[PATCH v8 00/10] drm/sun4i: Allwinner MIPI-DSI Burst mode support

[PATCH v8 00/10] drm/sun4i: Allwinner MIPI-DSI Burst mode support

[Jagan Teki]

This is next version changes for Allwinner MIPI-DSI Burst mode support.

All these changes are grabbed from previous versions[1][2] and grouped
it in a proper order so-that it can help to review and merge easy.

Changes for v8:
- rebase on master
- rework on commit messages
- include drq changes from previous version
Changes for v7:
- rebase on master
- collect Merlijn Wajer Tested-by credits.
Changes for v6:
- fixed all burst mode patches as per previous version comments
- rebase on master
- update proper commit message
- dropped unneeded comments
- order the patches that make review easy
Changes for v5, v4, v3, v2:
- use proper return value for tcon0 probe
- add logic to get tcon0 divider values
- simplify timings code to support burst mode
- fix drq computation return values
- update proper commit messages
- rebase on master

[1] https://patchwork.kernel.org/cover/10792981/
[2] https://patchwork.kernel.org/cover/10686655/

Any inputs?
Jagan.

Jagan Teki (10):
  drm/sun4i: sun6i_mipi_dsi: Compute burst mode loop N1 instruction
    delay
  drm/sun4i: sun6i_mipi_dsi: Support instruction loop selection
  drm/sun4i: sun6i_mipi_dsi: Setup burst mode timings
  drm/sun4i: sun6i_mipi_dsi: Fix TCON DRQ set bits
  drm/sun4i: sun6i_mipi_dsi: Simplify drq to support all modes
  drm/sun4i: tcon: Export get tcon0 routine
  drm/sun4i: sun6i_mipi_dsi: Probe tcon0 during dsi_bind
  drm/sun4i: sun6i_mipi_dsi: Setup burst mode
  drm/sun4i: sun6i_mipi_dsi: Enable trail_inv and trail_fill controls
  drm/sun4i: sun6i_mipi_dsi: Enable HBP, HSA_HSE for burst mode

 drivers/gpu/drm/sun4i/sun4i_tcon.c     |   3 +-
 drivers/gpu/drm/sun4i/sun4i_tcon.h     |   1 +
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 149 ++++++++++++++++++++++---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h |   1 +
 4 files changed, 138 insertions(+), 16 deletions(-)

-- 
2.18.0.321.gffc6fa0e3

[PATCH v8 01/10] drm/sun4i: sun6i_mipi_dsi: Compute burst mode loop N1 instruction delay

[Jagan Teki]

Loop N1 instruction delay varies between burst and non-burst video modes.

1) for burst mode panels it is computed based on the panel pixel clock
   along with horizontal sync and porch timings.
2) for non-burst mode panels, it is same as existing (50 - 1)

Reference code is available in BSP (from linux-sunxi
drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c)

dsi_dev[sel]->dsi_inst_loop_num.bits.loop_n1=
(panel->lcd_ht-panel->lcd_x)*(150)/(panel->lcd_dclk_freq*8) - 50;
=> (((mode->htotal - mode->hdisplay) * 150) /
     ((mode->clock / 1000) * 8)) - 50;

This patch add loop N1 computation for burst mode by simplifying
existing code to support all possible modes.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 20 +++++++++++++++++++-
 1 file changed, 19 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 3a28d70dbdc1..8184fbcfd9fd 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -355,6 +355,24 @@ static void sun6i_dsi_inst_init(struct sun6i_dsi *dsi,
 		     SUN6I_DSI_INST_JUMP_CFG_NUM(1));
 };
 
+static u16 sun6i_dsi_setup_inst_delay(struct sun6i_dsi *dsi,
+				      struct drm_display_mode *mode)
+{
+	struct mipi_dsi_device *device = dsi->device;
+	u32 hsync_porch, dclk;
+	u16 delay;
+
+	hsync_porch = (mode->htotal - mode->hdisplay);
+	dclk = (mode->clock / 1000);
+
+	if (device->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
+		delay = ((hsync_porch * 150) / (dclk * 8)) - 50;
+	else
+		delay = 50 - 1;
+
+	return delay;
+}
+
 static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi,
 					   struct drm_display_mode *mode)
 {
@@ -401,7 +419,7 @@ static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi,
 static void sun6i_dsi_setup_inst_loop(struct sun6i_dsi *dsi,
 				      struct drm_display_mode *mode)
 {
-	u16 delay = 50 - 1;
+	u16 delay = sun6i_dsi_setup_inst_delay(dsi, mode);
 
 	regmap_write(dsi->regs, SUN6I_DSI_INST_LOOP_NUM_REG(0),
 		     SUN6I_DSI_INST_LOOP_NUM_N0(50 - 1) |
-- 
2.18.0.321.gffc6fa0e3

