[U-Boot] [PATCHv2 5/8] drivers: mtd: spi: Modify read/write command for sfl256s flash.

[Sourav Poddar]

Reading using the already supported read command is causing regression
after 4k bytes, as a result doing a page by page read. Its happening, because
ti qpsi controller CS will get de asserted after 4096 bytes. 

Signed-off-by: Sourav Poddar <sourav.poddar at ti.com>
---
 drivers/mtd/spi/spi_flash.c |   32 +++++++++++++++++++++++++++++++-
 1 files changed, 31 insertions(+), 1 deletions(-)

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index 6a6fe37..5f8db7b 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -303,6 +303,36 @@ int spi_flash_cmd_read_fast(struct spi_flash *flash, u32 offset,
 		else
 			read_len = remain_len;
 
+#ifdef CONFIG_TI_QSPI
+		unsigned long page_addr, byte_addr, page_size;
+		size_t chunk_len, actual;
+		int ret = 0;
+
+		page_size = flash->page_size;
+		page_addr = offset / page_size;
+		byte_addr = offset % page_size;
+
+		for (actual = 0; actual < read_len; actual += chunk_len) {
+			chunk_len = min(read_len - actual, page_size - byte_addr);
+
+			cmd[1] = page_addr >> 8;
+			cmd[2] = page_addr;
+			cmd[3] = byte_addr;
+
+			ret = spi_flash_read_common(flash, cmd, sizeof(cmd),
+					data + actual, chunk_len);
+			if (ret < 0) {
+				debug("SF: read failed");
+				break;
+			}
+
+			byte_addr += chunk_len;
+			if (byte_addr == page_size) {
+				page_addr++;
+				byte_addr = 0;
+			}
+		}
+#else
 		spi_flash_addr(offset, cmd);
 
 		ret = spi_flash_read_common(flash, cmd, sizeof(cmd),
@@ -311,7 +341,7 @@ int spi_flash_cmd_read_fast(struct spi_flash *flash, u32 offset,
 			debug("SF: read failed\n");
 			break;
 		}
-
+#endif
 		offset += read_len;
 		len -= read_len;
 		data += read_len;
-- 
1.7.1