[U-Boot] [PATCH v2] i2c: intel_i2c: SMBus driver PCI addition (e.g. BayTrail)

[Simon Glass]

Hi,

On 15 August 2016 at 23:03, Heiko Schocher <hs at denx.de> wrote:
> Hello Simon, Stefan,
>
>
> Am 16.08.2016 um 06:50 schrieb Simon Glass:
>>
>> Hi Stefan,
>>
>> On 15 August 2016 at 04:02, Stefan Roese <sr at denx.de> wrote:
>>>
>>> Hi Simon,
>>>
>>>
>>> On 10.08.2016 04:59, Simon Glass wrote:
>>>>
>>>>
>>>> On 8 August 2016 at 23:41, Stefan Roese <sr at denx.de> wrote:
>>>>>
>>>>>
>>>>> This patch adds support for the SMBus block read/write functionality.
>>>>> Other protocols like the SMBus quick command need to get added
>>>>> if this is needed.
>>>>>
>>>>> This patch also removed the SMBus related defines from the Ivybridge
>>>>> pch.h header. As they are integrated in this driver and should be
>>>>> used from here. This change is added in this patch to avoid compile
>>>>> breakage to keep the source git bisectable.
>>>>>
>>>>> Tested on a congatec BayTrail board to configure the SMSC2513 USB
>>>>> hub.
>>>>>
>>>>> Signed-off-by: Stefan Roese <sr at denx.de>
>>>>> Cc: Bin Meng <bmeng.cn at gmail.com>
>>>>> Cc: Simon Glass <sjg at chromium.org>
>>>>> Cc: Heiko Schocher <hs at denx.de>
>>>>> Cc: George McCollister <george.mccollister at gmail.com>
>>>>> ---
>>>>> v2:
>>>>> - Avoid using BSS. Patch from Simon intergrated to fix problem before
>>>>>    relocation.
>>>>> - Remove IvyBridge code and add PCI device for IvyBridge (Panther Point
>>>>>    PCH).
>>>>> - Add overrun check to smbus_block_read() as suggested by George
>>>>>
>>>>>   arch/x86/include/asm/arch-ivybridge/pch.h |  26 ---
>>>>>   drivers/i2c/intel_i2c.c                   | 290
>>>>> +++++++++++++++++++++++++++---
>>>>>   2 files changed, 269 insertions(+), 47 deletions(-)
>>>>>
>>>>
>>>> This does not crash, but I see nothing on the bus with 'i2c dev 0; i2c
>>>> probe'. Is that expected?
>>>
>>>
>>>
>>> This depends on the devices available on the I2C bus. As SMBus defines
>>> multiples protocols (byte read/write, block read/write...), and your
>>> I2C devices probably don't support the currently implemented block
>>> read/write protocol, we need to find a way configure / switch the SMBus
>>> protocol. Do you have an idea on how to do this? Perhaps we need to add
>>> a config call for this to switch between the different protocols? And
>>> also add a way to do this from the cmdline. Perhaps "i2c flags" can be
>>> used for this?
>>
>>
>> Yes I suppose a flag is the best idea. You should be able to add one
>> to the existing flags. Then it can be configured from the device or
>> via the command line 'i2c flags'.
>
>
> Yes, an "i2c flag" seems a good solution.
>
> Hmm.. thinking about it ...
>
> May we need such a functionality like in linux:/include/uapi/linux/i2c.h
> I2C_FUNC_* and i2c_check_functionality() ?

Possibly. I wonder if struct dm_i2c_bus could have a capability flags value?

Regards,
Simon