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

   1 /* SPDX-License-Identifier: GPL-2.0 */
   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
  11 /* This file contains the necessary definitions to get the basic gpio
  12  * pin configuration done such as setting a pin to input or output or
  13  * changing the pull-{up,down} configurations.
  14  */
  15
  16 /* Note, this interface is being added to the s3c64xx arch first and will
  17  * be added to the s3c24xx systems later.
  18  */
  19
  20 #ifndef __PLAT_GPIO_CFG_H
  21 #define __PLAT_GPIO_CFG_H __FILE__
  22
  23 #include <linux/types.h>
  24
  25 typedef unsigned int __bitwise samsung_gpio_pull_t;
  26
  27 /* forward declaration if gpio-core.h hasn't been included */
  28 struct samsung_gpio_chip;
  29
  30 /**
  31  * struct samsung_gpio_cfg GPIO configuration
  32  * @cfg_eint: Configuration setting when used for external interrupt source
  33  * @get_pull: Read the current pull configuration for the GPIO
  34  * @set_pull: Set the current pull configuration for the GPIO
  35  * @set_config: Set the current configuration for the GPIO
  36  * @get_config: Read the current configuration for the GPIO
  37  *
  38  * Each chip can have more than one type of GPIO bank available and some
  39  * have different capabilites even when they have the same control register
  40  * layouts. Provide an point to vector control routine and provide any
  41  * per-bank configuration information that other systems such as the
  42  * external interrupt code will need.
  43  *
  44  * @sa samsung_gpio_cfgpin
  45  * @sa s3c_gpio_getcfg
  46  * @sa s3c_gpio_setpull
  47  * @sa s3c_gpio_getpull
  48  */
  49 struct samsung_gpio_cfg {
  50         unsigned int    cfg_eint;
  51
  52         samsung_gpio_pull_t     (*get_pull)(struct samsung_gpio_chip *chip, unsigned offs);
  53         int             (*set_pull)(struct samsung_gpio_chip *chip, unsigned offs,
  54                                     samsung_gpio_pull_t pull);
  55
  56         unsigned (*get_config)(struct samsung_gpio_chip *chip, unsigned offs);
  57         int      (*set_config)(struct samsung_gpio_chip *chip, unsigned offs,
  58                                unsigned config);
  59 };
  60
  61 #define S3C_GPIO_SPECIAL_MARK   (0xfffffff0)
  62 #define S3C_GPIO_SPECIAL(x)     (S3C_GPIO_SPECIAL_MARK | (x))
  63
  64 /* Defines for generic pin configurations */
  65 #define S3C_GPIO_INPUT  (S3C_GPIO_SPECIAL(0))
  66 #define S3C_GPIO_OUTPUT (S3C_GPIO_SPECIAL(1))
  67 #define S3C_GPIO_SFN(x) (S3C_GPIO_SPECIAL(x))
  68
  69 #define samsung_gpio_is_cfg_special(_cfg) \
  70         (((_cfg) & S3C_GPIO_SPECIAL_MARK) == S3C_GPIO_SPECIAL_MARK)
  71
  72 /**
  73  * s3c_gpio_cfgpin() - Change the GPIO function of a pin.
  74  * @pin pin The pin number to configure.
  75  * @to to The configuration for the pin's function.
  76  *
  77  * Configure which function is actually connected to the external
  78  * pin, such as an gpio input, output or some form of special function
  79  * connected to an internal peripheral block.
  80  *
  81  * The @to parameter can be one of the generic S3C_GPIO_INPUT, S3C_GPIO_OUTPUT
  82  * or S3C_GPIO_SFN() to indicate one of the possible values that the helper
  83  * will then generate the correct bit mask and shift for the configuration.
  84  *
  85  * If a bank of GPIOs all needs to be set to special-function 2, then
  86  * the following code will work:
  87  *
  88  *      for (gpio = start; gpio < end; gpio++)
  89  *              s3c_gpio_cfgpin(gpio, S3C_GPIO_SFN(2));
  90  *
  91  * The @to parameter can also be a specific value already shifted to the
  92  * correct position in the control register, although these are discouraged
  93  * in newer kernels and are only being kept for compatibility.
