Re: [PATCH v2 1/2] Input: Add device_enable handler to DaVinci Keyscan platform data

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Thu, Nov 19, 2009 at 10:32:21AM -0600, Miguel Aguilar wrote:
> Hi Dmitry,
>
>>>  +	if (pdata->device_enable) {
>>> +		error = pdata->device_enable(dev);
>>> +		if (error < 0) {
>>> +			dev_dbg(dev, "device enable function failed\n");
>>> +			return error;
>>> +		}
>>> +	}
>>> +
>>
>> Hi Miguel,
>>
>> Does this need to live in the driver? Why can't platform code do this
>> for us?
>>
>> Thanks.
>>
>
> The reason to invoke the device_enable function in the driver is because 
> in the testing process of the key scan driver a issue was found when the 
> key scan is built as a module.
>
> There is a specific PINMUX configuration that only should be set if the 
> key scan driver is loaded in the kernel to avoid pin conflicts. So when 
> the key scan is built as a module the board file (or platform code) 
> doesn't know if the key scan is loaded or not, so that's why the driver 
> is the one who must invoke the device_enable function in the probe 
> function.
>

I see... What happens if PINMUX is set but there isn't a driver? Also,
what happens when you unload the module? Don't you need a similar call
to disable PINMUX configuration?

-- 
Dmitry