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

[Jagan Teki]

On 10 October 2014 19:05, Simon Glass <sjg at chromium.org> wrote:
> 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.

OK, I will give my first level comments by tomorrow (IST)
May be this will prolong least by next week end, if something need to change.

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

Will comment again on this.

thanks!
-- 
Jagan.