On Thu, 17 Dec 2020 00:38:06 +0200
Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote:
> On Wed, Dec 16, 2020 at 11:41 PM Gwendal Grignou <gwendal@xxxxxxxxxxxx> wrote:
> >
> > As some firmware does not notify on illuminance changes, add a
> > trigger to be able to query light via software (sysfs-trigger or
> > hrtrigger).
> > Add a hardware trigger set as the default trigger to maintain backward
> > compatibility.
> >
> > Check iio_info reports the sensor as buffer capable:
> > iio:device0: acpi-als (buffer capable)
> >
> > To test, check we can get data on demand on an Intel based chromebook:
> >
> > IIO_DEV="iio:device0"
> > echo 1 > iio_sysfs_trigger/add_trigger
> > cat trigger2/name > ${IIO_DEV}/trigger/current_trigger
> > for i in ${IIO_DEV}/scan_elements/*_en ${IIO_DEV}/buffer/enable ; do
> > echo 1 > $i
> > done
> > od -x /dev/${IIO_DEV} &
> > echo 1 > trigger2/trigger_now
>
> Few nitpicks below. After addressing, take my
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
> assuming that backward compatibility has been tested as well.
>
> > Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
> > ---
> > Changes in v4:
> > Added comments when pf->timestamp is 0 and valid. Fix spelling.
> > Changes in v5:
> > Improve commit message readability, add note about backward
> > compatibility.
> > Remove unneeded include file.
> >
> > drivers/iio/light/acpi-als.c | 89 ++++++++++++++++++++++++++----------
> > 1 file changed, 66 insertions(+), 23 deletions(-)
> >
> > diff --git a/drivers/iio/light/acpi-als.c b/drivers/iio/light/acpi-als.c
> > index fd20808d4a119..80fe0da51fad3 100644
> > --- a/drivers/iio/light/acpi-als.c
> > +++ b/drivers/iio/light/acpi-als.c
> > @@ -16,11 +16,14 @@
> > #include <linux/module.h>
> > #include <linux/acpi.h>
> > #include <linux/err.h>
> > +#include <linux/irq.h>
> > #include <linux/mutex.h>
> >
> > #include <linux/iio/iio.h>
> > #include <linux/iio/buffer.h>
> > -#include <linux/iio/kfifo_buf.h>
> > +#include <linux/iio/trigger.h>
> > +#include <linux/iio/triggered_buffer.h>
> > +#include <linux/iio/trigger_consumer.h>
> >
> > #define ACPI_ALS_CLASS "als"
> > #define ACPI_ALS_DEVICE_NAME "acpi-als"
> > @@ -59,6 +62,7 @@ static const struct iio_chan_spec acpi_als_channels[] = {
> > struct acpi_als {
> > struct acpi_device *device;
> > struct mutex lock;
> > + struct iio_trigger *trig;
> >
> > s32 evt_buffer[ACPI_ALS_EVT_BUFFER_SIZE / sizeof(s32)] __aligned(8);
> > };
> > @@ -102,33 +106,20 @@ static void acpi_als_notify(struct acpi_device *device, u32 event)
> > {
> > struct iio_dev *indio_dev = acpi_driver_data(device);
> > struct acpi_als *als = iio_priv(indio_dev);
> > - s32 *buffer = als->evt_buffer;
> > - s64 time_ns = iio_get_time_ns(indio_dev);
> > - s32 val;
> > - int ret;
> >
> > - mutex_lock(&als->lock);
> > -
> > - memset(buffer, 0, ACPI_ALS_EVT_BUFFER_SIZE);
> > + if (!iio_buffer_enabled(indio_dev) ||
> > + !iio_trigger_using_own(indio_dev))
>
> I guess it can be located on one line.
>
> I hope those functions have no side effects. In that case you may
> invert logic (save 2 characters)
>
> if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev))
You can but at cost of indenting the whole following block on level further.
I'm not that fussed, but in general that doesn't seem like a good idea to
save two characters here.
Gwendal made that not too bad in v6 by removing the read that appears to
be unnecessary.
