[PATCH] media: atmel: atmel-sama5d2-isc: fix YUYV format

[Eugen Hristev]

SAMA5D2 does not have the YCYC field for the RLP (rounding, limiting, packaging)
module.
The YCYC field is supposed to work with interleaved YUV formats like YUYV.
In SAMA5D2, we have to use YYCC field, which is used for both planar formats
like YUV420 and interleaved formats like YUYV.
Fix the according rlp callback to replace the generic YCYC field (which makes
more sense from a logical point of view) with the required YYCC field.

Fixes: 0733a77ae78c ("media: atmel: atmel-isc-base: add support for more formats and additional pipeline modules")
Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
---
Hello Hans,

This should go on top of my ISC series which you sent a PR for :
https://lore.kernel.org/linux-media/57e15ed1-61c7-0240-5bf3-115de3bbec9c@xxxxxxxxx/

I noticed this was introduced with one of the commits.
It would be great if it can go as a fix for 5.14 , if not together with the
initial series.

Thanks !
Eugen

 .../media/platform/atmel/atmel-sama5d2-isc.c    | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/media/platform/atmel/atmel-sama5d2-isc.c b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
index cab2989103f9..34efd12fef55 100644
--- a/drivers/media/platform/atmel/atmel-sama5d2-isc.c
+++ b/drivers/media/platform/atmel/atmel-sama5d2-isc.c
@@ -255,6 +255,23 @@ void isc_sama5d2_config_rlp(struct isc_device *isc)
 	struct regmap *regmap = isc->regmap;
 	u32 rlp_mode = isc->config.rlp_cfg_mode;
 
+	/*
+	 * In sama5d2, the YUV planar modes and the YUYV modes are treated
+	 * in the same way in RLP register.
+	 * Normally, YYCC mode should be Luma(n) - Color B(n) - Color R (n)
+	 * and YCYC should be Luma(n + 1) - Color B (n) - Luma (n) - Color R (n)
+	 * but in sama5d2, the YCYC mode does not exist, and YYCC must be
+	 * selected for both planar and interleaved modes, as in fact
+	 * both modes are supported.
+	 *
+	 * Thus, if the YCYC mode is selected, replace it with the
+	 * sama5d2-compliant mode which is YYCC .
+	 */
+	if ((rlp_mode & ISC_RLP_CFG_MODE_YCYC) == ISC_RLP_CFG_MODE_YCYC) {
+		rlp_mode &= ~ISC_RLP_CFG_MODE_MASK;
+		rlp_mode |= ISC_RLP_CFG_MODE_YYCC;
+	}
+
 	regmap_update_bits(regmap, ISC_RLP_CFG + isc->offsets.rlp,
 			   ISC_RLP_CFG_MODE_MASK, rlp_mode);
 }
-- 
2.25.1