From 6a6df2d9113856a4371ca4f1cb29221790320307 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Thu, 31 Jan 2013 14:27:00 +0000 Subject: [PATCH] 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 Signed-off-by: Jonathan Cameron --- drivers/staging/iio/gyro/adxrs450_core.c | 48 ++++++++++++++++++++++---------- 1 file 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; -- 2.11.0