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 #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 configuration 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
 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 */