[PATCH 2/3] mtd: spinand: use the spi-mem poll status APIs

[patrice.chotard at foss.st.com]

From: Christophe Kerello <christophe.kerello at foss.st.com>

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

Signed-off-by: Christophe Kerello <christophe.kerello at foss.st.com>
Signed-off-by: Patrice Chotard <patrice.chotard at foss.st.com>
---
 drivers/mtd/nand/spi/core.c | 22 ++++++++++++++++++----
 include/linux/mtd/spinand.h |  1 +
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/spi/core.c b/drivers/mtd/nand/spi/core.c
index 17f63f95f4a2..916f435257bd 100644
--- a/drivers/mtd/nand/spi/core.c
+++ b/drivers/mtd/nand/spi/core.c
@@ -475,18 +475,32 @@ 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);
+	unsigned long timeo =  jiffies + msecs_to_jiffies(SPINAND_STATUS_TIMEOUT_MS);
 	u8 status;
 	int ret;
 
-	do {
-		ret = spinand_read_status(spinand, &status);
+	ret = spi_mem_poll_status(spinand->spimem, &op, STATUS_BUSY, 0,
+				  SPINAND_STATUS_TIMEOUT_MS);
+	if (ret != -EOPNOTSUPP) {
 		if (ret)
 			return ret;
 
+		status = *spinand->scratchbuf;
+
 		if (!(status & STATUS_BUSY))
 			goto out;
-	} while (time_before(jiffies, timeo));
+	} else {
+		do {
+			ret = spinand_read_status(spinand, &status);
+			if (ret)
+				return ret;
+
+			if (!(status & STATUS_BUSY))
+				goto out;
+		} while (time_before(jiffies, timeo));
+	}
 
 	/*
 	 * Extra read, just in case the STATUS_READY bit has changed
diff --git a/include/linux/mtd/spinand.h b/include/linux/mtd/spinand.h
index 6bb92f26833e..28ee481d96eb 100644
--- a/include/linux/mtd/spinand.h
+++ b/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
-- 
2.17.1