Re: [PATCH v2 6/6] Input: Add ChromeOS EC keyboard driver

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

On Wed, Feb 13, 2013 at 10:45:07PM -0800, Simon Glass wrote:
> >>
> >> +config KEYBOARD_CROS_EC
> >> +     tristate "ChromeOS EC keyboard"
> >> +     select INPUT_MATRIXKMAP
> >> +     select MFD_CROS_EC
> >
> > Is this select safe? I.e. does MFD_CROS_EC depend on anything else?
> 
> I'll remove it, since it isn't required, and it's true that it does
> need other things.

Instead of droppign the dependency completely I think it should "depens
on MFD_CROS_EC"

> >> +
> >> +static void cros_ec_keyb_close(struct input_dev *dev)
> >> +{
> >> +     struct cros_ec_keyb *ckdev = input_get_drvdata(dev);
> >> +
> >> +     blocking_notifier_chain_unregister(&ckdev->ec->event_notifier,
> >> +                                        &ckdev->notifier);
> >> +     blocking_notifier_chain_unregister(&ckdev->ec->wake_notifier,
> >> +                                        &ckdev->wake_notifier);
> >
> > Why is this done via a notifier instead of regular resume method?
> 
> Because we only call the notifer in resume when we were not waking on
> a keyboard event. We use it to flush the keyboard. It was a late
> change so there might be a better way, but this driver does not have a
> resume handler.

Right and the question is why does not it have resume handler and why
you inventing your own resume infrastructure instead of using the
standard one.

> >> +
> >> +static int cros_ec_keyb_probe(struct platform_device *pdev)
> >> +{
> >> +     struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
> >> +     struct device *dev = ec->dev;
> >> +     struct cros_ec_keyb *ckdev = NULL;
> >> +     struct input_dev *idev = NULL;
> >> +     struct device_node *np;
> >> +     int err;
> >> +
> >> +     np = of_find_matching_node(NULL, cros_ec_kbc_of_match);
> >
> > And if we don't find it?
> 
> Added error checking.
> 
> >
> >> +
> >> +     ckdev = kzalloc(sizeof(*ckdev), GFP_KERNEL);
> >> +     if (!ckdev) {
> >> +             dev_err(dev, "cannot allocate memory for ckdev\n");
> >> +             return -ENOMEM;
> >> +     }
> >> +     pdev->dev.of_node = np;
> >
> > Huh? I'd expect the platform device be fully set up (including DT data)
> > before the driver is called.
> 
> This is a child of the mfd driver cros_ec, so I don't think that
> works. Or maybe I'm just not sure how to plumb it in so it is
> automatic. Or maybe I just need to add the id to the device info
> below?

Who creates this device? Whoever does this should set up the
pdev->dev.of_node. This is not this driver's responsibility.

And then you add the id to the table below and matching is done
automatically.

Thanks.

-- 
Dmitry