于 2013年09月05日 17:11, Gupta, Pekon 写道:
No, SPI generic framework (struct spi_transfer, spi_message,...)
should be kept independent of any MTD flash specific data handlers.
<wangyuhang2014@xxxxxxxxx> added two new fields (tx_nbits, rx_nbits)
to spi_device because those properties are part of SPI protocol.
But, 'dummy_cycles' is no related to SPI protocol. So it should be kept out
of SPI generic framework.
This is where if you could use DT based approach, things would have been
simpler, because you give end-user the freedom to enter device-info from
device datasheet.
ok. i think i do not need to change the spi code now.
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> > Example: How to select opcodes in DT ?
> > (step-1) eliminate opcode which cannot be used due to board constrains.
> > your board connects only 2 data I/O between device and controller, So you
> > cannot use any of the QUAD Read opcodes. Thus your choice is limited to
> > DUAL or SINGLE modes only.
> we have 4 data I/O lines between the device and controller, i only need
> the Quad mode.:)
>
May be because you are currently working on a development EVM or
demo board, so you can live with QUAD mode.
But when customer will have custom boards with different QSPI devices
then you would end-up supporting all sorts of configurations:-)
And in production scenarios, it’s the price economics which mostly dominates
which part to choose and how to connect it on board.
Like as I remember some freescale boards have WINBOND QSPI flash
which uses different opcodes and semantics, so you might need to support
that too in future.
So my suggestion is think again. As you are inviting lot of re-work for yourself
and for others too:-)
Anyway, if you really want to continue with this is, then please re-name
include/linux/mtd/spi-nor.h to
include/linux/mtd/spi-fsl-quadspi.h
because something specific for your driver should not conflict with
generic spi-nor framework added later.
i think there is no specific thing for this driver. The S25FL128S is a
common flash,
other person may uses it too. Could you show me what is specific?
so, i prefer to spi-nor.h.
thanks
Huang Shijie
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