[PATCH v8 02/10] drm/sun4i: sun6i_mipi_dsi: Support instruction loop selection

[Jagan Teki]

Instruction loop selection would require before writing
loop number registers, so enable idle, LP11 bits on
loop selection register.

Reference code available in BSP (from linux-sunxi/
drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c)

(dsi_dev[sel]->dsi_inst_loop_sel.dwval = 2<<(4*DSI_INST_ID_LP11) |
	3<<(4*DSI_INST_ID_DLY);

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 8184fbcfd9fd..1a0707468121 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -421,6 +421,9 @@ static void sun6i_dsi_setup_inst_loop(struct sun6i_dsi *dsi,
 {
 	u16 delay = sun6i_dsi_setup_inst_delay(dsi, mode);
 
+	regmap_write(dsi->regs, SUN6I_DSI_INST_LOOP_SEL_REG,
+		     DSI_INST_ID_HSC  << (4 * DSI_INST_ID_LP11) |
+		     DSI_INST_ID_HSD  << (4 * DSI_INST_ID_DLY));
 	regmap_write(dsi->regs, SUN6I_DSI_INST_LOOP_NUM_REG(0),
 		     SUN6I_DSI_INST_LOOP_NUM_N0(50 - 1) |
 		     SUN6I_DSI_INST_LOOP_NUM_N1(delay));
-- 
2.18.0.321.gffc6fa0e3

[PATCH v8 03/10] drm/sun4i: sun6i_mipi_dsi: Setup burst mode timings

[Jagan Teki]

Burst mode display timings are different from conventional video mode.

For burst mode most of the timings hsa, hbp, hfp, vblk are 0 and hblk
is computed as (mode->hdisplay * Bpp)

This patch simply add burst mode timings without touching existing mode
timings.

Reference code taken from BSP (from linux-sunxi/
drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c)

dsi_hsa  = 0;
dsi_hbp  = 0;
dsi_hact = x*dsi_pixel_bits[format]/8;
dsi_hblk = dsi_hact;
dsi_hfp  = 0;
dsi_vblk = 0;

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 1a0707468121..4362d9df1da6 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -516,6 +516,12 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi,
 
 	/* Do all timing calculations up front to allocate buffer space */
 
+	if (device->mode_flags & MIPI_DSI_MODE_VIDEO_BURST) {
+		hbp = hfp = hsa = vblk = 0;
+		hblk = (mode->hdisplay * Bpp);
+		goto alloc_buf;
+	}
+
 	/*
 	 * A sync period is composed of a blanking packet (4 bytes +
 	 * payload + 2 bytes) and a sync event packet (4 bytes). Its
@@ -554,6 +560,7 @@ static void sun6i_dsi_setup_timings(struct sun6i_dsi *dsi,
 
 	vblk = sun6i_dsi_get_timings_vblk(dsi, mode, hblk);
 
+alloc_buf:
 	/* How many bytes do we need to send all payloads? */
 	bytes = max_t(size_t, max(max(hfp, hblk), max(hsa, hbp)), vblk);
 	buffer = kmalloc(bytes, GFP_KERNEL);
-- 
2.18.0.321.gffc6fa0e3

[PATCH v8 04/10] drm/sun4i: sun6i_mipi_dsi: Fix TCON DRQ set bits

[Jagan Teki]

TCON DRQ for non-burst DSI mode can computed based on horizontal
front porch value, but the current driver trying to include sync
timings along with front porch resulting wrong drq.

This patch is trying to update the drq by subtracting hsync_start
with hdisplay, which is horizontal front porch.

