PM / Domains: add setter for dev.pm_domain

Adds a function that sets the pointer to dev_pm_domain in struct device
and that warns if the device has already finished probing. The reason
why we want to enforce that is because in the general case that can
cause problems and also that we can simplify code quite a bit if we can
always assume that.

This patch also changes all current code that directly sets the
dev.pm_domain pointer.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

8 files changed, 47 insertions, 16 deletions

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index 047281a6..c570b1d 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -18,6 +18,7 @@
 #include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/clk-lpss.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/delay.h>
 
@@ -875,13 +876,14 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
 
 	switch (action) {
 	case BUS_NOTIFY_BIND_DRIVER:
-		pdev->dev.pm_domain = &acpi_lpss_pm_domain;
+		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
 		break;
 	case BUS_NOTIFY_DRIVER_NOT_BOUND:
 	case BUS_NOTIFY_UNBOUND_DRIVER:
 		pdev->dev.pm_domain = NULL;
 		break;
 	case BUS_NOTIFY_ADD_DEVICE:
+		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
 		if (pdata->dev_desc->flags & LPSS_LTR)
 			return sysfs_create_group(&pdev->dev.kobj,
 						  &lpss_attr_group);
@@ -889,6 +891,7 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
 	case BUS_NOTIFY_DEL_DEVICE:
 		if (pdata->dev_desc->flags & LPSS_LTR)
 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
+		dev_pm_domain_set(&pdev->dev, NULL);
 		break;
 	default:
 		break;
diff --git a/drivers/acpi/device_pm.c b/drivers/acpi/device_pm.c
index 08a02cd..cd2c3d6 100644
--- a/drivers/acpi/device_pm.c
+++ b/drivers/acpi/device_pm.c
@@ -22,6 +22,7 @@
 #include <linux/export.h>
 #include <linux/mutex.h>
 #include <linux/pm_qos.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 
 #include "internal.h"
@@ -1059,7 +1060,7 @@ static void acpi_dev_pm_detach(struct device *dev, bool power_off)
 	struct acpi_device *adev = ACPI_COMPANION(dev);
 
 	if (adev && dev->pm_domain == &acpi_general_pm_domain) {
-		dev->pm_domain = NULL;
+		dev_pm_domain_set(dev, NULL);
 		acpi_remove_pm_notifier(adev);
 		if (power_off) {
 			/*
@@ -1111,7 +1112,7 @@ int acpi_dev_pm_attach(struct device *dev, bool power_on)
 		return -EBUSY;
 
 	acpi_add_pm_notifier(adev, dev, acpi_pm_notify_work_func);
-	dev->pm_domain = &acpi_general_pm_domain;
+	dev_pm_domain_set(dev, &acpi_general_pm_domain);
 	if (power_on) {
 		acpi_dev_pm_full_power(adev);
 		acpi_device_wakeup(adev, ACPI_STATE_S0, false);
diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c
index c39b861..272a52e 100644
--- a/drivers/base/power/clock_ops.c
+++ b/drivers/base/power/clock_ops.c
@@ -15,6 +15,7 @@
 #include <linux/clkdev.h>
 #include <linux/slab.h>
 #include <linux/err.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 
 #ifdef CONFIG_PM_CLK
@@ -348,7 +349,7 @@ static int pm_clk_notify(struct notifier_block *nb,
 		if (error)
 			break;
 
-		dev->pm_domain = clknb->pm_domain;
+		dev_pm_domain_set(dev, clknb->pm_domain);
 		if (clknb->con_ids[0]) {
 			for (con_id = clknb->con_ids; *con_id; con_id++)
 				pm_clk_add(dev, *con_id);
@@ -361,7 +362,7 @@ static int pm_clk_notify(struct notifier_block *nb,
 		if (dev->pm_domain != clknb->pm_domain)
 			break;
 
-		dev->pm_domain = NULL;
+		dev_pm_domain_set(dev, NULL);
 		pm_clk_destroy(dev);
 		break;
 	}
diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
index f48e333..02812bc 100644
--- a/drivers/base/power/common.c
+++ b/drivers/base/power/common.c
@@ -128,3 +128,24 @@ void dev_pm_domain_detach(struct device *dev, bool power_off)
 		dev->pm_domain->detach(dev, power_off);
 }
 EXPORT_SYMBOL_GPL(dev_pm_domain_detach);
+
+/**
+ * dev_pm_domain_set - Set PM domain of a device.
+ * @dev: Device whose PM domain is to be set.
+ * @pd: PM domain to be set, or NULL.
+ *
+ * Sets the PM domain the device belongs to. The PM domain of a device needs
+ * to be set before its probe finishes (it's bound to a driver).
+ *
+ * This function must be called with the device lock held.
+ */
+void dev_pm_domain_set(struct device *dev, struct dev_pm_domain *pd)
+{
+	if (dev->pm_domain == pd)
+		return;
+
+	WARN(device_is_bound(dev),
+	     "PM domains can only be changed for unbound devices\n");
+	dev->pm_domain = pd;
+}
+EXPORT_SYMBOL_GPL(dev_pm_domain_set);
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 167418e..abbac6f 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1177,10 +1177,11 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
 	}
 
 	dev->power.subsys_data->domain_data = &gpd_data->base;
-	dev->pm_domain = &genpd->domain;
 
 	spin_unlock_irq(&dev->power.lock);
 
