From 1715e0ccd3b8cd4c1ee76076e1e7452b113be193 Mon Sep 17 00:00:00 2001 From: Irina Tirdea Date: Thu, 24 Mar 2016 11:29:27 +0200 Subject: [PATCH] iio: accel: bmc150: optimize transfers in trigger handler Some i2c busses (e.g.: Synopsys DesignWare I2C adapter) need to enable/disable the bus at each i2c transfer and must wait for the enable/disable to happen before sending the data. When reading data in the trigger handler, the bmc150 accel driver does one bus transfer for each axis. This has an impact on the frequency of the accelerometer at high sample rates due to additional delays introduced by the bus at each transfer. Reading all axis values in one bus transfer reduces the delays introduced by the bus. Signed-off-by: Irina Tirdea Signed-off-by: Jonathan Cameron --- drivers/iio/accel/bmc150-accel-core.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-) diff --git a/drivers/iio/accel/bmc150-accel-core.c b/drivers/iio/accel/bmc150-accel-core.c index cc52366ad4ad..58df97df562b 100644 --- a/drivers/iio/accel/bmc150-accel-core.c +++ b/drivers/iio/accel/bmc150-accel-core.c @@ -989,6 +989,7 @@ static const struct iio_event_spec bmc150_accel_event = { .realbits = (bits), \ .storagebits = 16, \ .shift = 16 - (bits), \ + .endianness = IIO_LE, \ }, \ .event_spec = &bmc150_accel_event, \ .num_event_specs = 1 \ @@ -1114,21 +1115,14 @@ static irqreturn_t bmc150_accel_trigger_handler(int irq, void *p) struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct bmc150_accel_data *data = iio_priv(indio_dev); - int bit, ret, i = 0; - unsigned int raw_val; + int ret; mutex_lock(&data->mutex); - for (bit = 0; bit < AXIS_MAX; bit++) { - ret = regmap_bulk_read(data->regmap, - BMC150_ACCEL_AXIS_TO_REG(bit), &raw_val, - 2); - if (ret < 0) { - mutex_unlock(&data->mutex); - goto err_read; - } - data->buffer[i++] = raw_val; - } + ret = regmap_bulk_read(data->regmap, BMC150_ACCEL_REG_XOUT_L, + data->buffer, AXIS_MAX * 2); mutex_unlock(&data->mutex); + if (ret < 0) + goto err_read; iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, pf->timestamp); -- 2.34.1