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
Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
---
Changes in v7:
Rebased : no need to set indio_dev->modes directly anymore.
Changes in v6:
Inverted logic in acpi_als_notify()
Put timestamp comments in the same paragraph.
Changes in v5:
Improve commit message readability, add note about backward
compatibility.
Remove unneeded include file.
Changes in v4:
Added comments when pf->timestamp is 0 and valid. Fix spelling.
drivers/iio/light/acpi-als.c | 96 +++++++++++++++++++++++++-----------
1 file changed, 68 insertions(+), 28 deletions(-)
diff --git a/drivers/iio/light/acpi-als.c b/drivers/iio/light/acpi-als.c
index a2107945cff93..30393f08e0825 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 +106,19 @@ 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);
-
- switch (event) {
- case ACPI_ALS_NOTIFY_ILLUMINANCE:
- ret = acpi_als_read_value(als, ACPI_ALS_ILLUMINANCE, &val);
- if (ret < 0)
- goto out;
- *buffer++ = val;
- break;
- default:
- /* Unhandled event */
- dev_dbg(&device->dev, "Unhandled ACPI ALS event (%08x)!\n",
- event);
- goto out;
+ if (iio_buffer_enabled(indio_dev) && iio_trigger_using_own(indio_dev)) {
+ switch (event) {
+ case ACPI_ALS_NOTIFY_ILLUMINANCE:
+ iio_trigger_poll_chained(als->trig);
+ break;
+ default:
+ /* Unhandled event */
+ dev_dbg(&device->dev,
+ "Unhandled ACPI ALS event (%08x)!\n",
+ event);
+ }
}
-
- 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,
@@ -159,6 +149,41 @@ 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.
+ *
+ * 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;
@@ -181,8 +206,23 @@ static int acpi_als_add(struct acpi_device *device)
indio_dev->channels = acpi_als_channels;
indio_dev->num_channels = ARRAY_SIZE(acpi_als_channels);
- ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
- INDIO_BUFFER_SOFTWARE, NULL);
+ als->trig = devm_iio_trigger_alloc(dev, "%s-dev%d", indio_dev->name, indio_dev->id);
+ if (!als->trig)
+ return -ENOMEM;
+
+ 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;
--
2.31.0.rc2.261.g7f71774620-goog
