gpio_pull_t)0x00) |
118 | #define S3C_GPIO_PULL_DOWN ((__force samsung_gpio_pull_t)0x01) |
119 | #define S3C_GPIO_PULL_UP ((__force samsung_gpio_pull_t)0x02) |
120 | |
121 | /** |
122 | * s3c_gpio_setpull() - set the state of a gpio pin pull resistor |
123 | * @pin: The pin number to configure the pull resistor. |
124 | * @pull: The configuration for the pull resistor. |
125 | * |
126 | * This function sets the state of the pull-{up,down} resistor for the |
127 | * specified pin. It will return 0 if successful, or a negative error |
128 | * code if the pin cannot support the requested pull setting. |
129 | * |
130 | * @pull is one of S3C_GPIO_PULL_NONE, S3C_GPIO_PULL_DOWN or S3C_GPIO_PULL_UP. |
131 | */ |
132 | extern int s3c_gpio_setpull(unsigned int pin, samsung_gpio_pull_t pull); |
133 | |
134 | /* configure `all` aspects of an gpio */ |
135 | |
136 | /** |
137 | * s3c_gpio_cfgall_range() - configure range of gpio functtion and pull. |
138 | * @start: The gpio number to start at. |
139 | * @nr: The number of gpio to configure from @start. |
140 | * @cfg: The configuration to use |
141 | * @pull: The pull setting to use. |
142 | * |
143 | * Run s3c_gpio_cfgpin() and s3c_gpio_setpull() over the gpio range starting |
144 | * @gpio and running for @size. |
145 | * |
146 | * @sa s3c_gpio_cfgpin |
147 | * @sa s3c_gpio_setpull |
148 | * @sa s3c_gpio_cfgpin_range |
149 | */ |
150 | extern int s3c_gpio_cfgall_range(unsigned int start, unsigned int nr, |
151 | unsigned int cfg, samsung_gpio_pull_t pull); |
152 | |
153 | static inline int s3c_gpio_cfgrange_nopull(unsigned int pin, unsigned int size, |
154 | unsigned int cfg) |
155 | { |
156 | return s3c_gpio_cfgall_range(start: pin, nr: size, cfg, S3C_GPIO_PULL_NONE); |
157 | } |
158 | |
159 | #endif /* __PLAT_GPIO_CFG_H */ |
160 | |