drm/panel-simple: Fix dotclock for Ortustech COM37H3M
The currently listed dotclock disagrees with the currently
listed vrefresh rate. Change the dotclock to match the vrefresh.
There are two variants of the COM37H3M panel.
The older one's COM37H3M05DTC data sheet specifies:
MIN TYP MAX
CLK frequency fCLK -- 22.4 26.3 MHz (in VGA mode)
VSYNC Frequency fVSYNC 54 60 66 Hz
VSYNC cycle time tv -- 650 -- H
HSYNC frequency fHSYNC -- 39.3 -- kHz
HSYNC cycle time th -- 570 -- CLK
The newer one's COM37H3M99DTC data sheet says:
MIN TYP MAX
CLK frequency fCLK 18 19.8 27 MHz
VSYNC Frequency fVSYNC 54 60 66 Hz
VSYNC cycle time tv 646 650 700 H
HSYNC frequency fHSYNC -- 39.0 50.0 kHz
HSYNC cycle time th 504 508 630 CLK
So we choose a parameter set that lies within the specs
of both variants. We start at .vrefresh = 60,
choose .htotal = 570 and .vtotal = 650 and end up
in a clock of 22.230 MHz.
Reported-by: Ville Syrjala <ville.syrjala@linux.intel.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/e63a0533ad5b5142373437ef758aedbdb716152d.1583826198.git.hns@goldelico.com
diff --git a/drivers/gpu/drm/panel/panel-simple.c b/drivers/gpu/drm/panel/panel-simple.c
index 20e0f9a..e84dac0 100644
--- a/drivers/gpu/drm/panel/panel-simple.c
+++ b/drivers/gpu/drm/panel/panel-simple.c
@@ -2617,15 +2617,15 @@
};
static const struct drm_display_mode ortustech_com37h3m_mode = {
- .clock = 22153,
+ .clock = 22230,
.hdisplay = 480,
- .hsync_start = 480 + 8,
- .hsync_end = 480 + 8 + 10,
- .htotal = 480 + 8 + 10 + 10,
+ .hsync_start = 480 + 40,
+ .hsync_end = 480 + 40 + 10,
+ .htotal = 480 + 40 + 10 + 40,
.vdisplay = 640,
.vsync_start = 640 + 4,
- .vsync_end = 640 + 4 + 3,
- .vtotal = 640 + 4 + 3 + 4,
+ .vsync_end = 640 + 4 + 2,
+ .vtotal = 640 + 4 + 2 + 4,
.vrefresh = 60,
.flags = DRM_MODE_FLAG_NVSYNC | DRM_MODE_FLAG_NHSYNC,
};
