drivers/iio/common/st_sensors/st_sensors_i2c.c

/*
 * STMicroelectronics sensors i2c library driver
 *
 * Copyright 2012-2013 STMicroelectronics Inc.
 *
 * Denis Ciocca <denis.ciocca@st.com>
 *
 * Licensed under the GPL-2.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/iio/iio.h>
#include <linux/of_device.h>
#include <linux/acpi.h>

#include <linux/iio/common/st_sensors_i2c.h>


#define ST_SENSORS_I2C_MULTIREAD	0x80

static unsigned int st_sensors_i2c_get_irq(struct iio_dev *indio_dev)
{
	struct st_sensor_data *sdata = iio_priv(indio_dev);

	return to_i2c_client(sdata->dev)->irq;
}

static int st_sensors_i2c_read_byte(struct st_sensor_transfer_buffer *tb,
				struct device *dev, u8 reg_addr, u8 *res_byte)
{
	int err;

	err = i2c_smbus_read_byte_data(to_i2c_client(dev), reg_addr);
	if (err < 0)
		goto st_accel_i2c_read_byte_error;

	*res_byte = err & 0xff;

st_accel_i2c_read_byte_error:
	return err < 0 ? err : 0;
}

static int st_sensors_i2c_read_multiple_byte(
		struct st_sensor_transfer_buffer *tb, struct device *dev,
			u8 reg_addr, int len, u8 *data, bool multiread_bit)
{
	if (multiread_bit)
		reg_addr |= ST_SENSORS_I2C_MULTIREAD;

	return i2c_smbus_read_i2c_block_data_or_emulated(to_i2c_client(dev),
							 reg_addr, len, data);
}

static int st_sensors_i2c_write_byte(struct st_sensor_transfer_buffer *tb,
				struct device *dev, u8 reg_addr, u8 data)
{
	return i2c_smbus_write_byte_data(to_i2c_client(dev), reg_addr, data);
}

static const struct st_sensor_transfer_function st_sensors_tf_i2c = {
	.read_byte = st_sensors_i2c_read_byte,
	.write_byte = st_sensors_i2c_write_byte,
	.read_multiple_byte = st_sensors_i2c_read_multiple_byte,
};

void st_sensors_i2c_configure(struct iio_dev *indio_dev,
		struct i2c_client *client, struct st_sensor_data *sdata)
{
	i2c_set_clientdata(client, indio_dev);

	indio_dev->dev.parent = &client->dev;
	indio_dev->name = client->name;

	sdata->dev = &client->dev;
	sdata->tf = &st_sensors_tf_i2c;
	sdata->get_irq_data_ready = st_sensors_i2c_get_irq;
}
EXPORT_SYMBOL(st_sensors_i2c_configure);

#ifdef CONFIG_ACPI
int st_sensors_match_acpi_device(struct device *dev)
{
	const struct acpi_device_id *acpi_id;
	kernel_ulong_t driver_data = 0;

	if (ACPI_HANDLE(dev)) {
		acpi_id = acpi_match_device(dev->driver->acpi_match_table, dev);
		if (!acpi_id) {
			dev_err(dev, "No driver data\n");
			return -EINVAL;
		}
		driver_data = acpi_id->driver_data;
	}
	return driver_data;
}
EXPORT_SYMBOL(st_sensors_match_acpi_device);
#endif

MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
MODULE_DESCRIPTION("STMicroelectronics ST-sensors i2c driver");
MODULE_LICENSE("GPL v2");