drivers/iio/pressure/zpa2326_i2c.c

   1 /*
   2  * Murata ZPA2326 I2C pressure and temperature sensor driver
   3  *
   4  * Copyright (c) 2016 Parrot S.A.
   5  *
   6  * Author: Gregor Boirie <gregor.boirie@parrot.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 as published by
  10  * the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  15  * more details.
  16  */
  17
  18 #include <linux/module.h>
  19 #include <linux/regmap.h>
  20 #include <linux/i2c.h>
  21 #include <linux/of_device.h>
  22 #include "zpa2326.h"
  23
  24 /*
  25  * read_flag_mask:
  26  *   - address bit 7 must be set to request a register read operation
  27  */
  28 static const struct regmap_config zpa2326_regmap_i2c_config = {
  29         .reg_bits       = 8,
  30         .val_bits       = 8,
  31         .writeable_reg  = zpa2326_isreg_writeable,
  32         .readable_reg   = zpa2326_isreg_readable,
  33         .precious_reg   = zpa2326_isreg_precious,
  34         .max_register   = ZPA2326_TEMP_OUT_H_REG,
  35         .read_flag_mask = BIT(7),
  36         .cache_type     = REGCACHE_NONE,
  37 };
  38
  39 static unsigned int zpa2326_i2c_hwid(const struct i2c_client *client)
  40 {
  41 #define ZPA2326_SA0(_addr)          (_addr & BIT(0))
  42 #define ZPA2326_DEVICE_ID_SA0_SHIFT (1)
  43
  44         /* Identification register bit 1 mirrors device address bit 0. */
  45         return (ZPA2326_DEVICE_ID |
  46                 (ZPA2326_SA0(client->addr) << ZPA2326_DEVICE_ID_SA0_SHIFT));
  47 }
  48
  49 static int zpa2326_probe_i2c(struct i2c_client          *client,
  50                              const struct i2c_device_id *i2c_id)
  51 {
  52         struct regmap *regmap;
  53
  54         regmap = devm_regmap_init_i2c(client, &zpa2326_regmap_i2c_config);
  55         if (IS_ERR(regmap)) {
  56                 dev_err(&client->dev, "failed to init registers map");
  57                 return PTR_ERR(regmap);
  58         }
  59
  60         return zpa2326_probe(&client->dev, i2c_id->name, client->irq,
  61                              zpa2326_i2c_hwid(client), regmap);
  62 }
  63
  64 static int zpa2326_remove_i2c(struct i2c_client *client)
  65 {
  66         zpa2326_remove(&client->dev);
  67
  68         return 0;
  69 }
  70
  71 static const struct i2c_device_id zpa2326_i2c_ids[] = {
  72         { "zpa2326", 0 },
  73         { },
  74 };
  75 MODULE_DEVICE_TABLE(i2c, zpa2326_i2c_ids);
  76
  77 #if defined(CONFIG_OF)
  78 static const struct of_device_id zpa2326_i2c_matches[] = {
  79         { .compatible = "murata,zpa2326" },
  80         { }
  81 };
  82 MODULE_DEVICE_TABLE(of, zpa2326_i2c_matches);
  83 #endif
  84
  85 static struct i2c_driver zpa2326_i2c_driver = {
  86         .driver = {
  87                 .name           = "zpa2326-i2c",
  88                 .of_match_table = of_match_ptr(zpa2326_i2c_matches),
  89                 .pm             = ZPA2326_PM_OPS,
  90         },
  91         .probe    = zpa2326_probe_i2c,
  92         .remove   = zpa2326_remove_i2c,
  93         .id_table = zpa2326_i2c_ids,
  94 };
  95 module_i2c_driver(zpa2326_i2c_driver);
  96
  97 MODULE_AUTHOR("Gregor Boirie <gregor.boirie@parrot.com>");
  98 MODULE_DESCRIPTION("I2C driver for Murata ZPA2326 pressure sensor");
  99 MODULE_LICENSE("GPL v2");