[PATCHv2 07/10] drivers: mtd: m25p80: Adapt driver to support memory mapped read.

[Sourav Poddar <sourav.poddar@xxxxxx>]

Adapt driver to do a memory mapped read.

Signed-off-by: Sourav Poddar <sourav.poddar@xxxxxx>
---
v1->v2:
 - Add a check to Wait for the previous erase/write to
   finish.
 - Ensure proper locking
 drivers/mtd/devices/m25p80.c |   20 ++++++++++++++++++++
 1 files changed, 20 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index b90c7e5..eb75d84 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -109,6 +109,7 @@ struct m25p {
 	u8			program_opcode;
 	u8			*command;
 	enum read_type		flash_read;
+	void __iomem *mem_addr;
 };
 
 static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
@@ -515,6 +516,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
 	size_t *retlen, u_char *buf)
 {
 	struct m25p *flash = mtd_to_m25p(mtd);
+	struct spi_master *master = flash->spi->master;
 	struct spi_transfer t[2];
 	struct spi_message m;
 	uint8_t opcode;
@@ -523,6 +525,20 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
 	pr_debug("%s: %s from 0x%08x, len %zd\n", dev_name(&flash->spi->dev),
 			__func__, (u32)from, len);
 
+	if (master->mmap) {
+		mutex_lock(&flash->lock);
+		/* Wait till previous write/erase is done. */
+		if (wait_till_ready(flash)) {
+			mutex_unlock(&flash->lock);
+			return 1;
+		}
+		flash->mem_addr = master->get_buf(master);
+		memcpy(buf, flash->mem_addr + from, len);
+		master->put_buf(master);
+		*retlen = len;
+		goto out;
+	}
+
 	spi_message_init(&m);
 	memset(t, 0, (sizeof t));
 
@@ -558,6 +574,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
 
 	*retlen = m.actual_length - m25p_cmdsz(flash) - dummy;
 
+out:
 	mutex_unlock(&flash->lock);
 
 	return 0;
@@ -1286,6 +1303,9 @@ static int m25p_probe(struct spi_device *spi)
 		flash->addr_width = 3;
 	}
 
+	if (spi->master->configure_from_slave)
+		m25p80_fill_flash_information(flash);
+
 	dev_info(&spi->dev, "%s (%lld Kbytes)\n", id->name,
 			(long long)flash->mtd.size >> 10);
 
-- 
1.7.1

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