Some devices within power domains with performance states do not
support DVFS, but still need to vote on a default/static state
while they are active. They can express this using the 'required-opps'
property in device tree, which points to the phandle of the OPP
supported by the corresponding power-domains.
Add support to parse this information from DT and then set the
specified performance state during attach and drop it on detach.
runtime suspend/resume callbacks already have logic to drop/set
the vote as needed and should take care of dropping the default
perf state vote on runtime suspend and restore it back on runtime
resume.
Signed-off-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>
---
drivers/base/power/domain.c | 28 ++++++++++++++++++++++++++--
include/linux/pm_domain.h | 1 +
2 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index a934c67..b9b5a9b 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -2598,6 +2598,12 @@ static void genpd_dev_pm_detach(struct device *dev, bool power_off)
dev_dbg(dev, "removing from PM domain %s\n", pd->name);
+ /* Drop the default performance state */
+ if (dev_gpd_data(dev)->default_pstate) {
+ dev_pm_genpd_set_performance_state(dev, 0);
+ dev_gpd_data(dev)->default_pstate = 0;
+ }
+
for (i = 1; i < GENPD_RETRY_MAX_MS; i <<= 1) {
ret = genpd_remove_device(pd, dev);
if (ret != -EAGAIN)
@@ -2637,6 +2643,8 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
{
struct of_phandle_args pd_args;
struct generic_pm_domain *pd;
+ struct device_node *np;
+ int pstate;
int ret;
ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
@@ -2675,10 +2683,26 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
genpd_unlock(pd);
}
- if (ret)
+ if (ret) {
genpd_remove_device(pd, dev);
+ return -EPROBE_DEFER;
+ }
+
+ /* Set the default performance state */
+ np = dev->of_node;
+ if (of_parse_phandle(np, "required-opps", index)) {
+ pstate = of_get_required_opp_performance_state(np, index);
+ if (pstate < 0) {
+ ret = pstate;
+ dev_err(dev, "failed to set required performance state for power-domain %s: %d\n",
+ pd->name, ret);
+ } else {
+ dev_pm_genpd_set_performance_state(dev, pstate);
+ dev_gpd_data(dev)->default_pstate = pstate;
+ }
+ }
- return ret ? -EPROBE_DEFER : 1;
+ return ret ? ret : 1;
}
/**
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index 21a0577..67017c9 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -198,6 +198,7 @@ struct generic_pm_domain_data {
struct notifier_block *power_nb;
int cpu;
unsigned int performance_state;
+ unsigned int default_pstate;
unsigned int rpm_pstate;
ktime_t next_wakeup;
void *data;
--
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