1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Copyright (c) 2023 Analog Devices, Inc. 4 * Driver for the DS4520 I/O Expander 5 */ 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 0xF0 15 #define DS4520_IO_CONTROL0 0xF2 16 #define DS4520_IO_STATUS0 0xF8 17 18 static const struct regmap_config ds4520_regmap_config = { 19 .reg_bits = 8, 20 .val_bits = 8, 21 }; 22 23 static 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 base; 29 int ret; 30 31 ret = device_property_read_u32(dev, "reg", &base); 32 if (ret) 33 return dev_err_probe(dev, ret, "Missing 'reg' property.\n"); 34 35 regmap = devm_regmap_init_i2c(client, &ds4520_regmap_config); 36 if (IS_ERR(regmap)) 37 return dev_err_probe(dev, PTR_ERR(regmap), 38 "Failed to allocate register map\n"); 39 40 config.regmap = regmap; 41 config.parent = dev; 42 43 config.reg_dat_base = base + DS4520_IO_STATUS0; 44 config.reg_set_base = base + DS4520_PULLUP0; 45 config.reg_dir_out_base = base + DS4520_IO_CONTROL0; 46 47 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &config)); 48 } 49 50 static const struct of_device_id ds4520_gpio_of_match_table[] = { 51 { .compatible = "adi,ds4520-gpio" }, 52 { } 53 }; 54 MODULE_DEVICE_TABLE(of, ds4520_gpio_of_match_table); 55 56 static const struct i2c_device_id ds4520_gpio_id_table[] = { 57 { "ds4520-gpio" }, 58 { } 59 }; 60 MODULE_DEVICE_TABLE(i2c, ds4520_gpio_id_table); 61 62 static struct i2c_driver ds4520_gpio_driver = { 63 .driver = { 64 .name = "ds4520-gpio", 65 .of_match_table = ds4520_gpio_of_match_table, 66 }, 67 .probe = ds4520_gpio_probe, 68 .id_table = ds4520_gpio_id_table, 69 }; 70 module_i2c_driver(ds4520_gpio_driver); 71 72 MODULE_DESCRIPTION("DS4520 I/O Expander"); 73 MODULE_AUTHOR("Okan Sahin <okan.sahin@analog.com>"); 74 MODULE_LICENSE("GPL"); 75