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.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c b/drivers/phy/samsung/phy-exynos5-usbdrd.c
index 0d818b7..cfa9b8b 100644 (file)
--- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
+++ b/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;