[PATCHv2 0/3] PM operations for software nodes

[PATCHv2 0/3] PM operations for software nodes

[Heikki Krogerus]

Hi,

This is the second version of this series. Rafael pointed out in v1
that I was not handling bus PM ops correctly. He also requested that I
put a comment to the code explaining things a little.

The original v1 series:
https://lore.kernel.org/linux-acpi/20200825135951.53340-1-heikki.krogerus@linux.intel.com/

Heikki Krogerus (3):
  software node: Power management operations for software nodes
  software node: Introduce device_add_software_node()
  usb: dwc3: pci: Register a software node for the dwc3 platform device

 drivers/base/power/common.c |   8 +-
 drivers/base/swnode.c       | 738 +++++++++++++++++++++++++++++++++++-
 drivers/usb/dwc3/dwc3-pci.c | 175 +++++----
 include/linux/property.h    |  13 +
 4 files changed, 835 insertions(+), 99 deletions(-)

-- 
2.28.0

[PATCHv2 1/3] software node: Power management operations for software nodes

[Heikki Krogerus]

The software node specific PM operations make it possible to
handle most PM related quirks separately in their own
functions instead of conditionally in the device driver's
generic PM functions (and in some cases all over the
driver). The software node specific PM operations will also
reduce the need to pass platform data in some cases, for
example from a core MFD driver to the child device drivers,
as from now on the core MFD driver will be able to implement
the PM quirks directly for the child devices without the
need to touch the drivers of those child devices.

If a software node includes the PM operations, those PM
operations are always executed separately on top of the
other PM operations of the device, so the software node will
never replace any of the "normal" PM operations of the
device (including the PM domain's operations, class's or
bus's PM operations, the device drivers own operations, or
any other).

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
 drivers/base/power/common.c |   8 +-
 drivers/base/swnode.c       | 693 +++++++++++++++++++++++++++++++++++-
 include/linux/property.h    |  10 +
 3 files changed, 701 insertions(+), 10 deletions(-)

diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
index bbddb267c2e69..b64cd4690ac63 100644
--- a/drivers/base/power/common.c
+++ b/drivers/base/power/common.c
@@ -109,8 +109,14 @@ int dev_pm_domain_attach(struct device *dev, bool power_on)
 	ret = acpi_dev_pm_attach(dev, power_on);
 	if (!ret)
 		ret = genpd_dev_pm_attach(dev);
+	if (ret < 0)
+		return ret;
 
-	return ret < 0 ? ret : 0;
+	ret = software_node_dev_pm_attach(dev, power_on);
+	if (ret)
+		dev_pm_domain_detach(dev, power_on);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
 
diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 010828fc785bc..595a9c240fede 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -8,6 +8,8 @@
 
 #include <linux/device.h>
 #include <linux/kernel.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
 #include <linux/property.h>
 #include <linux/slab.h>
 
@@ -48,6 +50,19 @@ EXPORT_SYMBOL_GPL(is_software_node);
 				     struct swnode, fwnode) : NULL;	\
 	})
 
+static inline struct swnode *dev_to_swnode(struct device *dev)
+{
+	struct fwnode_handle *fwnode = dev_fwnode(dev);
+
+	if (!fwnode)
+		return NULL;
+
+	if (!is_software_node(fwnode))
+		fwnode = fwnode->secondary;
+
+	return to_swnode(fwnode);
+}
+
 static struct swnode *
 software_node_to_swnode(const struct software_node *node)
 {
@@ -344,6 +359,673 @@ void property_entries_free(const struct property_entry *properties)
 }
 EXPORT_SYMBOL_GPL(property_entries_free);
 
