usb: phy: phy-mv-usb: convert to readl_poll_timeout_atomic()

Use readl_poll_timeout_atomic() to simplify code
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1600668815-12135-9-git-send-email-chunfeng.yun@mediatek.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/phy/phy-mv-usb.c

@@ -8,6 +8,7 @@
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/uaccess.h>
 #include <linux/device.h>
 #include <linux/proc_fs.h>
@@ -135,8 +136,8 @@ static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
 
 static int mv_otg_reset(struct mv_otg *mvotg)
 {
-	unsigned int loops;
 	u32 tmp;
+	int ret;
 
 	/* Stop the controller */
 	tmp = readl(&mvotg->op_regs->usbcmd);
@@ -146,15 +147,12 @@ static int mv_otg_reset(struct mv_otg *mvotg)
 	/* Reset the controller to get default values */
 	writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
 
-	loops = 500;
-	while (readl(&mvotg->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
-		if (loops == 0) {
+	ret = readl_poll_timeout_atomic(&mvotg->op_regs->usbcmd, tmp,
+				(tmp & USBCMD_CTRL_RESET), 10, 10000);
+	if (ret < 0) {
 		dev_err(&mvotg->pdev->dev,
 			"Wait for RESET completed TIMEOUT\n");
-			return -ETIMEDOUT;
-		}
-		loops--;
-		udelay(20);
+		return ret;
 	}
 
 	writel(0x0, &mvotg->op_regs->usbintr);