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 */ 179