| Message ID | 20241206-lpm-v6-10-constraints-pmdomain-v6-1-833980158c68@baylibre.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere, archived |
| Headers | show |
| Series | pmdomain: ti_sci: collect and send low-power mode constraints | expand |
On Dec 06, 2024 at 14:12:50 -0800, Kevin Hilman wrote: > For each device in a TI SCI PM domain, check whether the device has > any resume latency constraints set via per-device PM QoS. If > constraints are set, send them to DM via the new SCI constraints API. > > Checking for constraints happen for each device before system-wide > suspend (via ->suspend() hook.) > > An important detail here is that the PM domain driver inserts itself > into the path of both the ->suspend() and ->resume() hook path > of *all* devices in the PM domain. This allows generic PM domain code > to handle the constraint management and communication with TI SCI. > > Further, this allows device drivers to use existing PM QoS APIs to > add/update constraints. > > DM firmware clears constraints during its resume, so Linux has > to check/update/send constraints each time system suspends. > > Also note that the PM QoS framework uses usecs as the units for > latency whereas the TI SCI firmware uses msecs, so a conversion is > needed before passing to TI SCI. > > Co-developed-by: Vibhore Vardhan <vibhore@ti.com> > Signed-off-by: Vibhore Vardhan <vibhore@ti.com> > Reviewed-by: Markus Schneider-Pargmann <msp@baylibre.com> > Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> > Tested-by: Dhruva Gole <d-gole@ti.com> > Signed-off-by: Kevin Hilman <khilman@baylibre.com> > --- > drivers/pmdomain/ti/ti_sci_pm_domains.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 55 insertions(+) > > diff --git a/drivers/pmdomain/ti/ti_sci_pm_domains.c b/drivers/pmdomain/ti/ti_sci_pm_domains.c > index 0e4bd749d067309654307484c5bb98711bf06daf..963fe1901c959197d5d8b5d34fd8420dfb180087 100644 > --- a/drivers/pmdomain/ti/ti_sci_pm_domains.c > +++ b/drivers/pmdomain/ti/ti_sci_pm_domains.c > @@ -13,6 +13,8 @@ > #include <linux/platform_device.h> > #include <linux/pm_domain.h> > #include <linux/slab.h> > +#include <linux/pm_qos.h> > +#include <linux/pm_runtime.h> nit: Do we not need to sort these includes alphabetically? > #include <linux/soc/ti/ti_sci_protocol.h> > #include <dt-bindings/soc/ti,sci_pm_domain.h> > > @@ -51,6 +53,32 @@ struct ti_sci_pm_domain { > > #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd) > > +static inline bool ti_sci_pd_is_valid_constraint(s32 val) > +{ > + return val != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; > +} > + > +#ifdef CONFIG_PM_SLEEP > +static void ti_sci_pd_set_lat_constraint(struct device *dev, s32 val) > +{ > + struct generic_pm_domain *genpd = pd_to_genpd(dev->pm_domain); > + struct ti_sci_pm_domain *pd = genpd_to_ti_sci_pd(genpd); > + const struct ti_sci_handle *ti_sci = pd->parent->ti_sci; > + u16 val_ms; > + int ret; > + > + /* PM QoS latency unit is usecs, TI SCI uses msecs */ > + val_ms = val / USEC_PER_MSEC; > + ret = ti_sci->ops.pm_ops.set_latency_constraint(ti_sci, val_ms, TISCI_MSG_CONSTRAINT_SET); > + if (ret) > + dev_err(dev, "ti_sci_pd: set latency constraint failed: ret=%d\n", > + ret); > + else > + dev_dbg(dev, "ti_sci_pd: ID:%d set latency constraint %d\n", > + pd->idx, val); > +} > +#endif > + > /* > * ti_sci_pd_power_off(): genpd power down hook > * @domain: pointer to the powerdomain to power off > @@ -79,6 +107,26 @@ static int ti_sci_pd_power_on(struct generic_pm_domain *domain) > return ti_sci->ops.dev_ops.get_device(ti_sci, pd->idx); > } > > +#ifdef CONFIG_PM_SLEEP > +static int ti_sci_pd_suspend(struct device *dev) > +{ > + int ret; > + s32 val; > + > + ret = pm_generic_suspend(dev); > + if (ret) > + return ret; > + > + val = dev_pm_qos_read_value(dev, DEV_PM_QOS_RESUME_LATENCY); > + if (ti_sci_pd_is_valid_constraint(val)) > + ti_sci_pd_set_lat_constraint(dev, val); > + > + return 0; > +} > +#else > +#define ti_sci_pd_suspend NULL > +#endif > + > /* > * ti_sci_pd_xlate(): translation service for TI SCI genpds > * @genpdspec: DT identification data for the genpd > @@ -182,6 +230,13 @@ static int ti_sci_pm_domain_probe(struct platform_device *pdev) > pd->pd.flags |= GENPD_FLAG_ACTIVE_WAKEUP; > pd->idx = args.args[0]; > pd->parent = pd_provider; > + /* > + * If SCI constraint functions are present, then firmware > + * supports the constraints API. > + */ > + if (pd_provider->ti_sci->ops.pm_ops.set_device_constraint && > + pd_provider->ti_sci->ops.pm_ops.set_latency_constraint) > + pd->pd.domain.ops.suspend = ti_sci_pd_suspend; Rest looks good. Reviewed-by: Dhruva Gole <d-gole@ti.com>
diff --git a/drivers/pmdomain/ti/ti_sci_pm_domains.c b/drivers/pmdomain/ti/ti_sci_pm_domains.c index 0e4bd749d067309654307484c5bb98711bf06daf..963fe1901c959197d5d8b5d34fd8420dfb180087 100644 --- a/drivers/pmdomain/ti/ti_sci_pm_domains.c +++ b/drivers/pmdomain/ti/ti_sci_pm_domains.c @@ -13,6 +13,8 @@ #include <linux/platform_device.h> #include <linux/pm_domain.h> #include <linux/slab.h> +#include <linux/pm_qos.h> +#include <linux/pm_runtime.h> #include <linux/soc/ti/ti_sci_protocol.h> #include <dt-bindings/soc/ti,sci_pm_domain.h> @@ -51,6 +53,32 @@ struct ti_sci_pm_domain { #define genpd_to_ti_sci_pd(gpd) container_of(gpd, struct ti_sci_pm_domain, pd) +static inline bool ti_sci_pd_is_valid_constraint(s32 val) +{ + return val != PM_QOS_RESUME_LATENCY_NO_CONSTRAINT; +} + +#ifdef CONFIG_PM_SLEEP +static void ti_sci_pd_set_lat_constraint(struct device *dev, s32 val) +{ + struct generic_pm_domain *genpd = pd_to_genpd(dev->pm_domain); + struct ti_sci_pm_domain *pd = genpd_to_ti_sci_pd(genpd); + const struct ti_sci_handle *ti_sci = pd->parent->ti_sci; + u16 val_ms; + int ret; + + /* PM QoS latency unit is usecs, TI SCI uses msecs */ + val_ms = val / USEC_PER_MSEC; + ret = ti_sci->ops.pm_ops.set_latency_constraint(ti_sci, val_ms, TISCI_MSG_CONSTRAINT_SET); + if (ret) + dev_err(dev, "ti_sci_pd: set latency constraint failed: ret=%d\n", + ret); + else + dev_dbg(dev, "ti_sci_pd: ID:%d set latency constraint %d\n", + pd->idx, val); +} +#endif + /* * ti_sci_pd_power_off(): genpd power down hook * @domain: pointer to the powerdomain to power off @@ -79,6 +107,26 @@ static int ti_sci_pd_power_on(struct generic_pm_domain *domain) return ti_sci->ops.dev_ops.get_device(ti_sci, pd->idx); } +#ifdef CONFIG_PM_SLEEP +static int ti_sci_pd_suspend(struct device *dev) +{ + int ret; + s32 val; + + ret = pm_generic_suspend(dev); + if (ret) + return ret; + + val = dev_pm_qos_read_value(dev, DEV_PM_QOS_RESUME_LATENCY); + if (ti_sci_pd_is_valid_constraint(val)) + ti_sci_pd_set_lat_constraint(dev, val); + + return 0; +} +#else +#define ti_sci_pd_suspend NULL +#endif + /* * ti_sci_pd_xlate(): translation service for TI SCI genpds * @genpdspec: DT identification data for the genpd @@ -182,6 +230,13 @@ static int ti_sci_pm_domain_probe(struct platform_device *pdev) pd->pd.flags |= GENPD_FLAG_ACTIVE_WAKEUP; pd->idx = args.args[0]; pd->parent = pd_provider; + /* + * If SCI constraint functions are present, then firmware + * supports the constraints API. + */ + if (pd_provider->ti_sci->ops.pm_ops.set_device_constraint && + pd_provider->ti_sci->ops.pm_ops.set_latency_constraint) + pd->pd.domain.ops.suspend = ti_sci_pd_suspend; pm_genpd_init(&pd->pd, NULL, true);