+/* -------------------------------------------------------------------------- */
+/* Power management operations */
+
+/*
+ * The power management operations in software nodes are handled with a power
+ * management domain - a "wrapper" PM domain:
+ *
+ *   When PM operations are supplied as part of the software node, the primary
+ *   PM domain of the device is stored and replaced with a device specific
+ *   software node PM domain. The software node PM domain's PM operations, which
+ *   are implemented below, will then always call the matching PM operation of
+ *   the primary PM domain (which was stored) on top of the software node's own
+ *   operation.
+ *
+ * If the device does not have primary PM domain, the software node PM wrapper
+ * operations below will also call the classes, buses and device type's PM
+ * operations, and of course the device driver's own PM operations if they are
+ * implemented. The priority of those calls follows drivers/base/power/domain.c:
+ *
+ * 1) device type
+ * 2) class
+ * 3) bus
+ * 4) driver
+ *
+ * NOTE. The software node PM operation is always called before the primary
+ * PM domain with resume/on callbacks, and after the primary PM domain with
+ * suspend/off callbacks. This order is used because the software node PM
+ * operations are primarily meant to be used to implement quirks, quirks that
+ * may be needed to power on the device to a point where it is even possible to
+ * execute the primary PM domain's resume/on routines.
+ */
+
+#ifdef CONFIG_PM
+struct swnode_pm_domain {
+	struct dev_pm_domain pm_domain;
+	struct dev_pm_domain *primary;
+};
+
+#define to_swnode_pm_domain(d) \
+		container_of(d, struct swnode_pm_domain, pm_domain)
+
+static int software_node_runtime_suspend(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.runtime_suspend)
+		ret = domain->primary->ops.runtime_suspend(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->runtime_suspend)
+		ret = dev->type->pm->runtime_suspend(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->runtime_suspend)
+		ret = dev->class->pm->runtime_suspend(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
+		ret = dev->bus->pm->runtime_suspend(dev);
+	else
+		ret = pm_generic_runtime_suspend(dev);
+
+	if (ret || !swnode->node->pm->runtime_suspend)
+		return ret;
+
+	return swnode->node->pm->runtime_suspend(dev);
+}
+
+static int software_node_runtime_resume(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->runtime_resume) {
+		ret = swnode->node->pm->runtime_resume(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.runtime_resume)
+		ret = domain->primary->ops.runtime_resume(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->runtime_resume)
+		ret = dev->type->pm->runtime_resume(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->runtime_resume)
+		ret = dev->class->pm->runtime_resume(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
+		ret = dev->bus->pm->runtime_resume(dev);
+	else
+		ret = pm_generic_runtime_resume(dev);
+
+	return ret;
+}
+
+static int software_node_runtime_idle(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret = 0;
+
+	if (domain->primary && domain->primary->ops.runtime_idle)
+		ret = domain->primary->ops.runtime_idle(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle)
+		ret = dev->type->pm->runtime_idle(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->runtime_idle)
+		ret = dev->class->pm->runtime_idle(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle)
+		ret = dev->bus->pm->runtime_idle(dev);
+	else if (dev->driver && dev->driver->pm && dev->driver->pm->runtime_idle)
+		ret = dev->driver->pm->runtime_idle(dev);
+
+	if (ret || !swnode->node->pm->runtime_idle)
+		return ret;
+
+	return swnode->node->pm->runtime_idle(dev);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int software_node_prepare(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.prepare)
+		ret = domain->primary->ops.prepare(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->prepare)
+		ret = dev->type->pm->prepare(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->prepare)
+		ret = dev->class->pm->prepare(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->prepare)
+		ret = dev->bus->pm->prepare(dev);
+	else
+		ret = pm_generic_prepare(dev);
+
+	if (ret || !swnode->node->pm->prepare)
+		return ret;
+
+	return swnode->node->pm->prepare(dev);
+}
+
+static void software_node_complete(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+
+	if (swnode->node->pm->complete)
+		swnode->node->pm->complete(dev);
+
+	if (domain->primary && domain->primary->ops.complete)
