phy: samsung: Use readl_poll_timeout function

Instead of a busy waiting while loop using udelay
use readl_poll_timeout function to check the condition
is met or timeout occurs in crport_handshake function.
readl_poll_timeout is called in non atomic context so
it safe to sleep until the condition is met.
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Link: https://lore.kernel.org/r/20200720173502.542-1-linux.amoon@gmail.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/samsung/phy-exynos5-usbdrd.c

@@ -16,6 +16,7 @@
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
+#include <linux/iopoll.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/mutex.h>
@@ -556,41 +557,25 @@ static int exynos5_usbdrd_phy_power_off(struct phy *phy)
 static int crport_handshake(struct exynos5_usbdrd_phy *phy_drd,
 			    u32 val, u32 cmd)
 {
-	u32 usec = 100;
 	unsigned int result;
+	int err;
 
 	writel(val | cmd, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
 
-	do {
-		result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
-		if (result & PHYREG1_CR_ACK)
-			break;
-
-		udelay(1);
-	} while (usec-- > 0);
-
-	if (!usec) {
-		dev_err(phy_drd->dev,
-			"CRPORT handshake timeout1 (0x%08x)\n", val);
-		return -ETIME;
+	err = readl_poll_timeout(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1,
+				 result, (result & PHYREG1_CR_ACK), 1, 100);
+	if (err == -ETIMEDOUT) {
+		dev_err(phy_drd->dev, "CRPORT handshake timeout1 (0x%08x)\n", val);
+		return err;
 	}
 
-	usec = 100;
-
 	writel(val, phy_drd->reg_phy + EXYNOS5_DRD_PHYREG0);
 
-	do {
-		result = readl(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1);
-		if (!(result & PHYREG1_CR_ACK))
-			break;
-
-		udelay(1);
-	} while (usec-- > 0);
-
-	if (!usec) {
-		dev_err(phy_drd->dev,
-			"CRPORT handshake timeout2 (0x%08x)\n", val);
-		return -ETIME;
+	err = readl_poll_timeout(phy_drd->reg_phy + EXYNOS5_DRD_PHYREG1,
+				 result, !(result & PHYREG1_CR_ACK), 1, 100);
+	if (err == -ETIMEDOUT) {
+		dev_err(phy_drd->dev, "CRPORT handshake timeout2 (0x%08x)\n", val);
+		return err;
 	}
 
 	return 0;