On 29/05/18 11:04, Ulf Hansson wrote:
> To support devices being partitioned across multiple PM domains, let's
> begin with extending genpd to cope with these kind of configurations.
>
> Therefore, add a new exported function genpd_dev_pm_attach_by_id(), which
> is similar to the existing genpd_dev_pm_attach(), but with the difference
> that it allows its callers to provide an index to the PM domain that it
> wants to attach.
>
> Note that, genpd_dev_pm_attach_by_id() shall only be called by the driver
> core / PM core, similar to how the existing dev_pm_domain_attach() makes
> use of genpd_dev_pm_attach(). However, this is implemented by following
> changes on top.
>
> Because, only one PM domain can be attached per device, genpd needs to
> create a virtual device that it can attach/detach instead. More precisely,
> let the new function genpd_dev_pm_attach_by_id() register a virtual struct
> device via calling device_register(). Then let it attach this device to the
> corresponding PM domain, rather than the one that is provided by the
> caller. The actual attaching is done via re-using the existing genpd OF
> functions.
>
> At successful attachment, genpd_dev_pm_attach_by_id() returns the created
> virtual device, which allows the caller to operate on it to deal with power
> management. Following changes on top, provides more details in this
> regards.
>
> To deal with detaching of a PM domain for the multiple PM domains case,
> let's also extend the existing genpd_dev_pm_detach() function, to cover the
> cleanup of the created virtual device, via make it call device_unregister()
> on it. In this way, there is no need to introduce a new function to deal
> with detach for the multiple PM domain case, but instead the existing one
> is re-used.
>
> Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
> ---
>
> Changes in v2:
> - Fixed comments from Jon. Clarified function descriptions
> and changelog.
>
> ---
> drivers/base/power/domain.c | 80 +++++++++++++++++++++++++++++++++++++
> include/linux/pm_domain.h | 8 ++++
> 2 files changed, 88 insertions(+)
>
> diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
> index 2af99bfcbe3c..2b496d79159d 100644
> --- a/drivers/base/power/domain.c
> +++ b/drivers/base/power/domain.c
> @@ -2171,6 +2171,15 @@ struct generic_pm_domain *of_genpd_remove_last(struct device_node *np)
> }
> EXPORT_SYMBOL_GPL(of_genpd_remove_last);
>
> +static void genpd_release_dev(struct device *dev)
> +{
> + kfree(dev);
> +}
> +
> +static struct bus_type genpd_bus_type = {
> + .name = "genpd",
> +};
> +
> /**
> * genpd_dev_pm_detach - Detach a device from its PM domain.
> * @dev: Device to detach.
> @@ -2208,6 +2217,10 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)
>
> /* Check if PM domain can be powered off after removing this device. */
> genpd_queue_power_off_work(pd);
> +
> + /* Unregister the device if it was created by genpd. */
> + if (dev->bus == &genpd_bus_type)
> + device_unregister(dev);
> }
>
> static void genpd_dev_pm_sync(struct device *dev)
> @@ -2298,6 +2311,67 @@ int genpd_dev_pm_attach(struct device *dev)
> }
> EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
>
> +/**
> + * genpd_dev_pm_attach_by_id() - Attach a device to one of its PM domain.
> + * @dev: Device to attach.
Can you update the description of the above as well?
Thanks
Jon
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