Re: [PATCH 2/2] i2c/designware: Provide optional i2c bus recovery function

[Rajeev kumar <rajeev-dlh.kumar-qxv4g6HH51o@public.gmane.org>]

On 2/27/2012 12:57 PM, Laxman Dewangan wrote:
> On Monday 27 February 2012 12:51 PM, Shubhrajyoti Datta wrote:
>> On Fri, Feb 24, 2012 at 5:01 PM, Viresh Kumar<viresh.kumar-qxv4g6HH51o@public.gmane.org>   wrote:
>>> From: Vincenzo Frascino<vincenzo.frascino-qxv4g6HH51o@public.gmane.org>
>>>
>>> Add optional i2c_recover_bus() function to the Synopsys DesignWare I2C adapter
>>> driver that performs i2c bus recovery after timeout. The scope of this routine
>>> is to define i2c bus recovery procedure as specified in the i2c protocol Rev. 03
>>> section 3.16 titled "Bus clear".
>> What do you do in the function ?
>>
>> Could we have it in the driver file itself?
>>
> I think bus recovery mechanism is to send  extra clock on SCL line by
> toggling the pin (using gpio apis) and keep watching of sda line whether
> it becomes high or not.
> We can put this algorithms in the some common file (i2c/algos/) and so
> if any i2c bus driver want to use, they can use it.
> Little background: I am working on tegra i2c controller and we have
> similar logic in tegra-i2c driver which we want to upstream.
> If similar function is in common place, we can use this and need not to
> duplicating it on every bus driver.
>

I agreed with Laxman, as this is the protocol issue and so it should not 
be in each individual driver. It should be the part of framework 
itself. We need to implement something like 
drivers/i2c/busses/i2c-gpio.c.  We need to investigate more on it.


Best Regards
Rajeev

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