arch/arm/plat-samsung/include/plat/gpio-cfg.h

   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 /**
  81  * s3c_gpio_getcfg - Read the current function for a GPIO pin
  82  * @pin: The pin to read the configuration value for.
  83  *
  84  * Read the configuration state of the given @pin, returning a value that
  85  * could be passed back to s3c_gpio_cfgpin().
  86  *
  87  * @sa s3c_gpio_cfgpin
  88  */
  89 extern unsigned s3c_gpio_getcfg(unsigned int pin);
  90
  91 /* Define values for the pull-{up,down} available for each gpio pin.
  92  *
  93  * These values control the state of the weak pull-{up,down} resistors
  94  * available on most pins on the S3C series. Not all chips support both
  95  * up or down settings, and it may be dependant on the chip that is being
  96  * used to whether the particular mode is available.
  97  */
  98 #define S3C_GPIO_PULL_NONE      ((__force s3c_gpio_pull_t)0x00)
  99 #define S3C_GPIO_PULL_DOWN      ((__force s3c_gpio_pull_t)0x01)
 100 #define S3C_GPIO_PULL_UP        ((__force s3c_gpio_pull_t)0x02)
 101
 102 /**
 103  * s3c_gpio_setpull() - set the state of a gpio pin pull resistor
 104  * @pin: The pin number to configure the pull resistor.
 105  * @pull: The configuration for the pull resistor.
 106  *
 107  * This function sets the state of the pull-{up,down} resistor for the
 108  * specified pin. It will return 0 if successfull, or a negative error
 109  * code if the pin cannot support the requested pull setting.
 110 */
 111 extern int s3c_gpio_setpull(unsigned int pin, s3c_gpio_pull_t pull);
 112
 113 /**
 114  * s3c_gpio_getpull() - get the pull resistor state of a gpio pin
 115  * @pin: The pin number to get the settings for
 116  *
 117  * Read the pull resistor value for the specified pin.
 118 */
 119 extern s3c_gpio_pull_t s3c_gpio_getpull(unsigned int pin);
 120
 121 #endif /* __PLAT_GPIO_CFG_H */