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

[Ulf Hansson <ulf.hansson@linaro.org>]

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