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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (c) 2023 Analog Devices, Inc.4 * Driver for the DS4520 I/O Expander5 */6 7#include <linux/device.h>8#include <linux/gpio/driver.h>9#include <linux/gpio/regmap.h>10#include <linux/i2c.h>11#include <linux/property.h>12#include <linux/regmap.h>13 14#define DS4520_PULLUP0 0xF015#define DS4520_IO_CONTROL0 0xF216#define DS4520_IO_STATUS0 0xF817 18static const struct regmap_config ds4520_regmap_config = {19 .reg_bits = 8,20 .val_bits = 8,21};22 23static int ds4520_gpio_probe(struct i2c_client *client)24{25 struct gpio_regmap_config config = { };26 struct device *dev = &client->dev;27 struct regmap *regmap;28 u32 ngpio;29 u32 base;30 int ret;31 32 ret = device_property_read_u32(dev, "reg", &base);33 if (ret)34 return dev_err_probe(dev, ret, "Missing 'reg' property.\n");35 36 ret = device_property_read_u32(dev, "ngpios", &ngpio);37 if (ret)38 return dev_err_probe(dev, ret, "Missing 'ngpios' property.\n");39 40 regmap = devm_regmap_init_i2c(client, &ds4520_regmap_config);41 if (IS_ERR(regmap))42 return dev_err_probe(dev, PTR_ERR(regmap),43 "Failed to allocate register map\n");44 45 config.regmap = regmap;46 config.parent = dev;47 config.ngpio = ngpio;48 49 config.reg_dat_base = base + DS4520_IO_STATUS0;50 config.reg_set_base = base + DS4520_PULLUP0;51 config.reg_dir_out_base = base + DS4520_IO_CONTROL0;52 53 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &config));54}55 56static const struct of_device_id ds4520_gpio_of_match_table[] = {57 { .compatible = "adi,ds4520-gpio" },58 { }59};60MODULE_DEVICE_TABLE(of, ds4520_gpio_of_match_table);61 62static const struct i2c_device_id ds4520_gpio_id_table[] = {63 { "ds4520-gpio" },64 { }65};66MODULE_DEVICE_TABLE(i2c, ds4520_gpio_id_table);67 68static struct i2c_driver ds4520_gpio_driver = {69 .driver = {70 .name = "ds4520-gpio",71 .of_match_table = ds4520_gpio_of_match_table,72 },73 .probe = ds4520_gpio_probe,74 .id_table = ds4520_gpio_id_table,75};76module_i2c_driver(ds4520_gpio_driver);77 78MODULE_DESCRIPTION("DS4520 I/O Expander");79MODULE_AUTHOR("Okan Sahin <okan.sahin@analog.com>");80MODULE_LICENSE("GPL");81