Re: [PATCH 1/5] hwmon: (core) Inherit power properties to hdev

[Guenter Roeck <linux@roeck-us.net>]

On Tue, Oct 16, 2018 at 06:24:22PM -0700, Nicolin Chen wrote:
> The new hdev is a child device related to the original parent
> hwmon driver and its device. However, it doesn't support the
> power features, typically being defined in the parent driver.
> 
> So this patch inherits three necessary power properties from
> the parent dev to hdev: power, pm_domain and driver pointers.
> 
> Note that the dev->driver pointer is the place that contains
> a dev_pm_ops pointer defined in the parent device driver and
> the pm runtime core also checks this pointer:
>        if (!cb && dev->driver && dev->driver->pm)
> 
> Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
> ---
>  drivers/hwmon/hwmon.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
> index 975c95169884..7c064e1218ba 100644
> --- a/drivers/hwmon/hwmon.c
> +++ b/drivers/hwmon/hwmon.c
> @@ -625,6 +625,9 @@ __hwmon_device_register(struct device *dev, const char *name, void *drvdata,
>  	hwdev->name = name;
>  	hdev->class = &hwmon_class;
>  	hdev->parent = dev;
> +	hdev->driver = dev->driver;
> +	hdev->power = dev->power;
> +	hdev->pm_domain = dev->pm_domain;

dev can, unfortunately, be NULL

>  	hdev->of_node = dev ? dev->of_node : NULL;

... as you can see here.

Guenter

>  	hwdev->chip = chip;
>  	dev_set_drvdata(hdev, drvdata);
> -- 
> 2.17.1
>