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/* SPDX-License-Identifier: GPL-2.0 */
* Copyright 2008 Openmoko, Inc.
* Copyright 2008 Simtec Electronics
* Ben Dooks <>
* 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)
/* Defines for generic pin configurations */
#define S3C_GPIO_SFN(x) (S3C_GPIO_SPECIAL(x))
#define samsung_gpio_is_cfg_special(_cfg) \
* 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.
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 */