Hi, Guennadi
On 12/30/2014 4:36 PM, Guennadi Liakhovetski wrote:
Hi Laurent,
First of all, sorry, I am currently on a holiday, so, replies are delayed,
real work (reviewing or anything else) is impossible.
Thanks for your review in holiday. That's very helpful.
On Tue, 30 Dec 2014, Laurent Pinchart wrote:
Hi Guennadi,
On Friday 26 December 2014 11:38:11 Guennadi Liakhovetski wrote:
On Fri, 26 Dec 2014, Laurent Pinchart wrote:
On Friday 26 December 2014 10:14:26 Guennadi Liakhovetski wrote:
On Fri, 26 Dec 2014, Laurent Pinchart wrote:
On Friday 26 December 2014 14:37:14 Josh Wu wrote:
[snip]
Talking about mclk and xvclk is quite confusing. There's no mclk from
an ov2640 point of view. The ov2640 driver should call
v4l2_clk_get("xvclk").
Yes, I also was thinking about this, and yes, requesting a "xvclk" clock
would be more logical. But then, as you write below, if we let the
v4l2_clk wrapper first check for a CCF "xvclk" clock, say, none is
found. How do we then find the exported "mclk" V4L2 clock? Maybe
v4l2_clk_get() should use two names?..
Given that v4l2_clk_get() is only used by soc-camera drivers and that they
all call it with the clock name set to "mclk", I wonder whether we
couldn't just get rid of struct v4l2_clk.id and ignore the id argument to
v4l2_clk_get() when CCF isn't available. Maybe we've overdesigned
v4l2_clk :-)
Sure, that'd be fine with me, if everyone else agrees.
Can you submit a patch ? That's the best way to find out if anyone objects.
Can do, sure, once I am back home and find time for this.
[snip]
v4l2_clk_get() should try to get the clock from CCF with a call to
clk_get() first, and then look at the list of v4l2-specific clocks.
Yes, how will it find the "mclk" when "xvclk" (or any other name) is
requested? We did discuss this in the beginning and agreed to use a
fixed clock name for the time being...
Please see above.
That's at least how I had envisioned it when v4l2_clk_get() was
introduced. Let's remember that v4l2_clk was designed as a temporary
workaround for platforms not implementing CCF yet. Is that still
needed,
or could be instead just get rid of it now ?
I didn't check, but I don't think all platforms, handled by soc-camera,
support CCF yet.
After a quick check it looks like only OMAP1 and SH Mobile are missing.
Atmel, MX2, MX3 and R-Car all support CCF. PXA27x has CCF support but
doesn't enable it yet for an unknown (to me) reason.
The CEU driver is used on both arch/sh and arch/arm/mach-shmobile. The
former will most likely never receive CCF support, and the latter is
getting fixed. As arch/sh isn't maintained anymore I would be fine with
dropping CEU support for it.
OMAP1 is thus the only long-term show-stopper. What should we do with it ?
Indeed, what should we? :)
You're listed as the soc-camera maintainer, so you should provide an answer to
that question :-)
Thanks for ar reminder;)
I'll propose one, let's drop the omap1-camera driver (I've
CC'ed the original author of the driver to this e-mail).
Let's see what they reply, but I don't tgink Josh will want to wait that
long.
Thanks. it's indeed true for me.
And until omap1 is in the mainline we cannot drop v4l2_clk.
So I think the better way right now for ov2640 driver is still request
both the v4l2_clock: mclk, and the clock: xvclk in probe().
In that way, we can take our time to introduce other patches to merged
these two clocks.
Does it make sense?
Best Regards,
Josh Wu
Thanks
Guennadi
--
Regards,
Laurent Pinchart
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
