[PATCH v2 5/9] drm/vc4: hdmi: Swap CSC matrix channels for YUV444

[Maxime Ripard <maxime@cerno.tech>]

From: Dave Stevenson <dave.stevenson@raspberrypi.com>

YUV444 and YUV422 actually require the same matrix, but programmed
differently.

We've dealt with it in the past by having two matrices, with the one
for YUV444 reordered to accomodate the hardware.

This gets in the way of subsequent reworks so let's define a function
that will take the coefficients swap into account, and remove the now
redundant YUV444 matrix.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
---
 drivers/gpu/drm/vc4/vc4_hdmi.c | 39 +++++++++++++++++++--------------------
 1 file changed, 19 insertions(+), 20 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index e5e7fe4c6a63..78c17166f296 100644
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -1233,7 +1233,7 @@ static const u16 vc5_hdmi_csc_full_rgb_to_limited_rgb[3][4] = {
 };
 
 /*
- * Conversion between Full Range RGB and Full Range YUV422 using the
+ * Conversion between Full Range RGB and Limited Range YUV using the
  * BT.709 Colorspace
  *
  *
@@ -1243,28 +1243,12 @@ static const u16 vc5_hdmi_csc_full_rgb_to_limited_rgb[3][4] = {
  *
  * Matrix is signed 2p13 fixed point, with signed 9p6 offsets
  */
-static const u16 vc5_hdmi_csc_full_rgb_to_limited_yuv422_bt709[3][4] = {
+static const u16 vc5_hdmi_csc_full_rgb_to_limited_bt709[3][4] = {
 	{ 0x05d2, 0x1394, 0x01fa, 0x0400 },
 	{ 0xfccc, 0xf536, 0x0e00, 0x2000 },
 	{ 0x0e00, 0xf34a, 0xfeb8, 0x2000 },
 };
 
-/*
- * Conversion between Full Range RGB and Full Range YUV444 using the
- * BT.709 Colorspace
- *
- * [ -0.100268 -0.337232  0.437500  128 ]
- * [  0.437500 -0.397386 -0.040114  128 ]
- * [  0.181906  0.611804  0.061758  16  ]
- *
- * Matrix is signed 2p13 fixed point, with signed 9p6 offsets
- */
-static const u16 vc5_hdmi_csc_full_rgb_to_limited_yuv444_bt709[3][4] = {
-	{ 0xfccc, 0xf536, 0x0e00, 0x2000 },
-	{ 0x0e00, 0xf34a, 0xfeb8, 0x2000 },
-	{ 0x05d2, 0x1394, 0x01fa, 0x0400 },
-};
-
 static void vc5_hdmi_set_csc_coeffs(struct vc4_hdmi *vc4_hdmi,
 				    const u16 coeffs[3][4])
 {
@@ -1278,6 +1262,20 @@ static void vc5_hdmi_set_csc_coeffs(struct vc4_hdmi *vc4_hdmi,
 	HDMI_WRITE(HDMI_CSC_34_33, (coeffs[2][3] << 16) | coeffs[2][2]);
 }
 
+static void vc5_hdmi_set_csc_coeffs_swap(struct vc4_hdmi *vc4_hdmi,
+					 const u16 coeffs[3][4])
+{
+	lockdep_assert_held(&vc4_hdmi->hw_lock);
+
+	/* YUV444 needs the CSC matrices using the channels in a different order */
+	HDMI_WRITE(HDMI_CSC_12_11, (coeffs[1][1] << 16) | coeffs[1][0]);
+	HDMI_WRITE(HDMI_CSC_14_13, (coeffs[1][3] << 16) | coeffs[1][2]);
+	HDMI_WRITE(HDMI_CSC_22_21, (coeffs[2][1] << 16) | coeffs[2][0]);
+	HDMI_WRITE(HDMI_CSC_24_23, (coeffs[2][3] << 16) | coeffs[2][2]);
+	HDMI_WRITE(HDMI_CSC_32_31, (coeffs[0][1] << 16) | coeffs[0][0]);
+	HDMI_WRITE(HDMI_CSC_34_33, (coeffs[0][3] << 16) | coeffs[0][2]);
+}
+
 static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
 			       struct drm_connector_state *state,
 			       const struct drm_display_mode *mode)
@@ -1300,7 +1298,8 @@ static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
 
 	switch (vc4_state->output_format) {
 	case VC4_HDMI_OUTPUT_YUV444:
-		vc5_hdmi_set_csc_coeffs(vc4_hdmi, vc5_hdmi_csc_full_rgb_to_limited_yuv444_bt709);
+		vc5_hdmi_set_csc_coeffs_swap(vc4_hdmi,
+					     vc5_hdmi_csc_full_rgb_to_limited_bt709);
 		break;
 
 	case VC4_HDMI_OUTPUT_YUV422:
@@ -1315,7 +1314,7 @@ static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
 		if_cfg |= VC4_SET_FIELD(VC5_DVP_HT_VEC_INTERFACE_CFG_SEL_422_FORMAT_422_LEGACY,
 					VC5_DVP_HT_VEC_INTERFACE_CFG_SEL_422);
 
-		vc5_hdmi_set_csc_coeffs(vc4_hdmi, vc5_hdmi_csc_full_rgb_to_limited_yuv422_bt709);
+		vc5_hdmi_set_csc_coeffs(vc4_hdmi, vc5_hdmi_csc_full_rgb_to_limited_bt709);
 		break;
 
 	case VC4_HDMI_OUTPUT_RGB:

-- 
2.39.1