On Tue, 7 May 2019 10:02:25 +0200
Sean Nyekjaer <sean@xxxxxxxxxx> wrote:
> This adds support for using iio triggers, this is needed because
> our hardware guys forgot to connect the irq pins from imu device
> to the SoC.
>
> Signed-off-by: Sean Nyekjaer <sean@xxxxxxxxxx>
Hi Sean
A small question on the size of the buffer needed inline. Otherwise looks
good to me.
> ---
> drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 37 ++++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> index 1ca69598678f..65ab853202de 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> @@ -40,8 +40,11 @@
> #include <linux/kernel.h>
> #include <linux/module.h>
> #include <linux/delay.h>
> +#include <linux/iio/buffer.h>
> #include <linux/iio/iio.h>
> #include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> #include <linux/pm.h>
> #include <linux/regmap.h>
> #include <linux/bitfield.h>
> @@ -945,6 +948,30 @@ static int st_lsm6dsx_init_hw_timer(struct st_lsm6dsx_hw *hw)
> return 0;
> }
>
> +static irqreturn_t st_lsm6dsx_trigger_handler(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct st_lsm6dsx_sensor *sensor = iio_priv(indio_dev);
> + u16 buffer[4 * sizeof(s64)/sizeof(u16)];
The size may well be correct, but that particular way of expressing it doesn't make
it terribly clear.
It seems a bit large... You need the space for the timestamp, so it needs to be
padded to a u64, but that would still require your other channels to need
more than 2*sizeof(s64)/sizeof(u16) u16s which is 9 or more of them.
> + int tmp, bit;
> +
> + memset(buffer, 0, sizeof(buffer));
> +
> + for_each_set_bit(bit, indio_dev->active_scan_mask, indio_dev->masklength) {
> + st_lsm6dsx_read_oneshot(sensor,
> + indio_dev->channels[bit].address, &tmp);
> + buffer[bit] = tmp;
> + }
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, buffer,
> + iio_get_time_ns(indio_dev));
> +
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + return IRQ_HANDLED;
> +}
> +
> static int st_lsm6dsx_init_device(struct st_lsm6dsx_hw *hw)
> {
> u8 drdy_int_reg;
> @@ -1093,6 +1120,16 @@ int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id, const char *name,
> err = st_lsm6dsx_fifo_setup(hw);
> if (err < 0)
> return err;
> + } else {
> + for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
> + err = devm_iio_triggered_buffer_setup(hw->dev,
> + hw->iio_devs[i], NULL,
> + st_lsm6dsx_trigger_handler, NULL);
> + if (err < 0) {
> + dev_err(hw->dev, "iio triggered buffer setup failed\n");
> + return err;
> + }
> + }
> }
>
> for (i = 0; i < ST_LSM6DSX_ID_MAX; i++) {