+		domain->primary->ops.complete(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->complete)
+		dev->type->pm->complete(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->complete)
+		dev->class->pm->complete(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->complete)
+		dev->bus->pm->complete(dev);
+	else
+		pm_generic_complete(dev);
+}
+
+static int software_node_suspend(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.suspend)
+		ret = domain->primary->ops.suspend(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->suspend)
+		ret = dev->type->pm->suspend(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->suspend)
+		ret = dev->class->pm->suspend(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->suspend)
+		ret = dev->bus->pm->suspend(dev);
+	else
+		ret = pm_generic_suspend(dev);
+
+	if (ret || !swnode->node->pm->suspend)
+		return ret;
+
+	return swnode->node->pm->suspend(dev);
+}
+
+static int software_node_resume(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->resume) {
+		ret = swnode->node->pm->resume(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.resume)
+		ret = domain->primary->ops.resume(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->resume)
+		ret = dev->type->pm->resume(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->resume)
+		ret = dev->class->pm->resume(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->resume)
+		ret = dev->bus->pm->resume(dev);
+	else
+		ret = pm_generic_resume(dev);
+
+	return ret;
+}
+
+static int software_node_freeze(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.freeze)
+		ret = domain->primary->ops.freeze(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->freeze)
+		ret = dev->type->pm->freeze(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->freeze)
+		ret = dev->class->pm->freeze(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->freeze)
+		ret = dev->bus->pm->freeze(dev);
+	else
+		ret = pm_generic_freeze(dev);
+
+	if (ret || !swnode->node->pm->freeze)
+		return ret;
+
+	return swnode->node->pm->freeze(dev);
+}
+
+static int software_node_thaw(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->thaw) {
+		ret = swnode->node->pm->thaw(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.thaw)
+		ret = domain->primary->ops.thaw(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->thaw)
+		ret = dev->type->pm->thaw(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->thaw)
+		ret = dev->class->pm->thaw(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->thaw)
+		ret = dev->bus->pm->thaw(dev);
+	else
+		ret = pm_generic_thaw(dev);
+
+	return ret;
+}
+
+static int software_node_poweroff(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.poweroff)
+		ret = domain->primary->ops.poweroff(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->poweroff)
+		ret = dev->type->pm->poweroff(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->poweroff)
+		ret = dev->class->pm->poweroff(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->poweroff)
+		ret = dev->bus->pm->poweroff(dev);
+	else
+		ret = pm_generic_poweroff(dev);
+
+	if (ret || !swnode->node->pm->poweroff)
+		return ret;
+
+	return swnode->node->pm->poweroff(dev);
+}
+
+static int software_node_restore(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->restore) {
+		ret = swnode->node->pm->restore(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.restore)
+		ret = domain->primary->ops.restore(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->restore)
+		ret = dev->type->pm->restore(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->restore)
+		ret = dev->class->pm->restore(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->restore)
+		ret = dev->bus->pm->restore(dev);
+	else
+		ret = pm_generic_restore(dev);
+
+	return ret;
+}
+
+static int software_node_suspend_late(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.suspend_late)
+		ret = domain->primary->ops.suspend_late(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->suspend_late)
+		ret = dev->type->pm->suspend_late(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->suspend_late)
+		ret = dev->class->pm->suspend_late(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->suspend_late)
+		ret = dev->bus->pm->suspend_late(dev);
+	else
+		ret = pm_generic_suspend_late(dev);
+
+	if (ret || !swnode->node->pm->suspend_late)
+		return ret;
+
+	return swnode->node->pm->suspend_late(dev);
+}
+
+static int software_node_resume_early(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->resume_early) {
+		ret = swnode->node->pm->resume_early(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.resume_early)
