Re: [PATCH 2/2] i2c/designware: Provide optional i2c bus recovery function
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Hello Shubhrajyoti On 2/27/2012 2:42 PM, Shubhrajyoti Datta wrote:
On Mon, Feb 27, 2012 at 12:57 PM, Laxman Dewangan<ldewangan@xxxxxxxxxx> 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@xxxxxx> wrote:From: Vincenzo Frascino<vincenzo.frascino@xxxxxx> 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)You mean the SCL I didnt understand the gpio part? Why is gpio needed?
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.
and keep watching of sda line whether itbecomes 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.-- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html .
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