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 typedef unsigned int __bitwise__ s5p_gpio_drvstr_t;
  31
  32 /* forward declaration if gpio-core.h hasn't been included */
  33 struct samsung_gpio_chip;
  34
  35 /**
  36  * struct samsung_gpio_cfg GPIO configuration
  37  * @cfg_eint: Configuration setting when used for external interrupt source
  38  * @get_pull: Read the current pull configuration for the GPIO
  39  * @set_pull: Set the current pull configuraiton for the GPIO
  40  * @set_config: Set the current configuration for the GPIO
  41  * @get_config: Read the current configuration for the GPIO
  42  *
  43  * Each chip can have more than one type of GPIO bank available and some
  44  * have different capabilites even when they have the same control register
  45  * layouts. Provide an point to vector control routine and provide any
  46  * per-bank configuration information that other systems such as the
  47  * external interrupt code will need.
  48  *
  49  * @sa samsung_gpio_cfgpin
  50  * @sa s3c_gpio_getcfg
  51  * @sa s3c_gpio_setpull
  52  * @sa s3c_gpio_getpull
  53  */
  54 struct samsung_gpio_cfg {
  55         unsigned int    cfg_eint;
  56
  57         samsung_gpio_pull_t     (*get_pull)(struct samsung_gpio_chip *chip, unsigned offs);
  58         int             (*set_pull)(struct samsung_gpio_chip *chip, unsigned offs,
  59                                     samsung_gpio_pull_t pull);
  60
  61         unsigned (*get_config)(struct samsung_gpio_chip *chip, unsigned offs);
  62         int      (*set_config)(struct samsung_gpio_chip *chip, unsigned offs,
  63                                unsigned config);
  64 };
  65
  66 #define S3C_GPIO_SPECIAL_MARK   (0xfffffff0)
  67 #define S3C_GPIO_SPECIAL(x)     (S3C_GPIO_SPECIAL_MARK | (x))
  68
  69 /* Defines for generic pin configurations */
  70 #define S3C_GPIO_INPUT  (S3C_GPIO_SPECIAL(0))
  71 #define S3C_GPIO_OUTPUT (S3C_GPIO_SPECIAL(1))
  72 #define S3C_GPIO_SFN(x) (S3C_GPIO_SPECIAL(x))
  73
  74 #define samsung_gpio_is_cfg_special(_cfg) \
  75         (((_cfg) & S3C_GPIO_SPECIAL_MARK) == S3C_GPIO_SPECIAL_MARK)
  76
  77 /**
  78  * s3c_gpio_cfgpin() - Change the GPIO function of a pin.
  79  * @pin pin The pin number to configure.
  80  * @to to The configuration for the pin's function.
  81  *
  82  * Configure which function is actually connected to the external
  83  * pin, such as an gpio input, output or some form of special function
  84  * connected to an internal peripheral block.
  85  *
  86  * The @to parameter can be one of the generic S3C_GPIO_INPUT, S3C_GPIO_OUTPUT
  87  * or S3C_GPIO_SFN() to indicate one of the possible values that the helper
  88  * will then generate the correct bit mask and shift for the configuration.
  89  *
  90  * If a bank of GPIOs all needs to be set to special-function 2, then
  91  * the following code will work:
  92  *
  93  *      for (gpio = start; gpio < end; gpio++)
  94  *              s3c_gpio_cfgpin(gpio, S3C_GPIO_SFN(2));
  95  *
  96  * The @to parameter can also be a specific value already shifted to the
  97  * correct position in the control register, although these are discouraged
  98  * in newer kernels and are only being kept for compatibility.
  99  */
 100 extern int s3c_gpio_cfgpin(unsigned int pin, unsigned int to);
 101
 102 /**
 103  * s3c_gpio_getcfg - Read the current function for a GPIO pin
 104  * @pin: The pin to read the configuration value for.
 105  *
 106  * Read the configuration state of the given @pin, returning a value that
 107  * could be passed back to s3c_gpio_cfgpin().
 108  *
 109  * @sa s3c_gpio_cfgpin
 110  */
 111 extern unsigned s3c_gpio_getcfg(unsigned int pin);
 112
 113 /**
 114  * s3c_gpio_cfgpin_range() - Change the GPIO function for configuring pin range
 115  * @start: The pin number to start at
 116  * @nr: The number of pins to configure from @start.
 117  * @cfg: The configuration for the pin's function
 118  *
 119  * Call s3c_gpio_cfgpin() for the @nr pins starting at @start.
 120  *
 121  * @sa s3c_gpio_cfgpin.
 122  */
 123 extern int s3c_gpio_cfgpin_range(unsigned int start, unsigned int nr,
 124                                  unsigned int cfg);
 125
 126 /* Define values for the pull-{up,down} available for each gpio pin.
 127  *
 128  * These values control the state of the weak pull-{up,down} resistors
 129  * available on most pins on the S3C series. Not all chips support both
 130  * up or down settings, and it may be dependent on the chip that is being
 131  * used to whether the particular mode is available.
 132  */
 133 #define S3C_GPIO_PULL_NONE      ((__force samsung_gpio_pull_t)0x00)
 134 #define S3C_GPIO_PULL_DOWN      ((__force samsung_gpio_pull_t)0x01)
 135 #define S3C_GPIO_PULL_UP        ((__force samsung_gpio_pull_t)0x02)
 136
 137 /**
 138  * s3c_gpio_setpull() - set the state of a gpio pin pull resistor
 139  * @pin: The pin number to configure the pull resistor.
