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
17#include <linux/iio/common/st_sensors_i2c.h>
18
19
20#define ST_SENSORS_I2C_MULTIREAD	0x80
21
22static unsigned int st_sensors_i2c_get_irq(struct iio_dev *indio_dev)
23{
24	struct st_sensor_data *sdata = iio_priv(indio_dev);
25
26	return to_i2c_client(sdata->dev)->irq;
27}
28
29static int st_sensors_i2c_read_byte(struct st_sensor_transfer_buffer *tb,
30				struct device *dev, u8 reg_addr, u8 *res_byte)
31{
32	int err;
33
34	err = i2c_smbus_read_byte_data(to_i2c_client(dev), reg_addr);
35	if (err < 0)
36		goto st_accel_i2c_read_byte_error;
37
38	*res_byte = err & 0xff;
39
40st_accel_i2c_read_byte_error:
41	return err < 0 ? err : 0;
42}
43
44static int st_sensors_i2c_read_multiple_byte(
45		struct st_sensor_transfer_buffer *tb, struct device *dev,
46			u8 reg_addr, int len, u8 *data, bool multiread_bit)
47{
48	if (multiread_bit)
49		reg_addr |= ST_SENSORS_I2C_MULTIREAD;
50
51	return i2c_smbus_read_i2c_block_data(to_i2c_client(dev),
52							reg_addr, len, data);
53}
54
55static int st_sensors_i2c_write_byte(struct st_sensor_transfer_buffer *tb,
56				struct device *dev, u8 reg_addr, u8 data)
57{
58	return i2c_smbus_write_byte_data(to_i2c_client(dev), reg_addr, data);
59}
60
61static const struct st_sensor_transfer_function st_sensors_tf_i2c = {
62	.read_byte = st_sensors_i2c_read_byte,
63	.write_byte = st_sensors_i2c_write_byte,
64	.read_multiple_byte = st_sensors_i2c_read_multiple_byte,
65};
66
67void st_sensors_i2c_configure(struct iio_dev *indio_dev,
68		struct i2c_client *client, struct st_sensor_data *sdata)
69{
70	i2c_set_clientdata(client, indio_dev);
71
72	indio_dev->dev.parent = &client->dev;
73	indio_dev->name = client->name;
74
75	sdata->dev = &client->dev;
76	sdata->tf = &st_sensors_tf_i2c;
77	sdata->get_irq_data_ready = st_sensors_i2c_get_irq;
78}
79EXPORT_SYMBOL(st_sensors_i2c_configure);
80
81#ifdef CONFIG_OF
82/**
83 * st_sensors_of_i2c_probe() - device tree probe for ST I2C sensors
84 * @client: the I2C client device for the sensor
85 * @match: the OF match table for the device, containing compatible strings
86 *	but also a .data field with the corresponding internal kernel name
87 *	used by this sensor.
88 *
89 * In effect this function matches a compatible string to an internal kernel
90 * name for a certain sensor device, so that the rest of the autodetection can
91 * rely on that name from this point on. I2C client devices will be renamed
92 * to match the internal kernel convention.
93 */
94void st_sensors_of_i2c_probe(struct i2c_client *client,
95			     const struct of_device_id *match)
96{
97	const struct of_device_id *of_id;
98
99	of_id = of_match_device(match, &client->dev);
100	if (!of_id)
101		return;
102
103	/* The name from the OF match takes precedence if present */
104	strncpy(client->name, of_id->data, sizeof(client->name));
105	client->name[sizeof(client->name) - 1] = '\0';
106}
107EXPORT_SYMBOL(st_sensors_of_i2c_probe);
108#endif
109
110MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
111MODULE_DESCRIPTION("STMicroelectronics ST-sensors i2c driver");
112MODULE_LICENSE("GPL v2");
113