Current code:
------------
mode->hsync_end - mode->hdisplay => horizontal front porch + sync

With this patch:
----------------
mode->hsync_start - mode->hdisplay => horizontal front porch

BSP code form BPI-M64-bsp is computing TCON DRQ set bits
for non-burts as (from linux-sunxi/
drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c)

=> panel->lcd_ht -    panel->lcd_x - panel->lcd_hbp
=> (timmings->hor_front_porch + panel->lcd_hbp + panel->lcd_x)
   - panel->lcd_x - panel->hbp
=> timmings->hor_front_porch
=> mode->hsync_start - mode->hdisplay

So, update the DRQ set bits accordingly.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 4362d9df1da6..a4360aed17bf 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -402,9 +402,9 @@ static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi,
 	struct mipi_dsi_device *device = dsi->device;
 	u32 val = 0;
 
-	if ((mode->hsync_end - mode->hdisplay) > 20) {
+	if ((mode->hsync_start - mode->hdisplay) > 20) {
 		/* Maaaaaagic */
-		u16 drq = (mode->hsync_end - mode->hdisplay) - 20;
+		u16 drq = (mode->hsync_start - mode->hdisplay) - 20;
 
 		drq *= mipi_dsi_pixel_format_to_bpp(device->format);
 		drq /= 32;
-- 
2.18.0.321.gffc6fa0e3

[PATCH v8 05/10] drm/sun4i: sun6i_mipi_dsi: Simplify drq to support all modes

[Jagan Teki]

Allwinner MIPI DSI drq has enable mode bit and set bits.
1) drq for non-burst, with front porch less than 20 would need to
   set both enable mode bit and set bits.
2) drq for non-burst, with front porch greater or equal to 20 would
   not require to do any drq bit setup.
3) drq for burst mode, would only need to set enable mode bit.

This patch simplifies existing drq code by grouping into
sun6i_dsi_get_drq and support all video modes.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 39 ++++++++++++++++----------
 1 file changed, 24 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index a4360aed17bf..ab95e2a873b5 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -355,6 +355,28 @@ static void sun6i_dsi_inst_init(struct sun6i_dsi *dsi,
 		     SUN6I_DSI_INST_JUMP_CFG_NUM(1));
 };
 
+static int sun6i_dsi_get_drq(struct sun6i_dsi *dsi,
+			      struct drm_display_mode *mode)
+{
+	struct mipi_dsi_device *device = dsi->device;
+
+	if (device->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
+		return SUN6I_DSI_TCON_DRQ_ENABLE_MODE;
+
+	if ((mode->hsync_start - mode->hdisplay) > 20) {
+		/* Maaaaaagic */
+		u16 drq = (mode->hsync_start - mode->hdisplay) - 20;
+
+		drq *= mipi_dsi_pixel_format_to_bpp(device->format);
+		drq /= 32;
+
+		return (SUN6I_DSI_TCON_DRQ_ENABLE_MODE |
+			SUN6I_DSI_TCON_DRQ_SET(drq));
+	}
+
+	return 0;
+}
+
 static u16 sun6i_dsi_setup_inst_delay(struct sun6i_dsi *dsi,
 				      struct drm_display_mode *mode)
 {
@@ -399,21 +421,8 @@ static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi,
 static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi,
 				  struct drm_display_mode *mode)
 {
-	struct mipi_dsi_device *device = dsi->device;
-	u32 val = 0;
-
-	if ((mode->hsync_start - mode->hdisplay) > 20) {
-		/* Maaaaaagic */
-		u16 drq = (mode->hsync_start - mode->hdisplay) - 20;
-
-		drq *= mipi_dsi_pixel_format_to_bpp(device->format);
-		drq /= 32;
-
-		val = (SUN6I_DSI_TCON_DRQ_ENABLE_MODE |
-		       SUN6I_DSI_TCON_DRQ_SET(drq));
-	}
-
-	regmap_write(dsi->regs, SUN6I_DSI_TCON_DRQ_REG, val);
+	regmap_write(dsi->regs, SUN6I_DSI_TCON_DRQ_REG,
+		     sun6i_dsi_get_drq(dsi, mode));
 }
 
 static void sun6i_dsi_setup_inst_loop(struct sun6i_dsi *dsi,
-- 
2.18.0.321.gffc6fa0e3

[PATCH v8 06/10] drm/sun4i: tcon: Export get tcon0 routine

[Jagan Teki]

Sometimes tcon attributes like tcon divider, clock rate etc are needed
in interface drivers like DSI. So for such cases interface driver must
probe the respective tcon and get the attributes.

