[PATCH] drm/msm/dsi: Parse lane swap information from DT

[Hai Li]

Lane swap configuration is based on the board design.
This change allows the DSI host to get this information
from device tree, instead of hardcoding in driver.

Signed-off-by: Hai Li <hali at codeaurora.org>
---
 Documentation/devicetree/bindings/drm/msm/dsi.txt | 13 ++++++
 drivers/gpu/drm/msm/dsi/dsi_host.c                | 49 +++++++++++++++++------
 2 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/Documentation/devicetree/bindings/drm/msm/dsi.txt b/Documentation/devicetree/bindings/drm/msm/dsi.txt
index d56923c..febcc51 100644
--- a/Documentation/devicetree/bindings/drm/msm/dsi.txt
+++ b/Documentation/devicetree/bindings/drm/msm/dsi.txt
@@ -44,6 +44,17 @@ Optional properties:
 - port: DSI controller output port. This contains one endpoint subnode, with its
   remote-endpoint set to the phandle of the connected panel's endpoint.
   See Documentation/devicetree/bindings/graph.txt for device graph info.
+- qcom,dsi-logical-lane-swap: Character string to swap logical lane to physical
+  lane mapping. Supported lane mappings:
+  "0123": Logic 0->Phys 0; Logic 1->Phys 1; Logic 2->Phys 2; Logic 3->Phys 3;
+  "3012": Logic 3->Phys 0; Logic 0->Phys 1; Logic 1->Phys 2; Logic 2->Phys 3;
+  "2301": Logic 2->Phys 0; Logic 3->Phys 1; Logic 0->Phys 2; Logic 1->Phys 3;
+  "1230": Logic 1->Phys 0; Logic 2->Phys 1; Logic 3->Phys 2; Logic 0->Phys 3;
+  "0321": Logic 0->Phys 0; Logic 3->Phys 1; Logic 2->Phys 2; Logic 1->Phys 3;
+  "1032": Logic 1->Phys 0; Logic 0->Phys 1; Logic 3->Phys 2; Logic 2->Phys 3;
+  "2103": Logic 2->Phys 0; Logic 1->Phys 1; Logic 0->Phys 2; Logic 3->Phys 3;
+  "3210": Logic 3->Phys 0; Logic 2->Phys 1; Logic 1->Phys 2; Logic 0->Phys 3;
+  Default value is "0123", which means no lane swap.
 
 DSI PHY:
 Required properties:
@@ -129,6 +140,8 @@ Example:
 				remote-endpoint = <&panel_in>;
 			};
 		};
+
+		qcom,dsi-logical-lane-swap = "0123";
 	};
 
 	mdss_dsi_phy0: qcom,mdss_dsi_phy at fd922a00 {
diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 8d82973f..eaba417 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -131,6 +131,7 @@ struct msm_dsi_host {
 	enum mipi_dsi_pixel_format format;
 	unsigned long mode_flags;
 
+	u32 dlane_swap;
 	u32 dma_cmd_ctrl_restore;
 
 	bool registered;
@@ -684,19 +685,9 @@ static void dsi_ctrl_config(struct msm_dsi_host *msm_host, bool enable,
 	data = DSI_CTRL_CLK_EN;
 
 	DBG("lane number=%d", msm_host->lanes);
-	if (msm_host->lanes == 2) {
-		data |= DSI_CTRL_LANE1 | DSI_CTRL_LANE2;
-		/* swap lanes for 2-lane panel for better performance */
-		dsi_write(msm_host, REG_DSI_LANE_SWAP_CTRL,
-			DSI_LANE_SWAP_CTRL_DLN_SWAP_SEL(LANE_SWAP_1230));
-	} else {
-		/* Take 4 lanes as default */
-		data |= DSI_CTRL_LANE0 | DSI_CTRL_LANE1 | DSI_CTRL_LANE2 |
-			DSI_CTRL_LANE3;
-		/* Do not swap lanes for 4-lane panel */
-		dsi_write(msm_host, REG_DSI_LANE_SWAP_CTRL,
-			DSI_LANE_SWAP_CTRL_DLN_SWAP_SEL(LANE_SWAP_0123));
-	}
+	data |= ((DSI_CTRL_LANE0 << msm_host->lanes) - DSI_CTRL_LANE0);
+	dsi_write(msm_host, REG_DSI_LANE_SWAP_CTRL,
+		DSI_LANE_SWAP_CTRL_DLN_SWAP_SEL(msm_host->dlane_swap));
 
 	if (!(flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
 		dsi_write(msm_host, REG_DSI_LANE_CTRL,
@@ -1289,6 +1280,9 @@ static int dsi_host_attach(struct mipi_dsi_host *host,
 	struct msm_dsi_host *msm_host = to_msm_dsi_host(host);
 	int ret;
 
+	if (dsi->lanes > 4 || dsi->channel > 3)
+		return -EINVAL;
+
 	msm_host->channel = dsi->channel;
 	msm_host->lanes = dsi->lanes;
 	msm_host->format = dsi->format;
@@ -1344,6 +1338,33 @@ static struct mipi_dsi_host_ops dsi_host_ops = {
 	.transfer = dsi_host_transfer,
 };
 
+static void dsi_parse_dlane_swap(struct msm_dsi_host *msm_host,
+				struct device_node *np)
+{
+	const char *lane_swap;
+
+	lane_swap = of_get_property(np, "qcom,dsi-logical-lane-swap", NULL);
+
+	if (!lane_swap)
+		msm_host->dlane_swap = LANE_SWAP_0123;
+	else if (!strncmp(lane_swap, "3012", 5))
+		msm_host->dlane_swap = LANE_SWAP_3012;
+	else if (!strncmp(lane_swap, "2301", 5))
+		msm_host->dlane_swap = LANE_SWAP_2301;
+	else if (!strncmp(lane_swap, "1230", 5))
+		msm_host->dlane_swap = LANE_SWAP_1230;
+	else if (!strncmp(lane_swap, "0321", 5))
+		msm_host->dlane_swap = LANE_SWAP_0321;
+	else if (!strncmp(lane_swap, "1032", 5))
+		msm_host->dlane_swap = LANE_SWAP_1032;
+	else if (!strncmp(lane_swap, "2103", 5))
+		msm_host->dlane_swap = LANE_SWAP_2103;
+	else if (!strncmp(lane_swap, "3210", 5))
+		msm_host->dlane_swap = LANE_SWAP_3210;
+	else
+		msm_host->dlane_swap = LANE_SWAP_0123;
+}
+
 static int dsi_host_parse_dt(struct msm_dsi_host *msm_host)
 {
 	struct device *dev = &msm_host->pdev->dev;
@@ -1358,6 +1379,8 @@ static int dsi_host_parse_dt(struct msm_dsi_host *msm_host)
 		return ret;
 	}
 
+	dsi_parse_dlane_swap(msm_host, np);
+
 	/*
 	 * Get the first endpoint node. In our case, dsi has one output port
 	 * to which the panel is connected. Don't return an error if a port
-- 
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