mtd: spinand: use the spi-mem poll status APIs

Make use of spi-mem poll status APIs to let advanced controllers
optimize wait operations.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>

drivers/mtd/nand/spi/core.c

@@ -475,18 +475,19 @@ static int spinand_erase_op(struct spinand_device *spinand,
 
 static int spinand_wait(struct spinand_device *spinand, u8 *s)
 {
-	unsigned long timeo =  jiffies + msecs_to_jiffies(400);
+	struct spi_mem_op op = SPINAND_GET_FEATURE_OP(REG_STATUS,
+						      spinand->scratchbuf);
 	u8 status;
 	int ret;
 
-	do {
-		ret = spinand_read_status(spinand, &status);
-		if (ret)
-			return ret;
+	ret = spi_mem_poll_status(spinand->spimem, &op, STATUS_BUSY, 0,
+				  SPINAND_STATUS_TIMEOUT_MS);
+	if (ret)
+		return ret;
 
-		if (!(status & STATUS_BUSY))
-			goto out;
-	} while (time_before(jiffies, timeo));
+	status = *spinand->scratchbuf;
+	if (!(status & STATUS_BUSY))
+		goto out;
 
 	/*
 	 * Extra read, just in case the STATUS_READY bit has changed

include/linux/mtd/spinand.h

@@ -170,6 +170,7 @@ struct spinand_op;
 struct spinand_device;
 
 #define SPINAND_MAX_ID_LEN	4
+#define SPINAND_STATUS_TIMEOUT_MS	400
 
 /**
  * struct spinand_id - SPI NAND id structure