+		ret = domain->primary->ops.resume_early(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->resume_early)
+		ret = dev->type->pm->resume_early(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->resume_early)
+		ret = dev->class->pm->resume_early(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->resume_early)
+		ret = dev->bus->pm->resume_early(dev);
+	else
+		pm_generic_resume_early(dev);
+
+	return 0;
+}
+
+static int software_node_freeze_late(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.freeze_late)
+		ret = domain->primary->ops.freeze_late(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->freeze_late)
+		ret = dev->type->pm->freeze_late(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->freeze_late)
+		ret = dev->class->pm->freeze_late(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->freeze_late)
+		ret = dev->bus->pm->freeze_late(dev);
+	else
+		ret = pm_generic_freeze_late(dev);
+
+	if (ret || !swnode->node->pm->freeze_late)
+		return ret;
+
+	return swnode->node->pm->freeze_late(dev);
+}
+
+static int software_node_thaw_early(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->thaw_early) {
+		ret = swnode->node->pm->thaw_early(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.thaw_early)
+		ret = domain->primary->ops.thaw_early(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->thaw_early)
+		ret = dev->type->pm->thaw_early(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->thaw_early)
+		ret = dev->class->pm->thaw_early(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->thaw_early)
+		ret = dev->bus->pm->thaw_early(dev);
+	else
+		ret = pm_generic_thaw_early(dev);
+
+	return ret;
+}
+
+static int software_node_poweroff_late(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.poweroff_late)
+		ret = domain->primary->ops.poweroff_late(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->poweroff_late)
+		ret = dev->type->pm->poweroff_late(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->poweroff_late)
+		ret = dev->class->pm->poweroff_late(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->poweroff_late)
+		ret = dev->bus->pm->poweroff_late(dev);
+	else
+		ret = pm_generic_poweroff_late(dev);
+
+	if (ret || !swnode->node->pm->poweroff_late)
+		return ret;
+
+	return swnode->node->pm->poweroff(dev);
+}
+
+static int software_node_restore_early(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->restore_early) {
+		ret = swnode->node->pm->restore_early(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.restore_early)
+		ret = domain->primary->ops.restore_early(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->restore_early)
+		ret = dev->type->pm->restore_early(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->restore_early)
+		ret = dev->class->pm->restore_early(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->restore_early)
+		ret = dev->bus->pm->restore_early(dev);
+	else
+		ret = pm_generic_restore_early(dev);
+
+	return ret;
+}
+
+static int software_node_suspend_noirq(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.suspend_noirq)
+		ret = domain->primary->ops.suspend_noirq(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->suspend_noirq)
+		ret = dev->type->pm->suspend_noirq(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->suspend_noirq)
+		ret = dev->class->pm->suspend_noirq(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->suspend_noirq)
+		ret = dev->bus->pm->suspend_noirq(dev);
+	else
+		ret = pm_generic_suspend_noirq(dev);
+
+	if (ret || !swnode->node->pm->suspend_noirq)
+		return ret;
+
+	return swnode->node->pm->suspend_noirq(dev);
+}
+
+static int software_node_resume_noirq(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->resume_noirq) {
+		ret = swnode->node->pm->resume_noirq(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.resume_noirq)
+		ret = domain->primary->ops.resume_noirq(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->resume_noirq)
+		ret = dev->type->pm->resume_noirq(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->resume_noirq)
+		ret = dev->class->pm->resume_noirq(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->resume_noirq)
+		ret = dev->bus->pm->resume_noirq(dev);
+	else
+		ret = pm_generic_resume_noirq(dev);
+
+	return ret;
+}
+
+static int software_node_freeze_noirq(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.freeze_noirq)
+		ret = domain->primary->ops.freeze_noirq(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->freeze_noirq)
+		ret = dev->type->pm->freeze_noirq(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->freeze_noirq)
