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

[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'.

Regards,
Simon