/*
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* STMicroelectronics sensors spi library driver
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*
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* Copyright 2012-2013 STMicroelectronics Inc.
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*
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* Denis Ciocca <denis.ciocca@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/slab.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/common/st_sensors_spi.h>
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#define ST_SENSORS_SPI_MULTIREAD 0xc0
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#define ST_SENSORS_SPI_READ 0x80
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static unsigned int st_sensors_spi_get_irq(struct iio_dev *indio_dev)
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{
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struct st_sensor_data *sdata = iio_priv(indio_dev);
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return to_spi_device(sdata->dev)->irq;
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}
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static int st_sensors_spi_read(struct st_sensor_transfer_buffer *tb,
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struct device *dev, u8 reg_addr, int len, u8 *data, bool multiread_bit)
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{
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int err;
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struct spi_transfer xfers[] = {
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{
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.tx_buf = 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 = 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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mutex_lock(&tb->buf_lock);
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if ((multiread_bit) && (len > 1))
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tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_MULTIREAD;
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else
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tb->tx_buf[0] = reg_addr | ST_SENSORS_SPI_READ;
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err = spi_sync_transfer(to_spi_device(dev), xfers, ARRAY_SIZE(xfers));
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if (err)
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goto acc_spi_read_error;
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memcpy(data, tb->rx_buf, len);
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mutex_unlock(&tb->buf_lock);
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return len;
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acc_spi_read_error:
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mutex_unlock(&tb->buf_lock);
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return err;
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}
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static int st_sensors_spi_read_byte(struct st_sensor_transfer_buffer *tb,
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struct device *dev, u8 reg_addr, u8 *res_byte)
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{
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return st_sensors_spi_read(tb, dev, reg_addr, 1, res_byte, false);
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}
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static int st_sensors_spi_read_multiple_byte(
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struct st_sensor_transfer_buffer *tb, struct device *dev,
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u8 reg_addr, int len, u8 *data, bool multiread_bit)
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{
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return st_sensors_spi_read(tb, dev, reg_addr, len, data, multiread_bit);
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}
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static int st_sensors_spi_write_byte(struct st_sensor_transfer_buffer *tb,
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struct device *dev, u8 reg_addr, u8 data)
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{
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int err;
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struct spi_transfer xfers = {
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.tx_buf = tb->tx_buf,
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.bits_per_word = 8,
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.len = 2,
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};
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mutex_lock(&tb->buf_lock);
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tb->tx_buf[0] = reg_addr;
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tb->tx_buf[1] = data;
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err = spi_sync_transfer(to_spi_device(dev), &xfers, 1);
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mutex_unlock(&tb->buf_lock);
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return err;
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}
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static const struct st_sensor_transfer_function st_sensors_tf_spi = {
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.read_byte = st_sensors_spi_read_byte,
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.write_byte = st_sensors_spi_write_byte,
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.read_multiple_byte = st_sensors_spi_read_multiple_byte,
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};
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void st_sensors_spi_configure(struct iio_dev *indio_dev,
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struct spi_device *spi, struct st_sensor_data *sdata)
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{
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spi_set_drvdata(spi, indio_dev);
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indio_dev->dev.parent = &spi->dev;
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indio_dev->name = spi->modalias;
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sdata->dev = &spi->dev;
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sdata->tf = &st_sensors_tf_spi;
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sdata->get_irq_data_ready = st_sensors_spi_get_irq;
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}
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EXPORT_SYMBOL(st_sensors_spi_configure);
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MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
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MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver");
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MODULE_LICENSE("GPL v2");
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