mmc: sdhci-of-at91: wait for calibration done before proceed

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: dbdea70 ("mmc: sdhci-of-at91: fix CALCR register being rewritten")
Fixes: 727d836 ("mmc: sdhci-of-at91: add DT property to enable calibration on full reset")
Signed-off-by: Claudiu Beznea <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Ulf Hansson <[email protected]>

Author: claudiubeznea

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");
 	}
 }