Since tcon0 probe is already available, via sun4i_get_tcon0 function,
export the same instead of probing tcon explicitly.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
---
 drivers/gpu/drm/sun4i/sun4i_tcon.c | 3 ++-
 drivers/gpu/drm/sun4i/sun4i_tcon.h | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 7136fc91c603..4bb36ceb786b 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -221,7 +221,7 @@ EXPORT_SYMBOL(sun4i_tcon_enable_vblank);
  * are located in TCON0. This helper returns a pointer to TCON0's
  * sun4i_tcon structure, or NULL if not found.
  */
-static struct sun4i_tcon *sun4i_get_tcon0(struct drm_device *drm)
+struct sun4i_tcon *sun4i_get_tcon0(struct drm_device *drm)
 {
 	struct sun4i_drv *drv = drm->dev_private;
 	struct sun4i_tcon *tcon;
@@ -235,6 +235,7 @@ static struct sun4i_tcon *sun4i_get_tcon0(struct drm_device *drm)
 
 	return NULL;
 }
+EXPORT_SYMBOL(sun4i_get_tcon0);
 
 void sun4i_tcon_set_mux(struct sun4i_tcon *tcon, int channel,
 			const struct drm_encoder *encoder)
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
index b5214d71610f..a52696db14a5 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -274,6 +274,7 @@ struct sun4i_tcon {
 struct drm_bridge *sun4i_tcon_find_bridge(struct device_node *node);
 struct drm_panel *sun4i_tcon_find_panel(struct device_node *node);
 
+struct sun4i_tcon *sun4i_get_tcon0(struct drm_device *drm);
 void sun4i_tcon_enable_vblank(struct sun4i_tcon *tcon, bool enable);
 void sun4i_tcon_mode_set(struct sun4i_tcon *tcon,
 			 const struct drm_encoder *encoder,
-- 
2.18.0.321.gffc6fa0e3

[PATCH v8 07/10] drm/sun4i: sun6i_mipi_dsi: Probe tcon0 during dsi_bind

[Jagan Teki]

Probe tcon0 during dsi_bind, so-that the tcon attributes like
divider value, clock rate can get whenever it need.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 7 +++++++
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 1 +
 2 files changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index ab95e2a873b5..62b4c822bf18 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -25,6 +25,7 @@
 #include <drm/drm_probe_helper.h>
 
 #include "sun4i_drv.h"
+#include "sun4i_tcon.h"
 #include "sun6i_mipi_dsi.h"
 
 #include <video/mipi_display.h>
@@ -996,6 +997,7 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,
 	struct drm_device *drm = data;
 	struct sun4i_drv *drv = drm->dev_private;
 	struct sun6i_dsi *dsi = dev_get_drvdata(dev);
+	struct sun4i_tcon *tcon0 = sun4i_get_tcon0(drm);
 	int ret;
 
 	if (!dsi->panel)
@@ -1003,6 +1005,11 @@ static int sun6i_dsi_bind(struct device *dev, struct device *master,
 
 	dsi->drv = drv;
 
+	if (!tcon0)
+		return -EINVAL;
+
+	dsi->tcon = tcon0;
+
 	drm_encoder_helper_add(&dsi->encoder,
 			       &sun6i_dsi_enc_helper_funcs);
 	ret = drm_encoder_init(drm,
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
index a07090579f84..747c451a9a20 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
@@ -26,6 +26,7 @@ struct sun6i_dsi {
 
 	struct device		*dev;
 	struct sun4i_drv	*drv;
+	struct sun4i_tcon	*tcon;
 	struct mipi_dsi_device	*device;
 	struct drm_panel	*panel;
 };
-- 
2.18.0.321.gffc6fa0e3

[PATCH v8 08/10] drm/sun4i: sun6i_mipi_dsi: Setup burst mode

[Jagan Teki]

Burst mode in DSI would require separate setup initialization
with respect to conventional video mode.

