Commit 7671f494 authored by AKASHI Takahiro's avatar AKASHI Takahiro Committed by Linus Walleij
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gpio: gpio-by-pinctrl: add pinctrl based generic GPIO driver 



The ARM SCMI pinctrl protocol allows GPIO access.  Instead of creating
a new SCMI GPIO driver, this driver is a generic GPIO driver that uses
standard pinctrl interfaces.

Signed-off-by: default avatarAKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: default avatarLinus Walleij <linusw@kernel.org>
Acked-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Reviewed-by: default avatarAndy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: default avatarLinus Walleij <linusw@kernel.org>
parent 05a8a80e

drivers/gpio/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -246,6 +246,19 @@ config GPIO_BRCMSTB 
	help

	  Say yes here to enable GPIO support for Broadcom STB (BCM7XXX) SoCs.



config GPIO_BY_PINCTRL

	tristate "GPIO support based on a pure pin control backend"

	depends on GPIOLIB

	help

	  Support for generic GPIO handling based on top of pin control.

	  Traditionally, firmware creates a GPIO interface or a pin

	  controller interface and we have a driver to support it.  But

	  in SCMI, the pin control interface is generic and we can

	  create a simple GPIO device based on the pin control interface

	  without doing anything custom.



	  This driver used to do GPIO over the ARM SCMI protocol.



config GPIO_CADENCE

	tristate "Cadence GPIO support"

	depends on OF_GPIO

drivers/gpio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ obj-$(CONFIG_GPIO_BD9571MWV) += gpio-bd9571mwv.o 
obj-$(CONFIG_GPIO_BLZP1600)		+= gpio-blzp1600.o

obj-$(CONFIG_GPIO_BRCMSTB)		+= gpio-brcmstb.o

obj-$(CONFIG_GPIO_BT8XX)		+= gpio-bt8xx.o

obj-$(CONFIG_GPIO_BY_PINCTRL)		+= gpio-by-pinctrl.o

obj-$(CONFIG_GPIO_CADENCE)		+= gpio-cadence.o

obj-$(CONFIG_GPIO_CGBC)			+= gpio-cgbc.o

obj-$(CONFIG_GPIO_CLPS711X)		+= gpio-clps711x.o

drivers/gpio/gpio-by-pinctrl.c

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// SPDX-License-Identifier: GPL-2.0

//

// Copyright (C) 2026 Linaro Inc.

//   Author: AKASHI takahiro <takahiro.akashi@linaro.org>



#include <linux/errno.h>

#include <linux/gpio/driver.h>

#include <linux/mod_devicetable.h>

#include <linux/module.h>

#include <linux/pinctrl/consumer.h>

#include <linux/platform_device.h>

#include <linux/types.h>



#include "gpiolib.h"



static int pin_control_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)

{

	unsigned long config;

	int ret;



	config = PIN_CONFIG_OUTPUT_ENABLE;

	ret = pinctrl_gpio_get_config(gc, offset, &config);

	if (ret)

		return ret;

	if (config)

		return GPIO_LINE_DIRECTION_OUT;



	return GPIO_LINE_DIRECTION_IN;

}



static int pin_control_gpio_direction_output(struct gpio_chip *chip,

					     unsigned int offset, int val)

{

	return pinctrl_gpio_direction_output(chip, offset);

}



static int pin_control_gpio_get(struct gpio_chip *chip, unsigned int offset)

{

	unsigned long config;

	int ret;



	config = PIN_CONFIG_LEVEL;

	ret = pinctrl_gpio_get_config(chip, offset, &config);

	if (ret)

		return ret;



	return !!config;

}



static int pin_control_gpio_set(struct gpio_chip *chip, unsigned int offset,

				int val)

{

	unsigned long config;



	config = pinconf_to_config_packed(PIN_CONFIG_LEVEL, val);

	return pinctrl_gpio_set_config(chip, offset, config);

}



static int pin_control_gpio_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;

	struct gpio_chip *chip;



	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);

	if (!chip)

		return -ENOMEM;



	chip->label = dev_name(dev);

	chip->parent = dev;

	chip->base = -1;



	chip->request = gpiochip_generic_request;

	chip->free = gpiochip_generic_free;

	chip->get_direction = pin_control_gpio_get_direction;

	chip->direction_input = pinctrl_gpio_direction_input;

	chip->direction_output = pin_control_gpio_direction_output;

	chip->get = pin_control_gpio_get;

	chip->set = pin_control_gpio_set;

	chip->set_config = gpiochip_generic_config;



	return devm_gpiochip_add_data(dev, chip, NULL);

}



static const struct of_device_id pin_control_gpio_match[] = {

	{ .compatible = "scmi-pinctrl-gpio" },

	{ /* sentinel */ }

};

MODULE_DEVICE_TABLE(of, pin_control_gpio_match);



static struct platform_driver pin_control_gpio_driver = {

	.probe = pin_control_gpio_probe,

	.driver = {

		.name = "pin-control-gpio",

		.of_match_table = pin_control_gpio_match,

	},

};

module_platform_driver(pin_control_gpio_driver);



MODULE_AUTHOR("AKASHI Takahiro <takahiro.akashi@linaro.org>");

MODULE_DESCRIPTION("Pinctrl based GPIO driver");

MODULE_LICENSE("GPL");