On Fri, 4 Dec 2020 11:48:03 -0800
Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:
> Allow setting frequency below 1Hz or sub 1Hz precision.
> Useful for slow sensors like ALS.
>
> Test frequency is set properly:
> modprobe iio-trig-hrtimer && \
> mkdir /sys/kernel/config/iio/triggers/hrtimer/t1 && \
> cd /sys/bus/iio/devices/triggerX ;
> for i in 1 .1 .01 .001 ; do
> echo $i > sampling_frequency
> cat sampling_frequency
> done
>
> Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
Looks good to me. I'd like this one to sit on the list a little longer though
+ it's missed this cycle anyway so we have plenty of time!
Jonathan
> ---
> drivers/iio/trigger/iio-trig-hrtimer.c | 25 +++++++++++++++----------
> 1 file changed, 15 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/iio/trigger/iio-trig-hrtimer.c b/drivers/iio/trigger/iio-trig-hrtimer.c
> index a5e670726717f..06acd6dc79a8c 100644
> --- a/drivers/iio/trigger/iio-trig-hrtimer.c
> +++ b/drivers/iio/trigger/iio-trig-hrtimer.c
> @@ -22,7 +22,7 @@
> struct iio_hrtimer_info {
> struct iio_sw_trigger swt;
> struct hrtimer timer;
> - unsigned long sampling_frequency;
> + int sampling_frequency[2];
> ktime_t period;
> };
>
> @@ -38,7 +38,9 @@ ssize_t iio_hrtimer_show_sampling_frequency(struct device *dev,
> struct iio_trigger *trig = to_iio_trigger(dev);
> struct iio_hrtimer_info *info = iio_trigger_get_drvdata(trig);
>
> - return snprintf(buf, PAGE_SIZE, "%lu\n", info->sampling_frequency);
> + return iio_format_value(buf, IIO_VAL_INT_PLUS_MICRO,
> + ARRAY_SIZE(info->sampling_frequency),
> + info->sampling_frequency);
> }
>
> static
> @@ -48,18 +50,21 @@ ssize_t iio_hrtimer_store_sampling_frequency(struct device *dev,
> {
> struct iio_trigger *trig = to_iio_trigger(dev);
> struct iio_hrtimer_info *info = iio_trigger_get_drvdata(trig);
> - unsigned long val;
> - int ret;
> + unsigned long long val;
> + int integer, fract, ret;
>
> - ret = kstrtoul(buf, 10, &val);
> + ret = iio_str_to_fixpoint(buf, 100, &integer, &fract);
> if (ret)
> return ret;
>
> - if (!val || val > NSEC_PER_SEC)
> + val = fract + 1000 * integer;
> +
> + if (!val || val > NSEC_PER_SEC * 1000)
> return -EINVAL;
>
> - info->sampling_frequency = val;
> - info->period = NSEC_PER_SEC / val;
> + info->sampling_frequency[0] = integer;
> + info->sampling_frequency[1] = fract * 1000;
> + info->period = NSEC_PER_SEC * 1000 / val;
>
> return len;
> }
> @@ -135,8 +140,8 @@ static struct iio_sw_trigger *iio_trig_hrtimer_probe(const char *name)
> hrtimer_init(&trig_info->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
> trig_info->timer.function = iio_hrtimer_trig_handler;
>
> - trig_info->sampling_frequency = HRTIMER_DEFAULT_SAMPLING_FREQUENCY;
> - trig_info->period = NSEC_PER_SEC / trig_info->sampling_frequency;
> + trig_info->sampling_frequency[0] = HRTIMER_DEFAULT_SAMPLING_FREQUENCY;
> + trig_info->period = NSEC_PER_SEC / trig_info->sampling_frequency[0];
>
> ret = iio_trigger_register(trig_info->swt.trigger);
> if (ret)