Allwinner DSI controller would need below sequence to setup the
burst mode.
1) configure the burst drq.
2) configure the burst line.
3) finally enable mode.

- To configure burst drq, controller would require to compute the
  edge0, edge1 and fill into burst mode register.

- To configure burst line, controller would require to compute the
  line, sync values and fill into burst line register.

- Enable burst mode, would require to enable burst mode bit in DSI
  control register.

Since there is no direct documentation for these computations
the edge and line formulas are taken from BSP code (from linux-sunxi/
drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c)

line_num = panel->lcd_ht*dsi_pixel_bits[panel->lcd_dsi_format]/
	  (8*panel->lcd_dsi_lane);
edge1 = sync_point+(panel->lcd_x+panel->lcd_hbp+20)*
	dsi_pixel_bits[panel->lcd_dsi_format] /(8*panel->lcd_dsi_lane);
edge1 = (edge1>line_num)?line_num:edge1;
edge0 = edge1+(panel->lcd_x+40)*tcon_div/8;
edge0 = (edge0>line_num)?(edge0-line_num):1;

Note: edge0 computation would require tcon0 divider and it's value is
always 4 in Allwinner BSP. This patch find out the divider value at
runtime by reading tcon clocks.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 70 ++++++++++++++++++++++++--
 1 file changed, 67 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 62b4c822bf18..63b83b47cf0d 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -356,6 +356,41 @@ static void sun6i_dsi_inst_init(struct sun6i_dsi *dsi,
 		     SUN6I_DSI_INST_JUMP_CFG_NUM(1));
 };
 
+static u32 sun6i_dsi_get_edge1(struct sun6i_dsi *dsi,
+			       struct drm_display_mode *mode, u32 sync_point)
+{
+	struct mipi_dsi_device *device = dsi->device;
+	unsigned int bpp = mipi_dsi_pixel_format_to_bpp(device->format);
+	u32 hact_sync_bp;
+
+	/* Horizontal timings duration excluding front porch */
+	hact_sync_bp = (mode->hdisplay + mode->htotal - mode->hsync_start);
+
+	return (sync_point + ((hact_sync_bp + 20) * bpp / (8 * device->lanes)));
+}
+
+static u32 sun6i_dsi_get_edge0(struct sun6i_dsi *dsi,
+			       struct drm_display_mode *mode, u32 edge1)
+{
+	struct sun4i_tcon *tcon = dsi->tcon;
+	unsigned long dclk_rate, dclk_parent_rate, tcon0_div;
+
+	dclk_rate = clk_get_rate(tcon->dclk);
+	dclk_parent_rate = clk_get_rate(clk_get_parent(tcon->dclk));
+	tcon0_div = dclk_parent_rate / dclk_rate;
+
+	return (edge1 + (mode->hdisplay + 40) * tcon0_div / 8);
+}
+
+static u32 sun6i_dsi_get_line_num(struct sun6i_dsi *dsi,
+				  struct drm_display_mode *mode)
+{
+	struct mipi_dsi_device *device = dsi->device;
+	unsigned int bpp = mipi_dsi_pixel_format_to_bpp(device->format);
+
+	return (mode->htotal * bpp / (8 * device->lanes));
+}
+
 static int sun6i_dsi_get_drq(struct sun6i_dsi *dsi,
 			      struct drm_display_mode *mode)
 {
@@ -422,8 +457,32 @@ static u16 sun6i_dsi_get_video_start_delay(struct sun6i_dsi *dsi,
 static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi,
 				  struct drm_display_mode *mode)
 {
-	regmap_write(dsi->regs, SUN6I_DSI_TCON_DRQ_REG,
-		     sun6i_dsi_get_drq(dsi, mode));
+	struct mipi_dsi_device *device = dsi->device;
+	u32 sync_point = 40;
+	u32 line_num = sun6i_dsi_get_line_num(dsi, mode);
+	u32 edge1 = sun6i_dsi_get_edge1(dsi, mode, sync_point);
+	u32 edge0 = sun6i_dsi_get_edge0(dsi, mode, edge1);
+	u32 val;
+
+	if (edge1 > line_num)
+		edge1 = line_num;
+
+	if (edge0 > line_num)
+		edge0 -= line_num;
+	else
+		edge0 = 1;
+
+	regmap_write(dsi->regs, SUN6I_DSI_BURST_DRQ_REG,
+		     SUN6I_DSI_BURST_DRQ_EDGE1(edge1) |
+		     SUN6I_DSI_BURST_DRQ_EDGE0(edge0));
+	regmap_write(dsi->regs, SUN6I_DSI_BURST_LINE_REG,
+		     SUN6I_DSI_BURST_LINE_NUM(line_num) |
+		     SUN6I_DSI_BURST_LINE_SYNC_POINT(sync_point));
+
+	/* enable burst mode */
+	regmap_read(dsi->regs, SUN6I_DSI_BASIC_CTL_REG, &val);
+	val |= SUN6I_DSI_BASIC_CTL_VIDEO_BURST;
+	regmap_write(dsi->regs, SUN6I_DSI_BASIC_CTL_REG, val);
 }
 