  94  */
  95 extern int s3c_gpio_cfgpin(unsigned int pin, unsigned int to);
  96
  97 /**
  98  * s3c_gpio_getcfg - Read the current function for a GPIO pin
  99  * @pin: The pin to read the configuration value for.
 100  *
 101  * Read the configuration state of the given @pin, returning a value that
 102  * could be passed back to s3c_gpio_cfgpin().
 103  *
 104  * @sa s3c_gpio_cfgpin
 105  */
 106 extern unsigned s3c_gpio_getcfg(unsigned int pin);
 107
 108 /**
 109  * s3c_gpio_cfgpin_range() - Change the GPIO function for configuring pin range
 110  * @start: The pin number to start at
 111  * @nr: The number of pins to configure from @start.
 112  * @cfg: The configuration for the pin's function
 113  *
 114  * Call s3c_gpio_cfgpin() for the @nr pins starting at @start.
 115  *
 116  * @sa s3c_gpio_cfgpin.
 117  */
 118 extern int s3c_gpio_cfgpin_range(unsigned int start, unsigned int nr,
 119                                  unsigned int cfg);
 120
 121 /* Define values for the pull-{up,down} available for each gpio pin.
 122  *
 123  * These values control the state of the weak pull-{up,down} resistors
 124  * available on most pins on the S3C series. Not all chips support both
 125  * up or down settings, and it may be dependent on the chip that is being
 126  * used to whether the particular mode is available.
 127  */
 128 #define S3C_GPIO_PULL_NONE      ((__force samsung_gpio_pull_t)0x00)
 129 #define S3C_GPIO_PULL_DOWN      ((__force samsung_gpio_pull_t)0x01)
 130 #define S3C_GPIO_PULL_UP        ((__force samsung_gpio_pull_t)0x02)
 131
 132 /**
 133  * s3c_gpio_setpull() - set the state of a gpio pin pull resistor
 134  * @pin: The pin number to configure the pull resistor.
 135  * @pull: The configuration for the pull resistor.
 136  *
 137  * This function sets the state of the pull-{up,down} resistor for the
 138  * specified pin. It will return 0 if successful, or a negative error
 139  * code if the pin cannot support the requested pull setting.
 140  *
 141  * @pull is one of S3C_GPIO_PULL_NONE, S3C_GPIO_PULL_DOWN or S3C_GPIO_PULL_UP.
 142 */
 143 extern int s3c_gpio_setpull(unsigned int pin, samsung_gpio_pull_t pull);
 144
 145 /**
 146  * s3c_gpio_getpull() - get the pull resistor state of a gpio pin
 147  * @pin: The pin number to get the settings for
 148  *
 149  * Read the pull resistor value for the specified pin.
 150 */
 151 extern samsung_gpio_pull_t s3c_gpio_getpull(unsigned int pin);
 152
 153 /* configure `all` aspects of an gpio */
 154
 155 /**
 156  * s3c_gpio_cfgall_range() - configure range of gpio functtion and pull.
 157  * @start: The gpio number to start at.
 158  * @nr: The number of gpio to configure from @start.
 159  * @cfg: The configuration to use
 160  * @pull: The pull setting to use.
 161  *
 162  * Run s3c_gpio_cfgpin() and s3c_gpio_setpull() over the gpio range starting
 163  * @gpio and running for @size.
 164  *
 165  * @sa s3c_gpio_cfgpin
 166  * @sa s3c_gpio_setpull
 167  * @sa s3c_gpio_cfgpin_range
 168  */
 169 extern int s3c_gpio_cfgall_range(unsigned int start, unsigned int nr,
 170                                  unsigned int cfg, samsung_gpio_pull_t pull);
 171
 172 static inline int s3c_gpio_cfgrange_nopull(unsigned int pin, unsigned int size,
 173                                            unsigned int cfg)
 174 {
 175         return s3c_gpio_cfgall_range(pin, size, cfg, S3C_GPIO_PULL_NONE);
 176 }
 177
 178 #endif /* __PLAT_GPIO_CFG_H */