[PATCH v4 0/7] mtd: spi-nor: add a new framework for SPI NOR

Jagan Teki jagannadh.teki at gmail.com
Fri Jan 17 12:06:49 EST 2014


On Fri, Jan 17, 2014 at 2:09 PM, Jagan Teki <jagannadh.teki at gmail.com> wrote:
> On Fri, Jan 17, 2014 at 12:24 PM, Huang Shijie <b32955 at freescale.com> wrote:
>> On Fri, Jan 17, 2014 at 12:36:08PM +0530, Jagan Teki wrote:
>>> >> 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?
>> Take drivers/spi/spi-imx.c for example, if you connect a NOR to it, you only
>> need to add a NOR device node in the device tree. In the probe, it will call
>> the m25p80.c to probe the NOR device.
>>
>> But if we connect other device to it. you should set another device node for it.
>>
>> I am not sure if your controller driver can works as the spi-imx.c
>
> My question here was - this new framework suggest to write a two
> different controller
> drivers one is for non spi-nor and spi-nor models? do you agree that?
>
> And also one important note from your design was spi-nor mode is
> completely bypassing
> Linux spi core is that the good idea?

I feel these are good points to discuss all.
1. With new framework seems like we need two separate controller drivers
    one for non spi-nor and one for spi-nor with single controller hw
2. With spi-nor implementation though the hw is spi complaint but the sw is
   completely ignoring the Linux SPI core interaction.

I feel above two points are technically wrong - Please correct me if am wrong
but need all developers will join..thanks!

-- 
Jagan.



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