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Commit 6a6df2d9 authored by Lars-Peter Clausen's avatar Lars-Peter Clausen Committed by Jonathan Cameron
Browse files

Partially revert "staging:iio:gyro:adxrs450 make more use of spi_read and spi_write." 



This partially reverts commit cb449687. There is
no apparent reason why we should split a transaction which consists out of
multiple transfers into multiple transactions each having one transfer. While
this works it introduces a bunch of unnecessary context switch and additional
setup costs.

Signed-off-by: default avatarLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 999517f6

drivers/staging/iio/gyro/adxrs450_core.c

+34 −14
Original line number Diff line number Diff line
@@ -34,8 +34,21 @@ static int adxrs450_spi_read_reg_16(struct iio_dev *indio_dev, 
				    u8 reg_address,

				    u16 *val)

{

	struct spi_message msg;

	struct adxrs450_state *st = iio_priv(indio_dev);

	int ret;

	struct spi_transfer xfers[] = {

		{

			.tx_buf = st->tx,

			.bits_per_word = 8,

			.len = 4,

			.cs_change = 1,

		}, {

			.rx_buf = st->rx,

			.bits_per_word = 8,

			.len = 4,

		},

	};



	mutex_lock(&st->buf_lock);

	st->tx[0] = ADXRS450_READ_DATA | (reg_address >> 7);
@@ -46,13 +59,10 @@ static int adxrs450_spi_read_reg_16(struct iio_dev *indio_dev, 
	if (!(hweight32(be32_to_cpu(*(u32 *)st->tx)) & 1))

		st->tx[3]  |= ADXRS450_P;



	ret = spi_write(st->us, st->tx, 4);

	if (ret) {

		dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n",

			reg_address);

		goto error_ret;

	}

	ret = spi_read(st->us, st->rx, 4);

	spi_message_init(&msg);

	spi_message_add_tail(&xfers[0], &msg);

	spi_message_add_tail(&xfers[1], &msg);

	ret = spi_sync(st->us, &msg);

	if (ret) {

		dev_err(&st->us->dev, "problem while reading 16 bit register 0x%02x\n",

				reg_address);
@@ -105,8 +115,21 @@ static int adxrs450_spi_write_reg_16(struct iio_dev *indio_dev, 
 **/

static int adxrs450_spi_sensor_data(struct iio_dev *indio_dev, s16 *val)

{

	struct spi_message msg;

	struct adxrs450_state *st = iio_priv(indio_dev);

	int ret;

	struct spi_transfer xfers[] = {

		{

			.tx_buf = st->tx,

			.bits_per_word = 8,

			.len = 4,

			.cs_change = 1,

		}, {

			.rx_buf = st->rx,

			.bits_per_word = 8,

			.len = 4,

		},

	};



	mutex_lock(&st->buf_lock);

	st->tx[0] = ADXRS450_SENSOR_DATA;
@@ -114,13 +137,10 @@ static int adxrs450_spi_sensor_data(struct iio_dev *indio_dev, s16 *val) 
	st->tx[2] = 0;

	st->tx[3] = 0;



	ret = spi_write(st->us, st->tx, 4);

	if (ret) {

		dev_err(&st->us->dev, "Problem while reading sensor data\n");

		goto error_ret;

	}



	ret = spi_read(st->us, st->rx, 4);

	spi_message_init(&msg);

	spi_message_add_tail(&xfers[0], &msg);

	spi_message_add_tail(&xfers[1], &msg);

	ret = spi_sync(st->us, &msg);

	if (ret) {

		dev_err(&st->us->dev, "Problem while reading sensor data\n");

		goto error_ret;