On Fri, Jan 17, 2014 at 7:32 AM, Huang Shijie <b32955@xxxxxxxxxxxxx> wrote:
> On Thu, Jan 16, 2014 at 03:09:13PM +0530, Jagan Teki wrote:
>> >>> After this patch, the layer is like:
>> >>> MTD
>> >>> ------------------------
>> >>> spi-nor
>> >>> ------------------------
>> >>> m25p80
>> >>> ------------------------
>> >>> spi bus driver
>> >>> ------------------------
>> >>> SPI NOR chip
>>
>> Just for looking on your new framework, is that above link correct.
>> I guess it should be MTD -- m25p80 -- spi-nor -- spi bus driver -- SPI NOR chip
>
> I do not think so.
> The spi-nor layer does not contact with the spi bus driver directly.
Yes - now I understand the flow from seeing the code.
With your new framework
1. not an exact spi-nor
have one controller driver at drivers/spi/* will register to spi core.
have m25p80.c will scan the flash details from
drivers/mtd/spi-nor/spi-nor.c and
m25p80 will register the MTD core and for transfer calls m25p80
will calls spi core.
2. spi-nor style
have one controller driver at drivers/mtd/spi-nor/fsl-quadspi.c
will register MTD core
and scan the flash details from drivers/mtd/spi-nor/spi-nor.c and
for transfer will calls
through direct writel and readl with cmd+data fashion.
Correct me If my understanding was wrong.
>
>> >> 3) Can you explain your framework precisely take an example of like
>> >> spi_controller_A with spi_flash_A
>> >> and qspi_controller_B and qspi_flash_B - how will this new framework
>> >> operates.
>> >>
>> > The framework is just cloned from the m25p80.c, and extract the common code,
>> > and provides more
>> > hooks such as
>> >
>> > @prepare/unpreare: used to do some work before or after the
>> > read/write/erase/lock/unlock.
>> > @read_xfer/write_xfer: We can use these two hooks to code all
>> > the following hooks if the driver tries to implement them
>> > by itself.
>> > @read_reg: used to read the registers, such as read status register,
>> > read configure register.
>> > @write_reg: used to write the registers, such as write enable,
>> > erase sector.
>> > @read_id: read out the ID info.
>> > @wait_till_ready: wait till the NOR becomes ready.
>> > @read: read out the data from the NOR.
>> > @write: write data to the NOR.
>> > @erase: erase a sector of the NOR.
>> >
>>
>> My basic question is like I have a qspi spi controller in my SOC and I
>> designed two boards B1 and B2
>
> okay.
>
>> B1 with quad spi controller connected with non-flash as a slave and B2
>> with quad spi controller connected
>> with quad flash as a slave.
> You can use the framework for B2. But for B1, you should not use the framework,
> since this framework is just for the SPI-NOR. If you do not connected with
> a NOR, i think it's better to code another driver for your controller.
Means we have two separate controller drivers for same controller one
with spi-nor and
another with spi is it?
Do you think this is a good idea, I understand you have a complete and
well guided new
spi-nor framework.
--
Thanks,
Jagan.
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