Added HiFiBerry Digi+ Pro driver

[hifiberry]

This adds support for the HiFiBerry Digi+ Pro. It is similar to the Digi+, but uses a different clock configuration. Therefore it won't work with the existing driver and the driver has been updated now to support both the standard and the Pro version.

Signed-off-by: Daniel Matuschek [email protected]

[hifiberry]

Just forgot to note: The driver is fully backwards compatible.

[pelwell]

I'm out of the office until the end of the week, but from a brief look:

• The clk_pins node isn't referenced anywhere, so it is probably doing nothing.
• The overlay comment mentions DigiG - is that correct?
• Hard-coding the pin numbers in the driver is a bit ugly when their are convenience functions to read them from DT.
• Kernel coding standards say that one line if bodies should not use braces.
• There is no README entry for the overlay.

[hifiberry]

Thanks for the feedback. I will look into these and update the patch.

[hifiberry]

GPIO configuration has moved to the device tree now
cleaned up unused parts in device tree file
added documentation
fixed braces

[clivem]

@hifiberry Just a heads-up, @pelwell , told me to use gpiod (#include <linux/gpio/consumer.h>) not the old gpio mechanism, when I wanted to get at GPIO22 from the driver, for mute on the IQAudIO AMP board. You appear to be using the "deprecated" old way.

[hifiberry]

@pelwell : should the GPIO interface be changed?

[pelwell]

The example is missing a hyphen.

[pelwell]

Yes, I think you should - devm_gpiod_get is a better way to read the GPIOs from DT, the only issue being that the overlay will have to call the property "clock-gpios" (the function parameter would be "clock") instead of "clock-pins", a name I prefer because pins makes people think of the 40-way header. Look for mute_gpio in iqaudio-dac.c as an example of the preferred method.

[ghost]

@pelwell The code has been changed now to use the GPIO consumer interface.

[pelwell]

Much better - I hope you also feel it is an improvement, and not just jumping through hoops.

[hifiberry]

Thanks, I'm always interested in feedback to improve the code.