usb: fotg210-hcd: 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/1600668815-12135-6-git-send-email-chunfeng.yun@mediatek.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/fotg210-hcd.c

@@ -32,6 +32,7 @@
 #include <linux/uaccess.h>
 #include <linux/platform_device.h>
 #include <linux/io.h>
+#include <linux/iopoll.h>
 #include <linux/clk.h>
 
 #include <asm/byteorder.h>
@@ -883,18 +884,15 @@ static int handshake(struct fotg210_hcd *fotg210, void __iomem *ptr,
 		u32 mask, u32 done, int usec)
 {
 	u32 result;
+	int ret;
 
-	do {
-		result = fotg210_readl(fotg210, ptr);
-		if (result == ~(u32)0)		/* card removed */
+	ret = readl_poll_timeout_atomic(ptr, result,
+					((result & mask) == done ||
+					 result == U32_MAX), 1, usec);
+	if (result == U32_MAX)		/* card removed */
 		return -ENODEV;
-		result &= mask;
-		if (result == done)
-			return 0;
-		udelay(1);
-		usec--;
-	} while (usec > 0);
-	return -ETIMEDOUT;
+
+	return ret;
 }
 
 /* Force HC to halt state from unknown (EHCI spec section 2.3).