[U-Boot] [PATCH v3 0/29] Introduce driver model support for SPI, SPI flash, cros_ec

[Simon Glass]

Hi Jagan,

On 10 October 2014 07:30, Jagan Teki <jagannadh.teki at gmail.com> wrote:
> Hi Simon,
>
> On 10 October 2014 07:36, Simon Glass <sjg at chromium.org> wrote:
>> Hi Jagan,
>>
>> On 9 October 2014 04:33, Jagan Teki <jagannadh.teki at gmail.com> wrote:
>>> On 9 October 2014 02:03, Simon Glass <sjg at chromium.org> wrote:
>>>> Hi,
>>>>
>>>> On 29 September 2014 13:34, Simon Glass <sjg at chromium.org> wrote:
>>>>> Up until now driver model has not been used for any type of bus. Buses
>>>>> have some unique properties and needs, so we cannot claim that driver
>>>>> model can cover all the common cases unless we have converted a bus over
>>>>> to driver model.
>>>>>
>>>>> SPI is a reasonable choice for this next step. It has a fairly simple
>>>>> API and not too many dependencies. The main one is SPI flash so we may
>>>>> as well convert that also. Since the boards I test with have cros_ec I
>>>>> have also included that, for SPI only.
>>>>>
>>>>> The technique used is make use of driver model's supported data structures
>>>>> to hold information currently kept by each subsystem in a private data
>>>>> structure. Since 'struct spi_slave' relates to the slave device on the bus
>>>>> it is stored in the 'parent' data with each child device of the bus.
>>>>> Since 'struct spi_flash' is a standard interface used for each SPI flash
>>>>> driver, it is stored in the SPI FLash uclass's private data for each
>>>>> device.
>>>>>
>>>>> New defines are created to enable driver model for each subsystem. These
>>>>> are:
>>>>>
>>>>>    CONFIG_DM_SPI
>>>>>    CONFIG_DM_SPI_FLASH
>>>>>    CONFIG_DM_CROS_EC
>>>>>
>>>>> This allows us to move some boards and drivers to driver model, while
>>>>> leaving others behind. A 'big bang' conversion of everything to driver
>>>>> model, even at a subsystem level, is never going to work.
>>>>>
>>>>> There is some cost in changing the uclass interface after it is created,
>>>>> so if you have limited time, please spend it reviewing the uclass
>>>>> interfaces in spi.h and spi_flash.h. These need to be supported by each
>>>>> driver, so changing them later may involve changing multiple drivers.
>>>>>
>>>>> To assist with the conversion of other SPI drivers, a README file is
>>>>> added to walk through the process.
>>>>>
>>>>> So far, sandbox, exynos and tegra drivers are converted over.
>>>>>
>>>>> As always, driver model patches are available at u-boot-dm.git branch
>>>>> 'working'. There is a branch for just this series called 'spi-working'.
>>>>
>>>> I think this has had enough time out there. So I will push this to
>>>> dm/next later this week.
>>>
>>> Sorry - I need to review a lot wrt v3.
>>> I do understand that it has been in enough time, but this causes a
>>> significant changes on
>>> entire framework, please hold on for a while I need to think with
>>> respect on qspi stuff with in
>>> the spi framework.
>>
>> Well I'm not sure it supports setting of the flags that are needed for
>> that. I don't have a platform to test with anyway.
>>
>> On the other hand adding that support to driver model could easily be
>> a separate effort. I don't see a good reason to hold up the core SPI /
>> SPI flash support.
>
> Partially agreed at this moment, let me think and review the whole stuff.
> I would place all these stuff on to my master-next, once I'm OK.
>
> Any changes based on my strategy wrt qspi stuff - I may change these.
> But I will push all these later on the 13/10 release.
>
> Comments?

Actually I'd like to bring this through the dm tree as I have a lot of
dependent series that need to go that way. What is your timeline for
further review of v3? I'm planning to push this to dm/next soon.

I suggest adding the qspi stuff to sandbox. Then it will be easier to
test with driver model. What do you think?

Regards,
Simon