Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

OMAPDSS: HDMI5: Change DDC timings

The DDC scl high and low times were set to the minimum values
from the i2c specification, but the i2c specification takes into
account the rise time and fall time to calculate the frequency.
To pass HDMI certification DDC can not exceed 100kHz therefore in
a system where the rise times and fall times are negligible the high
and low times for scl need to be 10us.

Signed-off-by: Jim Lodes <jim.lodes@garmin.com>
Signed-off-by: J.D. Schroeder <jay.schroeder@garmin.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

authored by

Jim Lodes and committed by
Tomi Valkeinen
4bafcbc7 08f707ac

+4 -4
+2 -2
drivers/gpu/drm/omapdrm/dss/hdmi5_core.c
··· 51 51 { 52 52 void __iomem *base = core->base; 53 53 const unsigned long long iclk = 266000000; /* DSS L3 ICLK */ 54 - const unsigned ss_scl_high = 4000; /* ns */ 55 - const unsigned ss_scl_low = 4700; /* ns */ 54 + const unsigned ss_scl_high = 4600; /* ns */ 55 + const unsigned ss_scl_low = 5400; /* ns */ 56 56 const unsigned fs_scl_high = 600; /* ns */ 57 57 const unsigned fs_scl_low = 1300; /* ns */ 58 58 const unsigned sda_hold = 1000; /* ns */
+2 -2
drivers/video/fbdev/omap2/omapfb/dss/hdmi5_core.c
··· 51 51 { 52 52 void __iomem *base = core->base; 53 53 const unsigned long long iclk = 266000000; /* DSS L3 ICLK */ 54 - const unsigned ss_scl_high = 4000; /* ns */ 55 - const unsigned ss_scl_low = 4700; /* ns */ 54 + const unsigned ss_scl_high = 4600; /* ns */ 55 + const unsigned ss_scl_low = 5400; /* ns */ 56 56 const unsigned fs_scl_high = 600; /* ns */ 57 57 const unsigned fs_scl_low = 1300; /* ns */ 58 58 const unsigned sda_hold = 1000; /* ns */