mtd: cfi: Add support for status register polling

The status register is optional in the AMD command sets, but it's
presence can be checked by reading out CFI table entry 0xc bit 0.
If the register is present, prefer using it's bit 7 to determine
if the flash is busy over reading the flash ; this is needed ie.
on Hyperflash memories.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Signed-off-by: Stefan Roese <sr@denx.de>

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index df04a42..8a5babe 100644 (file)
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -544,7 +544,16 @@ static int flash_is_busy (flash_info_t * info, flash_sect_t sect)
 #ifdef CONFIG_FLASH_CFI_LEGACY
        case CFI_CMDSET_AMD_LEGACY:
 #endif
-               retval = flash_toggle (info, sect, 0, AMD_STATUS_TOGGLE);
+               if (info->sr_supported) {
+                       flash_write_cmd (info, sect, info->addr_unlock1,
+                                        FLASH_CMD_READ_STATUS);
+                       retval = !flash_isset (info, sect, 0,
+                                              FLASH_STATUS_DONE);
+               } else {
+                       retval = flash_toggle (info, sect, 0,
+                                              AMD_STATUS_TOGGLE);
+               }
+
                break;
        default:
                retval = 0;
@@ -1685,6 +1694,7 @@ static void cmdset_amd_read_jedec_ids(flash_info_t *info)
 {
        ushort bankId = 0;
        uchar  manuId;
+       uchar  lsbits;
 
        flash_write_cmd(info, 0, 0, AMD_CMD_RESET);
        flash_unlock_seq(info, 0);
@@ -1700,6 +1710,9 @@ static void cmdset_amd_read_jedec_ids(flash_info_t *info)
        }
        info->manufacturer_id = manuId;
 
+       lsbits = flash_read_uchar(info, FLASH_OFFSET_LOWER_SW_BITS);
+       info->sr_supported = lsbits & BIT(0);
+
        switch (info->chipwidth){
        case FLASH_CFI_8BIT:
                info->device_id = flash_read_uchar (info,

diff --git a/include/flash.h b/include/flash.h
index 0eedb1e..dc67cb2 100644 (file)
--- a/include/flash.h
+++ b/include/flash.h
@@ -42,6 +42,7 @@ typedef struct {
        ushort  cfi_offset;             /* offset for cfi query                 */
        ulong   addr_unlock1;           /* unlock address 1 for AMD flash roms  */
        ulong   addr_unlock2;           /* unlock address 2 for AMD flash roms  */
+       uchar   sr_supported;           /* status register supported            */
        const char *name;               /* human-readable name                  */
 #endif
 #ifdef CONFIG_MTD

diff --git a/include/mtd/cfi_flash.h b/include/mtd/cfi_flash.h
index eade2b3..095725a 100644 (file)
--- a/include/mtd/cfi_flash.h
+++ b/include/mtd/cfi_flash.h
@@ -62,6 +62,7 @@
 
 #define FLASH_OFFSET_MANUFACTURER_ID   0x00
 #define FLASH_OFFSET_DEVICE_ID         0x01
+#define FLASH_OFFSET_LOWER_SW_BITS     0x0C
 #define FLASH_OFFSET_DEVICE_ID2                0x0E
 #define FLASH_OFFSET_DEVICE_ID3                0x0F
 #define FLASH_OFFSET_CFI               0x55