Re: [PATCH v2 3/3] pwm: Add Ingenic JZ4740 support

From: Thierry Reding
Date: Tue Sep 11 2012 - 01:02:14 EST


On Mon, Sep 10, 2012 at 11:51:48PM +0200, Lars-Peter Clausen wrote:
> On 09/10/2012 02:05 PM, Thierry Reding wrote:
> > This commit moves the driver to drivers/pwm and converts it to the new
> > PWM framework.
> >
> > Signed-off-by: Thierry Reding <thierry.reding@xxxxxxxxxxxxxxxxx>
>
> Seems to work, thanks a lot. This one and patch 2:
>
> Acked-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
> Tested-by: Lars-Peter Clausen <lars@xxxxxxxxxx>
>
> But I noticed a different problem. Some drivers using the pwm API depend on
> HAVE_PWM (e.g. the pwm beeper driver), but the generic PWM framework does not
> select HAVE_PWM, so I couldn't select the pwm beeper driver. Imo the generic
> PWM framework should select HAVE_PWM

Does it also work if you add || PWM to the PWM beeper driver's depends?
I thought I had done something similar for pwm-backlight, but looking at
the logs I didn't. The reason was that it also uses the new APIs
introduced by the PWM subsystem. For pwm-beeper the situation is
different because it only uses the legacy API and therefore can work
with both the legacy and new frameworks.

I think selecting HAVE_PWM won't work properly because it isn't provided
by all architectures. So you might end up with PWM enabled on PowerPC,
which doesn't define HAVE_PWM and will probably give you Kconfig
warnings and will still not let you select pwm-beeper.

Thierry

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