+		ret = dev->class->pm->freeze_noirq(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->freeze_noirq)
+		ret = dev->bus->pm->freeze_noirq(dev);
+	else
+		ret = pm_generic_freeze_noirq(dev);
+
+	if (ret || !swnode->node->pm->freeze_noirq)
+		return ret;
+
+	return swnode->node->pm->freeze_noirq(dev);
+}
+
+static int software_node_thaw_noirq(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->thaw_noirq) {
+		ret = swnode->node->pm->thaw_noirq(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.thaw_noirq)
+		ret = domain->primary->ops.thaw_noirq(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->thaw_noirq)
+		ret = dev->type->pm->thaw_noirq(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->thaw_noirq)
+		ret = dev->class->pm->thaw_noirq(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->thaw_noirq)
+		ret = dev->bus->pm->thaw_noirq(dev);
+	else
+		ret = pm_generic_thaw_noirq(dev);
+
+	return ret;
+}
+
+static int software_node_poweroff_noirq(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (domain->primary && domain->primary->ops.poweroff_noirq)
+		ret = domain->primary->ops.poweroff_noirq(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->poweroff_noirq)
+		ret = dev->type->pm->poweroff_noirq(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->poweroff_noirq)
+		ret = dev->class->pm->poweroff_noirq(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->poweroff_noirq)
+		ret = dev->bus->pm->poweroff_noirq(dev);
+	else
+		ret = pm_generic_poweroff_noirq(dev);
+
+	if (ret || !swnode->node->pm->poweroff)
+		return ret;
+
+	return swnode->node->pm->poweroff_noirq(dev);
+}
+
+static int software_node_restore_noirq(struct device *dev)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+	struct swnode *swnode = dev_to_swnode(dev);
+	int ret;
+
+	if (swnode->node->pm->restore_noirq) {
+		ret = swnode->node->pm->restore_noirq(dev);
+		if (ret)
+			return ret;
+	}
+
+	if (domain->primary && domain->primary->ops.restore_noirq)
+		ret = domain->primary->ops.restore_noirq(dev);
+	else if (dev->type && dev->type->pm && dev->type->pm->restore_noirq)
+		ret = dev->type->pm->restore_noirq(dev);
+	else if (dev->class && dev->class->pm && dev->class->pm->restore_noirq)
+		ret = dev->class->pm->restore_noirq(dev);
+	else if (dev->bus && dev->bus->pm && dev->bus->pm->restore_noirq)
+		ret = dev->bus->pm->restore_noirq(dev);
+	else
+		ret = pm_generic_restore_noirq(dev);
+
+	return ret;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops software_node_pm_ops = {
+	.runtime_suspend = software_node_runtime_suspend,
+	.runtime_resume = software_node_runtime_resume,
+	.runtime_idle = software_node_runtime_idle,
+#ifdef CONFIG_PM_SLEEP
+	.prepare = software_node_prepare,
+	.complete = software_node_complete,
+	.suspend = software_node_suspend,
+	.resume = software_node_resume,
+	.freeze = software_node_freeze,
+	.thaw = software_node_thaw,
+	.poweroff = software_node_poweroff,
+	.restore = software_node_restore,
+	.suspend_late = software_node_suspend_late,
+	.resume_early = software_node_resume_early,
+	.freeze_late = software_node_freeze_late,
+	.thaw_early = software_node_thaw_early,
+	.poweroff_late = software_node_poweroff_late,
+	.restore_early = software_node_restore_early,
+	.suspend_noirq = software_node_suspend_noirq,
+	.resume_noirq = software_node_resume_noirq,
+	.freeze_noirq = software_node_freeze_noirq,
+	.thaw_noirq = software_node_thaw_noirq,
+	.poweroff_noirq = software_node_poweroff_noirq,
+	.restore_noirq = software_node_restore_noirq,
+#endif /* CONFIG_PM_SLEEP */
+};
+
+static void software_node_dev_pm_detach(struct device *dev, bool power_off)
+{
+	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
+
+	if (domain->primary && domain->primary->detach) {
+		dev->pm_domain = domain->primary;
+		domain->primary->detach(dev, power_off);
+	} else {
+		dev_pm_domain_set(dev, NULL);
+	}
+
+	kfree(domain);
+}
+
+int software_node_dev_pm_attach(struct device *dev, bool power_on)
+{
+	struct swnode *swnode = dev_to_swnode(dev);
+	struct swnode_pm_domain *domain;
+
+	if (!swnode || !swnode->node->pm)
+		return 0;
+
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (!domain)
+		return -ENOMEM;
+
+	if (dev->pm_domain)
+		domain->pm_domain = *dev->pm_domain;
+
+	domain->primary = dev->pm_domain;
+	domain->pm_domain.ops = software_node_pm_ops;
+	domain->pm_domain.detach = software_node_dev_pm_detach;
+
+	dev_pm_domain_set(dev, &domain->pm_domain);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(software_node_dev_pm_attach);
+#endif /* CONFIG_PM */
+
 /* -------------------------------------------------------------------------- */
 /* fwnode operations */
 
