Re: [PATCH RFC] Input: Add Microchip AR1021 i2c touchscreen

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

Hi Chrisitian,

On Fri, Jan 31, 2014 at 12:40:19PM +0100, Christian Gmeiner wrote:
> >> --- /dev/null
> >> +++ b/drivers/input/touchscreen/ar1021_i2c.c
> >> @@ -0,0 +1,201 @@
> >> +/*
> >> + * Microchip AR1021 driver for I2C
> >> + *
> >> + * Author: Christian Gmeiner <christian.gmeiner@gmail.com>
> >> + *
> >> + * License: GPL as published by the FSF.

By the way, you probably do not want GPL v1 to apply... Maybe say GPL v2
or GPL v2 and later (depending on your preference and the license of the
code you used as a base)?

> >> +
> >> +static int ar1021_i2c_resume(struct device *dev)
> >> +{
> >> +     struct i2c_client *client = to_i2c_client(dev);
> >> +
> >> +     enable_irq(client->irq);
> >
> > You do not want to enable IRQ if there are no users (nobody opened
> > device).
> >
> 
> Okay.. but then I also do not need the disable_irq(..) call in
> ar1021_i2c_suspend
> and can totally remove the PM stuff - or?

No, I think you still need the PM methods, you just need to check if
device is opened (take dev->mutex, check dev->users) and decide if you
need to enable/disable IRQ or not.

-- 
Dmitry