shmobile: Use power domains for platform runtime PM

shmobile platforms replace the runtime PM callbacks of the platform
bus type with their own routines, but this means that the callbacks
are replaced system-wide.  This may not be the right approach if the
platform devices on the system are not of the same type (e.g. some
of them belong to an SoC and the others are located in separate
chips), because in those cases they may require different handling.
Thus it is better to use power domains to override the platform bus
type's PM handling, as it generally is possible to use different
power domains for devices with different PM requirements.

Define a default power domain for shmobile in both the SH and ARM
falvors and use it to override the platform bus type's PM callbacks.
Since the suspend and hibernate callbacks of the new "default" power
domains need to be the same and the platform bus type's suspend and
hibernate callbacks for the time being, export those callbacks so
that can be used outside of the platform bus type code.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

arch/arm/mach-shmobile/pm_runtime.c

@@ -66,11 +66,11 @@ static void platform_pm_runtime_bug(struct device *dev,
 		dev_err(dev, "runtime pm suspend before resume\n");
 }
 
-int platform_pm_runtime_suspend(struct device *dev)
+static int default_platform_runtime_suspend(struct device *dev)
 {
 	struct pm_runtime_data *prd = __to_prd(dev);
 
-	dev_dbg(dev, "platform_pm_runtime_suspend()\n");
+	dev_dbg(dev, "%s()\n", __func__);
 
 	platform_pm_runtime_bug(dev, prd);
 
@@ -82,11 +82,11 @@ int platform_pm_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-int platform_pm_runtime_resume(struct device *dev)
+static int default_platform_runtime_resume(struct device *dev)
 {
 	struct pm_runtime_data *prd = __to_prd(dev);
 
-	dev_dbg(dev, "platform_pm_runtime_resume()\n");
+	dev_dbg(dev, "%s()\n", __func__);
 
 	platform_pm_runtime_init(dev, prd);
 
@@ -98,12 +98,21 @@ int platform_pm_runtime_resume(struct device *dev)
 	return 0;
 }
 
-int platform_pm_runtime_idle(struct device *dev)
+static int default_platform_runtime_idle(struct device *dev)
 {
 	/* suspend synchronously to disable clocks immediately */
 	return pm_runtime_suspend(dev);
 }
 
+static struct dev_power_domain default_power_domain = {
+	.ops = {
+		.runtime_suspend = default_platform_runtime_suspend,
+		.runtime_resume = default_platform_runtime_resume,
+		.runtime_idle = default_platform_runtime_idle,
+		USE_PLATFORM_PM_SLEEP_OPS
+	},
+};
+
 static int platform_bus_notify(struct notifier_block *nb,
 			       unsigned long action, void *data)
 {
@@ -114,10 +123,12 @@ static int platform_bus_notify(struct notifier_block *nb,
 
 	if (action == BUS_NOTIFY_BIND_DRIVER) {
 		prd = devres_alloc(__devres_release, sizeof(*prd), GFP_KERNEL);
-		if (prd)
+		if (prd) {
 			devres_add(dev, prd);
-		else
+			dev->pwr_domain = &default_power_domain;
+		} else {
 			dev_err(dev, "unable to alloc memory for runtime pm\n");
+		}
 	}
 
 	return 0;

arch/sh/kernel/cpu/shmobile/pm_runtime.c

@@ -139,7 +139,7 @@ void platform_pm_runtime_suspend_idle(void)
 	queue_work(pm_wq, &hwblk_work);
 }
 
-int platform_pm_runtime_suspend(struct device *dev)
+static int default_platform_runtime_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct pdev_archdata *ad = &pdev->archdata;
@@ -147,7 +147,7 @@ int platform_pm_runtime_suspend(struct device *dev)
 	int hwblk = ad->hwblk_id;
 	int ret = 0;
 
-	dev_dbg(dev, "platform_pm_runtime_suspend() [%d]\n", hwblk);
+	dev_dbg(dev, "%s() [%d]\n", __func__, hwblk);
 
 	/* ignore off-chip platform devices */
 	if (!hwblk)
@@ -183,20 +183,20 @@ int platform_pm_runtime_suspend(struct device *dev)
 	mutex_unlock(&ad->mutex);
 
 out:
-	dev_dbg(dev, "platform_pm_runtime_suspend() [%d] returns %d\n",
-		hwblk, ret);
+	dev_dbg(dev, "%s() [%d] returns %d\n",
+		 __func__, hwblk, ret);
 
 	return ret;
 }
 
-int platform_pm_runtime_resume(struct device *dev)
+static int default_platform_runtime_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct pdev_archdata *ad = &pdev->archdata;
 	int hwblk = ad->hwblk_id;
 	int ret = 0;
 
-	dev_dbg(dev, "platform_pm_runtime_resume() [%d]\n", hwblk);
+	dev_dbg(dev, "%s() [%d]\n", __func__, hwblk);
 
 	/* ignore off-chip platform devices */
 	if (!hwblk)
@@ -228,19 +228,19 @@ int platform_pm_runtime_resume(struct device *dev)
 	 */
 	mutex_unlock(&ad->mutex);
 out:
-	dev_dbg(dev, "platform_pm_runtime_resume() [%d] returns %d\n",
-		hwblk, ret);
+	dev_dbg(dev, "%s() [%d] returns %d\n",
+		__func__, hwblk, ret);
 
 	return ret;
 }
 
-int platform_pm_runtime_idle(struct device *dev)
+static int default_platform_runtime_idle(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	int hwblk = pdev->archdata.hwblk_id;
 	int ret = 0;
 
-	dev_dbg(dev, "platform_pm_runtime_idle() [%d]\n", hwblk);
+	dev_dbg(dev, "%s() [%d]\n", __func__, hwblk);
 
 	/* ignore off-chip platform devices */
 	if (!hwblk)
@@ -252,10 +252,19 @@ int platform_pm_runtime_idle(struct device *dev)
 	/* suspend synchronously to disable clocks immediately */
 	ret = pm_runtime_suspend(dev);
 out:
-	dev_dbg(dev, "platform_pm_runtime_idle() [%d] done!\n", hwblk);
+	dev_dbg(dev, "%s() [%d] done!\n", __func__, hwblk);
 	return ret;
 }
 
+static struct dev_power_domain default_power_domain = {
+	.ops = {
+		.runtime_suspend = default_platform_runtime_suspend,
+		.runtime_resume = default_platform_runtime_resume,
+		.runtime_idle = default_platform_runtime_idle,
+		USE_PLATFORM_PM_SLEEP_OPS
+	},
+};
+
 static int platform_bus_notify(struct notifier_block *nb,
 			       unsigned long action, void *data)
 {
@@ -276,6 +285,7 @@ static int platform_bus_notify(struct notifier_block *nb,
 		hwblk_disable(hwblk_info, hwblk);
 		/* make sure driver re-inits itself once */
 		__set_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
+		dev->pwr_domain = &default_power_domain;
 		break;
 	/* TODO: add BUS_NOTIFY_BIND_DRIVER and increase idle count */
 	case BUS_NOTIFY_BOUND_DRIVER:
@@ -289,6 +299,7 @@ static int platform_bus_notify(struct notifier_block *nb,
 		__set_bit(PDEV_ARCHDATA_FLAG_INIT, &pdev->archdata.flags);
 		break;
 	case BUS_NOTIFY_DEL_DEVICE:
+		dev->pwr_domain = NULL;
 		break;
 	}
 	return 0;