Setting up burst mode display would require to compute
- Horizontal timing edge values to fill burst drq register
- Line, sync values to fill burst line 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;

Signed-off-by: Jagan Teki <[email protected]>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 72 ++++++++++++++++++++++++--
 1 file changed, 68 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c 
b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 66a01061e51d..0182408f8932 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -364,6 +364,41 @@ 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)
 {
@@ -499,9 +534,32 @@ 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_TCON_DRQ_ENABLE_MODE |
-                    SUN6I_DSI_TCON_DRQ_SET(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,
@@ -726,7 +784,13 @@ 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_TCON_DRQ_ENABLE_MODE |
+                    SUN6I_DSI_TCON_DRQ_SET(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

_______________________________________________
dri-devel mailing list
[email protected]
https://lists.freedesktop.org/mailman/listinfo/dri-devel

Reply via email to