linux/drivers/gpio/gpio-ds4520.c
Okan Sahin 659ad5f7ef 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: Okan Sahin <okan.sahin@analog.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-07-29 15:56:33 +02:00

81 lines
2.0 KiB
C

// 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");