[PATCH 4/8] drm/tidss: Add support for Dual Link LVDS Bus Format

[Aradhya Bhatia]

The 2 OLDI TXes in the AM625 SoC can be synced together to output a 2K
resolution video.

Add support in the driver for the discovery of such a dual mode
connection on the OLDI video port, using the values of "ti,oldi-mode"
property.

Signed-off-by: Aradhya Bhatia <a-bhatia1 at ti.com>
---
 drivers/gpu/drm/tidss/tidss_dispc.c | 39 +++++++++++++++++++++--------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/tidss/tidss_dispc.c b/drivers/gpu/drm/tidss/tidss_dispc.c
index add725fa682b..fb1fdecfc83a 100644
--- a/drivers/gpu/drm/tidss/tidss_dispc.c
+++ b/drivers/gpu/drm/tidss/tidss_dispc.c
@@ -853,25 +853,36 @@ void dispc_set_irqenable(struct dispc_device *dispc, dispc_irq_t mask)
 	}
 }
 
-enum dispc_oldi_mode_reg_val { SPWG_18 = 0, JEIDA_24 = 1, SPWG_24 = 2 };
+enum dispc_oldi_mode_reg_val {
+	SPWG_18		= 0,
+	JEIDA_24	= 1,
+	SPWG_24		= 2,
+	DL_SPWG_18	= 4,
+	DL_JEIDA_24	= 5,
+	DL_SPWG_24	= 6,
+};
 
 struct dispc_bus_format {
 	u32 bus_fmt;
 	u32 data_width;
 	bool is_oldi_fmt;
+	bool is_dual_link;
 	enum dispc_oldi_mode_reg_val oldi_mode_reg_val;
 };
 
 static const struct dispc_bus_format dispc_bus_formats[] = {
-	{ MEDIA_BUS_FMT_RGB444_1X12,		12, false, 0 },
-	{ MEDIA_BUS_FMT_RGB565_1X16,		16, false, 0 },
-	{ MEDIA_BUS_FMT_RGB666_1X18,		18, false, 0 },
-	{ MEDIA_BUS_FMT_RGB888_1X24,		24, false, 0 },
-	{ MEDIA_BUS_FMT_RGB101010_1X30,		30, false, 0 },
-	{ MEDIA_BUS_FMT_RGB121212_1X36,		36, false, 0 },
-	{ MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,	18, true, SPWG_18 },
-	{ MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,	24, true, SPWG_24 },
-	{ MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,	24, true, JEIDA_24 },
+	{ MEDIA_BUS_FMT_RGB444_1X12,		12, false, false, 0 },
+	{ MEDIA_BUS_FMT_RGB565_1X16,		16, false, false, 0 },
+	{ MEDIA_BUS_FMT_RGB666_1X18,		18, false, false, 0 },
+	{ MEDIA_BUS_FMT_RGB888_1X24,		24, false, false, 0 },
+	{ MEDIA_BUS_FMT_RGB101010_1X30,		30, false, false, 0 },
+	{ MEDIA_BUS_FMT_RGB121212_1X36,		36, false, false, 0 },
+	{ MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,	18, true, false, SPWG_18 },
+	{ MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,	24, true, false, SPWG_24 },
+	{ MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,	24, true, false, JEIDA_24 },
+	{ MEDIA_BUS_FMT_RGB666_1X7X3_SPWG,	18, true, true, DL_SPWG_18 },
+	{ MEDIA_BUS_FMT_RGB888_1X7X4_SPWG,	24, true, true, DL_SPWG_24 },
+	{ MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA,	24, true, true, DL_JEIDA_24 },
 };
 
 static const
@@ -880,9 +891,15 @@ struct dispc_bus_format *dispc_vp_find_bus_fmt(struct dispc_device *dispc,
 					       u32 bus_fmt, u32 bus_flags)
 {
 	unsigned int i;
+	bool is_dual_link = false;
+
+	if (dispc->feat->vp_bus_type[hw_videoport] == DISPC_VP_OLDI &&
+	    dispc->oldi_mode == OLDI_DUAL_LINK)
+		is_dual_link = true;
 
 	for (i = 0; i < ARRAY_SIZE(dispc_bus_formats); ++i) {
-		if (dispc_bus_formats[i].bus_fmt == bus_fmt)
+		if (dispc_bus_formats[i].bus_fmt == bus_fmt &&
+		    dispc_bus_formats[i].is_dual_link == is_dual_link)
 			return &dispc_bus_formats[i];
 	}
 
-- 
2.37.0