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))
> + 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
>
--
With Best Regards,
Andy Shevchenko
