Re: [PATCH] ASoC:pcm512x: Make PLL lock output selectable via device tree.
From: Howard Mitchell
Date: Mon Mar 23 2015 - 07:24:34 EST
On 23/03/15 11:00, Peter Rosin wrote:
Howard Mitchell wrote:
On 22/03/15 16:24, Mark Brown wrote:
On Fri, Mar 20, 2015 at 09:22:43PM +0000, Howard Mitchell wrote:
+ if (pcm512x->pll_lock) {
+ if (of_property_read_u32(np, "pll-lock", &val) >= 0) {
+ if (val > 6) {
+ dev_err(dev, "Invalid pll-lock\n");
+ ret = -EINVAL;
+ goto err_clk;
+ }
+ pcm512x->pll_lock = val;
+ }
This breaks existing boards which rely on GPIO 4 being set as the lock
output. This is very unfortunate since it's a silly thing for the
driver to default to but nontheless we should really continue to support
them - at a guess Peter's board is relying on this, and even if it isn't
someone else's might.
I take your point, but the reason I pushed this patch was that I wanted
to use GPIO4 for pll-out and unfortunately because the pll-lock
configuration is after the pll-out configuration it stomps on it. If I
modify the patch to provide a default for pll-lock I will then be
obliged to specify pll-lock on another GPIO. The pcm5122 has limited IO
so being forced to have a GPIO for pll-lock seems wrong to me. A future
user of the device may well decide to use the GPIOs for other purposes
and therefore not want a pll-lock signal at all. Surely we should allow
for that possibility?
Given that Peter has indicated that he'd be happy with this solution and
that this code hasn't reached a published kernel would it be reasonable
to go ahead with my current patch (happy to clean up the indent issues
that Peter pointed out of course)?
Strongly agreed that we should fix this before it is published (I assumed
that is was included in 3.19, it felt so long ago that Mark merged it...). My
preference would be to remove the pll-lock things entirely though. Assuming
you don't need it for your board of course, but I doubt it from your description.
I used it to make sure I had understood the chip correctly, that's all.
Cheers,
Peter
I'd be happy to remove it entirely. I only used it as you did as a debug
tool. Let's see what Mark thinks.....
- Howard
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