release/src-rt-6.x.4708/linux/linux-2.6.36/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 typedef unsigned int __bitwise__ s5p_gpio_drvstr_t;
  29
  30 /* forward declaration if gpio-core.h hasn't been included */
  31 struct s3c_gpio_chip;
  32
  33 /**
  34  * struct s3c_gpio_cfg GPIO configuration
  35  * @cfg_eint: Configuration setting when used for external interrupt source
  36  * @get_pull: Read the current pull configuration for the GPIO
  37  * @set_pull: Set the current pull configuraiton for the GPIO
  38  * @set_config: Set the current configuration for the GPIO
  39  * @get_config: Read the current configuration for the GPIO
  40  *
  41  * Each chip can have more than one type of GPIO bank available and some
  42  * have different capabilites even when they have the same control register
  43  * layouts. Provide an point to vector control routine and provide any
  44  * per-bank configuration information that other systems such as the
  45  * external interrupt code will need.
  46  *
  47  * @sa s3c_gpio_cfgpin
  48  * @sa s3c_gpio_getcfg
  49  * @sa s3c_gpio_setpull
  50  * @sa s3c_gpio_getpull
  51  */
  52 struct s3c_gpio_cfg {
  53         unsigned int    cfg_eint;
  54
  55         s3c_gpio_pull_t (*get_pull)(struct s3c_gpio_chip *chip, unsigned offs);
  56         int             (*set_pull)(struct s3c_gpio_chip *chip, unsigned offs,
  57                                     s3c_gpio_pull_t pull);
  58
  59         unsigned (*get_config)(struct s3c_gpio_chip *chip, unsigned offs);
  60         int      (*set_config)(struct s3c_gpio_chip *chip, unsigned offs,
  61                                unsigned config);
  62 };
  63
  64 #define S3C_GPIO_SPECIAL_MARK   (0xfffffff0)
  65 #define S3C_GPIO_SPECIAL(x)     (S3C_GPIO_SPECIAL_MARK | (x))
  66
  67 /* Defines for generic pin configurations */
  68 #define S3C_GPIO_INPUT  (S3C_GPIO_SPECIAL(0))
  69 #define S3C_GPIO_OUTPUT (S3C_GPIO_SPECIAL(1))
  70 #define S3C_GPIO_SFN(x) (S3C_GPIO_SPECIAL(x))
  71
  72 #define s3c_gpio_is_cfg_special(_cfg) \
  73         (((_cfg) & S3C_GPIO_SPECIAL_MARK) == S3C_GPIO_SPECIAL_MARK)
  74
  75 /**
  76  * s3c_gpio_cfgpin() - Change the GPIO function of a pin.
  77  * @pin pin The pin number to configure.
  78  * @to to The configuration for the pin's function.
  79  *
  80  * Configure which function is actually connected to the external
  81  * pin, such as an gpio input, output or some form of special function
  82  * connected to an internal peripheral block.
  83  *
  84  * The @to parameter can be one of the generic S3C_GPIO_INPUT, S3C_GPIO_OUTPUT
  85  * or S3C_GPIO_SFN() to indicate one of the possible values that the helper
  86  * will then generate the correct bit mask and shift for the configuration.
  87  *
  88  * If a bank of GPIOs all needs to be set to special-function 2, then
  89  * the following code will work:
  90  *
  91  *      for (gpio = start; gpio < end; gpio++)
  92  *              s3c_gpio_cfgpin(gpio, S3C_GPIO_SFN(2));
  93  *
  94  * The @to parameter can also be a specific value already shifted to the
  95  * correct position in the control register, although these are discouraged
  96  * in newer kernels and are only being kept for compatibility.
  97  */
  98 extern int s3c_gpio_cfgpin(unsigned int pin, unsigned int to);
  99
 100 /**
 101  * s3c_gpio_getcfg - Read the current function for a GPIO pin
 102  * @pin: The pin to read the configuration value for.
 103  *
 104  * Read the configuration state of the given @pin, returning a value that
 105  * could be passed back to s3c_gpio_cfgpin().
 106  *
 107  * @sa s3c_gpio_cfgpin
 108  */
 109 extern unsigned s3c_gpio_getcfg(unsigned int pin);
 110
 111 /* Define values for the pull-{up,down} available for each gpio pin.
 112  *
 113  * These values control the state of the weak pull-{up,down} resistors
 114  * available on most pins on the S3C series. Not all chips support both
 115  * up or down settings, and it may be dependant on the chip that is being
 116  * used to whether the particular mode is available.
 117  */
 118 #define S3C_GPIO_PULL_NONE      ((__force s3c_gpio_pull_t)0x00)
 119 #define S3C_GPIO_PULL_DOWN      ((__force s3c_gpio_pull_t)0x01)
 120 #define S3C_GPIO_PULL_UP        ((__force s3c_gpio_pull_t)0x02)
 121
 122 /**
 123  * s3c_gpio_setpull() - set the state of a gpio pin pull resistor
 124  * @pin: The pin number to configure the pull resistor.
 125  * @pull: The configuration for the pull resistor.
 126  *
 127  * This function sets the state of the pull-{up,down} resistor for the
 128  * specified pin. It will return 0 if successfull, or a negative error
 129  * code if the pin cannot support the requested pull setting.
 130  *
 131  * @pull is one of S3C_GPIO_PULL_NONE, S3C_GPIO_PULL_DOWN or S3C_GPIO_PULL_UP.
 132 */
 133 extern int s3c_gpio_setpull(unsigned int pin, s3c_gpio_pull_t pull);
 134
 135 /**
 136  * s3c_gpio_getpull() - get the pull resistor state of a gpio pin
 137  * @pin: The pin number to get the settings for
 138  *
 139  * Read the pull resistor value for the specified pin.
 140 */
 141 extern s3c_gpio_pull_t s3c_gpio_getpull(unsigned int pin);
 142
 143 /* Define values for the drvstr available for each gpio pin.
 144  *
 145  * These values control the value of the output signal driver strength,
 146  * configurable on most pins on the S5P series.
 147  */
 148 #define S5P_GPIO_DRVSTR_LV1     ((__force s5p_gpio_drvstr_t)0x0)
 149 #define S5P_GPIO_DRVSTR_LV2     ((__force s5p_gpio_drvstr_t)0x2)
 150 #define S5P_GPIO_DRVSTR_LV3     ((__force s5p_gpio_drvstr_t)0x1)
 151 #define S5P_GPIO_DRVSTR_LV4     ((__force s5p_gpio_drvstr_t)0x3)
 152
 153 /**
 154  * s5c_gpio_get_drvstr() - get the driver streght value of a gpio pin
 155  * @pin: The pin number to get the settings for
 156  *
 157  * Read the driver streght value for the specified pin.
 158 */
 159 extern s5p_gpio_drvstr_t s5p_gpio_get_drvstr(unsigned int pin);
 160
 161 /**
 162  * s3c_gpio_set_drvstr() - set the driver streght value of a gpio pin
 163  * @pin: The pin number to configure the driver streght value
 164  * @drvstr: The new value of the driver strength
 165  *
 166  * This function sets the driver strength value for the specified pin.
 167  * It will return 0 if successfull, or a negative error code if the pin
 168  * cannot support the requested setting.
 169 */
 170 extern int s5p_gpio_set_drvstr(unsigned int pin, s5p_gpio_drvstr_t drvstr);
 171
 172 #endif /* __PLAT_GPIO_CFG_H */