[PATCH 07/10] media: microchip-isc: fix pfe_cfg0_bps comment

[Balakrishnan Sambath]

The @pfe_cfg0_bps comment claimed the field holds the "number of
hardware data lines connected to the ISC". It does not. The field
stores the pre-shifted PFE_CFG0 BPS value (e.g. ISC_PFE_CFG0_BPS_EIGHT,
which is 0x4 << 28) and is ORed straight into the PFE_CFG0 register
word in microchip-isc-base.c.

The old wording invites a reader to treat it as a small bit-depth
integer (8, 10, 12) and compare or do arithmetic on it directly, which
silently breaks since the value is shifted into bits 30:28. Document
what the field really holds and how to read the bit-depth back out with
FIELD_GET(ISC_PFE_CFG0_BPS_MASK, ...).

Signed-off-by: Balakrishnan Sambath <balakrishnan.s@xxxxxxxxxxxxx>
---
 drivers/media/platform/microchip/microchip-isc.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/microchip/microchip-isc.h b/drivers/media/platform/microchip/microchip-isc.h
index f5e322c2e36b..b084459f4583 100644
--- a/drivers/media/platform/microchip/microchip-isc.h
+++ b/drivers/media/platform/microchip/microchip-isc.h
@@ -62,7 +62,11 @@ struct isc_subdev_entity {
  * @mbus_code:		V4L2 media bus format code.
  * @cfa_baycfg:		If this format is RAW BAYER, indicate the type of bayer.
 			this is either BGBG, RGRG, etc.
- * @pfe_cfg0_bps:	Number of hardware data lines connected to the ISC
+ * @pfe_cfg0_bps:	Pre-shifted ISC_PFE_CFG0 BPS field value (e.g.
+			ISC_PFE_CFG0_BPS_EIGHT), not a plain bit-depth integer.
+			OR it directly into the PFE_CFG0 register word, or use
+			FIELD_GET(ISC_PFE_CFG0_BPS_MASK, ...) to obtain the
+			3-bit BPS field value.
  * @raw:		If the format is raw bayer.
  */
 

-- 
2.34.1