Re: [PATCH] mfd: qcom-spmi-pmic: Add support for more chips versions

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Wed, Nov 5, 2014 at 11:54 PM, Ivan T. Ivanov <iivanov@xxxxxxxxxx> wrote:
>
> On Wed, 2014-11-05 at 17:36 -0800, Bjorn Andersson wrote:
>> On Wed, Nov 5, 2014 at 10:31 AM, Ivan T. Ivanov <iivanov@xxxxxxxxxx> wrote:
[..]
>> > Some of the child device drivers have to know PMIC chip revision.
>> >
>>
>> So your plan is to have a strstr(parent->compatible, "-v2") there?
>
> Actually also PMIC subtype (pm8841, pm8226...) is also required, so
> the plan is to have something like this:
>
> {
>         static const struct of_device_id pmic_match_table[] = {
>                 { .compatible = "qcom,pm8941-v1.0" },
>                 { .compatible = "qcom,pm8841-v0.0" },
>                 { }
>
>         };
>
>         const struct of_device_id *match;
>
>         match = of_match_device(pmic_match_table, pdev->dev.parent);
>         if (match) {
>                 dev_info(&pdev->dev, "%s chip detected\n", match->compatible);
>         }
> }
>

To me this is a hack, you should not alter the devicetree to make it
"better express the hardware". Either you know these things from boot
and they go in device tree, or you can probe them and they should not
go in device tree.

If you really need these values you should expose them through some api.

>>
>> Could you be a little bit more elaborate on what you're trying to do
>> and which child devices that might be?
>
> For example ADC drivers are required temperature compensation based
> on PMIC variant and chip manufacturer.
>

I see, is that compensation of any practical value? Or is the
compensation of academic proportions?

Regards,
Bjorn
--
To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux ARM Kernel]     [Linux ARM]     [Linux Omap]     [Fedora ARM]     [Linux for Sparc]     [IETF Annouce]     [Security]     [Bugtraq]     [Linux MIPS]     [ECOS]     [Asterisk Internet PBX]     [Linux API]

  Powered by Linux