1 files changed, 26 insertions, 14 deletions

diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 98df5bcc02f3..25efd331ef28 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -33,7 +33,7 @@
 /* Flash opcodes. */
 #define OPCODE_WREN             0x06    /* Write enable */
 #define OPCODE_RDSR             0x05    /* Read status register */
-#define OPCODE_READ             0x03    /* Read data bytes (low frequency) */
+#define OPCODE_NORM_READ        0x03    /* Read data bytes (low frequency) */
 #define OPCODE_FAST_READ        0x0b    /* Read data bytes (high frequency) */
 #define OPCODE_PP               0x02    /* Page program (up to 256 bytes) */
 #define OPCODE_BE_4K            0x20    /* Erase 4KiB block */
@@ -52,7 +52,15 @@
 
 /* Define max times to check status register before we give up. */
 #define MAX_READY_WAIT_COUNT    100000
+#define CMD_SIZE                4
 
+#ifdef CONFIG_M25PXX_USE_FAST_READ
+#define OPCODE_READ     OPCODE_FAST_READ
+#define FAST_READ_DUMMY_BYTE 1
+#else
+#define OPCODE_READ     OPCODE_NORM_READ
+#define FAST_READ_DUMMY_BYTE 0
+#endif
 
 #ifdef CONFIG_MTD_PARTITIONS
 #define mtd_has_partitions()    (1)
@@ -68,7 +76,7 @@ struct m25p {
         struct mtd_info         mtd;
         unsigned                partitioned:1;
         u8                      erase_opcode;
-        u8                      command[4];
+        u8                      command[CMD_SIZE + FAST_READ_DUMMY_BYTE];
 };
 
 static inline struct m25p *mtd_to_m25p(struct mtd_info *mtd)
@@ -151,7 +159,7 @@ static int wait_till_ready(struct m25p *flash)
 static int erase_sector(struct m25p *flash, u32 offset)
 {
         DEBUG(MTD_DEBUG_LEVEL3, "%s: %s %dKiB at 0x%08x\n",
-                        flash->spi->dev.bus_id, __FUNCTION__,
+                        flash->spi->dev.bus_id, __func__,
                         flash->mtd.erasesize / 1024, offset);
 
         /* Wait until finished previous write command. */
@@ -167,7 +175,7 @@ static int erase_sector(struct m25p *flash, u32 offset)
         flash->command[2] = offset >> 8;
         flash->command[3] = offset;
 
-        spi_write(flash->spi, flash->command, sizeof(flash->command));
+        spi_write(flash->spi, flash->command, CMD_SIZE);
 
         return 0;
 }
@@ -188,7 +196,7 @@ static int m25p80_erase(struct mtd_info *mtd, struct erase_info *instr)
         u32 addr,len;
 
         DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %d\n",
-                        flash->spi->dev.bus_id, __FUNCTION__, "at",
+                        flash->spi->dev.bus_id, __func__, "at",
                         (u32)instr->addr, instr->len);
 
         /* sanity checks */
@@ -240,7 +248,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
         struct spi_message m;
 
         DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
-                        flash->spi->dev.bus_id, __FUNCTION__, "from",
+                        flash->spi->dev.bus_id, __func__, "from",
                         (u32)from, len);
 
         /* sanity checks */
@@ -253,8 +261,12 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
         spi_message_init(&m);
         memset(t, 0, (sizeof t));
 
+        /* NOTE:
+         * OPCODE_FAST_READ (if available) is faster.
+         * Should add 1 byte DUMMY_BYTE.
+         */
         t[0].tx_buf = flash->command;
-        t[0].len = sizeof(flash->command);
+        t[0].len = CMD_SIZE + FAST_READ_DUMMY_BYTE;
         spi_message_add_tail(&t[0], &m);
 
         t[1].rx_buf = buf;
@@ -287,7 +299,7 @@ static int m25p80_read(struct mtd_info *mtd, loff_t from, size_t len,
 
         spi_sync(flash->spi, &m);
 
-        *retlen = m.actual_length - sizeof(flash->command);
+        *retlen = m.actual_length - CMD_SIZE - FAST_READ_DUMMY_BYTE;
 
         mutex_unlock(&flash->lock);
 
@@ -308,7 +320,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
         struct spi_message m;
 
         DEBUG(MTD_DEBUG_LEVEL2, "%s: %s %s 0x%08x, len %zd\n",
-                        flash->spi->dev.bus_id, __FUNCTION__, "to",
+                        flash->spi->dev.bus_id, __func__, "to",
                         (u32)to, len);
 
         if (retlen)
@@ -325,7 +337,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
         memset(t, 0, (sizeof t));
 
         t[0].tx_buf = flash->command;
-        t[0].len = sizeof(flash->command);
+        t[0].len = CMD_SIZE;
         spi_message_add_tail(&t[0], &m);
 
         t[1].tx_buf = buf;
@@ -354,7 +366,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
 
                 spi_sync(flash->spi, &m);
 
-                *retlen = m.actual_length - sizeof(flash->command);
+                *retlen = m.actual_length - CMD_SIZE;
         } else {
                 u32 i;
 
@@ -364,7 +376,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
                 t[1].len = page_size;
                 spi_sync(flash->spi, &m);
 
-                *retlen = m.actual_length - sizeof(flash->command);
+                *retlen = m.actual_length - CMD_SIZE;
 
                 /* write everything in PAGESIZE chunks */
                 for (i = page_size; i < len; i += page_size) {
@@ -387,8 +399,7 @@ static int m25p80_write(struct mtd_info *mtd, loff_t to, size_t len,
                         spi_sync(flash->spi, &m);
 
                         if (retlen)
-                                *retlen += m.actual_length
-                                        - sizeof(flash->command);
+                                *retlen += m.actual_length - CMD_SIZE;
                 }
         }
 
@@ -435,6 +446,7 @@ static struct flash_info __devinitdata m25p_data [] = {
         { "at25fs040",  0x1f6604, 64 * 1024, 8, SECT_4K, },
 
         { "at25df041a", 0x1f4401, 64 * 1024, 8, SECT_4K, },
+        { "at25df641",  0x1f4800, 64 * 1024, 128, SECT_4K, },
 
         { "at26f004",   0x1f0400, 64 * 1024, 8, SECT_4K, },
         { "at26df081a", 0x1f4501, 64 * 1024, 16, SECT_4K, },