@@ -845,20 +1527,13 @@ EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
 
 int software_node_notify(struct device *dev, unsigned long action)
 {
-	struct fwnode_handle *fwnode = dev_fwnode(dev);
 	struct swnode *swnode;
 	int ret;
 
-	if (!fwnode)
-		return 0;
-
-	if (!is_software_node(fwnode))
-		fwnode = fwnode->secondary;
-	if (!is_software_node(fwnode))
+	swnode = dev_to_swnode(dev);
+	if (!swnode)
 		return 0;
 
-	swnode = to_swnode(fwnode);
-
 	switch (action) {
 	case KOBJ_ADD:
 		ret = sysfs_create_link(&dev->kobj, &swnode->kobj,
diff --git a/include/linux/property.h b/include/linux/property.h
index 2d4542629d80b..33b25c8bd4052 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -453,11 +453,13 @@ static inline void *device_connection_find_match(struct device *dev,
  * @name: Name of the software node
  * @parent: Parent of the software node
  * @properties: Array of device properties
+ * @pm: Power management operations
  */
 struct software_node {
 	const char *name;
 	const struct software_node *parent;
 	const struct property_entry *properties;
+	const struct dev_pm_ops *pm;
 };
 
 bool is_software_node(const struct fwnode_handle *fwnode);
@@ -479,6 +481,14 @@ int software_node_register(const struct software_node *node);
 void software_node_unregister(const struct software_node *node);
 
 int software_node_notify(struct device *dev, unsigned long action);
+#ifdef CONFIG_PM
+int software_node_dev_pm_attach(struct device *dev, bool power_on);
+#else
+static inline int software_node_dev_pm_attach(struct device *dev, bool power_on)
+{
+	return 0;
+}
+#endif /* CONFIG_PM */
 
 struct fwnode_handle *
 fwnode_create_software_node(const struct property_entry *properties,
-- 
2.28.0

[PATCHv2 2/3] software node: Introduce device_add_software_node()

[Heikki Krogerus]

This helper will register a software node and then assign
it to device at the same time. The function will also make
sure that the device can't have more than one software node.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
 drivers/base/swnode.c    | 45 ++++++++++++++++++++++++++++++++++++++++
 include/linux/property.h |  3 +++
 2 files changed, 48 insertions(+)

diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
index 595a9c240fede..0001fbea19cff 100644
--- a/drivers/base/swnode.c
+++ b/drivers/base/swnode.c
@@ -1525,6 +1525,51 @@ void fwnode_remove_software_node(struct fwnode_handle *fwnode)
 }
 EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
 
