From mboxrd@z Thu Jan  1 00:00:00 1970
From: Viresh Kumar <viresh.kumar-qxv4g6HH51o@public.gmane.org>
Subject: Re: [PATCH 2/2] i2c/designware: Provide optional i2c bus recovery
 function
Date: Mon, 27 Feb 2012 15:57:38 +0530
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To: Rajeev KUMAR <rajeev-dlh.kumar-qxv4g6HH51o@public.gmane.org>, Shubhrajyoti Datta <omaplinuxkernel-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
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List-Id: linux-i2c@vger.kernel.org

On 2/27/2012 3:40 PM, Rajeev KUMAR wrote:
> In some i2c controller (like synopsys) you dont have control over i2c 
> data and clock lines. So clock toggling, you need to use gpio lines 
> which in turns maps on sda and scl line.
> 
> For the controller in which you have control over sda and scl line there 
> is not need for gpio lines. You can directly write on registers.
> 
> So to make the function more generic its better to control i2c lines 
> with gpio.

There would be many drivers where we need to convert i2c pins to gpio pins
and generate clock pulses:

gpio_request(gpio);
gpio_set_direction(gpio, out, 0);

for (i = 1; i < count; i++) {
	gpio set val(gpio, 1);
	gpio set val(gpio, 0);
}

gpio_free(gpio);

we can give generalized function inside i2c framework for this, so that multiple
drivers can use it.

Secondly there are drivers/devices where control of pins is available. For them
we can provide driver hooks.

I would try to provide a patch for this ASAP. Other suggestions are welcome.

-- 
viresh