[PATCH v6 01/22] drm/sun4i: sun6i_mipi_dsi: Compute burst mode loop N1 instruction delay

Jagan Teki
2019-01-24T19:59:31Z

Loop N1 instruction delay varies between burst and non-burst
video modes. for burst mode panels it is computed based on the
panel clock along with horizontal sync and porch timings and
the rest it is simply (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;

So, this patch add loop N1 computation for burst mode, for non-burst
which is already available.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
---
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