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 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 56 static const struct of_device_id ds4520_gpio_of_match_table[] = { 57 { .compatible = "adi,ds4520-gpio" }, 58 { } 59 }; 60 MODULE_DEVICE_TABLE(of, ds4520_gpio_of_match_table); 61 62 static const struct i2c_device_id ds4520_gpio_id_table[] = { 63 { "ds4520-gpio" }, 64 { } 65 }; 66 MODULE_DEVICE_TABLE(i2c, ds4520_gpio_id_table); 67 68 static 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 }; 76 module_i2c_driver(ds4520_gpio_driver); 77 78 MODULE_DESCRIPTION("DS4520 I/O Expander"); 79 MODULE_AUTHOR("Okan Sahin <okan.sahin@analog.com>"); 80 MODULE_LICENSE("GPL"); 81