Re: [PATCH] iio: adc: ti-adc128s052: Fix number of channels when device tree is used

[Andy Shevchenko]

On Fri, Jul 1, 2022 at 1:02 AM Nishanth Menon <nm@xxxxxx> wrote:
>
> When device_match_data is called - with device tree, of_match list is

device_get_match_data() ?

> looked up to find the data, which by default is 0. So, no matter which
> kind of device compatible we use, we match with config 0 which implies
> we enable 8 channels even on devices that do not have 8 channels.
>
> Solve it by providing the match data similar to what we do with the ACPI
> lookup information.
>
> Fixes: 9e611c9e5a20 ("iio: adc128s052: Add OF match table")
> Cc: <stable@xxxxxxxxxxxxxxx> # 5.0+
> Signed-off-by: Nishanth Menon <nm@xxxxxx>

...

> +       { .compatible = "ti,adc128s052", .data = 0},

No assignment, 0 _is_ the default here.

> +       { .compatible = "ti,adc122s021", .data = 1},
> +       { .compatible = "ti,adc122s051", .data = 1},
> +       { .compatible = "ti,adc122s101", .data = 1},
> +       { .compatible = "ti,adc124s021", .data = 2},
> +       { .compatible = "ti,adc124s051", .data = 2},
> +       { .compatible = "ti,adc124s101", .data = 2},

What you need _ideally_ is rather use pointers to data structure where
each of that chip is defined, then it will be as simple as


const struct my_custom_drvdata *data;

data = device_get_match_data(dev);

Where my_custom_drvdata::num_of_channels will be already assigned to
whatever you want on a per chip basis.

If the number of channels is the only data you have, then yes, cast it
to void * in the OF ID table and

num = (uintptr_t)device_get_match_data(dev);

will suffice.

-- 
With Best Regards,
Andy Shevchenko