video: dw-mipi-dsi: driver-specific configuration of phy timings

The timing values for dw-dsi are often dependent on the used display and
according to Philippe Cornu will most likely also depend on the used phy
technology in the soc-specific implementation.

To solve this and allow specific implementations to define them as needed
add a new get_timing callback to phy_ops and call this from the dphy_timing
function to retrieve the necessary values for the specific mode.

This is based on the Linux commit [1] and adapted to the U-Boot driver.

[1] 25ed8aeb9c39 ("drm/bridge/synopsys: dsi: driver-specific configuration of phy timings")

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

2 files changed, 27 insertions, 6 deletions

diff --git a/drivers/video/dw_mipi_dsi.c b/drivers/video/dw_mipi_dsi.c
index 2743836fb4..44a60ac532 100644
--- a/drivers/video/dw_mipi_dsi.c
+++ b/drivers/video/dw_mipi_dsi.c
@@ -645,8 +645,13 @@ static void dw_mipi_dsi_vertical_timing_config(struct dw_mipi_dsi *dsi,
 
 static void dw_mipi_dsi_dphy_timing_config(struct dw_mipi_dsi *dsi)
 {
+	const struct mipi_dsi_phy_ops *phy_ops = dsi->phy_ops;
+	struct mipi_dsi_phy_timing timing = {0x40, 0x40, 0x40, 0x40};
 	u32 hw_version;
 
+	if (phy_ops->get_timing)
+		phy_ops->get_timing(dsi->device, dsi->lane_mbps, &timing);
+
 	/*
 	 * TODO dw drv improvements
 	 * data & clock lane timers should be computed according to panel
@@ -658,16 +663,16 @@ static void dw_mipi_dsi_dphy_timing_config(struct dw_mipi_dsi *dsi)
 	hw_version = dsi_read(dsi, DSI_VERSION) & VERSION;
 
 	if (hw_version >= HWVER_131) {
-		dsi_write(dsi, DSI_PHY_TMR_CFG, PHY_HS2LP_TIME_V131(0x40) |
-			  PHY_LP2HS_TIME_V131(0x40));
+		dsi_write(dsi, DSI_PHY_TMR_CFG, PHY_HS2LP_TIME_V131(timing.data_hs2lp) |
+			  PHY_LP2HS_TIME_V131(timing.data_lp2hs));
 		dsi_write(dsi, DSI_PHY_TMR_RD_CFG, MAX_RD_TIME_V131(10000));
 	} else {
-		dsi_write(dsi, DSI_PHY_TMR_CFG, PHY_HS2LP_TIME(0x40) |
-			  PHY_LP2HS_TIME(0x40) | MAX_RD_TIME(10000));
+		dsi_write(dsi, DSI_PHY_TMR_CFG, PHY_HS2LP_TIME(timing.data_hs2lp) |
+			  PHY_LP2HS_TIME(timing.data_lp2hs) | MAX_RD_TIME(10000));
 	}
 
-	dsi_write(dsi, DSI_PHY_TMR_LPCLK_CFG, PHY_CLKHS2LP_TIME(0x40)
-		  | PHY_CLKLP2HS_TIME(0x40));
+	dsi_write(dsi, DSI_PHY_TMR_LPCLK_CFG, PHY_CLKHS2LP_TIME(timing.clk_hs2lp)
+		  | PHY_CLKLP2HS_TIME(timing.clk_lp2hs));
 }
 
 static void dw_mipi_dsi_dphy_interface_config(struct dw_mipi_dsi *dsi)
diff --git a/include/mipi_dsi.h b/include/mipi_dsi.h
index c8a7d3daef..55c7ab3328 100644
--- a/include/mipi_dsi.h
+++ b/include/mipi_dsi.h
@@ -97,6 +97,20 @@ struct mipi_dsi_host_ops {
 };
 
 /**
+ * struct mipi_dsi_phy_timing - DSI host phy timings
+ * @data_hs2lp: High Speed to Low Speed Data Transition Time
+ * @data_lp2hs: Low Speed to High Speed Data Transition Time
+ * @clk_hs2lp: High Speed to Low Speed Clock Transition Time
+ * @clk_lp2hs: Low Speed to High Speed Clock Transition Time
+ */
+struct mipi_dsi_phy_timing {
+	u16 data_hs2lp;
+	u16 data_lp2hs;
+	u16 clk_hs2lp;
+	u16 clk_lp2hs;
+};
+
+/**
  * struct mipi_dsi_phy_ops - DSI host physical operations
  * @init: initialized host physical part
  * @get_lane_mbps: get lane bitrate per lane (mbps)
@@ -107,6 +121,8 @@ struct mipi_dsi_phy_ops {
 	int (*get_lane_mbps)(void *priv_data, struct display_timing *timings,
 			     u32 lanes, u32 format, unsigned int *lane_mbps);
 	void (*post_set_mode)(void *priv_data,  unsigned long mode_flags);
+	int (*get_timing)(void *priv_data, unsigned int lane_mbps,
+			  struct mipi_dsi_phy_timing *timing);
 };
 
 /**