Re: [RFC PATCH v3 1/5] rtc: add device selector for rtc_class_ops callbacks

["Danilo Krummrich" <dakr@kernel.org>]

On Fri Jan 16, 2026 at 5:21 PM CET, Ke Sun wrote:
> diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
> index baf1a8ca8b2b1..eddcc5a69db3b 100644
> --- a/drivers/rtc/dev.c
> +++ b/drivers/rtc/dev.c
> @@ -410,7 +410,7 @@ static long rtc_dev_ioctl(struct file *file,
>  		}
>  		default:
>  			if (rtc->ops->param_get)
> -				err = rtc->ops->param_get(rtc->dev.parent, &param);
> +				err = rtc->ops->param_get(rtc_ops_dev(rtc), &param);
>  			else
>  				err = -EINVAL;
>  		}

<snip>

> +/**
> + * rtc_ops_dev - Get the device pointer for RTC ops callbacks
> + * @rtc: RTC device
> + *
> + * Returns &rtc->dev if RTC_OPS_USE_RTC_DEV flag is set,
> + * otherwise returns rtc->dev.parent.
> + */
> +static inline struct device *rtc_ops_dev(struct rtc_device *rtc)
> +{
> +	if (test_bit(RTC_OPS_USE_RTC_DEV, &rtc->flags))
> +		return &rtc->dev;
> +	return rtc->dev.parent;
> +}

I understand that the idea is to gradually convert all drivers to use the RTC
device, rather than it's parent device in RTC device callbacks.

My main concern is that once that has been achieved it's still not what we want
to have eventually, i.e. RTC device callbacks should ideally take a struct
rtc_device as argument and not the embedded base struct device.

I.e. we'd kick off a conversion process that won't reach the actual desired
state.