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/*
* STMicroelectronics hts221 spi 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/spi/spi.h>
#include <linux/slab.h>
#include "hts221.h"
#define SENSORS_SPI_READ 0x80
#define SPI_AUTO_INCREMENT 0x40
static int hts221_spi_read(struct device *dev, u8 addr, int len, u8 *data)
{
int err;
struct spi_device *spi = to_spi_device(dev);
struct iio_dev *iio_dev = spi_get_drvdata(spi);
struct hts221_hw *hw = iio_priv(iio_dev);
struct spi_transfer xfers[] = {
{
.tx_buf = hw->tb.tx_buf,
.bits_per_word = 8,
.len = 1,
},
{
.rx_buf = hw->tb.rx_buf,
.bits_per_word = 8,
.len = len,
}
};
if (len > 1)
addr |= SPI_AUTO_INCREMENT;
hw->tb.tx_buf[0] = addr | SENSORS_SPI_READ;
err = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));
if (err < 0)
return err;
memcpy(data, hw->tb.rx_buf, len * sizeof(u8));
return len;
}
static int hts221_spi_write(struct device *dev, u8 addr, int len, u8 *data)
{
struct spi_device *spi = to_spi_device(dev);
struct iio_dev *iio_dev = spi_get_drvdata(spi);
struct hts221_hw *hw = iio_priv(iio_dev);
struct spi_transfer xfers = {
.tx_buf = hw->tb.tx_buf,
.bits_per_word = 8,
.len = len + 1,
};
if (len >= HTS221_TX_MAX_LENGTH)
return -ENOMEM;
if (len > 1)
addr |= SPI_AUTO_INCREMENT;
hw->tb.tx_buf[0] = addr;
memcpy(&hw->tb.tx_buf[1], data, len);
return spi_sync_transfer(spi, &xfers, 1);
}
static const struct hts221_transfer_function hts221_transfer_fn = {
.read = hts221_spi_read,
.write = hts221_spi_write,
};
static int hts221_spi_probe(struct spi_device *spi)
{
struct hts221_hw *hw;
struct iio_dev *iio_dev;
iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*hw));
if (!iio_dev)
return -ENOMEM;
spi_set_drvdata(spi, iio_dev);
hw = iio_priv(iio_dev);
hw->name = spi->modalias;
hw->dev = &spi->dev;
hw->irq = spi->irq;
hw->tf = &hts221_transfer_fn;
return hts221_probe(iio_dev);
}
static const struct of_device_id hts221_spi_of_match[] = {
{ .compatible = "st,hts221", },
{},
};
MODULE_DEVICE_TABLE(of, hts221_spi_of_match);
static const struct spi_device_id hts221_spi_id_table[] = {
{ HTS221_DEV_NAME },
{},
};
MODULE_DEVICE_TABLE(spi, hts221_spi_id_table);
static struct spi_driver hts221_driver = {
.driver = {
.name = "hts221_spi",
.pm = &hts221_pm_ops,
.of_match_table = of_match_ptr(hts221_spi_of_match),
},
.probe = hts221_spi_probe,
.id_table = hts221_spi_id_table,
};
module_spi_driver(hts221_driver);
MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
MODULE_DESCRIPTION("STMicroelectronics hts221 spi driver");
MODULE_LICENSE("GPL v2");
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