[PATCH] [MTD] [CHIPS] stm_flash: new ST PSD4256G compatible flash chip driver

Mike Frysinger vapier.adi at gmail.com
Sat Sep 19 16:28:26 EDT 2009


On Sat, Sep 19, 2009 at 16:08, David Woodhouse wrote:
> On Sat, 2009-06-13 at 06:59 -0400, Mike Frysinger wrote:
>> The ST PSD4256G Flash In-System Programming (ISP) part is a multifunction
>> device.  Since all of the different pieces are memory mapped, this is a
>> driver for the NOR flash component.  All the other pieces can use generic
>> memory based drivers.  Unfortunately, this is not a CFI compliant part in
>> any way, so we need a dedicated chip driver for it.
>
> Hrm. This looks very similar to cfi_cmdset_0002.c, which we _do_ already
> use with non-CFI-compliant parts.
>
> CFI is just the _probe_ method. We can probe chips using the JEDEC
> method too, and that works just fine -- jedec_probe.c will "invoke" the
> appropriate command set driver.
>
> Can't you do the same?

afaik, it isnt JEDEC compliant either.  you can find the data sheet here:
http://www.st.com/stonline/products/literature/ds/8116/psd4256g6v.htm

so if i created a probe function that created a fake cfi table and
then called cfi_cmdset_0002(), you think the read/write/erase
functions would work ?  i dont see any mapping drivers that do this
kind of thing.  where can i find an example ?
-mike



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