Commit 659ad5f7 authored by Okan Sahin's avatar Okan Sahin Committed by Bartosz Golaszewski
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gpio: ds4520: Add ADI DS4520 GPIO Expander Support 



The DS4520 is a 9-bit nonvolatile (NV) I/O expander.
It offers users a digitally programmable alternative
to hardware jumpers and mechanical switches that are
being used to control digital logic node.

Signed-off-by: default avatarOkan Sahin <okan.sahin@analog.com>
Signed-off-by: default avatarBartosz Golaszewski <bartosz.golaszewski@linaro.org>
parent 451c923d

drivers/gpio/Kconfig

+11 −0
Original line number Diff line number Diff line
@@ -1029,6 +1029,17 @@ config GPIO_FXL6408 
	  To compile this driver as a module, choose M here: the module will

	  be called gpio-fxl6408.



config GPIO_DS4520

	tristate "DS4520 I2C GPIO expander"

	select REGMAP_I2C

	select GPIO_REGMAP

	help

	  GPIO driver for ADI DS4520 I2C-based GPIO expander.

	  Say yes here to enable the GPIO driver for the ADI DS4520 chip.



	  To compile this driver as a module, choose M here: the module will

	  be called gpio-ds4520.



config GPIO_GW_PLD

	tristate "Gateworks PLD GPIO Expander"

	depends on OF_GPIO

drivers/gpio/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -52,6 +52,7 @@ obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o 
obj-$(CONFIG_GPIO_DA9055)		+= gpio-da9055.o

obj-$(CONFIG_GPIO_DAVINCI)		+= gpio-davinci.o

obj-$(CONFIG_GPIO_DLN2)			+= gpio-dln2.o

obj-$(CONFIG_GPIO_DS4520)		+= gpio-ds4520.o

obj-$(CONFIG_GPIO_DWAPB)		+= gpio-dwapb.o

obj-$(CONFIG_GPIO_EIC_SPRD)		+= gpio-eic-sprd.o

obj-$(CONFIG_GPIO_ELKHARTLAKE)		+= gpio-elkhartlake.o

drivers/gpio/gpio-ds4520.c

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+80 −0
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// SPDX-License-Identifier: GPL-2.0-or-later

/*

 * Copyright (c) 2023 Analog Devices, Inc.

 * Driver for the DS4520 I/O Expander

 */



#include <linux/device.h>

#include <linux/gpio/driver.h>

#include <linux/gpio/regmap.h>

#include <linux/i2c.h>

#include <linux/property.h>

#include <linux/regmap.h>



#define DS4520_PULLUP0		0xF0

#define DS4520_IO_CONTROL0	0xF2

#define DS4520_IO_STATUS0	0xF8



static const struct regmap_config ds4520_regmap_config = {

	.reg_bits = 8,

	.val_bits = 8,

};



static int ds4520_gpio_probe(struct i2c_client *client)

{

	struct gpio_regmap_config config = { };

	struct device *dev = &client->dev;

	struct regmap *regmap;

	u32 ngpio;

	u32 base;

	int ret;



	ret = device_property_read_u32(dev, "reg", &base);

	if (ret)

		return dev_err_probe(dev, ret, "Missing 'reg' property.\n");



	ret = device_property_read_u32(dev, "ngpios", &ngpio);

	if (ret)

		return dev_err_probe(dev, ret, "Missing 'ngpios' property.\n");



	regmap = devm_regmap_init_i2c(client, &ds4520_regmap_config);

	if (IS_ERR(regmap))

		return dev_err_probe(dev, PTR_ERR(regmap),

				     "Failed to allocate register map\n");



	config.regmap = regmap;

	config.parent = dev;

	config.ngpio = ngpio;



	config.reg_dat_base = base + DS4520_IO_STATUS0;

	config.reg_set_base = base + DS4520_PULLUP0;

	config.reg_dir_out_base = base + DS4520_IO_CONTROL0;



	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &config));

}



static const struct of_device_id ds4520_gpio_of_match_table[] = {

	{ .compatible = "adi,ds4520-gpio" },

	{ }

};

MODULE_DEVICE_TABLE(of, ds4520_gpio_of_match_table);



static const struct i2c_device_id ds4520_gpio_id_table[] = {

	{ "ds4520-gpio" },

	{ }

};

MODULE_DEVICE_TABLE(i2c, ds4520_gpio_id_table);



static struct i2c_driver ds4520_gpio_driver = {

	.driver = {

		.name = "ds4520-gpio",

		.of_match_table = ds4520_gpio_of_match_table,

	},

	.probe = ds4520_gpio_probe,

	.id_table = ds4520_gpio_id_table,

};

module_i2c_driver(ds4520_gpio_driver);



MODULE_DESCRIPTION("DS4520 I/O Expander");

MODULE_AUTHOR("Okan Sahin <okan.sahin@analog.com>");

MODULE_LICENSE("GPL");