PM / Domains: Make it possible to use per-device domain callbacks

The current generic PM domains code requires that the same .stop(),
.start() and .active_wakeup() device callback routines be used for
all devices in the given domain, which is inflexible and may not
cover some specific use cases.  For this reason, make it possible to
use device specific .start()/.stop() and .active_wakeup() callback
routines by adding corresponding callback pointers to struct
generic_pm_domain_data.  Add a new helper routine,
pm_genpd_register_callbacks(), that can be used to populate
the new per-device callback pointers.

Modify the shmobile's power domains code to allow drivers to add
their own code to be run during the device stop and start operations
with the help of the new callback pointers.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@opensource.se>

1 files changed, 115 insertions, 37 deletions

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 6790cf7eba5a..94afaa2686a6 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -15,6 +15,23 @@
 #include <linux/err.h>
 #include <linux/sched.h>
 #include <linux/suspend.h>
+#include <linux/export.h>
+
+#define GENPD_DEV_CALLBACK(genpd, type, callback, dev)		\
+({								\
+	type (*__routine)(struct device *__d); 			\
+	type __ret = (type)0;					\
+								\
+	__routine = genpd->dev_ops.callback; 			\
+	if (__routine) {					\
+		__ret = __routine(dev); 			\
+	} else {						\
+		__routine = dev_gpd_data(dev)->ops.callback;	\
+		if (__routine) 					\
+			__ret = __routine(dev);			\
+	}							\
+	__ret;							\
+})
 
 static LIST_HEAD(gpd_list);
 static DEFINE_MUTEX(gpd_list_lock);
@@ -29,6 +46,16 @@ static struct generic_pm_domain *dev_to_genpd(struct device *dev)
 	return pd_to_genpd(dev->pm_domain);
 }
 
+static int genpd_stop_dev(struct generic_pm_domain *genpd, struct device *dev)
+{
+	return GENPD_DEV_CALLBACK(genpd, int, stop, dev);
+}
+
+static int genpd_start_dev(struct generic_pm_domain *genpd, struct device *dev)
+{
+	return GENPD_DEV_CALLBACK(genpd, int, start, dev);
+}
+
 static bool genpd_sd_counter_dec(struct generic_pm_domain *genpd)
 {
 	bool ret = false;
@@ -199,13 +226,9 @@ static int __pm_genpd_save_device(struct pm_domain_data *pdd,
 	mutex_unlock(&genpd->lock);
 
 	if (drv && drv->pm && drv->pm->runtime_suspend) {
-		if (genpd->start_device)
-			genpd->start_device(dev);
-
+		genpd_start_dev(genpd, dev);
 		ret = drv->pm->runtime_suspend(dev);
-
-		if (genpd->stop_device)
-			genpd->stop_device(dev);
+		genpd_stop_dev(genpd, dev);
 	}
 
 	mutex_lock(&genpd->lock);
@@ -235,13 +258,9 @@ static void __pm_genpd_restore_device(struct pm_domain_data *pdd,
 	mutex_unlock(&genpd->lock);
 
 	if (drv && drv->pm && drv->pm->runtime_resume) {
-		if (genpd->start_device)
-			genpd->start_device(dev);
-
+		genpd_start_dev(genpd, dev);
 		drv->pm->runtime_resume(dev);
-
-		if (genpd->stop_device)
-			genpd->stop_device(dev);
+		genpd_stop_dev(genpd, dev);
 	}
 
 	mutex_lock(&genpd->lock);
@@ -413,6 +432,7 @@ static void genpd_power_off_work_fn(struct work_struct *work)
 static int pm_genpd_runtime_suspend(struct device *dev)
 {
 	struct generic_pm_domain *genpd;
+	int ret;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
@@ -422,11 +442,9 @@ static int pm_genpd_runtime_suspend(struct device *dev)
 
 	might_sleep_if(!genpd->dev_irq_safe);
 
-	if (genpd->stop_device) {
-		int ret = genpd->stop_device(dev);
-		if (ret)
-			return ret;
-	}
+	ret = genpd_stop_dev(genpd, dev);
+	if (ret)
+		return ret;
 
 	/*
 	 * If power.irq_safe is set, this routine will be run with interrupts
@@ -502,8 +520,7 @@ static int pm_genpd_runtime_resume(struct device *dev)
 	mutex_unlock(&genpd->lock);
 
  out:
-	if (genpd->start_device)
-		genpd->start_device(dev);
+	genpd_start_dev(genpd, dev);
 
 	return 0;
 }
@@ -534,6 +551,12 @@ static inline void genpd_power_off_work_fn(struct work_struct *work) {}
 
 #ifdef CONFIG_PM_SLEEP
 
+static bool genpd_dev_active_wakeup(struct generic_pm_domain *genpd,
+				    struct device *dev)
+{
+	return GENPD_DEV_CALLBACK(genpd, bool, active_wakeup, dev);
+}
+
 /**
  * pm_genpd_sync_poweroff - Synchronously power off a PM domain and its masters.
  * @genpd: PM domain to power off, if possible.
@@ -590,7 +613,7 @@ static bool resume_needed(struct device *dev, struct generic_pm_domain *genpd)
 	if (!device_can_wakeup(dev))
 		return false;
 
