[PATCH 69/74] media: Documentation: uapi: Add the CAMSS IFE parameters

[bod]

From: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>

Document the parameters block the SM8650 IFE pixel path accepts on its
msm_vfeN_params node, and when queued parameters apply.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@xxxxxxxxxx>
---
 .../userspace-api/media/v4l/metafmt-qcom-isp.rst   | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/Documentation/userspace-api/media/v4l/metafmt-qcom-isp.rst b/Documentation/userspace-api/media/v4l/metafmt-qcom-isp.rst
index 77372b3a32d7d..0a7ef8b314423 100644
--- a/Documentation/userspace-api/media/v4l/metafmt-qcom-isp.rst
+++ b/Documentation/userspace-api/media/v4l/metafmt-qcom-isp.rst
@@ -141,6 +141,28 @@ and a gamma correction block:
 	for (unsigned int i = 0; i < CAMSS_GAMMA_LUT_SIZE; i++)
 		gamma->glut[i] = gamma->blut[i] = gamma->rlut[i] = i;
 
+IFE pixel path
+==============
+
+The pixel path of the SM8650 IFE consumes the format on its
+``msm_vfeN_params`` metadata output node. It accepts the following block, and
+rejects blocks of other types:
+
+.. flat-table:: IFE parameter blocks
+    :header-rows: 1
+    :stub-columns: 0
+
+    * - Parameter block
+      - Function
+    * - :c:type:`camss_params_aec_bhist`
+      - Region of the frame counted by the AEC Bayer histogram statistics,
+        :c:type:`camss_stats_bhist`.
+
+Parameters queued before the image node starts streaming apply from the first
+frame. Parameters queued while streaming apply from a following frame; the
+buffer is returned with the sequence number of the first frame they can
+affect.
+
 .. _v4l2-meta-fmt-qcom-isp-stats:
 
 *************************************

-- 
2.55.0