Re: [PATCH v6 0/2] add mcf54415 DAC driver

[Andy Shevchenko]

On Thu, Jun 18, 2026 at 11:04:14PM +0200, Angelo Dureghello wrote:
> This patchset adds a minimalistic DAC driver for the NXP mcf54415/6/7/8
> builtin DACs.
> 
> Currently the driver enables the raw write only. Feature as dma, sync, or
> format are not supoprted for this version.
> 
> Additional options suppoerted by the DAC module will be added to the driver
> later on, as needed.
> 
> The same patchset prepares the m68k/coldfire architecture to support
> the driver.
> 
> Below some basic tests done on stmark2 mcf54415-based board, voltage check
> on DAC0 and DAC1:
> 
> ~ # cd /sys/bus/iio/devices/iio:device0/
> /sys/bus/iio/devices/iio:device0 # ls
> name               out_voltage_scale  uevent
> out_voltage_raw    subsystem
> /sys/bus/iio/devices/iio:device0 # cat name
> mcf54415
> /sys/bus/iio/devices/iio:device0 # echo 4095 > out_voltage_raw 
> /sys/bus/iio/devices/iio:device0 # echo 2048 > out_voltage_raw 
> /sys/bus/iio/devices/iio:device0 # echo 4096 > out_voltage_raw 
> sh: write error: Invalid argument
> /sys/bus/iio/devices/iio:device0 # cat out_voltage_raw 
> 2048
> /sys/bus/iio/devices/iio:device0 # 
> 
> Same behavior for /sys/bus/iio/devices/iio:device1.
> 
> Generated a sine wave by shell script, sine shape is good.

Heard a presentation (Embedded Recipes IIRC) where one tried sine and real
sound (it was about sound DAC) was really awful. So, Can you try a bit more
sophisticated signal?

-- 
With Best Regards,
Andy Shevchenko