| Message ID | 20250613-pmdomain-hierarchy-onecell-v3-2-5c770676fce7@baylibre.com |
|---|---|
| State | New |
| Headers | show |
| Series | pmdomain: core: add support for domain hierarchies in DT | expand |
On Sat, 14 Jun 2025 at 00:39, Kevin Hilman <khilman@baylibre.com> wrote: > > Currently, PM domains can only support hierarchy for simple > providers (e.g. ones with #power-domain-cells = 0). > > Add more generic support for hierarchy by using nexus node > maps (c.f. section 2.5.1 of the DT spec.) > > For example, we could describe SCMI PM domains with multiple parents > domains (MAIN_PD and WKUP_PD) like this: > > scmi_pds: protocol@11 { > reg = <0x11>; > #power-domain-cells = <1>; > > power-domain-map = <15 &MAIN_PD>, > <19 &WKUP_PD>; > }; > > which should mean that <&scmi_pds 15> is a subdomain of MAIN_PD and > <&scmi_pds 19> is a subdomain of WKUP_PD. > > IOW, given an SCMI device which uses SCMI PM domains: > > main_timer0: timer@2400000 { > power-domains = <&scmi_pds 15>; > }; > > it already implies that main_timer0 is PM domain <&scmi_pds 15> > > With the new map, this *also* now implies <&scmi_pds 15> is a > subdomain of MAIN_PD. > > Signed-off-by: Kevin Hilman <khilman@baylibre.com> > --- > drivers/pmdomain/core.c | 24 ++++++++++++++++++++++-- > 1 file changed, 22 insertions(+), 2 deletions(-) > > diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c > index d6c1ddb807b2..adf022b45d95 100644 > --- a/drivers/pmdomain/core.c > +++ b/drivers/pmdomain/core.c > @@ -2998,8 +2998,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, > unsigned int index, unsigned int num_domains, > bool power_on) > { > - struct of_phandle_args pd_args; > - struct generic_pm_domain *pd; > + struct of_phandle_args pd_args, parent_args; > + struct generic_pm_domain *pd, *parent_pd = NULL; > int ret; > > ret = of_parse_phandle_with_args(dev->of_node, "power-domains", > @@ -3039,6 +3039,22 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, > goto err; > } > > + /* > + * Check for power-domain-map, which implies the primary > + * power-doamin is a subdomain of the parent found in the map. > + */ > + ret = of_parse_phandle_with_args_map(dev->of_node, "power-domains", > + "power-domain", index, &parent_args); > + if (!ret && (pd_args.np != parent_args.np)) { > + parent_pd = genpd_get_from_provider(&parent_args); > + of_node_put(parent_args.np); > + > + ret = pm_genpd_add_subdomain(parent_pd, pd); > + if (!ret) > + dev_dbg(dev, "adding PM domain %s as subdomain of %s\n", > + pd->name, parent_pd->name); > + } Please move the above new code to a separate shared genpd helper function, that genpd providers can call build the topology. This, to be consistent with the current way for how we usually add parent/child-domains in genpd (see of_genpd_add_subdomain). Moreover, we also need a corresponding "cleanup" helper function to remove the child-domain (subdomain) correctly, similar to of_genpd_remove_subdomain(). > + > ret = genpd_set_required_opp(dev, index); > if (ret) > goto err; > @@ -3056,6 +3072,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, > dev_gpd_data(dev)->default_pstate = 0; > } > > + if (parent_pd) > + pm_genpd_remove_subdomain(parent_pd, pd); > genpd_remove_device(pd, dev); > return -EPROBE_DEFER; > } > @@ -3063,6 +3081,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, > return 1; > > err: > + if (parent_pd) > + pm_genpd_remove_subdomain(parent_pd, pd); > genpd_remove_device(pd, dev); > return ret; > } > > -- > 2.49.0 > Kind regards Uffe
Ulf Hansson <ulf.hansson@linaro.org> writes: --text follows this line-- > On Sat, 14 Jun 2025 at 00:39, Kevin Hilman <khilman@baylibre.com> wrote: >> >> Currently, PM domains can only support hierarchy for simple >> providers (e.g. ones with #power-domain-cells = 0). >> >> Add more generic support for hierarchy by using nexus node >> maps (c.f. section 2.5.1 of the DT spec.) >> >> For example, we could describe SCMI PM domains with multiple parents >> domains (MAIN_PD and WKUP_PD) like this: >> >> scmi_pds: protocol@11 { >> reg = <0x11>; >> #power-domain-cells = <1>; >> >> power-domain-map = <15 &MAIN_PD>, >> <19 &WKUP_PD>; >> }; >> >> which should mean that <&scmi_pds 15> is a subdomain of MAIN_PD and >> <&scmi_pds 19> is a subdomain of WKUP_PD. >> >> IOW, given an SCMI device which uses SCMI PM domains: >> >> main_timer0: timer@2400000 { >> power-domains = <&scmi_pds 15>; >> }; >> >> it already implies that main_timer0 is PM domain <&scmi_pds 15> >> >> With the new map, this *also* now implies <&scmi_pds 15> is a >> subdomain of MAIN_PD. >> >> Signed-off-by: Kevin Hilman <khilman@baylibre.com> >> --- >> drivers/pmdomain/core.c | 24 ++++++++++++++++++++++-- >> 1 file changed, 22 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c >> index d6c1ddb807b2..adf022b45d95 100644 >> --- a/drivers/pmdomain/core.c >> +++ b/drivers/pmdomain/core.c >> @@ -2998,8 +2998,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, >> unsigned