drivers/iio/common/st_sensors/st_sensors_i2c.c

   1 /*
   2  * STMicroelectronics sensors i2c library driver
   3  *
   4  * Copyright 2012-2013 STMicroelectronics Inc.
   5  *
   6  * Denis Ciocca <denis.ciocca@st.com>
   7  *
   8  * Licensed under the GPL-2.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/slab.h>
  14 #include <linux/iio/iio.h>
  15 #include <linux/of_device.h>
  16 #include <linux/acpi.h>
  17
  18 #include <linux/iio/common/st_sensors_i2c.h>
  19
  20
  21 #define ST_SENSORS_I2C_MULTIREAD        0x80
  22
  23 static unsigned int st_sensors_i2c_get_irq(struct iio_dev *indio_dev)
  24 {
  25         struct st_sensor_data *sdata = iio_priv(indio_dev);
  26
  27         return to_i2c_client(sdata->dev)->irq;
  28 }
  29
  30 static int st_sensors_i2c_read_byte(struct st_sensor_transfer_buffer *tb,
  31                                 struct device *dev, u8 reg_addr, u8 *res_byte)
  32 {
  33         int err;
  34
  35         err = i2c_smbus_read_byte_data(to_i2c_client(dev), reg_addr);
  36         if (err < 0)
  37                 goto st_accel_i2c_read_byte_error;
  38
  39         *res_byte = err & 0xff;
  40
  41 st_accel_i2c_read_byte_error:
  42         return err < 0 ? err : 0;
  43 }
  44
  45 static int st_sensors_i2c_read_multiple_byte(
  46                 struct st_sensor_transfer_buffer *tb, struct device *dev,
  47                         u8 reg_addr, int len, u8 *data, bool multiread_bit)
  48 {
  49         if (multiread_bit)
  50                 reg_addr |= ST_SENSORS_I2C_MULTIREAD;
  51
  52         return i2c_smbus_read_i2c_block_data_or_emulated(to_i2c_client(dev),
  53                                                          reg_addr, len, data);
  54 }
  55
  56 static int st_sensors_i2c_write_byte(struct st_sensor_transfer_buffer *tb,
  57                                 struct device *dev, u8 reg_addr, u8 data)
  58 {
  59         return i2c_smbus_write_byte_data(to_i2c_client(dev), reg_addr, data);
  60 }
  61
  62 static const struct st_sensor_transfer_function st_sensors_tf_i2c = {
  63         .read_byte = st_sensors_i2c_read_byte,
  64         .write_byte = st_sensors_i2c_write_byte,
  65         .read_multiple_byte = st_sensors_i2c_read_multiple_byte,
  66 };
  67
  68 void st_sensors_i2c_configure(struct iio_dev *indio_dev,
  69                 struct i2c_client *client, struct st_sensor_data *sdata)
  70 {
  71         i2c_set_clientdata(client, indio_dev);
  72
  73         indio_dev->dev.parent = &client->dev;
  74         indio_dev->name = client->name;
  75
  76         sdata->dev = &client->dev;
  77         sdata->tf = &st_sensors_tf_i2c;
  78         sdata->get_irq_data_ready = st_sensors_i2c_get_irq;
  79 }
  80 EXPORT_SYMBOL(st_sensors_i2c_configure);
  81
  82 #ifdef CONFIG_ACPI
  83 int st_sensors_match_acpi_device(struct device *dev)
  84 {
  85         const struct acpi_device_id *acpi_id;
  86         kernel_ulong_t driver_data = 0;
  87
  88         if (ACPI_HANDLE(dev)) {
  89                 acpi_id = acpi_match_device(dev->driver->acpi_match_table, dev);
  90                 if (!acpi_id) {
  91                         dev_err(dev, "No driver data\n");
  92                         return -EINVAL;
  93                 }
  94                 driver_data = acpi_id->driver_data;
  95         }
  96         return driver_data;
  97 }
  98 EXPORT_SYMBOL(st_sensors_match_acpi_device);
  99 #endif
 100
 101 MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
 102 MODULE_DESCRIPTION("STMicroelectronics ST-sensors i2c driver");
 103 MODULE_LICENSE("GPL v2");