-	active_wakeup = genpd->active_wakeup && genpd->active_wakeup(dev);
+	active_wakeup = genpd_dev_active_wakeup(genpd, dev);
 	return device_may_wakeup(dev) ? active_wakeup : !active_wakeup;
 }
 
@@ -646,7 +669,7 @@ static int pm_genpd_prepare(struct device *dev)
 	/*
 	 * The PM domain must be in the GPD_STATE_ACTIVE state at this point,
 	 * so pm_genpd_poweron() will return immediately, but if the device
-	 * is suspended (e.g. it's been stopped by .stop_device()), we need
+	 * is suspended (e.g. it's been stopped by genpd_stop_dev()), we need
 	 * to make it operational.
 	 */
 	pm_runtime_resume(dev);
@@ -714,12 +737,10 @@ static int pm_genpd_suspend_noirq(struct device *dev)
 	if (ret)
 		return ret;
 
-	if (dev->power.wakeup_path
-	    && genpd->active_wakeup && genpd->active_wakeup(dev))
+	if (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev))
 		return 0;
 
-	if (genpd->stop_device)
-		genpd->stop_device(dev);
+	genpd_stop_dev(genpd, dev);
 
 	/*
 	 * Since all of the "noirq" callbacks are executed sequentially, it is
@@ -761,8 +782,7 @@ static int pm_genpd_resume_noirq(struct device *dev)
 	 */
 	pm_genpd_poweron(genpd);
 	genpd->suspended_count--;
-	if (genpd->start_device)
-		genpd->start_device(dev);
+	genpd_start_dev(genpd, dev);
 
 	return pm_generic_resume_noirq(dev);
 }
@@ -836,8 +856,7 @@ static int pm_genpd_freeze_noirq(struct device *dev)
 	if (ret)
 		return ret;
 
-	if (genpd->stop_device)
-		genpd->stop_device(dev);
+	genpd_stop_dev(genpd, dev);
 
 	return 0;
 }
@@ -864,8 +883,7 @@ static int pm_genpd_thaw_noirq(struct device *dev)
 	if (genpd->suspend_power_off)
 		return 0;
 
-	if (genpd->start_device)
-		genpd->start_device(dev);
+	genpd_start_dev(genpd, dev);
 
 	return pm_generic_thaw_noirq(dev);
 }
@@ -938,12 +956,10 @@ static int pm_genpd_dev_poweroff_noirq(struct device *dev)
 	if (ret)
 		return ret;
 
-	if (dev->power.wakeup_path
-	    && genpd->active_wakeup && genpd->active_wakeup(dev))
+	if (dev->power.wakeup_path && genpd_dev_active_wakeup(genpd, dev))
 		return 0;
 
-	if (genpd->stop_device)
-		genpd->stop_device(dev);
+	genpd_stop_dev(genpd, dev);
 
 	/*
 	 * Since all of the "noirq" callbacks are executed sequentially, it is
@@ -993,8 +1009,7 @@ static int pm_genpd_restore_noirq(struct device *dev)
 
 	pm_genpd_poweron(genpd);
 	genpd->suspended_count--;
-	if (genpd->start_device)
-		genpd->start_device(dev);
+	genpd_start_dev(genpd, dev);
 
 	return pm_generic_restore_noirq(dev);
 }
@@ -1280,6 +1295,69 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
 }
 
 /**
+ * pm_genpd_add_callbacks - Add PM domain callbacks to a given device.
+ * @dev: Device to add the callbacks to.
+ * @ops: Set of callbacks to add.
+ */
+int pm_genpd_add_callbacks(struct device *dev, struct gpd_dev_ops *ops)
+{
+	struct pm_domain_data *pdd;
+	int ret = 0;
+
+	if (!(dev && dev->power.subsys_data && ops))
+		return -EINVAL;
+
+	pm_runtime_disable(dev);
+	device_pm_lock();
+
+	pdd = dev->power.subsys_data->domain_data;
+	if (pdd) {
+		struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
+
+		gpd_data->ops = *ops;
+	} else {
+		ret = -EINVAL;
+	}
+
+	device_pm_unlock();
+	pm_runtime_enable(dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pm_genpd_add_callbacks);
+
+/**
+ * pm_genpd_remove_callbacks - Remove PM domain callbacks from a given device.
+ * @dev: Device to remove the callbacks from.
+ */
+int pm_genpd_remove_callbacks(struct device *dev)
+{
+	struct pm_domain_data *pdd;
+	int ret = 0;
+
+	if (!(dev && dev->power.subsys_data))
+		return -EINVAL;
+
+	pm_runtime_disable(dev);
+	device_pm_lock();
+
+	pdd = dev->power.subsys_data->domain_data;
+	if (pdd) {
+		struct generic_pm_domain_data *gpd_data = to_gpd_data(pdd);
+
+		gpd_data->ops = (struct gpd_dev_ops){ 0 };
+	} else {
+		ret = -EINVAL;
+	}
+
+	device_pm_unlock();
+	pm_runtime_enable(dev);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pm_genpd_remove_callbacks);
+
+/**
  * pm_genpd_init - Initialize a generic I/O PM domain object.
  * @genpd: PM domain object to initialize.
  * @gov: PM domain governor to associate with the domain (may be NULL).