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>
---
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))
+ 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.
+ *
+ * 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
