[PATCH 1/2] video: dw-mipi-dsi: driver-specific configuration of phy timings

[PATCH 1/2] video: dw-mipi-dsi: driver-specific configuration of phy timings

[Neil Armstrong]

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.

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

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

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/video/dw_mipi_dsi.c | 17 +++++++++++------
 include/mipi_dsi.h          | 16 ++++++++++++++++
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/drivers/video/dw_mipi_dsi.c b/drivers/video/dw_mipi_dsi.c
index b7bfbb5e50..8f909a4e9f 100644
--- a/drivers/video/dw_mipi_dsi.c
+++ b/drivers/video/dw_mipi_dsi.c
@@ -643,8 +643,13 @@ 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
@@ -656,16 +661,16 @@ 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
@@ -96,6 +96,20 @@ struct mipi_dsi_host_ops {
 			    const struct mipi_dsi_msg *msg);
 };
 
+/**
+ * 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
@@ -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);
 };
 
 /**
-- 
2.25.1

[PATCH 2/2] video: dw-mipi-dsi: permit configuring the escape clock rate

[Neil Armstrong]

The Amlogic D-PHY in the Amlogic AXG SoC Family does support a frequency
higher than 10MHz for the TX Escape Clock, thus make the target rate
configurable.

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

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

[1] a328ca7e4af3 ("drm/bridge: dw-mipi-dsi: permit configuring the escape clock rate")

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
 drivers/video/dw_mipi_dsi.c | 20 ++++++++++++++++----
 include/mipi_dsi.h          |  1 +
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/drivers/video/dw_mipi_dsi.c b/drivers/video/dw_mipi_dsi.c
index 8f909a4e9f..12a55cfbec 100644
--- a/drivers/video/dw_mipi_dsi.c
+++ b/drivers/video/dw_mipi_dsi.c
@@ -483,15 +483,27 @@ static void dw_mipi_dsi_set_mode(struct dw_mipi_dsi *dsi,
 
 static void dw_mipi_dsi_init_pll(struct dw_mipi_dsi *dsi)
 {
+	const struct mipi_dsi_phy_ops *phy_ops = dsi->phy_ops;
+	unsigned int esc_rate;
+	u32 esc_clk_division;
+
 	/*
 	 * The maximum permitted escape clock is 20MHz and it is derived from
-	 * lanebyteclk, which is running at "lane_mbps / 8".  Thus we want:
+	 * lanebyteclk, which is running at "lane_mbps / 8".
+	 */
+	if (phy_ops->get_esc_clk_rate)
+		phy_ops->get_esc_clk_rate(dsi->device, &esc_rate);
+	else
+		esc_rate = 20; /* Default to 20MHz */
+
+	/*
+	 * We want:
 	 *
-	 *     (lane_mbps >> 3) / esc_clk_division < 20
+	 *     (lane_mbps >> 3) / esc_clk_division < X
 	 * which is:
-	 *     (lane_mbps >> 3) / 20 > esc_clk_division
+	 *     (lane_mbps >> 3) / X > esc_clk_division
 	 */
-	u32 esc_clk_division = (dsi->lane_mbps >> 3) / 20 + 1;
+	esc_clk_division = (dsi->lane_mbps >> 3) / esc_rate + 1;
 
 	dsi_write(dsi, DSI_PWR_UP, RESET);
 
diff --git a/include/mipi_dsi.h b/include/mipi_dsi.h
index 55c7ab3328..4ca05f71e2 100644
--- a/include/mipi_dsi.h
+++ b/include/mipi_dsi.h
@@ -123,6 +123,7 @@ struct mipi_dsi_phy_ops {
 	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);
+	void (*get_esc_clk_rate)(void *priv_data, unsigned int *esc_clk_rate);
 };
 
 /**
-- 
2.25.1

[PATCH 1/2] video: dw-mipi-dsi: driver-specific configuration of phy timings

[Anatolij Gustschin]

On Fri,  2 Oct 2020 11:16:08 +0200
Neil Armstrong narmstrong at baylibre.com wrote:
...
> ---
>  drivers/video/dw_mipi_dsi.c | 17 +++++++++++------
>  include/mipi_dsi.h          | 16 ++++++++++++++++
>  2 files changed, 27 insertions(+), 6 deletions(-)

applied to u-boot-video/master, thanks!

--
Anatolij

[PATCH 2/2] video: dw-mipi-dsi: permit configuring the escape clock rate

[Anatolij Gustschin]

On Fri,  2 Oct 2020 11:16:09 +0200
Neil Armstrong narmstrong at baylibre.com wrote:
...
> ---
>  drivers/video/dw_mipi_dsi.c | 20 ++++++++++++++++----
>  include/mipi_dsi.h          |  1 +
>  2 files changed, 17 insertions(+), 4 deletions(-)

applied to u-boot-video/master, thanks!

--
Anatolij