+	dev_pm_domain_set(dev, &genpd->domain);
+
 	return gpd_data;
 
  err_free:
@@ -1194,9 +1195,10 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
 static void genpd_free_dev_data(struct device *dev,
 				struct generic_pm_domain_data *gpd_data)
 {
+	dev_pm_domain_set(dev, NULL);
+
 	spin_lock_irq(&dev->power.lock);
 
-	dev->pm_domain = NULL;
 	dev->power.subsys_data->domain_data = NULL;
 
 	spin_unlock_irq(&dev->power.lock);
diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
index 41edd5a..7b95ed2 100644
--- a/drivers/gpu/vga/vga_switcheroo.c
+++ b/drivers/gpu/vga/vga_switcheroo.c
@@ -36,6 +36,7 @@
 #include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/seq_file.h>
 #include <linux/uaccess.h>
@@ -918,17 +919,17 @@ int vga_switcheroo_init_domain_pm_ops(struct device *dev,
 		domain->ops.runtime_suspend = vga_switcheroo_runtime_suspend;
 		domain->ops.runtime_resume = vga_switcheroo_runtime_resume;
 
-		dev->pm_domain = domain;
+		dev_pm_domain_set(dev, domain);
 		return 0;
 	}
-	dev->pm_domain = NULL;
+	dev_pm_domain_set(dev, NULL);
 	return -EINVAL;
 }
 EXPORT_SYMBOL(vga_switcheroo_init_domain_pm_ops);
 
 void vga_switcheroo_fini_domain_pm_ops(struct device *dev)
 {
-	dev->pm_domain = NULL;
+	dev_pm_domain_set(dev, NULL);
 }
 EXPORT_SYMBOL(vga_switcheroo_fini_domain_pm_ops);
 
@@ -989,10 +990,10 @@ vga_switcheroo_init_domain_pm_optimus_hdmi_audio(struct device *dev,
 		domain->ops.runtime_resume =
 			vga_switcheroo_runtime_resume_hdmi_audio;
 
-		dev->pm_domain = domain;
+		dev_pm_domain_set(dev, domain);
 		return 0;
 	}
-	dev->pm_domain = NULL;
+	dev_pm_domain_set(dev, NULL);
 	return -EINVAL;
 }
 EXPORT_SYMBOL(vga_switcheroo_init_domain_pm_optimus_hdmi_audio);
diff --git a/drivers/misc/mei/pci-me.c b/drivers/misc/mei/pci-me.c
index 27678d8..75fc9c6 100644
--- a/drivers/misc/mei/pci-me.c
+++ b/drivers/misc/mei/pci-me.c
@@ -31,6 +31,7 @@
 #include <linux/jiffies.h>
 #include <linux/interrupt.h>
 
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 
 #include <linux/mei.h>
@@ -436,7 +437,7 @@ static inline void mei_me_set_pm_domain(struct mei_device *dev)
 		dev->pg_domain.ops.runtime_resume = mei_me_pm_runtime_resume;
 		dev->pg_domain.ops.runtime_idle = mei_me_pm_runtime_idle;
 
-		pdev->dev.pm_domain = &dev->pg_domain;
+		dev_pm_domain_set(&pdev->dev, &dev->pg_domain);
 	}
 }
 
@@ -448,7 +449,7 @@ static inline void mei_me_set_pm_domain(struct mei_device *dev)
 static inline void mei_me_unset_pm_domain(struct mei_device *dev)
 {
 	/* stop using pm callbacks if any */
-	dev->dev->pm_domain = NULL;
+	dev_pm_domain_set(dev->dev, NULL);
 }
 
 static const struct dev_pm_ops mei_me_pm_ops = {
diff --git a/drivers/misc/mei/pci-txe.c b/drivers/misc/mei/pci-txe.c
index 0882c02..71f8a74 100644
--- a/drivers/misc/mei/pci-txe.c
+++ b/drivers/misc/mei/pci-txe.c
@@ -27,6 +27,7 @@
 #include <linux/jiffies.h>
 #include <linux/interrupt.h>
 #include <linux/workqueue.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 
 #include <linux/mei.h>
@@ -388,7 +389,7 @@ static inline void mei_txe_set_pm_domain(struct mei_device *dev)
 		dev->pg_domain.ops.runtime_resume = mei_txe_pm_runtime_resume;
 		dev->pg_domain.ops.runtime_idle = mei_txe_pm_runtime_idle;
 
-		pdev->dev.pm_domain = &dev->pg_domain;
+		dev_pm_domain_set(&pdev->dev, &dev->pg_domain);
 	}
 }
 
@@ -400,7 +401,7 @@ static inline void mei_txe_set_pm_domain(struct mei_device *dev)
 static inline void mei_txe_unset_pm_domain(struct mei_device *dev)
 {
 	/* stop using pm callbacks if any */
-	dev->dev->pm_domain = NULL;
+	dev_pm_domain_set(dev->dev, NULL);
 }
 
 static const struct dev_pm_ops mei_txe_pm_ops = {