+/**
+ * device_add_software_node - Assign software node to a device
+ * @dev: The device the software node is meant for.
+ * @swnode: The software node.
+ *
+ * This function will register @swnode and make it the secondary firmware node
+ * pointer of @dev. If @dev has no primary node, then @swnode will become the primary
+ * node.
+ */
+int device_add_software_node(struct device *dev, const struct software_node *swnode)
+{
+	int ret;
+
+	/* Only one software node per device. */
+	if (dev_to_swnode(dev))
+		return -EBUSY;
+
+	ret = software_node_register(swnode);
+	if (ret)
+		return ret;
+
+	set_secondary_fwnode(dev, software_node_fwnode(swnode));
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(device_add_software_node);
+
+/**
+ * device_remove_software_node - Remove device's software node
+ * @dev: The device with the software node.
+ *
+ * This function will unregister the software node of @dev.
+ */
+void device_remove_software_node(struct device *dev)
+{
+	struct swnode *swnode;
+
+	swnode = dev_to_swnode(dev);
+	if (!swnode)
+		return;
+
+	kobject_put(&swnode->kobj);
+}
+EXPORT_SYMBOL_GPL(device_remove_software_node);
+
 int software_node_notify(struct device *dev, unsigned long action)
 {
 	struct swnode *swnode;
diff --git a/include/linux/property.h b/include/linux/property.h
index 33b25c8bd4052..993638e0a0b6e 100644
--- a/include/linux/property.h
+++ b/include/linux/property.h
@@ -495,4 +495,7 @@ fwnode_create_software_node(const struct property_entry *properties,
 			    const struct fwnode_handle *parent);
 void fwnode_remove_software_node(struct fwnode_handle *fwnode);
 
+int device_add_software_node(struct device *dev, const struct software_node *swnode);
+void device_remove_software_node(struct device *dev);
+
 #endif /* _LINUX_PROPERTY_H_ */
-- 
2.28.0

[PATCHv2 3/3] usb: dwc3: pci: Register a software node for the dwc3 platform device

[Heikki Krogerus]

By registering the software node directly instead of just
the properties in it, the driver can take advantage of also
the other features the software nodes have.

Initially using the nodes for isolating the Intel Broxton
specific power management quirk by handling it in Broxton's
very own power management operations (which are supplied as
part of the software node) instead of the drivers generic
ones.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Felipe Balbi <balbi@kernel.org>
---
 drivers/usb/dwc3/dwc3-pci.c | 175 ++++++++++++++++++------------------
 1 file changed, 86 insertions(+), 89 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-pci.c b/drivers/usb/dwc3/dwc3-pci.c
index 242b6210380a4..43cc0f602820d 100644
--- a/drivers/usb/dwc3/dwc3-pci.c
+++ b/drivers/usb/dwc3/dwc3-pci.c
@@ -54,17 +54,12 @@
  * struct dwc3_pci - Driver private structure
  * @dwc3: child dwc3 platform_device
  * @pci: our link to PCI bus
- * @guid: _DSM GUID
- * @has_dsm_for_pm: true for devices which need to run _DSM on runtime PM
  * @wakeup_work: work for asynchronous resume
  */
 struct dwc3_pci {
 	struct platform_device *dwc3;
 	struct pci_dev *pci;
 
-	guid_t guid;
-
-	unsigned int has_dsm_for_pm:1;
 	struct work_struct wakeup_work;
 };
 
@@ -108,6 +103,50 @@ static int dwc3_byt_enable_ulpi_refclock(struct pci_dev *pci)
 	return 0;
 }
 
+#ifdef CONFIG_PM
+static int dwc3_pci_intel_pm_dsm(struct device *dev, int param)
+{
+	union acpi_object *obj;
+	union acpi_object tmp;
+	union acpi_object argv4 = ACPI_INIT_DSM_ARGV4(1, &tmp);
+	guid_t guid;
+	int ret;
+
+	ret = guid_parse(PCI_INTEL_BXT_DSM_GUID, &guid);
+	if (ret)
+		return ret;
+
+	tmp.type = ACPI_TYPE_INTEGER;
+	tmp.integer.value = param;
+
+	obj = acpi_evaluate_dsm(ACPI_HANDLE(dev), &guid,
+				1, PCI_INTEL_BXT_FUNC_PMU_PWR, &argv4);
+	if (!obj) {
+		dev_err(dev, "failed to evaluate _DSM\n");
+		return -EIO;
+	}
+
+	ACPI_FREE(obj);
+
+	return 0;
+}
+
+static int dwc3_pci_intel_suspend(struct device *dev)
+{
+	return dwc3_pci_intel_pm_dsm(dev->parent, PCI_INTEL_BXT_STATE_D3);
+}
+
+static int dwc3_pci_intel_resume(struct device *dev)
+{
+	return dwc3_pci_intel_pm_dsm(dev->parent, PCI_INTEL_BXT_STATE_D0);
+}
+#endif /* CONFIG_PM */
+
+static const struct dev_pm_ops dwc3_pci_intel_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(dwc3_pci_intel_suspend, dwc3_pci_intel_resume)
+	SET_RUNTIME_PM_OPS(dwc3_pci_intel_suspend, dwc3_pci_intel_resume, NULL)
+};
+
 static const struct property_entry dwc3_pci_intel_properties[] = {
 	PROPERTY_ENTRY_STRING("dr_mode", "peripheral"),
 	PROPERTY_ENTRY_BOOL("linux,sysdev_is_parent"),
@@ -141,18 +180,28 @@ static const struct property_entry dwc3_pci_amd_properties[] = {
 	{}
 };
 
