Re: [RFC 1/2] ARM: Tegra: Device Tree Support: Update how sdhci devices are initialized

[Olof Johansson <olofj-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>]

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On Tue, May 10, 2011 at 3:03 PM, Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> wrote:

> John Bonesio wrote at Tuesday, May 10, 2011 2:14 PM:
> > This patch changes how sdhci devices are initialized so that a later
> patch can
> > easily add support for i2c devies.
> >
> > Signed-off-by: John Bonesio <bones-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
>
> > @@ -134,6 +57,25 @@ static __initdata struct tegra_clk_init_table
> > tegra_dt_clk_init_table[] = {
> >       { NULL,         NULL,           0,              0},
> >  };
> >
> > +static struct tegra_sdhci_platform_data sdhci_pdata1 = {
> > +     .cd_gpio        = -1,
> > +     .wp_gpio        = -1,
> > +     .power_gpio     = -1,
> > +};
> > +
> > +static struct tegra_sdhci_platform_data sdhci_pdata2 = {
> > +     .cd_gpio        = TEGRA_GPIO_SD2_CD,
> > +     .wp_gpio        = TEGRA_GPIO_SD2_WP,
> > +     .power_gpio     = TEGRA_GPIO_SD2_POWER,
> > +};
> > +
> > +static struct tegra_sdhci_platform_data sdhci_pdata4 = {
> > +     .cd_gpio        = TEGRA_GPIO_SD4_CD,
> > +     .wp_gpio        = TEGRA_GPIO_SD4_WP,
> > +     .power_gpio     = TEGRA_GPIO_SD4_POWER,
> > +     .is_8bit        = 1,
> > +};
> > +
>
> So I understand why board-dt is itself registering the SDHCI platform
> devices itself; so that the pdev initialization path is identical
> between fully hard-coded boards and board-dt.c.
>
> However, I'm surprised that we would include the platform data for
> those devices within that argument; if we do that, we'll end up needing
> different platform data for every board, and devicetree won't have
> bought us anything.
>
> In other words, I understood that board-dt would register all the
> platform devices within Tegra, but not set up any of the plataform
> data, and the device drivers for those devices would be updated to
> get their platform data from devicetree if available, then fall back
> to old-style platform data. In other words, the way the SDHCI drivers
> work today in the devicetree/test branch.
>
> If my understanding is correct, shouldn't the chunk above and the
> one below be removed?
>

That's if we cut everything over, I think. until then, this code should fill
in the platform_device and register it. But the values should come from the
device tree, and it should only register the controllers that are in the
tree (and not marked as disabled).


-Olof

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