[PATCH v2 1/2] mmc: sdhci-of-at91: wait for calibration done before proceed

[Adrian Hunter]

On 24/09/21 11:28 am, Claudiu Beznea wrote:
> Datasheet specifies that at the end of calibration the SDMMC_CALCR_EN
> bit will be cleared. No commands should be send before calibration is
> done.
> 
> Fixes: dbdea70f71d67 ("mmc: sdhci-of-at91: fix CALCR register being rewritten")
> Fixes: 727d836a375ad ("mmc: sdhci-of-at91: add DT property to enable calibration on full reset")
> Signed-off-by: Claudiu Beznea <claudiu.beznea at microchip.com>

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

> ---
> 
> Hi Nicolas,
> 
> I haven't added your tag from previous version as I changed the
> implementation to use read_poll_timeout().
> 
> Thank you,
> Claudiu Beznea
> 
>  drivers/mmc/host/sdhci-of-at91.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 5564d7b23e7c..134ba01d3063 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -11,6 +11,7 @@
>  #include <linux/delay.h>
>  #include <linux/err.h>
>  #include <linux/io.h>
> +#include <linux/iopoll.h>
>  #include <linux/kernel.h>
>  #include <linux/mmc/host.h>
>  #include <linux/mmc/slot-gpio.h>
> @@ -114,6 +115,7 @@ static void sdhci_at91_reset(struct sdhci_host *host, u8 mask)
>  {
>  	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>  	struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
> +	unsigned int tmp;
>  
>  	sdhci_reset(host, mask);
>  
> @@ -126,6 +128,10 @@ static void sdhci_at91_reset(struct sdhci_host *host, u8 mask)
>  
>  		sdhci_writel(host, calcr | SDMMC_CALCR_ALWYSON | SDMMC_CALCR_EN,
>  			     SDMMC_CALCR);
> +
> +		if (read_poll_timeout(sdhci_readl, tmp, !(tmp & SDMMC_CALCR_EN),
> +				      10, 20000, false, host, SDMMC_CALCR))
> +			dev_err(mmc_dev(host->mmc), "Failed to calibrate\n");
>  	}
>  }
>  
>