On 7/16/2021 10:43 AM, Rajendra Nayak wrote:
Some devics 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.
Also drop/set as part of runtime suspend/resume callbacks.
Signed-off-by: Rajendra Nayak <rnayak@xxxxxxxxxxxxxx>
---
drivers/base/power/domain.c | 29 ++++++++++++++++++++++++++++-
include/linux/pm_domain.h | 1 +
2 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index a934c67..eef5507 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -917,6 +917,10 @@ static int genpd_runtime_suspend(struct device *dev)
if (irq_safe_dev_in_no_sleep_domain(dev, genpd))
return 0;
+ /* Drop the default performance state */
+ if (dev_gpd_data(dev)->default_pstate)
+ dev_pm_genpd_set_performance_state(dev, 0);
+
genpd_lock(genpd);
gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
genpd_power_off(genpd, true, 0);
@@ -937,6 +941,7 @@ static int genpd_runtime_resume(struct device *dev)
{
struct generic_pm_domain *genpd;
struct generic_pm_domain_data *gpd_data = dev_gpd_data(dev);
+ unsigned int default_pstate = gpd_data->default_pstate;
struct gpd_timing_data *td = &gpd_data->td;
bool runtime_pm = pm_runtime_enabled(dev);
ktime_t time_start;
@@ -968,6 +973,9 @@ static int genpd_runtime_resume(struct device *dev)
if (ret)
return ret;
+ /* Set the default performance state */
+ if (default_pstate)
+ dev_pm_genpd_set_performance_state(dev, default_pstate);
out:
/* Measure resume latency. */
time_start = 0;
@@ -1000,6 +1008,8 @@ static int genpd_runtime_resume(struct device *dev)
genpd_stop_dev(genpd, dev);
err_poweroff:
if (!pm_runtime_is_irq_safe(dev) || genpd_is_irq_safe(genpd)) {
+ if (default_pstate)
+ dev_pm_genpd_set_performance_state(dev, 0);
genpd_lock(genpd);
gpd_data->rpm_pstate = genpd_drop_performance_state(dev);
genpd_power_off(genpd, true, 0);
@@ -2598,6 +2608,12 @@ 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)
@@ -2635,9 +2651,10 @@ static void genpd_dev_pm_sync(struct device *dev)
static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
unsigned int index, bool power_on)
{
+ struct device_node *np;
struct of_phandle_args pd_args;
struct generic_pm_domain *pd;
- int ret;
+ int ret, pstate;
ret = of_parse_phandle_with_args(dev->of_node, "power-domains",
"#power-domain-cells", index, &pd_args);
@@ -2678,6 +2695,16 @@ static int __genpd_dev_pm_attach(struct device *dev, struct device *base_dev,
if (ret)
genpd_remove_device(pd, dev);
+ /* Set the default performance state */
+ np = base_dev->of_node;
+ if (of_parse_phandle(np, "required-opps", index)) {
+ pstate = of_get_required_opp_performance_state(np, index);
+ if (pstate > 0) {
+ dev_pm_genpd_set_performance_state(dev, pstate);
+ dev_gpd_data(dev)->default_pstate = pstate;
+ }
+ }
I realized this needs better error handling after I sent it out,
I'll fix and respin.
+
return ret ? -EPROBE_DEFER : 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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