From 7e3d1eb123d804d2b1088782f458aed5eb36c684 Mon Sep 17 00:00:00 2001 From: Irina Tirdea Date: Thu, 24 Mar 2016 11:29:29 +0200 Subject: [PATCH] iio: accel: bmg160: 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 bmg160 gyro 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/gyro/bmg160_core.c | 17 ++++++----------- 1 file changed, 6 insertions(+), 11 deletions(-) diff --git a/drivers/iio/gyro/bmg160_core.c b/drivers/iio/gyro/bmg160_core.c index 8d6e5b132016..43570b8f686d 100644 --- a/drivers/iio/gyro/bmg160_core.c +++ b/drivers/iio/gyro/bmg160_core.c @@ -734,6 +734,7 @@ static const struct iio_event_spec bmg160_event = { .sign = 's', \ .realbits = 16, \ .storagebits = 16, \ + .endianness = IIO_LE, \ }, \ .event_spec = &bmg160_event, \ .num_event_specs = 1 \ @@ -773,20 +774,14 @@ static irqreturn_t bmg160_trigger_handler(int irq, void *p) struct iio_poll_func *pf = p; struct iio_dev *indio_dev = pf->indio_dev; struct bmg160_data *data = iio_priv(indio_dev); - int bit, ret, i = 0; - unsigned int val; + int ret; mutex_lock(&data->mutex); - for (bit = 0; bit < AXIS_MAX; bit++) { - ret = regmap_bulk_read(data->regmap, BMG160_AXIS_TO_REG(bit), - &val, 2); - if (ret < 0) { - mutex_unlock(&data->mutex); - goto err; - } - data->buffer[i++] = ret; - } + ret = regmap_bulk_read(data->regmap, BMG160_REG_XOUT_L, + data->buffer, AXIS_MAX * 2); mutex_unlock(&data->mutex); + if (ret < 0) + goto err; iio_push_to_buffers_with_timestamp(indio_dev, data->buffer, pf->timestamp); -- 2.20.1