Re: [PATCH v5 07/15] iio: sx9310: Use long instead of int for channel bitmaps

Jonathan Cameron
2020-08-16T09:36:46Z

On Thu, 6 Aug 2020 19:30:57 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Mon, 3 Aug 2020 17:58:07 -0600
> Daniel Campello <campello@chromium.org> wrote:
>
> > Uses for_each_set_bit() macro to loop over channel bitmaps.
> >
> > Signed-off-by: Daniel Campello <campello@chromium.org>
> > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> > Reviewed-by: Stephen Boyd <swboyd@chromium.org>
> Applied,
>
> Thanks,
>
> Jonathan

0-day sent a rather silly warning on this, but in the interests of
suppressing noisy warnings I've fixed it...

>
> > ---
> >
> > Changes in v5: None
> > Changes in v4: None
> > Changes in v3:
> > - Added static assert for number of channels.
> >
> > Changes in v2:
> > - Changed prox_stat to chan_prox_stat bitmap.
> >
> > drivers/iio/proximity/sx9310.c | 39 ++++++++++++++++++----------------
> > 1 file changed, 21 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
> > index 127b1ba79e2dea..f78500b8a5841e 100644
> > --- a/drivers/iio/proximity/sx9310.c
> > +++ b/drivers/iio/proximity/sx9310.c
> > @@ -119,6 +119,7 @@
> >
> > /* 4 hardware channels, as defined in STAT0: COMB, CS2, CS1 and CS0. */
> > #define SX9310_NUM_CHANNELS 4
> > +static_assert(SX9310_NUM_CHANNELS < BITS_PER_LONG);
> >
> > struct sx9310_data {
> > /* Serialize access to registers and channel configuration */
> > @@ -130,7 +131,7 @@ struct sx9310_data {
> > * Last reading of the proximity status for each channel.
> > * We only send an event to user space when this changes.
> > */
> > - bool prox_stat[SX9310_NUM_CHANNELS];
> > + unsigned long chan_prox_stat;
> > bool trigger_enabled;
> > /* Ensure correct alignment of timestamp when present. */
> > struct {
> > @@ -140,7 +141,8 @@ struct sx9310_data {
> > /* Remember enabled channels and sample rate during suspend. */
> > unsigned int suspend_ctrl0;
> > struct completion completion;
> > - unsigned int chan_read, chan_event;
> > + unsigned long chan_read;
> > + unsigned long chan_event;
> > int channel_users[SX9310_NUM_CHANNELS];
> > unsigned int whoami;
> > };
> > @@ -283,15 +285,16 @@ static const struct regmap_config sx9310_regmap_config = {
> > };
> >
> > static int sx9310_update_chan_en(struct sx9310_data *data,
> > - unsigned int chan_read,
> > - unsigned int chan_event)
> > + unsigned long chan_read,
> > + unsigned long chan_event)
> > {
> > int ret;
> > + unsigned long channels = chan_read | chan_event;
> >
> > - if ((data->chan_read | data->chan_event) != (chan_read | chan_event)) {
> > + if ((data->chan_read | data->chan_event) != channels) {
> > ret = regmap_update_bits(data->regmap, SX9310_REG_PROX_CTRL0,
> > SX9310_REG_PROX_CTRL0_SENSOREN_MASK,
> > - chan_read | chan_event);
> > + channels);
> > if (ret)
> > return ret;
> > }
> > @@ -532,6 +535,7 @@ static void sx9310_push_events(struct iio_dev *indio_dev)
> > unsigned int val, chan;
> > struct sx9310_data *data = iio_priv(indio_dev);
> > s64 timestamp = iio_get_time_ns(indio_dev);
> > + unsigned long prox_changed;
> >
> > /* Read proximity state on all channels */
> > ret = regmap_read(data->regmap, SX9310_REG_STAT0, &val);
> > @@ -540,24 +544,23 @@ static void sx9310_push_events(struct iio_dev *indio_dev)
> > return;
> > }
> >
> > - for (chan = 0; chan < SX9310_NUM_CHANNELS; chan++) {
> > + /*
> > + * Only iterate over channels with changes on proximity status that have
> > + * events enabled.
> > + */
> > + prox_changed = (data->chan_prox_stat ^ val) & data->chan_event;
> > +
> > + for_each_set_bit(chan, &prox_changed, SX9310_NUM_CHANNELS) {
> > int dir;
> > u64 ev;
> > - bool new_prox = val & BIT(chan);
> > -
> > - if (!(data->chan_event & BIT(chan)))
> > - continue;
> > - if (new_prox == data->prox_stat[chan])
> > - /* No change on this channel. */
> > - continue;
> >
> > - dir = new_prox ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;
> > + dir = val & BIT(chan) ? IIO_EV_DIR_FALLING : IIO_EV_DIR_RISING;

cpp check is moaning about no brackets around
val & BIT(CHAN) so I've added some.

> > ev = IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, chan,
> > IIO_EV_TYPE_THRESH, dir);
> >
> > iio_push_event(indio_dev, ev, timestamp);
> > - data->prox_stat[chan] = new_prox;
> > }
> > + data->chan_prox_stat = val;
> > }
> >
> > static irqreturn_t sx9310_irq_thread_handler(int irq, void *private)
> > @@ -714,13 +717,13 @@ static irqreturn_t sx9310_trigger_handler(int irq, void *private)
> > static int sx9310_buffer_preenable(struct iio_dev *indio_dev)
> > {
> > struct sx9310_data *data = iio_priv(indio_dev);
> > - unsigned int channels = 0;
> > + unsigned long channels = 0;
> > int bit, ret;
> >
> > mutex_lock(&data->mutex);
> > for_each_set_bit(bit, indio_dev->active_scan_mask,
> > indio_dev->masklength)
> > - channels |= BIT(indio_dev->channels[bit].channel);
> > + __set_bit(indio_dev->channels[bit].channel, &channels);
> >
> > ret = sx9310_update_chan_en(data, channels, data->chan_event);
> > mutex_unlock(&data->mutex);
>