[PATCH v10 07/11] drm/sun4i: dsi: Get tcon0_div at runtime

[Jagan Teki]

tcon0 divider is used while computing drq edge0 for burst mode
devices, currently driver is using default macro value 4 via
SUN6I_DSI_TCON_DIV.

Unfortunately not all the panel devices are working with this
default divider value 4, so to make future changes on this divider
value get the divider from tcon dot clock at runtime instead of
static macro value.

Tested-by: Merlijn Wajer <merlijn@xxxxxxxxxx>
Signed-off-by: Jagan Teki <jagan@xxxxxxxxxxxxxxxxxxxx>
---
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c | 8 +++++++-
 drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h | 2 --
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
index 1f9ed2642a47..5584e9c2f8bd 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.c
@@ -396,9 +396,15 @@ static u16 sun6i_dsi_get_drq_edge0(struct sun6i_dsi *dsi,
 				   struct drm_display_mode *mode,
 				   u16 line_num, u16 edge1)
 {
+	struct sun4i_tcon *tcon = dsi->tcon;
+	unsigned long dclk_rate, dclk_parent_rate, tcon0_div;
 	u16 edge0 = edge1;
 
-	edge0 += (mode->hdisplay + 40) * SUN6I_DSI_TCON_DIV / 8;
+	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;
+
+	edge0 += (mode->hdisplay + 40) * tcon0_div / 8;
 
 	if (edge0 > line_num)
 		return edge0 - line_num;
diff --git a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
index f2826e3ea165..156523859d82 100644
--- a/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
+++ b/drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h
@@ -13,8 +13,6 @@
 #include <drm/drm_encoder.h>
 #include <drm/drm_mipi_dsi.h>
 
-#define SUN6I_DSI_TCON_DIV	4
-
 struct sun6i_dsi {
 	struct drm_connector	connector;
 	struct drm_encoder	encoder;
-- 
2.18.0.321.gffc6fa0e3