1 /* linux/arch/arm/plat-s3c/include/plat/gpio-cfg.h
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 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 */
14
15 /* This file contains the necessary definitions to get the basic gpio
16 * pin configuration done such as setting a pin to input or output or
17 * changing the pull-{up,down} configurations.
18 */
19
20 /* Note, this interface is being added to the s3c64xx arch first and will
21 * be added to the s3c24xx systems later.
22 */
23
24 #ifndef __PLAT_GPIO_CFG_H
25 #define __PLAT_GPIO_CFG_H __FILE__
26
27 #include <linux/types.h>
28
29 typedef unsigned int __bitwise__ samsung_gpio_pull_t;
30
31 /* forward declaration if gpio-core.h hasn't been included */
32 struct samsung_gpio_chip;
33
34 /**
35 * struct samsung_gpio_cfg GPIO configuration
36 * @cfg_eint: Configuration setting when used for external interrupt source
37 * @get_pull: Read the current pull configuration for the GPIO
38 * @set_pull: Set the current pull configuraiton for the GPIO
39 * @set_config: Set the current configuration for the GPIO
40 * @get_config: Read the current configuration for the GPIO
41 *
42 * Each chip can have more than one type of GPIO bank available and some
43 * have different capabilites even when they have the same control register
44 * layouts. Provide an point to vector control routine and provide any
45 * per-bank configuration information that other systems such as the
46 * external interrupt code will need.
47 *
48 * @sa samsung_gpio_cfgpin
49 * @sa s3c_gpio_getcfg
50 * @sa s3c_gpio_setpull
51 * @sa s3c_gpio_getpull
52 */
53 struct samsung_gpio_cfg {
54 unsigned int cfg_eint;
55
56 samsung_gpio_pull_t (*get_pull)(struct samsung_gpio_chip *chip, unsigned offs);
57 int (*set_pull)(struct samsung_gpio_chip *chip, unsigned offs,
58 samsung_gpio_pull_t pull);
59
60 unsigned (*get_config)(struct samsung_gpio_chip *chip, unsigned offs);
61 int (*set_config)(struct samsung_gpio_chip *chip, unsigned offs,
62 unsigned config);
63 };
64
65 #define S3C_GPIO_SPECIAL_MARK (0xfffffff0)
66 #define S3C_GPIO_SPECIAL(x) (S3C_GPIO_SPECIAL_MARK | (x))
67
68 /* Defines for generic pin configurations */
69 #define S3C_GPIO_INPUT (S3C_GPIO_SPECIAL(0))
70 #define S3C_GPIO_OUTPUT (S3C_GPIO_SPECIAL(1))
71 #define S3C_GPIO_SFN(x) (S3C_GPIO_SPECIAL(x))
72
73 #define samsung_gpio_is_cfg_special(_cfg) \
74 (((_cfg) & S3C_GPIO_SPECIAL_MARK) == S3C_GPIO_SPECIAL_MARK)
75
76 /**
77 * s3c_gpio_cfgpin() - Change the GPIO function of a pin.
78 * @pin pin The pin number to configure.
79 * @to to The configuration for the pin's function.
80 *
81 * Configure which function is actually connected to the external
82 * pin, such as an gpio input, output or some form of special function
83 * connected to an internal peripheral block.
84 *
85 * The @to parameter can be one of the generic S3C_GPIO_INPUT, S3C_GPIO_OUTPUT
86 * or S3C_GPIO_SFN() to indicate one of the possible values that the helper
87 * will then generate the correct bit mask and shift for the configuration.
88 *
89 * If a bank of GPIOs all needs to be set to special-function 2, then
90 * the following code will work:
91 *
92 * for (gpio = start; gpio < end; gpio++)
93 * s3c_gpio_cfgpin(gpio, S3C_GPIO_SFN(2));
94 *
95 * The @to parameter can also be a specific value already shifted to the
96 * correct position in the control register, although these are discouraged
97 * in newer kernels and are only being kept for compatibility.
