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authorLars-Peter Clausen <lars@metafoo.de>2013-01-31 14:27:00 +0000
committerJonathan Cameron <jic23@kernel.org>2013-02-02 09:17:26 +0000
commit6a6df2d9113856a4371ca4f1cb29221790320307 (patch)
tree1137e5d81c2618740a97a750d4f3d5b29e44322d /drivers/staging/iio/gyro
parent999517f6742b4ca4692c041752afc4298fbbf0da (diff)
Partially revert "staging:iio:gyro:adxrs450 make more use of spi_read and spi_write."
This partially reverts commit cb4496876f03631eff913b3c608c964d48d61eb9. 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>
Diffstat (limited to 'drivers/staging/iio/gyro')
-rw-r--r--drivers/staging/iio/gyro/adxrs450_core.c48
1 files changed, 34 insertions, 14 deletions
diff --git a/drivers/staging/iio/gyro/adxrs450_core.c b/drivers/staging/iio/gyro/adxrs450_core.c
index f0ce81da8aca..318e8c9c6544 100644
--- a/drivers/staging/iio/gyro/adxrs450_core.c
+++ b/drivers/staging/iio/gyro/adxrs450_core.c
@@ -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;