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

From: Dmitry Torokhov
Date: Thu Feb 14 2013 - 12:31:37 EST


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
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