 static void sun6i_dsi_setup_inst_loop(struct sun6i_dsi *dsi,
@@ -708,7 +767,12 @@ static void sun6i_dsi_encoder_enable(struct drm_encoder *encoder)
 		     SUN6I_DSI_BASIC_CTL1_VIDEO_PRECISION |
 		     SUN6I_DSI_BASIC_CTL1_VIDEO_MODE);
 
-	sun6i_dsi_setup_burst(dsi, mode);
+	regmap_write(dsi->regs, SUN6I_DSI_TCON_DRQ_REG,
+		     sun6i_dsi_get_drq(dsi, mode));
+
+	if (device->mode_flags & MIPI_DSI_MODE_VIDEO_BURST)
+		sun6i_dsi_setup_burst(dsi, mode);
+
 	sun6i_dsi_setup_inst_loop(dsi, mode);
 	sun6i_dsi_setup_format(dsi, mode);
 	sun6i_dsi_setup_timings(dsi, mode);
-- 
2.18.0.321.gffc6fa0e3

[PATCH v8 09/10] drm/sun4i: sun6i_mipi_dsi: Enable trail_inv and trail_fill controls

[Jagan Teki]

The burst mode panels with 4-lane would require to enable trail bits
in DSI basic control register.

So, enable 2byte trail and trail_env for 4-lane burst mode devices.

Allwinner A64 BSP should also relie on same setup for enabling trail
bit in DSI controller.

Reference code avialable in BSP (from linux-sunxi/
drivers/video/sunxi/disp2/disp/de/lowlevel_sun50iw1/de_dsi.c)

if (panel->lcd_dsi_lane == 4)
{
   dsi_dev[sel]->dsi_basic_ctl.bits.trail_inv = 0xc;
   dsi_dev[sel]->dsi_basic_ctl.bits.trail_fill     = 1;
}

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Merlijn Wajer <merlijn@wizzup.org>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 63b83b47cf0d..ec9424b6da9e 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -34,6 +34,8 @@
 #define SUN6I_DSI_CTL_EN			BIT(0)
 
 #define SUN6I_DSI_BASIC_CTL_REG		0x00c
+#define SUN6I_DSI_BASIC_CTL_TRAIL_INV(n)	(((n) & 0xf) << 4)
+#define SUN6I_DSI_BASIC_CTL_TRAIL_FILL		BIT(3)
 #define SUN6I_DSI_BASIC_CTL_HBP_DIS		BIT(2)
 #define SUN6I_DSI_BASIC_CTL_HSA_HSE_DIS		BIT(1)
 #define SUN6I_DSI_BASIC_CTL_VIDEO_BURST		BIT(0)
@@ -482,6 +484,10 @@ static void sun6i_dsi_setup_burst(struct sun6i_dsi *dsi,
 	/* enable burst mode */
 	regmap_read(dsi->regs, SUN6I_DSI_BASIC_CTL_REG, &val);
 	val |= SUN6I_DSI_BASIC_CTL_VIDEO_BURST;
+	if (device->lanes == 4) {
+		val |= SUN6I_DSI_BASIC_CTL_TRAIL_INV(0xc);
+		val |= SUN6I_DSI_BASIC_CTL_TRAIL_FILL;
+	}
 	regmap_write(dsi->regs, SUN6I_DSI_BASIC_CTL_REG, val);
 }
 
-- 
2.18.0.321.gffc6fa0e3