staging: vc04_services: bcm2835-audio: Adding PWM support to audio driver

Greg KH gregkh at
Sun Mar 12 08:42:45 PDT 2017

On Sun, Mar 12, 2017 at 08:22:07AM -0700, Michael Zoran wrote:
> Hi Greg,
> I wrote a PWM based audio driver for the RPI that talks to the hardware
> directly.  I sent it to the ALSA people as a standalone driver, but the
> more I'm thinking about it the more I wonder if this should perhaps be
> part of the existing bcm2835-audio driver.
> I'm thinking the audio driver can have multiple "back ends" that are
> selectable through audio controls exported through ALSA.  It would also
> make it possible to prevent the firmware from trying to open the PWM
> hardware if it is being used directly by the driver from the ARM.  
> I'm also considering a hook into the standard PWM driver so that the
> hardware can't be used for random PWM if audio is being played.
> Is this something you would consider having in the
> vc04_services/bcm2835-audio driver in staging if I rewrite the driver?

I'll take anything in staging, that shouldn't be a question anyone has
to ask anymore :)

greg k-h

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