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SubjectRe: [PATCH v3 1/3] mmc: sdhci: use WP GPIO in sdhci_check_ro()
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On 12/02/19 4:07 PM, Thomas Petazzoni wrote:
> Even though SDHCI controllers may have a dedicated WP pin that can be
> queried using the SDHCI_PRESENT_STATE register, some platforms may
> chose to use a separate regular GPIO to route the WP signal. Such a
> GPIO is typically represented using the wp-gpios property in the
> Device Tree.
>
> Unfortunately, the current sdhci_check_ro() function does not make use
> of such GPIO when available: it either uses a host controller specific
> ->get_ro() operation, or uses the SDHCI_PRESENT_STATE. Several host
> controller specific ->get_ro() functions are implemented just to check
> a WP GPIO state.
>
> Instead of pushing this to more controller-specific implementations,
> let's handle this in the core SDHCI code, just like it is already done
> for the CD GPIO in sdhci_get_cd().
>
> The below patch simply changes sdhci_check_ro() to use the value of
> the WP GPIO if available.
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
> Changes since v2:
>
> - As suggested by Adrian Hunter, keep the argument of
> sdhci_check_ro() as it is: a "struct sdhci_host*"
>
> Changes since v1:
>
> - As suggested by Adrian Hunter, call the ->get_ro() if it exists
> before falling back to using mmc_gpio_get_ro(). Indeed, if the
> controller-specific code has implemented a ->get_ro() callback, it
> should take precedence over what the SDHCI core does.
>
> Due to this change, I have not added Thierry Redding Reviewed-by.
>
> - Fix typo in the commit log noticed by Thierry Redding.
> ---
> drivers/mmc/host/sdhci.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index df05352b6a4a..b3444d12c8c8 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -2033,6 +2033,8 @@ static int sdhci_check_ro(struct sdhci_host *host)
> is_readonly = 0;
> else if (host->ops->get_ro)
> is_readonly = host->ops->get_ro(host);
> + else if (mmc_can_gpio_ro(host->mmc))
> + is_readonly = mmc_gpio_get_ro(host->mmc);
> else
> is_readonly = !(sdhci_readl(host, SDHCI_PRESENT_STATE)
> & SDHCI_WRITE_PROTECT);
>

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