On Thu, Feb 27, 2020 at 6:59 PM john whittle <[email protected]> wrote:
>
> Greetings,
>
> I'm trying to load this MCP4725 IIO driver
>
> modprobe mcp4725
>
> echo "mcp4725 0x60" >/sys/bus/i2c/devices/i2c-2/new_device
>
>
> no problems up until i run dmesg and it doesnt recognize it as an iio device.
>
> root@beaglebone:/sys/bus/iio/devices# ls -l
> total 0
>
> run dmesg
>
>
> [  471.215225] mcp4725 2-0060: invalid platform or devicetree data
> [  471.232912] i2c i2c-2: new_device: Instantiated device mcp4725 at 0x60
>
> It works with other chips the mcp3422 for instance. exact same commands 
> except different address
>
> any thoughts? is this driver no good for beaglebone?

The kernel message gave you a hint of what's wrong.. "invalid platform
or devicetree data"...

The mcp4725 driver has a required property "vdd-supply" that must be
provided either thru the platform (legacy) or device tree data..

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/devicetree/bindings/iio/dac/mcp4725.txt

Start with a basic overlay (assuming P9_19/P9_20 right? )

https://github.com/beagleboard/bb.org-overlays/blob/master/src/arm/BB-I2C2-00A0.dts

and update this section for what your driver needs..

https://github.com/beagleboard/bb.org-overlays/blob/master/src/arm/BB-I2C2-00A0.dts#L84-L91

assuming it's v3.3 use:

vdd-supply = <&vmmcsd_fixed>;

Regards,

-- 
Robert Nelson
https://rcn-ee.com/

-- 
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