mtd: spi_flash: Add support for read if offset is odd

Add support ot read from flash if offset received is odd
incase of dual parallel. This fixes the issue of spi flash
read failures if received offset is odd

Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index 169c3ea93dfd6426df88e1e2742250629d34fcab..93d255e4c7625d014a2deda420e0bb2d9d233f05 100644 (file)
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -599,6 +599,27 @@ int spi_flash_cmd_read_ops(struct spi_flash *flash, u32 offset,
        u32 remain_len, read_len, read_addr, bank_addr;
        int bank_sel = 0;
        int ret = -1;
+#ifdef CONFIG_SF_DUAL_FLASH
+       u8 moveoffs = 0;
+       void *tempbuf = NULL;
+       size_t length = len;
+#endif
+
+#ifdef CONFIG_SF_DUAL_FLASH
+       /*
+        * Incase of dual parallel, if odd offset is received
+        * decrease it by 1 and read extra byte, otherwise
+        * any read with odd offset fails
+        */
+       if (flash->dual_flash == SF_DUAL_PARALLEL_FLASH) {
+               if (offset & 1) {
+                       offset -= 1;
+                       len += 1;
+                       moveoffs = 1;
+                       tempbuf = data;
+               }
+       }
+#endif
 
        /* Handle memory-mapped SPI */
        if (flash->memory_map) {
@@ -681,6 +702,15 @@ int spi_flash_cmd_read_ops(struct spi_flash *flash, u32 offset,
                data += read_len;
        }
 
+#ifdef CONFIG_SF_DUAL_FLASH
+       if (flash->dual_flash == SF_DUAL_PARALLEL_FLASH) {
+               if (moveoffs) {
+                       data = tempbuf + 1;
+                       memcpy(tempbuf, data, length);
+               }
+       }
+#endif
+
        free(cmd);
        return ret;
 }