mmc: sdhci-of-at91: replace while loop with read_poll_timeout

Replace while loop with read_poll_timeout().

Signed-off-by: Claudiu Beznea <[e-mail]>
Acked-by: Adrian Hunter <[e-mail]>
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Ulf Hansson <[e-mail]>

drivers/mmc/host/sdhci-of-at91.c

···
 static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
 {
 	u16 clk;
-	unsigned long timeout;
 
 	host->mmc->actual_clock = 0;
 
···
 	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
 
 	/* Wait max 20 ms */
-	timeout = 20;
-	while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
-		& SDHCI_CLOCK_INT_STABLE)) {
-		if (timeout == 0) {
-			pr_err("%s: Internal clock never stabilised.\n",
-			       mmc_hostname(host->mmc));
-			return;
-		}
-		timeout--;
-		mdelay(1);
+	if (read_poll_timeout(sdhci_readw, clk, (clk & SDHCI_CLOCK_INT_STABLE),
+			      1000, 20000, false, host, SDHCI_CLOCK_CONTROL)) {
+		pr_err("%s: Internal clock never stabilised.\n",
+		       mmc_hostname(host->mmc));
+		return;
 	}
 
 	clk |= SDHCI_CLOCK_CARD_EN;