• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 typedef unsigned int __bitwise__ s3c_gpio_pull_t;
28 
29 /* forward declaration if gpio-core.h hasn't been included */
30 struct s3c_gpio_chip;
31 
32 /**
33  * struct s3c_gpio_cfg GPIO configuration
34  * @cfg_eint: Configuration setting when used for external interrupt source
35  * @get_pull: Read the current pull configuration for the GPIO
36  * @set_pull: Set the current pull configuraiton for the GPIO
37  * @set_config: Set the current configuration for the GPIO
38  * @get_config: Read the current configuration for the GPIO
39  *
40  * Each chip can have more than one type of GPIO bank available and some
41  * have different capabilites even when they have the same control register
42  * layouts. Provide an point to vector control routine and provide any
43  * per-bank configuration information that other systems such as the
44  * external interrupt code will need.
45  */
46 struct s3c_gpio_cfg {
47 	unsigned int	cfg_eint;
48 
49 	s3c_gpio_pull_t	(*get_pull)(struct s3c_gpio_chip *chip, unsigned offs);
50 	int		(*set_pull)(struct s3c_gpio_chip *chip, unsigned offs,
51 				    s3c_gpio_pull_t pull);
52 
53 	unsigned (*get_config)(struct s3c_gpio_chip *chip, unsigned offs);
54 	int	 (*set_config)(struct s3c_gpio_chip *chip, unsigned offs,
55 			       unsigned config);
56 };
57 
58 #define S3C_GPIO_SPECIAL_MARK	(0xfffffff0)
59 #define S3C_GPIO_SPECIAL(x)	(S3C_GPIO_SPECIAL_MARK | (x))
60 
61 /* Defines for generic pin configurations */
62 #define S3C_GPIO_INPUT	(S3C_GPIO_SPECIAL(0))
63 #define S3C_GPIO_OUTPUT	(S3C_GPIO_SPECIAL(1))
64 #define S3C_GPIO_SFN(x)	(S3C_GPIO_SPECIAL(x))
65 
66 #define s3c_gpio_is_cfg_special(_cfg) \
67 	(((_cfg) & S3C_GPIO_SPECIAL_MARK) == S3C_GPIO_SPECIAL_MARK)
68 
69 /**
70  * s3c_gpio_cfgpin() - Change the GPIO function of a pin.
71  * @pin pin The pin number to configure.
72  * @pin to The configuration for the pin's function.
73  *
74  * Configure which function is actually connected to the external
75  * pin, such as an gpio input, output or some form of special function
76  * connected to an internal peripheral block.
77  */
78 extern int s3c_gpio_cfgpin(unsigned int pin, unsigned int to);
79 
80 /* Define values for the pull-{up,down} available for each gpio pin.
81  *
82  * These values control the state of the weak pull-{up,down} resistors
83  * available on most pins on the S3C series. Not all chips support both
84  * up or down settings, and it may be dependant on the chip that is being
85  * used to whether the particular mode is available.
86  */
87 #define S3C_GPIO_PULL_NONE	((__force s3c_gpio_pull_t)0x00)
88 #define S3C_GPIO_PULL_DOWN	((__force s3c_gpio_pull_t)0x01)
89 #define S3C_GPIO_PULL_UP	((__force s3c_gpio_pull_t)0x02)
90 
91 /**
92  * s3c_gpio_setpull() - set the state of a gpio pin pull resistor
93  * @pin: The pin number to configure the pull resistor.
94  * @pull: The configuration for the pull resistor.
95  *
96  * This function sets the state of the pull-{up,down} resistor for the
97  * specified pin. It will return 0 if successfull, or a negative error
98  * code if the pin cannot support the requested pull setting.
99 */
100 extern int s3c_gpio_setpull(unsigned int pin, s3c_gpio_pull_t pull);
101 
102 /**
103  * s3c_gpio_getpull() - get the pull resistor state of a gpio pin
104  * @pin: The pin number to get the settings for
105  *
106  * Read the pull resistor value for the specified pin.
107 */
108 extern s3c_gpio_pull_t s3c_gpio_getpull(unsigned int pin);
109 
110 #endif /* __PLAT_GPIO_CFG_H */
111