xref: /openbmc/linux/arch/arm/mach-s3c/gpio-cfg.h (revision 0d297df0)
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 
s3c_gpio_cfgrange_nopull(unsigned int pin,unsigned int size,unsigned int cfg)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(pin, size, cfg, S3C_GPIO_PULL_NONE);
157 }
158 
159 #endif /* __PLAT_GPIO_CFG_H */
160