mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-08-28 03:40:04 +00:00
Code Issues Releases Wiki Activity

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

Browse source 
This partially reverts commit cb4496876f. 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: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This commit is contained in:
Lars-Peter Clausen 2013-01-31 14:27:00 +00:00 committed by Jonathan Cameron
parent 999517f674
commit 6a6df2d911
1 changed files with 34 additions and 14 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

48
drivers/staging/iio/gyro/adxrs450_core.c
View file

@ -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;