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

Jonathan Cameron
2020-08-06T18:33:21Z

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

> ---
>
> 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;
> 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);