On Fri, May 27, 2022 at 05:35:36PM -0400, Stephen Boyd wrote:
> Quoting Dmitry Torokhov (2022-05-26 16:12:30)
> > From: Furquan Shaikh <furquan@xxxxxxxxxxxx>
> >
> > Some detachable/convertible x86 Chromebooks use EC buttons/switches
> > interface to signal volume up/down and other buttons. This configuration is
> > signalled via presence of GOOG0007 ACPI device. The main keyboard on such
> > Chromebooks is still using the standard 8042/atkbd combo.
> >
> > Signed-off-by: Furquan Shaikh <furquan@xxxxxxxxxxxx>
> > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > ---
>
> Reviewed-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
>
> Two questions below.
>
> > drivers/input/keyboard/cros_ec_keyb.c | 21 ++++++++++++++++++---
> > 1 file changed, 18 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
> > index e8338b1c5776..c14136b733a9 100644
> > --- a/drivers/input/keyboard/cros_ec_keyb.c
> > +++ b/drivers/input/keyboard/cros_ec_keyb.c
> > @@ -677,14 +678,19 @@ static const struct attribute_group cros_ec_keyb_attr_group = {
> >
> > static int cros_ec_keyb_probe(struct platform_device *pdev)
> > {
> > - struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
> > + struct cros_ec_device *ec;
> > struct device *dev = &pdev->dev;
> > struct cros_ec_keyb *ckdev;
> > bool buttons_switches_only = device_get_match_data(dev);
> > int err;
> >
> > - if (!dev->of_node)
> > - return -ENODEV;
> > + /*
> > + * If the parent ec device has not been probed yet, defer the probe of
> > + * this keyboard/button driver until later.
> > + */
> > + ec = dev_get_drvdata(pdev->dev.parent);
>
> Does cros_ec populate the child node before setting the drvdata? Or in
> ACPI designs this device is created as a child of cros_ec before the
> driver probes?
Yes, ACPI "bus" gets scanned and all device objects are created
regardless of the driver presence and whether probe has completed or
not.
Thanks.
--
Dmitry
