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linux-next/drivers/iio/humidity/hts221_i2c.c
Shrirang Bagul 25fc503e2d iio: humidity: Support acpi probe for hts211
Support driver probe by reading unique HID on systems based on ACPI instead
of DT compatible strings.

Signed-off-by: Shrirang Bagul <shrirang.bagul@canonical.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2016-12-03 08:56:28 +00:00

119 lines
2.6 KiB
C

/*
* STMicroelectronics hts221 i2c driver
*
* Copyright 2016 STMicroelectronics Inc.
*
* Lorenzo Bianconi <lorenzo.bianconi@st.com>
*
* Licensed under the GPL-2.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include "hts221.h"
#define I2C_AUTO_INCREMENT 0x80
static int hts221_i2c_read(struct device *dev, u8 addr, int len, u8 *data)
{
struct i2c_msg msg[2];
struct i2c_client *client = to_i2c_client(dev);
if (len > 1)
addr |= I2C_AUTO_INCREMENT;
msg[0].addr = client->addr;
msg[0].flags = client->flags;
msg[0].len = 1;
msg[0].buf = &addr;
msg[1].addr = client->addr;
msg[1].flags = client->flags | I2C_M_RD;
msg[1].len = len;
msg[1].buf = data;
return i2c_transfer(client->adapter, msg, 2);
}
static int hts221_i2c_write(struct device *dev, u8 addr, int len, u8 *data)
{
u8 send[len + 1];
struct i2c_msg msg;
struct i2c_client *client = to_i2c_client(dev);
if (len > 1)
addr |= I2C_AUTO_INCREMENT;
send[0] = addr;
memcpy(&send[1], data, len * sizeof(u8));
msg.addr = client->addr;
msg.flags = client->flags;
msg.len = len + 1;
msg.buf = send;
return i2c_transfer(client->adapter, &msg, 1);
}
static const struct hts221_transfer_function hts221_transfer_fn = {
.read = hts221_i2c_read,
.write = hts221_i2c_write,
};
static int hts221_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct hts221_hw *hw;
struct iio_dev *iio_dev;
iio_dev = devm_iio_device_alloc(&client->dev, sizeof(*hw));
if (!iio_dev)
return -ENOMEM;
i2c_set_clientdata(client, iio_dev);
hw = iio_priv(iio_dev);
hw->name = client->name;
hw->dev = &client->dev;
hw->irq = client->irq;
hw->tf = &hts221_transfer_fn;
return hts221_probe(iio_dev);
}
static const struct acpi_device_id hts221_acpi_match[] = {
{"SMO9100", 0},
{ },
};
MODULE_DEVICE_TABLE(acpi, hts221_acpi_match);
static const struct of_device_id hts221_i2c_of_match[] = {
{ .compatible = "st,hts221", },
{},
};
MODULE_DEVICE_TABLE(of, hts221_i2c_of_match);
static const struct i2c_device_id hts221_i2c_id_table[] = {
{ HTS221_DEV_NAME },
{},
};
MODULE_DEVICE_TABLE(i2c, hts221_i2c_id_table);
static struct i2c_driver hts221_driver = {
.driver = {
.name = "hts221_i2c",
.of_match_table = of_match_ptr(hts221_i2c_of_match),
.acpi_match_table = ACPI_PTR(hts221_acpi_match),
},
.probe = hts221_i2c_probe,
.id_table = hts221_i2c_id_table,
};
module_i2c_driver(hts221_driver);
MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
MODULE_DESCRIPTION("STMicroelectronics hts221 i2c driver");
MODULE_LICENSE("GPL v2");