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-rw-r--r--include/media/v4l2-common.h10
1 files changed, 9 insertions, 1 deletions
diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
index 9d6c236e8f14..39dd0c78d70f 100644
--- a/include/media/v4l2-common.h
+++ b/include/media/v4l2-common.h
@@ -623,7 +623,7 @@ int v4l2_link_freq_to_bitmap(struct device *dev, const u64 *fw_link_freqs,
/**
* devm_v4l2_sensor_clk_get - lookup and obtain a reference to a clock producer
- * for a camera sensor.
+ * for a camera sensor
*
* @dev: device for v4l2 sensor clock "consumer"
* @id: clock consumer ID
@@ -643,6 +643,14 @@ int v4l2_link_freq_to_bitmap(struct device *dev, const u64 *fw_link_freqs,
*
* In this case try to set the clock-frequency value to the provided clock.
*
+ * As the name indicates, this function may only be used on camera sensor
+ * devices. This is because generally only camera sensors do need a clock to
+ * query the frequency from, due to the requirement to configure the PLL for a
+ * given CSI-2 interface frequency where the sensor's external clock frequency
+ * is a factor. Additionally, the clock frequency tends to be available on ACPI
+ * firmware based systems for camera sensors specifically (if e.g. DisCo for
+ * Imaging compliant).
+ *
* Returns a pointer to a struct clk on success or an error pointer on failure.
*/
struct clk *devm_v4l2_sensor_clk_get(struct device *dev, const char *id);