127 lines
2.7 KiB
C
127 lines
2.7 KiB
C
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/*
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* STMicroelectronics hts221 spi driver
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*
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* Copyright 2016 STMicroelectronics Inc.
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*
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* Lorenzo Bianconi <lorenzo.bianconi@st.com>
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*
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* Licensed under the GPL-2.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/spi/spi.h>
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#include <linux/slab.h>
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#include "hts221.h"
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#define SENSORS_SPI_READ 0x80
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#define SPI_AUTO_INCREMENT 0x40
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static int hts221_spi_read(struct device *dev, u8 addr, int len, u8 *data)
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{
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int err;
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struct spi_device *spi = to_spi_device(dev);
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struct iio_dev *iio_dev = spi_get_drvdata(spi);
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struct hts221_hw *hw = iio_priv(iio_dev);
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struct spi_transfer xfers[] = {
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{
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.tx_buf = hw->tb.tx_buf,
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.bits_per_word = 8,
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.len = 1,
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},
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{
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.rx_buf = hw->tb.rx_buf,
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.bits_per_word = 8,
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.len = len,
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}
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};
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if (len > 1)
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addr |= SPI_AUTO_INCREMENT;
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hw->tb.tx_buf[0] = addr | SENSORS_SPI_READ;
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err = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));
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if (err < 0)
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return err;
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memcpy(data, hw->tb.rx_buf, len * sizeof(u8));
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return len;
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}
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static int hts221_spi_write(struct device *dev, u8 addr, int len, u8 *data)
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{
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struct spi_device *spi = to_spi_device(dev);
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struct iio_dev *iio_dev = spi_get_drvdata(spi);
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struct hts221_hw *hw = iio_priv(iio_dev);
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struct spi_transfer xfers = {
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.tx_buf = hw->tb.tx_buf,
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.bits_per_word = 8,
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.len = len + 1,
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};
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if (len >= HTS221_TX_MAX_LENGTH)
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return -ENOMEM;
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if (len > 1)
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addr |= SPI_AUTO_INCREMENT;
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hw->tb.tx_buf[0] = addr;
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memcpy(&hw->tb.tx_buf[1], data, len);
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return spi_sync_transfer(spi, &xfers, 1);
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}
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static const struct hts221_transfer_function hts221_transfer_fn = {
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.read = hts221_spi_read,
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.write = hts221_spi_write,
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};
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static int hts221_spi_probe(struct spi_device *spi)
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{
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struct hts221_hw *hw;
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struct iio_dev *iio_dev;
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iio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*hw));
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if (!iio_dev)
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return -ENOMEM;
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spi_set_drvdata(spi, iio_dev);
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hw = iio_priv(iio_dev);
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hw->name = spi->modalias;
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hw->dev = &spi->dev;
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hw->irq = spi->irq;
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hw->tf = &hts221_transfer_fn;
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return hts221_probe(iio_dev);
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}
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static const struct of_device_id hts221_spi_of_match[] = {
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{ .compatible = "st,hts221", },
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{},
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};
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MODULE_DEVICE_TABLE(of, hts221_spi_of_match);
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static const struct spi_device_id hts221_spi_id_table[] = {
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{ HTS221_DEV_NAME },
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{},
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};
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MODULE_DEVICE_TABLE(spi, hts221_spi_id_table);
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static struct spi_driver hts221_driver = {
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.driver = {
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.name = "hts221_spi",
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.pm = &hts221_pm_ops,
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.of_match_table = of_match_ptr(hts221_spi_of_match),
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},
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.probe = hts221_spi_probe,
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.id_table = hts221_spi_id_table,
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};
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module_spi_driver(hts221_driver);
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MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
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MODULE_DESCRIPTION("STMicroelectronics hts221 spi driver");
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MODULE_LICENSE("GPL v2");
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