mtd: spi-nor-core: Rework s25hx_t_post_bfpt_fixup() for flash's internal address...

The flash's internal address mode is tracked by nor->add_mode_nbytes and
it is set to 3 in BFPT parse. SEMPER multi-die package parts (>1Gb) are
3- or 4-byte address mode by default, depending on model number. We need
to make sure that 4-byte address mode is used for multi-die package parts.

For single-die package parts (<=1Gb), registers can be accessed by 3-byte
address. Read, program, and erase use the 4B opcodes that always take
4-byte address regardless of flash's internal address mode.

Signed-off-by: Takahiro Kuwano <Takahiro.Kuwano@infineon.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>

diff --git a/drivers/mtd/spi/spi-nor-core.c b/drivers/mtd/spi/spi-nor-core.c
index 4109e04..44674cb 100644 (file)
--- a/drivers/mtd/spi/spi-nor-core.c
+++ b/drivers/mtd/spi/spi-nor-core.c
@@ -161,6 +161,7 @@ struct sfdp_header {
 #define BFPT_DWORD15_QER_SR2_BIT1              (0x5UL << 20) /* Spansion */
 
 #define BFPT_DWORD16_SOFT_RST                  BIT(12)
+#define BFPT_DWORD16_EX4B_PWRCYC               BIT(21)
 
 #define BFPT_DWORD18_CMD_EXT_MASK              GENMASK(30, 29)
 #define BFPT_DWORD18_CMD_EXT_REP               (0x0UL << 29) /* Repeat */
@@ -3276,10 +3277,24 @@ static int s25hx_t_post_bfpt_fixup(struct spi_nor *nor,
        nor->erase_opcode = SPINOR_OP_SE_4B;
        nor->mtd.erasesize = nor->info->sector_size;
 
-       ret = set_4byte(nor, nor->info, 1);
-       if (ret)
-               return ret;
-       nor->addr_width = 4;
+       /*
+        * The default address mode in multi-die package parts (>1Gb) may be
+        * 3- or 4-byte, depending on model number. BootROM code in some SoCs
+        * use 3-byte mode for backward compatibility and should switch to
+        * 4-byte mode after BootROM phase. Since registers in the 2nd die are
+        * mapped within 32-bit address space, we need to make sure the flash is
+        * in 4-byte address mode. The default address mode can be distinguished
+        * by BFPT 16th DWORD. Power cycle exits 4-byte address mode if default
+        * is 3-byte address mode.
+        */
+       if (params->size > SZ_128M) {
+               if (bfpt->dwords[BFPT_DWORD(16)] & BFPT_DWORD16_EX4B_PWRCYC) {
+                       ret = set_4byte(nor, nor->info, 1);
+                       if (ret)
+                               return ret;
+               }
+               nor->addr_mode_nbytes = 4;
+       }
 
        /*
         * The page_size is set to 512B from BFPT, but it actually depends on