Re: [PATCH v2 18/18] iio: cros_ec: Use Hertz as unit for sampling frequency

From: Gwendal Grignou
Date: Tue Oct 22 2019 - 15:11:59 EST

On Mon, Oct 21, 2019 at 9:45 AM Jonathan Cameron <jic23@xxxxxxxxxx> wrote:
>
> On Sun, 20 Oct 2019 22:54:03 -0700
> Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:
>
> > To be compliant with other sensors, set and get sensor sampling
> > frequency in Hz, not mHz.
> >
> > Fixes: ae7b02ad2f32 ("iio: common: cros_ec_sensors: Expose
> > cros_ec_sensors frequency range via iio sysfs")
> >
> > Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
>
> Do we need to look at back porting this?
>
> Acked-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
>
> Not sure which path this set will take in, hence I've given
> acks for various patches incase it's not via me.
>
> Whole set is in general good to have, but I do worry a bit about
> people noticing ABI breakage. *crosses fingers*
I am planning to backport the sysfs change to older kernel.
I am adding some code to the clients that use the sysfs interface: if
frequency is absent, assume sample_frequency is the new frequency.
Clients should be able to handle both ABI, the code has been around
since 3.14.

>
> Jonathan
>
> > ---
> > No changes in v2.
> >
> > .../cros_ec_sensors/cros_ec_sensors_core.c | 32 +++++++++++--------
> > .../linux/iio/common/cros_ec_sensors_core.h | 6 ++--
> > 2 files changed, 22 insertions(+), 16 deletions(-)
> >
> > diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > index f50e239f9a1e9..76dc8cad1b4b5 100644
> > --- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > +++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
> > @@ -256,6 +256,7 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
> > struct cros_ec_dev *ec = sensor_hub->ec;
> > struct cros_ec_sensor_platform *sensor_platform = dev_get_platdata(dev);
> > u32 ver_mask;
> > + int frequencies[ARRAY_SIZE(state->frequencies) / 2] = { 0 };
> > int ret, i;
> >
> > platform_set_drvdata(pdev, indio_dev);
> > @@ -304,20 +305,22 @@ int cros_ec_sensors_core_init(struct platform_device *pdev,
> > state->calib[i].scale = MOTION_SENSE_DEFAULT_SCALE;
> >
> > /* 0 is a correct value used to stop the device */
> > - state->frequencies[0] = 0;
> > if (state->msg->version < 3) {
> > get_default_min_max_freq(state->resp->info.type,
> > - &state->frequencies[1],
> > - &state->frequencies[2],
> > + &frequencies[1],
> > + &frequencies[2],
> > &state->fifo_max_event_count);
> > } else {
> > - state->frequencies[1] =
> > - state->resp->info_3.min_frequency;
> > - state->frequencies[2] =
> > - state->resp->info_3.max_frequency;
> > + frequencies[1] = state->resp->info_3.min_frequency;
> > + frequencies[2] = state->resp->info_3.max_frequency;
> > state->fifo_max_event_count =
> > state->resp->info_3.fifo_max_event_count;
> > }
> > + for (i = 0; i < ARRAY_SIZE(frequencies); i++) {
> > + state->frequencies[2 * i] = frequencies[i] / 1000;
> > + state->frequencies[2 * i + 1] =
> > + (frequencies[i] % 1000) * 1000;
> > + }
> >
> > ret = devm_iio_triggered_buffer_setup(
> > dev, indio_dev, NULL,
> > @@ -707,7 +710,7 @@ int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
> > struct iio_chan_spec const *chan,
> > int *val, int *val2, long mask)
> > {
> > - int ret;
> > + int ret, frequency;
> >
> > switch (mask) {
> > case IIO_CHAN_INFO_SAMP_FREQ:
> > @@ -719,8 +722,10 @@ int cros_ec_sensors_core_read(struct cros_ec_sensors_core_state *st,
> > if (ret)
> > break;
> >
> > - *val = st->resp->sensor_odr.ret;
> > - ret = IIO_VAL_INT;
> > + frequency = st->resp->sensor_odr.ret;
> > + *val = frequency / 1000;
> > + *val2 = (frequency % 1000) * 1000;
> > + ret = IIO_VAL_INT_PLUS_MICRO;
> > break;
> > default:
> > ret = -EINVAL;
> > @@ -755,7 +760,7 @@ int cros_ec_sensors_core_read_avail(struct iio_dev *indio_dev,
> > case IIO_CHAN_INFO_SAMP_FREQ:
> > *length = ARRAY_SIZE(state->frequencies);
> > *vals = (const int *)&state->frequencies;
> > - *type = IIO_VAL_INT;
> > + *type = IIO_VAL_INT_PLUS_MICRO;
> > return IIO_AVAIL_LIST;
> > }
> >
> > @@ -777,12 +782,13 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
> > struct iio_chan_spec const *chan,
> > int val, int val2, long mask)
> > {
> > - int ret;
> > + int ret, frequency;
> >
> > switch (mask) {
> > case IIO_CHAN_INFO_SAMP_FREQ:
> > + frequency = val * 1000 + val2 / 1000;
> > st->param.cmd = MOTIONSENSE_CMD_SENSOR_ODR;
> > - st->param.sensor_odr.data = val;
> > + st->param.sensor_odr.data = frequency;
> >
> > /* Always roundup, so caller gets at least what it asks for. */
> > st->param.sensor_odr.roundup = 1;
> > diff --git a/include/linux/iio/common/cros_ec_sensors_core.h b/include/linux/iio/common/cros_ec_sensors_core.h
> > index 4df3abd151fbf..256447b136296 100644
> > --- a/include/linux/iio/common/cros_ec_sensors_core.h
> > +++ b/include/linux/iio/common/cros_ec_sensors_core.h
> > @@ -52,6 +52,8 @@ typedef irqreturn_t (*cros_ec_sensors_capture_t)(int irq, void *p);
> > * is always 8-byte aligned.
> > * @read_ec_sensors_data: function used for accessing sensors values
> > * @fifo_max_event_count: Size of the EC sensor FIFO
> > + * @frequencies: Table of known available frequencies:
> > + * 0, Min and Max in mHz.
> > */
> > struct cros_ec_sensors_core_state {
> > struct cros_ec_device *ec;
> > @@ -75,9 +77,7 @@ struct cros_ec_sensors_core_state {
> > unsigned long scan_mask, s16 *data);
> >
> > u32 fifo_max_event_count;
> > -
> > - /* Table of known available frequencies : 0, Min and Max in mHz */
> > - int frequencies[3];
> > + int frequencies[6];
> > };
> >
> > int cros_ec_sensors_read_lpc(struct iio_dev *indio_dev, unsigned long scan_mask,
>