[PATCH v5 3/3] drm/bridge: ti-sn65dsi83: Add reversed lvds lanes support

[Wojciech Dubowik <wojciech.dubowik@mt.com>]

From: Wojciech Dubowik <Wojciech.Dubowik@mt.com>

The chip supports output lvds lanes in two orders, the default <1 2 3 4>
and <4 3 2 1>. Add parsing of an optional output lvds data-lanes property
so we can inform chip that the lanes have been reversed.

Signed-off-by: Wojciech Dubowik <Wojciech.Dubowik@mt.com>
---
 drivers/gpu/drm/bridge/ti-sn65dsi83.c | 31 +++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/drivers/gpu/drm/bridge/ti-sn65dsi83.c b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
index f8a786953526..df44df2e872a 100644
--- a/drivers/gpu/drm/bridge/ti-sn65dsi83.c
+++ b/drivers/gpu/drm/bridge/ti-sn65dsi83.c
@@ -148,6 +148,18 @@ enum sn65dsi83_lvds_term {
 	OHM_200
 };
 
+enum {
+	LANE_MAPPING_NORMAL,
+	LANE_MAPPING_REVERSE,
+};
+
+#define DATA_LANES_COUNT	4
+
+static const u32 supported_data_lane_mapping[][DATA_LANES_COUNT] = {
+	[LANE_MAPPING_NORMAL] = { 1, 2, 3, 4 },
+	[LANE_MAPPING_REVERSE] = { 4, 3, 2, 1},
+};
+
 enum sn65dsi83_model {
 	MODEL_SN65DSI83,
 	MODEL_SN65DSI84,
@@ -163,6 +175,7 @@ struct sn65dsi83 {
 	struct regulator		*vcc;
 	bool				lvds_dual_link;
 	bool				lvds_dual_link_even_odd_swap;
+	bool				lvds_reverse_lanes_conf[2];
 	int				lvds_vod_swing_conf[2];
 	int				lvds_term_conf[2];
 	int				irq;
@@ -644,6 +657,10 @@ static void sn65dsi83_atomic_pre_enable(struct drm_bridge *bridge,
 	regmap_write(ctx->regmap, REG_LVDS_LANE,
 		     (ctx->lvds_dual_link_even_odd_swap ?
 		      REG_LVDS_LANE_EVEN_ODD_SWAP : 0) |
+		     (ctx->lvds_reverse_lanes_conf[CHANNEL_A] ?
+		      REG_LVDS_LANE_CHA_REVERSE_LVDS : 0) |
+		     (ctx->lvds_reverse_lanes_conf[CHANNEL_B] ?
+		      REG_LVDS_LANE_CHB_REVERSE_LVDS : 0) |
 		     (ctx->lvds_term_conf[CHANNEL_A] ?
 			  REG_LVDS_LANE_CHA_LVDS_TERM : 0) |
 		     (ctx->lvds_term_conf[CHANNEL_B] ?
@@ -833,6 +850,7 @@ static int sn65dsi83_parse_lvds_endpoint(struct sn65dsi83 *ctx, int channel)
 	u32 lvds_vod_swing_clk[2] = { 0, 1000000 };
 	/* Set default near end terminataion to 200 Ohm */
 	u32 lvds_term = 200;
+	u32 data_lanes[DATA_LANES_COUNT];
 	int lvds_vod_swing_conf;
 	int ret_data;
 	int ret_clock;
@@ -845,6 +863,19 @@ static int sn65dsi83_parse_lvds_endpoint(struct sn65dsi83 *ctx, int channel)
 	else
 		return -EINVAL;
 
+	ret_data = of_property_read_u32_array(endpoint, "data-lanes", data_lanes,
+			ARRAY_SIZE(data_lanes));
+	if (!ret_data) {
+		if (memcmp(data_lanes,
+				supported_data_lane_mapping[LANE_MAPPING_REVERSE],
+				ARRAY_SIZE(data_lanes)) == 0)
+			ctx->lvds_reverse_lanes_conf[channel] = true;
+		else if (memcmp(data_lanes,
+			   supported_data_lane_mapping[LANE_MAPPING_NORMAL],
+			   ARRAY_SIZE(data_lanes)) != 0)
+			return dev_err_probe(dev, -EINVAL, "invalid data lanes mapping\n");
+	}
+
 	ret_data = of_property_read_u32_array(endpoint, "ti,lvds-vod-swing-data-microvolt",
 					lvds_vod_swing_data, ARRAY_SIZE(lvds_vod_swing_data));
 	if (ret_data != 0 && ret_data != -EINVAL)
-- 
2.47.3