drivers/gpio/gpio-ds4520.c

   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");