On 26/07/17 17:02, Ludovic Desroches wrote:
> When the device is non removable, the card detect signal is often use
use -> used
> for another purpose i.e. muxed to another SoC peripheral or used as a
> GPIO. It could lead to wrong behaviors depending the defaut value of
defaut -> default
> this signal if not muxed to the SDHCI controller.
>
> Fixes: bb5f8ea4d514 ("mmc: sdhci-of-at91: introduce driver for the Atmel SDMMC")
> Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
Apart from spelling
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-of-at91.c | 36 +++++++++++++++++++++++++++++++++++-
> 1 file changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 88e9b5f35a62..6a389f35396e 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -31,6 +31,7 @@
>
> #define SDMMC_MC1R 0x204
> #define SDMMC_MC1R_DDR BIT(3)
> +#define SDMMC_MC1R_FCD BIT(7)
> #define SDMMC_CACR 0x230
> #define SDMMC_CACR_CAPWREN BIT(0)
> #define SDMMC_CACR_KEY (0x46 << 8)
> @@ -44,6 +45,15 @@ struct sdhci_at91_priv {
> bool restore_needed;
> };
>
> +static void sdhci_at91_set_force_card_detect(struct sdhci_host *host)
> +{
> + u8 mc1r;
> +
> + mc1r = readb(host->ioaddr + SDMMC_MC1R);
> + mc1r |= SDMMC_MC1R_FCD;
> + writeb(mc1r, host->ioaddr + SDMMC_MC1R);
> +}
> +
> static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
> {
> u16 clk;
> @@ -111,10 +121,18 @@ void sdhci_at91_set_uhs_signaling(struct sdhci_host *host, unsigned int timing)
> sdhci_set_uhs_signaling(host, timing);
> }
>
> +static void sdhci_at91_reset(struct sdhci_host *host, u8 mask)
> +{
> + sdhci_reset(host, mask);
> +
> + if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
> + sdhci_at91_set_force_card_detect(host);
> +}
> +
> static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
> .set_clock = sdhci_at91_set_clock,
> .set_bus_width = sdhci_set_bus_width,
> - .reset = sdhci_reset,
> + .reset = sdhci_at91_reset,
> .set_uhs_signaling = sdhci_at91_set_uhs_signaling,
> .set_power = sdhci_at91_set_power,
> };
> @@ -369,6 +387,22 @@ static int sdhci_at91_probe(struct platform_device *pdev)
> host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
> }
>
> + /*
> + * If the device attached to the MMC bus is not removable, it is safer
> + * to set the Force Card Detect bit. People often don't connect the
> + * card detect signal and use this pin for another purpose. If the card
> + * detect pin is not muxed to SDHCI controller, a default value is
> + * used. This value can be different from a SoC revision to another
> + * one. Problems come when this default value is not card present. To
> + * avoid this case, if the device is non removable then the card
> + * detection procedure using the SDMCC_CD signal is bypassed.
> + * This bit is resetted when a software reset for all command is
resetted -> reset
> + * performed so we need to implement our own reset function to set back
> + * this bit.
> + */
> + if (host->mmc->caps & MMC_CAP_NONREMOVABLE)
> + sdhci_at91_set_force_card_detect(host);
> +
> pm_runtime_put_autosuspend(&pdev->dev);
>
> return 0;
>
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