[U-Boot] [UBOOT][PATCHv3 4/7] driver: mtd: spi: Add memory mapped read support

[Sourav Poddar]

Qspi controller can have a memory mapped port which can be used for
data read. Added support to enable memory mapped port read.

This patch enables the following:
- It enables exchange of memory map address between mtd and qspi
through the introduction of "memory_map" flag.
- Add support to communicate to the driver that memory mapped
 transfer is to be started through introduction of new flags like
"SPI_XFER_MEM_MAP" and "SPI_XFER_MEM_MAP_END".

This will enable the spi controller to do memory mapped configurations
if required.

Signed-off-by: Sourav Poddar <sourav.poddar at ti.com>
---
 drivers/mtd/spi/spansion.c  |    1 +
 drivers/mtd/spi/spi_flash.c |    4 ++++
 include/spi.h               |    3 +++
 3 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/spi/spansion.c b/drivers/mtd/spi/spansion.c
index fa7ac8c..9d801a3 100644
--- a/drivers/mtd/spi/spansion.c
+++ b/drivers/mtd/spi/spansion.c
@@ -136,6 +136,7 @@ struct spi_flash *spi_flash_probe_spansion(struct spi_slave *spi, u8 *idcode)
 	flash->page_size = 256;
 	flash->sector_size = 256 * params->pages_per_sector;
 	flash->size = flash->sector_size * params->nr_sectors;
+	flash->memory_map = spi->memory_map;
 
 	return flash;
 }
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index 993a9d4..5ad2dc1 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -287,7 +287,9 @@ int spi_flash_cmd_read_quad(struct spi_flash *flash, u32 offset,
 
 	/* Handle memory-mapped SPI */
 	if (flash->memory_map) {
+		spi_xfer(flash->spi, 0, NULL, NULL, SPI_XFER_MEM_MAP);
 		memcpy(data, flash->memory_map + offset, len);
+		spi_xfer(flash->spi, 0, NULL, NULL, SPI_XFER_MEM_MAP_END);
 		return 0;
 	}
 
@@ -338,7 +340,9 @@ int spi_flash_cmd_read_fast(struct spi_flash *flash, u32 offset,
 
 	/* Handle memory-mapped SPI */
 	if (flash->memory_map) {
+		spi_xfer(flash->spi, 0, NULL, NULL, SPI_XFER_MEM_MAP);
 		memcpy(data, flash->memory_map + offset, len);
+		spi_xfer(flash->spi, 0, NULL, NULL, SPI_XFER_MEM_MAP_END);
 		return 0;
 	}
 
diff --git a/include/spi.h b/include/spi.h
index 9d4b2dc..559722f 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -28,6 +28,8 @@
 #define SPI_XFER_BEGIN	0x01			/* Assert CS before transfer */
 #define SPI_XFER_END	0x02			/* Deassert CS after transfer */
 #define SPI_QUAD	0x04			/* Use QUAD read command */
+#define SPI_XFER_MEM_MAP 0x08			/* Memory Mapped start */
+#define SPI_XFER_MEM_MAP_END 0x10		/* Memory Mapped End */
 
 /* Header byte that marks the start of the message */
 #define SPI_PREAMBLE_END_BYTE	0xec
@@ -47,6 +49,7 @@ struct spi_slave {
 	unsigned int	cs;
 	unsigned int max_write_size;
 	bool quad_enable;
+	void *memory_map;
 };
 
 /*-----------------------------------------------------------------------
-- 
1.7.1