 140  * @pull: The configuration for the pull resistor.
 141  *
 142  * This function sets the state of the pull-{up,down} resistor for the
 143  * specified pin. It will return 0 if successful, or a negative error
 144  * code if the pin cannot support the requested pull setting.
 145  *
 146  * @pull is one of S3C_GPIO_PULL_NONE, S3C_GPIO_PULL_DOWN or S3C_GPIO_PULL_UP.
 147 */
 148 extern int s3c_gpio_setpull(unsigned int pin, samsung_gpio_pull_t pull);
 149
 150 /**
 151  * s3c_gpio_getpull() - get the pull resistor state of a gpio pin
 152  * @pin: The pin number to get the settings for
 153  *
 154  * Read the pull resistor value for the specified pin.
 155 */
 156 extern samsung_gpio_pull_t s3c_gpio_getpull(unsigned int pin);
 157
 158 /* configure `all` aspects of an gpio */
 159
 160 /**
 161  * s3c_gpio_cfgall_range() - configure range of gpio functtion and pull.
 162  * @start: The gpio number to start at.
 163  * @nr: The number of gpio to configure from @start.
 164  * @cfg: The configuration to use
 165  * @pull: The pull setting to use.
 166  *
 167  * Run s3c_gpio_cfgpin() and s3c_gpio_setpull() over the gpio range starting
 168  * @gpio and running for @size.
 169  *
 170  * @sa s3c_gpio_cfgpin
 171  * @sa s3c_gpio_setpull
 172  * @sa s3c_gpio_cfgpin_range
 173  */
 174 extern int s3c_gpio_cfgall_range(unsigned int start, unsigned int nr,
 175                                  unsigned int cfg, samsung_gpio_pull_t pull);
 176
 177 static inline int s3c_gpio_cfgrange_nopull(unsigned int pin, unsigned int size,
 178                                            unsigned int cfg)
 179 {
 180         return s3c_gpio_cfgall_range(pin, size, cfg, S3C_GPIO_PULL_NONE);
 181 }
 182
 183 /* Define values for the drvstr available for each gpio pin.
 184  *
 185  * These values control the value of the output signal driver strength,
 186  * configurable on most pins on the S5P series.
 187  */
 188 #define S5P_GPIO_DRVSTR_LV1     ((__force s5p_gpio_drvstr_t)0x0)
 189 #define S5P_GPIO_DRVSTR_LV2     ((__force s5p_gpio_drvstr_t)0x2)
 190 #define S5P_GPIO_DRVSTR_LV3     ((__force s5p_gpio_drvstr_t)0x1)
 191 #define S5P_GPIO_DRVSTR_LV4     ((__force s5p_gpio_drvstr_t)0x3)
 192
 193 /**
 194  * s5c_gpio_get_drvstr() - get the driver streght value of a gpio pin
 195  * @pin: The pin number to get the settings for
 196  *
 197  * Read the driver streght value for the specified pin.
 198 */
 199 extern s5p_gpio_drvstr_t s5p_gpio_get_drvstr(unsigned int pin);
 200
 201 /**
 202  * s3c_gpio_set_drvstr() - set the driver streght value of a gpio pin
 203  * @pin: The pin number to configure the driver streght value
 204  * @drvstr: The new value of the driver strength
 205  *
 206  * This function sets the driver strength value for the specified pin.
 207  * It will return 0 if successful, or a negative error code if the pin
 208  * cannot support the requested setting.
 209 */
 210 extern int s5p_gpio_set_drvstr(unsigned int pin, s5p_gpio_drvstr_t drvstr);
 211
 212 /**
 213  * s5p_register_gpio_interrupt() - register interrupt support for a gpio group
 214  * @pin: The pin number from the group to be registered
 215  *
 216  * This function registers gpio interrupt support for the group that the
 217  * specified pin belongs to.
 218  *
 219  * The total number of gpio pins is quite large ob s5p series. Registering
 220  * irq support for all of them would be a resource waste. Because of that the
 221  * interrupt support for standard gpio pins is registered dynamically.
 222  *
 223  * It will return the irq number of the interrupt that has been registered
 224  * or -ENOMEM if no more gpio interrupts can be registered. It is allowed
 225  * to call this function more than once for the same gpio group (the group
 226  * will be registered only once).
 227  */
 228 extern int s5p_register_gpio_interrupt(int pin);
 229
 230 /** s5p_register_gpioint_bank() - add gpio bank for further gpio interrupt
 231  * registration (see s5p_register_gpio_interrupt function)
 232  * @chain_irq: chained irq number for the gpio int handler for this bank
 233  * @start: start gpio group number of this bank
 234  * @nr_groups: number of gpio groups handled by this bank
 235  *
 236  * This functions registers initial information about gpio banks that
 237  * can be later used by the s5p_register_gpio_interrupt() function to
 238  * enable support for gpio interrupt for particular gpio group.
 239  */
 240 #ifdef CONFIG_S5P_GPIO_INT
 241 extern int s5p_register_gpioint_bank(int chain_irq, int start, int nr_groups);
 242 #else
 243 #define s5p_register_gpioint_bank(chain_irq, start, nr_groups) do { } while (0)
 244 #endif
 245
 246 #endif /* __PLAT_GPIO_CFG_H */