str9x: faster flash erase of entire chip

The patch improves flash erase for STR9x in case of a full bank erase.
Then the chip erase command is used instead which improves speed significantly.

Also I think it might help if e.g. STR912 enters some state where flash banks are locked, and a chip erase command is the key for unlocking the flash.

diff --git a/src/flash/nor/str9x.c b/src/flash/nor/str9x.c
index 528e52e26901c0e32d0d05a8c98be5a35da982b3..cfe6a77709866742d622d0d4c2401c6637e570c0 100644 (file)
--- a/src/flash/nor/str9x.c
+++ b/src/flash/nor/str9x.c
@@ -223,6 +223,7 @@ static int str9x_erase(struct flash_bank *bank, int first, int last)
        uint32_t adr;
        uint8_t status;
        uint8_t erase_cmd;
+       int total_timeout;
 
        if (bank->target->state != TARGET_HALTED)
        {
@@ -230,16 +231,27 @@ static int str9x_erase(struct flash_bank *bank, int first, int last)
                return ERROR_TARGET_NOT_HALTED;
        }
 
-       /*A slower but stable way of erasing*/
-       /* Erase sector command */
-       erase_cmd = 0x20;
+       /* Check if we can erase whole bank */
+       if ((first == 0) && (last == (bank->num_sectors - 1)))
+       {
+               /* Optimize to run erase bank command instead of sector */
+               erase_cmd = 0x80;
+                /* Add timeout duration since erase bank takes more time */
+               total_timeout = 1000 * bank->num_sectors;
+       }
+       else
+       {
+               /* Erase sector command */
+               erase_cmd = 0x20;
+               total_timeout = 1000;
+       }
 
        for (i = first; i <= last; i++)
        {
                int retval;
                adr = bank->base + bank->sectors[i].offset;
 
-               /* erase sectors */
+               /* erase sectors or block */
                if ((retval = target_write_u16(target, adr, erase_cmd)) != ERROR_OK)
                {
                        return retval;
@@ -256,7 +268,8 @@ static int str9x_erase(struct flash_bank *bank, int first, int last)
                }
 
                int timeout;
-               for (timeout = 0; timeout < 1000; timeout++) {
+               for (timeout = 0; timeout < total_timeout; timeout++) 
+               {
                        if ((retval = target_read_u8(target, adr, &status)) != ERROR_OK)
                        {
                                return retval;
@@ -265,7 +278,7 @@ static int str9x_erase(struct flash_bank *bank, int first, int last)
                                break;
                        alive_sleep(1);
                }
-               if (timeout == 1000)
+               if (timeout == total_timeout)
                {
                        LOG_ERROR("erase timed out");
                        return ERROR_FAIL;
@@ -288,6 +301,10 @@ static int str9x_erase(struct flash_bank *bank, int first, int last)
                        LOG_ERROR("error erasing flash bank, status: 0x%x", status);
                        return ERROR_FLASH_OPERATION_FAILED;
                }
+
+               /* If we ran erase bank command, we are finished */
+               if (erase_cmd == 0x80)
+                       break;
        }
 
        for (i = first; i <= last; i++)