Re: [PATCH v2] mtd: spi-nor: Add support for SPI boot flash access for AMD Family 16h

From: Grandbois, Brett
Date: Mon Oct 29 2018 - 19:15:50 EST



On 28/10/18 1:39 am, Boris Brezillon wrote:
> Hi Brett,
>
> On Tue, 16 Oct 2018 00:57:41 +0000
> "Grandbois, Brett"<brett.grandbois@xxxxxxxxxxxx> wrote:
>
>> Add support to expose the SPI boot flash on AMD Family 16h CPUs as a
>> standard mtd device to give userspace BIOS updaters greater feature
>> support. The BIOS and Kernel Developer's Guide refers to this as the
>> 'SPI ROM' controller and so the driver follows that naming convention
>> for consistency.
>>
> We're currently trying to convert spi-nor controller drivers to the
> spi-mem interface [1]. Can you look at this new interface and tell me if
> you'd be able to implement it? If that's not possible, then I'd prefer
> to have this driver implement the mtd_info interface directly.

So from going over the spi-mem interface it looks like the intent is for these sorts of devices to be a standard spi_controller with only mem_ops defined and the transfer/_one/_one_message left as NULL? Is that correct? That's a bit of a pivot from how it's currently done (it's conceptually similar to the intel-spi-pci driver so I was following that) but I should be able to rework it to the new interface. This then lives under drivers/spi and thus should be submitted to linux-spi?


> Thanks,
>
> Boris
>
> [1]https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Flatest%2Fsource%2Finclude%2Flinux%2Fspi%2Fspi-mem.h%23L185&amp;data=02%7C01%7Cbrett.grandbois%40opengear.com%7Cf5244d9287534ea84b1208d63c226e8f%7Ca6251c26d21f4164a2251f4eaebf5f9a%7C0%7C0%7C636762515915097405&amp;sdata=9brGIXcEcLQu5g6WxaXT661%2Bjf8ULMQQpVdXzI36NTU%3D&amp;reserved=0