int index, unsigned int num_domains, >> bool power_on) >> { >> - struct of_phandle_args pd_args; >> - struct generic_pm_domain *pd; >> + struct of_phandle_args pd_args, parent_args; >> + struct generic_pm_domain *pd, *parent_pd = NULL; >> int ret; >> >> ret = of_parse_phandle_with_args(dev->of_node, "power-domains", >> @@ -3039,6 +3039,22 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, >> goto err; >> } >> >> + /* >> + * Check for power-domain-map, which implies the primary >> + * power-doamin is a subdomain of the parent found in the map. >> + */ >> + ret = of_parse_phandle_with_args_map(dev->of_node, "power-domains", >> + "power-domain", index, &parent_args); >> + if (!ret && (pd_args.np != parent_args.np)) { >> + parent_pd = genpd_get_from_provider(&parent_args); >> + of_node_put(parent_args.np); >> + >> + ret = pm_genpd_add_subdomain(parent_pd, pd); >> + if (!ret) >> + dev_dbg(dev, "adding PM domain %s as subdomain of %s\n", >> + pd->name, parent_pd->name); >> + } > > Please move the above new code to a separate shared genpd helper > function, that genpd providers can call build the topology. This, to > be consistent with the current way for how we usually add > parent/child-domains in genpd (see of_genpd_add_subdomain). Yeah, you had the same comment on v2, and I'm not ignoring you. But I thought that moving this code to when devices are attatched to domains (instead of when providers are created) would solve that problem. IOW, in this approach, `power-domain-map` is handled at the same time as a devices `power-domains = ` property. So, while I don't really understand the reason that every PM domain provider has to handle this individually, I've given that a try (see below.) > Moreover, we also need a corresponding "cleanup" helper function to > remove the child-domain (subdomain) correctly, similar to > of_genpd_remove_subdomain(). Yes, I'll handle that better once I get through this RFC phase to make sure I'm on th right path. OK, so below[1] is a shot at just adding helpers to the PM domain core. I will then uses these from the SCMI PM domains ->attach_dev() and ->detatch_dev callbacks. If you think this is better, I'll send a v4 tomorrow. Kevin [1] NOTE: this is based on v6.12 because that's where I have a functioning BSP for this SoC. If you're OK with this, I'll rebase to v6.15 and submit upstream.
diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c index d6c1ddb807b2..adf022b45d95 100644 --- a/drivers/pmdomain/core.c +++ b/drivers/pmdomain/core.c @@ -2998,8 +2998,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, unsigned int index, unsigned int num_domains, bool power_on) { - struct of_phandle_args pd_args; - struct generic_pm_domain *pd; + struct of_phandle_args pd_args, parent_args; + struct generic_pm_domain *pd, *parent_pd = NULL; int ret; ret = of_parse_phandle_with_args(dev->of_node, "power-domains", @@ -3039,6 +3039,22 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, goto err; } + /* + * Check for power-domain-map, which implies the primary + * power-doamin is a subdomain of the parent found in the map. + */ + ret = of_parse_phandle_with_args_map(dev->of_node, "power-domains", + "power-domain", index, &parent_args); + if (!ret && (pd_args.np != parent_args.np)) { + parent_pd = genpd_get_from_provider(&parent_args); + of_node_put(parent_args.np); + + ret = pm_genpd_add_subdomain(parent_pd, pd); + if (!ret) + dev_dbg(dev, "adding PM domain %s as subdomain of %s\n", + pd->name, parent_pd->name); + } + ret = genpd_set_required_opp(dev, index); if (ret) goto err; @@ -3056,6 +3072,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, dev_gpd_data(dev)->default_pstate = 0; } + if (parent_pd) + pm_genpd_remove_subdomain(parent_pd, pd); genpd_remove_device(pd, dev); return -EPROBE_DEFER; } @@ -3063,6 +3081,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev, return 1; err: + if (parent_pd) + pm_genpd_remove_subdomain(parent_pd, pd); genpd_remove_device(pd, dev); return ret; }
Currently, PM domains can only support hierarchy for simple providers (e.g. ones with #power-domain-cells = 0). Add more generic support for hierarchy by using nexus node maps (c.f. section 2.5.1 of the DT spec.) For example, we could describe SCMI PM domains with multiple parents domains (MAIN_PD and WKUP_PD) like this: scmi_pds: protocol@11 { reg = <0x11>; #power-domain-cells = <1>; power-domain-map = <15 &MAIN_PD>, <19 &WKUP_PD>; }; which should mean that <&scmi_pds 15> is a subdomain of MAIN_PD and <&scmi_pds 19> is a subdomain of WKUP_PD. IOW, given an SCMI device which uses SCMI PM domains: main_timer0: timer@2400000 { power-domains = <&scmi_pds 15>; }; it already implies that main_timer0 is PM domain <&scmi_pds 15> With the new map, this *also* now implies <&scmi_pds 15> is a subdomain of MAIN_PD. Signed-off-by: Kevin Hilman <khilman@baylibre.com> --- drivers/pmdomain/core.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-)