ST M29W320D incorrectly configured

[Corinna Schultz]

I'm having a problem getting the unlock addresses correctly configured  
for the ST M29W320D chip. CFI query data is shown below (from  
debugging statements I enabled and/or added to the driver). The chip  
is wired so that the #BYTE pin is low, putting the chip into x8 mode.  
The data bus is physically 8 bits.

I don't understand everything that's going on in the code, but it  
seems to me that the following code (taken from cfi_cmdset_0002.c,  
which sets the unlock addresses needed for writing and erasing) has a  
logic error. Maybe someone can explain it to me?

  if (    /* x16 in x8 mode */
     ((cfi->device_type == CFI_DEVICETYPE_X8) &&
      (cfi->cfiq->InterfaceDesc == 2))


The reason I think this is in error is that both the device type and  
the interfaceDesc are defined by the hardware, and not indicative of  
the mode. Besides, isn't this conditional actually testing if the chip  
is an X8 chip and supports x8 and x16 async modes?

As far as I know the only way to determine what mode the chip is in is  
to check the QRY string at the beginning of the query data on the chip.

According to the spec, page 12 of:   
http://www.amd.com/us-en/assets/content_type/DownloadableAssets/cfi_r20.pdf

An x16 device in x16 mode has QRY at addresses 10, 11, and 12 (hex)  
and Q null R at addresses 20, 21, and 22. An x16 device in x8 mode has  
QQR at addresses 20, 21, 22.

Since this chip is an x16 in x8 mode, the unlock addresses should be  
0xaaa and 0x555.

As can be seen below, the device_type is 2, which is  
CFI_DEVICE_TYPE_X16, and the InterfaceDesc is 2. But as I understand  
the spec, these values don't change whether the chip is in x16 mode or  
in x8 mode.

I'm not sure how to tell the version number of the driver, but  
gen_probe.c is at v 1.24, and cfi_cmdset_0002.c is at v.1.122, if that  
helps.


Here's the log:

physmap flash device: 400000 at ffc00000
Number of erase regions: 4
Primary Vendor Command Set: 0002 (AMD/Fujitsu Standard)
Primary Algorithm Table at 0040
Alternative Vendor Command Set: 0000 (None)
No Alternate Algorithm Table
Vcc Minimum:  2.7 V
Vcc Maximum:  3.6 V
Vpp Minimum: 11.5 V
Vpp Maximum: 12.5 V
Typical byte/word write timeout: 16 ?s
Maximum byte/word write timeout: 512 ?s
Full buffer write not supported
Typical block erase timeout: 1024 ms
Maximum block erase timeout: 16384 ms
Chip erase not supported
Device size: 0x400000 bytes (4 MiB)
Flash Device Interface description: 0x0002
   - supports x8 and x16 via BYTE# with asynchronous interface
Max. bytes in buffer write: 0x1
Number of Erase Block Regions: 4
   Erase Region #0: BlockSize 0x4000 bytes, 1 blocks
   Erase Region #1: BlockSize 0x2000 bytes, 2 blocks
   Erase Region #2: BlockSize 0x8000 bytes, 1 blocks
   Erase Region #3: BlockSize 0x10000 bytes, 63 blocks
phys_mapped_flash: Found 1 x16 devices at 0x0 in 8-bit bank
  Amd/Fujitsu Extended Query Table at 0x0040
   Silicon revision: 0
   Address sensitive unlock: Required
   Erase Suspend: Read/write
   Block protection: 1 sectors per group
   Temporary block unprotect: Supported
   Block protect/unprotect scheme: 4
   Number of simultaneous operations: 0
   Burst mode: Not supported
   Page mode: Not supported
   Vpp Supply Minimum Program/Erase Voltage: 11.5 V
   Vpp Supply Maximum Program/Erase Voltage: 12.5 V
   Top/Bottom Boot Block: Bottom boot
addr_unlock1: 555, addr_unlock2: 2aa
number of CFI chips: 1
cfi_cmdset_0002: Disabling erase-suspend-program due to code brokenness.


-Corinna Schultz
IBM LTC