[RFC PATCH] brcmfmac: add 43751 SDIO ids and initialization

[Ulf Hansson]

On Mon, 13 Mar 2023 at 22:42, Marc Gonzalez <marc.w.gonzalez at free.fr> wrote:
>
> On 13/03/2023 21:04, Martin Blumenstingl wrote:
>
> > On Mon, Mar 13, 2023 at 6:09 PM Marc Gonzalez wrote:
> > [...]
> >> QUESTION:
> >> It's not clear to me why we sleep twice for host->ios.power_delay_ms?
> >
> > I'm not sure but I think host->ios.power_delay_ms is independent from
> > the post-power-on-delay-ms property of "mmc-pwrseq-simple".
>
> They are distinct indeed (the props have the same name & similar purpose though).

Correct.

>
> host->ios.power_delay_ms is set via:
>
> drivers/mmc/core/host.c:        device_property_read_u32(dev, "post-power-on-delay-ms",

This is a property that may be specified in the host's OF node. See
Documentation/devicetree/bindings/mmc/mmc-controller.yaml.

> drivers/mmc/core/host.c-                                 &host->ios.power_delay_ms);

Note that the default value is set to 10 ms, in mmc_alloc_host(). So,
if you need a different value, that can be specified in DT.

>
>
> pwrseq->post_power_on_delay_ms is set via:
>
> drivers/mmc/core/pwrseq_simple.c:       device_property_read_u32(dev, "post-power-on-delay-ms",

This is a property that may be specified in the pwrseq OF node. See
Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.yaml.

> drivers/mmc/core/pwrseq_simple.c-                                &pwrseq->post_power_on_delay_ms);
>
>
> However, they are both used to delay mmc_power_up(),
> and the host delay is used to sleep twice, which I
> found confusing ;)

It's certainly a bit hairy to follow, but I think you have understood
things correctly.

>
> Regards
>

Looks like you are getting closer to the solution, at least for the
first step to make sure the SDIO card is getting detected properly.
Nice!

Kind regards
Uffe