>
> > + return;
> >
> > switch (event) {
> > case ACPI_ALS_NOTIFY_ILLUMINANCE:
> > - ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val);
> > - if (ret < 0)
> > - goto out;
> > - *buffer++ = val;
> > + iio_trigger_poll_chained(als->trig);
> > break;
> > default:
> > /* Unhandled event */
> > dev_dbg(&device->dev, "Unhandled ACPI ALS event (%08x)!\n",
> > event);
> > - goto out;
> > }
> > -
> > - iio_push_to_buffers_with_timestamp(indio_dev, als->evt_buffer, time_ns);
> > -
> > -out:
> > - mutex_unlock(&als->lock);
> > }
> >
> > static int acpi_als_read_raw(struct iio_dev *indio_dev,
> > @@ -159,12 +150,47 @@ static const struct iio_info acpi_als_info = {
> > .read_raw = acpi_als_read_raw,
> > };
> >
> > +static irqreturn_t acpi_als_trigger_handler(int irq, void *p)
> > +{
> > + struct iio_poll_func *pf = p;
> > + struct iio_dev *indio_dev = pf->indio_dev;
> > + struct acpi_als *als = iio_priv(indio_dev);
> > + s32 *buffer = als->evt_buffer;
> > + s32 val;
> > + int ret;
> > +
> > + mutex_lock(&als->lock);
> > +
> > + ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val);
> > + if (ret < 0)
> > + goto out;
> > + *buffer = val;
> > +
> > + /*
> > + * When coming from own trigger via polls, set polling function timestamp
> > + * here.
> > + * Given ACPI notifier is already in a thread and call function directly,
> > + * there is no need to set the timestamp in the notify function.
>
> Continue the second sentence of the previous line. No need to have it
> in a separate paragraph.
>
> > + *
> > + * If the timestamp was actually 0, the timestamp is set one more time.
> > + */
> > + if (!pf->timestamp)
> > + pf->timestamp = iio_get_time_ns(indio_dev);
> > +
> > + iio_push_to_buffers_with_timestamp(indio_dev, buffer, pf->timestamp);
> > +out:
> > + mutex_unlock(&als->lock);
> > + iio_trigger_notify_done(indio_dev->trig);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > static int acpi_als_add(struct acpi_device *device)
> > {
> > struct device *dev = &device->dev;
> > struct iio_dev *indio_dev;
> > - struct iio_buffer *buffer;
> > struct acpi_als *als;
> > + int ret;
> >
> > indio_dev = devm_iio_device_alloc(dev, sizeof(*als));
> > if (!indio_dev)
> > @@ -178,15 +204,32 @@ static int acpi_als_add(struct acpi_device *device)
> >
> > indio_dev->name = ACPI_ALS_DEVICE_NAME;
> > indio_dev->info = &acpi_als_info;
> > - indio_dev->modes = INDIO_BUFFER_SOFTWARE;
> > + indio_dev->modes = INDIO_DIRECT_MODE;
> > indio_dev->channels = acpi_als_channels;
> > indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels);
> >
> > - buffer = devm_iio_kfifo_allocate(dev);
> > - if (!buffer)
> > + als->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
> > + indio_dev->name,
> > + indio_dev->id);
> > + if (!als->trig)
> > return -ENOMEM;
> >
> > - iio_device_attach_buffer(indio_dev, buffer);
> > + iio_trigger_set_drvdata(als->trig, indio_dev);
> > + ret = devm_iio_trigger_register(dev, als->trig);
> > + if (ret)
> > + return ret;
> > + /*
> > + * Set hardware trigger by default to let events flow when
> > + * BIOS support notification.
> > + */
> > + indio_dev->trig = iio_trigger_get(als->trig);
> > +
> > + ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
> > + iio_pollfunc_store_time,
> > + acpi_als_trigger_handler,
> > + NULL);
> > + if (ret)
> > + return ret;
> >
> > return devm_iio_device_register(dev, indio_dev);
> > }
> > --
> > 2.29.2.729.g45daf8777d-goog
> >
>
>