98 */
99 extern int s3c_gpio_cfgpin(unsigned int pin, unsigned int to);
100
101 /**
102 * s3c_gpio_getcfg - Read the current function for a GPIO pin
103 * @pin: The pin to read the configuration value for.
104 *
105 * Read the configuration state of the given @pin, returning a value that
106 * could be passed back to s3c_gpio_cfgpin().
107 *
108 * @sa s3c_gpio_cfgpin
109 */
110 extern unsigned s3c_gpio_getcfg(unsigned int pin);
111
112 /**
113 * s3c_gpio_cfgpin_range() - Change the GPIO function for configuring pin range
114 * @start: The pin number to start at
115 * @nr: The number of pins to configure from @start.
116 * @cfg: The configuration for the pin's function
117 *
118 * Call s3c_gpio_cfgpin() for the @nr pins starting at @start.
119 *
120 * @sa s3c_gpio_cfgpin.
121 */
122 extern int s3c_gpio_cfgpin_range(unsigned int start, unsigned int nr,
123 unsigned int cfg);
124
125 /* Define values for the pull-{up,down} available for each gpio pin.
126 *
127 * These values control the state of the weak pull-{up,down} resistors
128 * available on most pins on the S3C series. Not all chips support both
129 * up or down settings, and it may be dependent on the chip that is being
130 * used to whether the particular mode is available.
131 */
132 #define S3C_GPIO_PULL_NONE ((__force samsung_gpio_pull_t)0x00)
133 #define S3C_GPIO_PULL_DOWN ((__force samsung_gpio_pull_t)0x01)
134 #define S3C_GPIO_PULL_UP ((__force samsung_gpio_pull_t)0x02)
135
136 /**
137 * s3c_gpio_setpull() - set the state of a gpio pin pull resistor
138 * @pin: The pin number to configure the pull resistor.
139 * @pull: The configuration for the pull resistor.
140 *
141 * This function sets the state of the pull-{up,down} resistor for the
142 * specified pin. It will return 0 if successful, or a negative error
143 * code if the pin cannot support the requested pull setting.
144 *
145 * @pull is one of S3C_GPIO_PULL_NONE, S3C_GPIO_PULL_DOWN or S3C_GPIO_PULL_UP.
146 */
147 extern int s3c_gpio_setpull(unsigned int pin, samsung_gpio_pull_t pull);
148
149 /**
150 * s3c_gpio_getpull() - get the pull resistor state of a gpio pin
151 * @pin: The pin number to get the settings for
152 *
153 * Read the pull resistor value for the specified pin.
154 */
155 extern samsung_gpio_pull_t s3c_gpio_getpull(unsigned int pin);
156
157 /* configure `all` aspects of an gpio */
158
159 /**
160 * s3c_gpio_cfgall_range() - configure range of gpio functtion and pull.
161 * @start: The gpio number to start at.
162 * @nr: The number of gpio to configure from @start.
163 * @cfg: The configuration to use
164 * @pull: The pull setting to use.
165 *
166 * Run s3c_gpio_cfgpin() and s3c_gpio_setpull() over the gpio range starting
167 * @gpio and running for @size.
168 *
169 * @sa s3c_gpio_cfgpin
170 * @sa s3c_gpio_setpull
171 * @sa s3c_gpio_cfgpin_range
172 */
173 extern int s3c_gpio_cfgall_range(unsigned int start, unsigned int nr,
174 unsigned int cfg, samsung_gpio_pull_t pull);
175
s3c_gpio_cfgrange_nopull(unsigned int pin,unsigned int size,unsigned int cfg)176 static inline int s3c_gpio_cfgrange_nopull(unsigned int pin, unsigned int size,
177 unsigned int cfg)
178 {
179 return s3c_gpio_cfgall_range(pin, size, cfg, S3C_GPIO_PULL_NONE);
180 }
181
182 #endif /* __PLAT_GPIO_CFG_H */
183