On 12.10.2015 19:00, Tony Lindgren wrote:
* Adam Ford <aford173@xxxxxxxxx> [151010 13:29]:
Tomi and Tony,
I am working on the LogicPD DM3730 Torpedo module. If I try to use the
DSS, I get the same errors as mentioned in these previous messages found
here:
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-May/255103.html
The patch is basicaly:
* >> drivers/video/fbdev/omap2/dss/dss.c | 5 +++--
*>* >> 1 file changed, 3 insertions(+), 2 deletions(-)
*>* >>
*>* >> diff --git a/drivers/video/fbdev/omap2/dss/dss.c
b/drivers/video/fbdev/omap2/dss/dss.c
*>* >> index d55266c..ad6561f 100644
*>* >> --- a/drivers/video/fbdev/omap2/dss/dss.c
*>* >> +++ b/drivers/video/fbdev/omap2/dss/dss.c
*>* >> @@ -707,9 +707,10 @@ static const struct dss_features
omap34xx_dss_feats __initconst = {
*>* >> .dpi_select_source = &dss_dpi_select_source_omap2_omap3,
*>* >> };
*>* >>
*>* >> +/* Supposedly 3630 can use div 32 mult 2, but that needs to be
rechecked */
*>* >> static const struct dss_features omap3630_dss_feats __initconst = {
*>* >> - .fck_div_max = 32,
*>* >> - .dss_fck_multiplier = 1,
*>* >> + .fck_div_max = 16,
*>* >> + .dss_fck_multiplier = 2,
*>* >
*>* > These values tell about the clock hardware, they are not settings that
*>* > can be changed to change the clock. OMAP3630 has a fixed x2 multiplier
*>* > and a divider with maximum value of 16.
*>* >
*>* > Tomi
*>* >
*>* >*
I don't see this mainstream yet, but the patch is from a while ago.
Do you guys know if this will make it into the kernel? Without it, I
cannot the DM3730 to DSS to operate correctly.
AFAIK 37xx is same as 3630 and does not work properly without the patch
above as we've seen.
Well, the patch is definitely wrong for 3630, as 3630 has divider range
from 1 to 32, as seen from the CM_CLKSEL_DSS register.
I can't find the fixed x2 multiplier from the TRM, but looking at the
.dts files, 3630 DSS gets the clock from dpll4_m4x2_ck, so maybe it is
there. Or maybe the clocks in the .dts files are wrong, and the
multplier in dss.c is right.
And looking at the TRM, "3.5.3.3.4 DPLL Clock Summary" hints strongly
that there is no x2 multiplier there, so it might be that the dts clock
files are not right.
Unfortunately I have no working omap3 devices to test this =(.
Tomi
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
