[linux-sunxi] [PATCH v7 01/23] 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 <ja...@amarulasolutions.com>
Tested-by: Merlijn Wajer <merl...@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 e3b34a345546..a5fcee750bee 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -354,6 +354,24 @@ 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)
 {
@@ -383,7 +401,7 @@ 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

-- 
You received this message because you are subscribed to the Google Groups 
"linux-sunxi" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to linux-sunxi+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.