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Diffstat (limited to '')
| -rw-r--r-- | arch/arm/mach-s3c/gpio-cfg.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/arch/arm/mach-s3c/gpio-cfg.h b/arch/arm/mach-s3c/gpio-cfg.h new file mode 100644 index 000000000..469c220e0 --- /dev/null +++ b/arch/arm/mach-s3c/gpio-cfg.h @@ -0,0 +1,178 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright 2008 Openmoko, Inc. + * Copyright 2008 Simtec Electronics + * http://armlinux.simtec.co.uk/ + * Ben Dooks <ben@simtec.co.uk> + * + * S3C Platform - GPIO pin configuration + */ + +/* This file contains the necessary definitions to get the basic gpio + * pin configuration done such as setting a pin to input or output or + * changing the pull-{up,down} configurations. + */ + +/* Note, this interface is being added to the s3c64xx arch first and will + * be added to the s3c24xx systems later. + */ + +#ifndef __PLAT_GPIO_CFG_H +#define __PLAT_GPIO_CFG_H __FILE__ + +#include <linux/types.h> + +typedef unsigned int __bitwise samsung_gpio_pull_t; + +/* forward declaration if gpio-core.h hasn't been included */ +struct samsung_gpio_chip; + +/** + * struct samsung_gpio_cfg GPIO configuration + * @cfg_eint: Configuration setting when used for external interrupt source + * @get_pull: Read the current pull configuration for the GPIO + * @set_pull: Set the current pull configuration for the GPIO + * @set_config: Set the current configuration for the GPIO + * @get_config: Read the current configuration for the GPIO + * + * Each chip can have more than one type of GPIO bank available and some + * have different capabilites even when they have the same control register + * layouts. Provide an point to vector control routine and provide any + * per-bank configuration information that other systems such as the + * external interrupt code will need. + * + * @sa samsung_gpio_cfgpin + * @sa s3c_gpio_getcfg + * @sa s3c_gpio_setpull + * @sa s3c_gpio_getpull + */ +struct samsung_gpio_cfg { + unsigned int cfg_eint; + + samsung_gpio_pull_t (*get_pull)(struct samsung_gpio_chip *chip, unsigned offs); + int (*set_pull)(struct samsung_gpio_chip *chip, unsigned offs, + samsung_gpio_pull_t pull); + + unsigned (*get_config)(struct samsung_gpio_chip *chip, unsigned offs); + int (*set_config)(struct samsung_gpio_chip *chip, unsigned offs, + unsigned config); +}; + +#define S3C_GPIO_SPECIAL_MARK (0xfffffff0) +#define S3C_GPIO_SPECIAL(x) (S3C_GPIO_SPECIAL_MARK | (x)) + +/* Defines for generic pin configurations */ +#define S3C_GPIO_INPUT (S3C_GPIO_SPECIAL(0)) +#define S3C_GPIO_OUTPUT (S3C_GPIO_SPECIAL(1)) +#define S3C_GPIO_SFN(x) (S3C_GPIO_SPECIAL(x)) + +#define samsung_gpio_is_cfg_special(_cfg) \ + (((_cfg) & S3C_GPIO_SPECIAL_MARK) == S3C_GPIO_SPECIAL_MARK) + +/** + * s3c_gpio_cfgpin() - Change the GPIO function of a pin. + * @pin pin The pin number to configure. + * @to to The configuration for the pin's function. + * + * Configure which function is actually connected to the external + * pin, such as an gpio input, output or some form of special function + * connected to an internal peripheral block. + * + * The @to parameter can be one of the generic S3C_GPIO_INPUT, S3C_GPIO_OUTPUT + * or S3C_GPIO_SFN() to indicate one of the possible values that the helper + * will then generate the correct bit mask and shift for the configuration. + * + * If a bank of GPIOs all needs to be set to special-function 2, then + * the following code will work: + * + * for (gpio = start; gpio < end; gpio++) + * s3c_gpio_cfgpin(gpio, S3C_GPIO_SFN(2)); + * + * The @to parameter can also be a specific value already shifted to the + * correct position in the control register, although these are discouraged + * in newer kernels and are only being kept for compatibility. + */ +extern int s3c_gpio_cfgpin(unsigned int pin, unsigned int to); + +/** + * s3c_gpio_getcfg - Read the current function for a GPIO pin + * @pin: The pin to read the configuration value for. + * + * Read the configuration state of the given @pin, returning a value that + * could be passed back to s3c_gpio_cfgpin(). + * + * @sa s3c_gpio_cfgpin + */ +extern unsigned s3c_gpio_getcfg(unsigned int pin); + +/** + * s3c_gpio_cfgpin_range() - Change the GPIO function for configuring pin range + * @start: The pin number to start at + * @nr: The number of pins to configure from @start. + * @cfg: The configuration for the pin's function + * + * Call s3c_gpio_cfgpin() for the @nr pins starting at @start. + * + * @sa s3c_gpio_cfgpin. + */ +extern int s3c_gpio_cfgpin_range(unsigned int start, unsigned int nr, + unsigned int cfg); + +/* Define values for the pull-{up,down} available for each gpio pin. + * + * These values control the state of the weak pull-{up,down} resistors + * available on most pins on the S3C series. Not all chips support both + * up or down settings, and it may be dependent on the chip that is being + * used to whether the particular mode is available. + */ +#define S3C_GPIO_PULL_NONE ((__force samsung_gpio_pull_t)0x00) +#define S3C_GPIO_PULL_DOWN ((__force samsung_gpio_pull_t)0x01) +#define S3C_GPIO_PULL_UP ((__force samsung_gpio_pull_t)0x02) + +/** + * s3c_gpio_setpull() - set the state of a gpio pin pull resistor + * @pin: The pin number to configure the pull resistor. + * @pull: The configuration for the pull resistor. + * + * This function sets the state of the pull-{up,down} resistor for the + * specified pin. It will return 0 if successful, or a negative error + * code if the pin cannot support the requested pull setting. + * + * @pull is one of S3C_GPIO_PULL_NONE, S3C_GPIO_PULL_DOWN or S3C_GPIO_PULL_UP. +*/ +extern int s3c_gpio_setpull(unsigned int pin, samsung_gpio_pull_t pull); + +/** + * s3c_gpio_getpull() - get the pull resistor state of a gpio pin + * @pin: The pin number to get the settings for + * + * Read the pull resistor value for the specified pin. +*/ +extern samsung_gpio_pull_t s3c_gpio_getpull(unsigned int pin); + +/* configure `all` aspects of an gpio */ + +/** + * s3c_gpio_cfgall_range() - configure range of gpio functtion and pull. + * @start: The gpio number to start at. + * @nr: The number of gpio to configure from @start. + * @cfg: The configuration to use + * @pull: The pull setting to use. + * + * Run s3c_gpio_cfgpin() and s3c_gpio_setpull() over the gpio range starting + * @gpio and running for @size. + * + * @sa s3c_gpio_cfgpin + * @sa s3c_gpio_setpull + * @sa s3c_gpio_cfgpin_range + */ +extern int s3c_gpio_cfgall_range(unsigned int start, unsigned int nr, + unsigned int cfg, samsung_gpio_pull_t pull); + +static inline int s3c_gpio_cfgrange_nopull(unsigned int pin, unsigned int size, + unsigned int cfg) +{ + return s3c_gpio_cfgall_range(pin, size, cfg, S3C_GPIO_PULL_NONE); +} + +#endif /* __PLAT_GPIO_CFG_H */ |