[PATCH 08/11] pmdomain: core: Add internal ->sync_state() support for genpd providers

Ulf Hansson
2025-04-17T14:25:46Z

If the genpd provider's fwnode doesn't have an associated struct device
with it, we can make use of the generic genpd->dev and it corresponding
driver internally in genpd to manage ->sync_state().

More precisely, while adding a genpd OF provider let's check if the fwnode
has a device and if not, make the preparation to handle ->sync_state()
internally through the genpd_provider_driver and the genpd_provider_bus.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
---
drivers/pmdomain/core.c | 36 ++++++++++++++++++++++++++++++++++++
include/linux/pm_domain.h | 7 +++++++
2 files changed, 43 insertions(+)

diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
index 512f89e6d302..9c5a77bf59d2 100644
--- a/drivers/pmdomain/core.c
+++ b/drivers/pmdomain/core.c
@@ -2374,6 +2374,7 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
INIT_WORK(&genpd->power_off_work, genpd_power_off_work_fn);
atomic_set(&genpd->sd_count, 0);
genpd->status = is_off ? GENPD_STATE_OFF : GENPD_STATE_ON;
+ genpd->sync_state = GENPD_SYNC_STATE_OFF;
genpd->device_count = 0;
genpd->provider = NULL;
genpd->device_id = -ENXIO;
@@ -2656,6 +2657,7 @@ int of_genpd_add_provider_simple(struct device_node *np,
struct generic_pm_domain *genpd)
{
struct fwnode_handle *fwnode;
+ struct device *dev;
int ret;

if (!np || !genpd)
@@ -2665,6 +2667,10 @@ int of_genpd_add_provider_simple(struct device_node *np,
return -EINVAL;

fwnode = &np->fwnode;
+ dev = fwnode->dev;
+
+ if (!dev)
+ genpd->sync_state = GENPD_SYNC_STATE_SIMPLE;

device_set_node(&genpd->dev, fwnode);

@@ -2718,8 +2724,10 @@ int of_genpd_add_provider_onecell(struct device_node *np,
{
struct generic_pm_domain *genpd;
struct fwnode_handle *fwnode;
+ struct device *dev;
unsigned int i;
int ret = -EINVAL;
+ bool sync_state = false;

if (!np || !data)
return -EINVAL;
@@ -2728,6 +2736,10 @@ int of_genpd_add_provider_onecell(struct device_node *np,
data->xlate = genpd_xlate_onecell;

fwnode = &np->fwnode;
+ dev = fwnode->dev;
+
+ if (!dev)
+ sync_state = true;

for (i = 0; i < data->num_domains; i++) {
genpd = data->domains[i];
@@ -2737,6 +2749,11 @@ int of_genpd_add_provider_onecell(struct device_node *np,
if (!genpd_present(genpd))
goto error;

+ if (sync_state) {
+ genpd->sync_state = GENPD_SYNC_STATE_ONECELL;
+ sync_state = false;
+ }
+
device_set_node(&genpd->dev, fwnode);

ret = device_add(&genpd->dev);
@@ -3453,6 +3470,25 @@ static void genpd_provider_remove(struct device *dev)

static void genpd_provider_sync_state(struct device *dev)
{
+ struct generic_pm_domain *genpd = container_of(dev, struct generic_pm_domain, dev);
+
+ switch (genpd->sync_state) {
+ case GENPD_SYNC_STATE_OFF:
+ break;
+
+ case GENPD_SYNC_STATE_ONECELL:
+ of_genpd_sync_state(dev);
+ break;
+
+ case GENPD_SYNC_STATE_SIMPLE:
+ genpd_lock(genpd);
+ genpd_power_off(genpd, false, 0);
+ genpd_unlock(genpd);
+ break;
+
+ default:
+ break;
+ }
}

static struct genpd_provider_drv genpd_provider_drv = {
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index e9a1f8975c4f..2185ee9e4f7c 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -127,6 +127,12 @@ enum genpd_notication {
GENPD_NOTIFY_ON,
};

+enum genpd_sync_state {
+ GENPD_SYNC_STATE_OFF = 0,
+ GENPD_SYNC_STATE_SIMPLE,
+ GENPD_SYNC_STATE_ONECELL,
+};
+
struct dev_power_governor {
bool (*power_down_ok)(struct dev_pm_domain *domain);
bool (*suspend_ok)(struct device *dev);
@@ -187,6 +193,7 @@ struct generic_pm_domain {
unsigned int performance_state; /* Aggregated max performance state */
cpumask_var_t cpus; /* A cpumask of the attached CPUs */
bool synced_poweroff; /* A consumer needs a synced poweroff */
+ enum genpd_sync_state sync_state; /* How sync_state is managed. */
int (*power_off)(struct generic_pm_domain *domain);
int (*power_on)(struct generic_pm_domain *domain);
struct raw_notifier_head power_notifiers; /* Power on/off notifiers */
--
2.43.0