+static const struct software_node dwc3_pci_intel_swnode = {
+	.properties = dwc3_pci_intel_properties,
+};
+
+static const struct software_node dwc3_pci_intel_pm_swnode = {
+	.properties = dwc3_pci_intel_properties,
+	.pm = &dwc3_pci_intel_pm_ops,
+};
+
+static const struct software_node dwc3_pci_intel_mrfld_swnode = {
+	.properties = dwc3_pci_mrfld_properties,
+};
+
+static const struct software_node dwc3_pci_amd_swnode = {
+	.properties = dwc3_pci_amd_properties,
+};
+
 static int dwc3_pci_quirks(struct dwc3_pci *dwc)
 {
 	struct pci_dev			*pdev = dwc->pci;
 
 	if (pdev->vendor == PCI_VENDOR_ID_INTEL) {
-		if (pdev->device == PCI_DEVICE_ID_INTEL_BXT ||
-		    pdev->device == PCI_DEVICE_ID_INTEL_BXT_M ||
-		    pdev->device == PCI_DEVICE_ID_INTEL_EHLLP) {
-			guid_parse(PCI_INTEL_BXT_DSM_GUID, &dwc->guid);
-			dwc->has_dsm_for_pm = true;
-		}
-
 		if (pdev->device == PCI_DEVICE_ID_INTEL_BYT) {
 			struct gpio_desc *gpio;
 			int ret;
@@ -221,7 +270,6 @@ static void dwc3_pci_resume_work(struct work_struct *work)
 
 static int dwc3_pci_probe(struct pci_dev *pci, const struct pci_device_id *id)
 {
-	struct property_entry *p = (struct property_entry *)id->driver_data;
 	struct dwc3_pci		*dwc;
 	struct resource		res[2];
 	int			ret;
@@ -264,7 +312,7 @@ static int dwc3_pci_probe(struct pci_dev *pci, const struct pci_device_id *id)
 	dwc->dwc3->dev.parent = dev;
 	ACPI_COMPANION_SET(&dwc->dwc3->dev, ACPI_COMPANION(dev));
 
-	ret = platform_device_add_properties(dwc->dwc3, p);
+	ret = device_add_software_node(&dwc->dwc3->dev, (void *)id->driver_data);
 	if (ret < 0)
 		goto err;
 
@@ -287,6 +335,7 @@ static int dwc3_pci_probe(struct pci_dev *pci, const struct pci_device_id *id)
 
 	return 0;
 err:
+	device_remove_software_node(&dwc->dwc3->dev);
 	platform_device_put(dwc->dwc3);
 	return ret;
 }
@@ -303,121 +352,86 @@ static void dwc3_pci_remove(struct pci_dev *pci)
 #endif
 	device_init_wakeup(&pci->dev, false);
 	pm_runtime_get(&pci->dev);
+	device_remove_software_node(&dwc->dwc3->dev);
 	platform_device_unregister(dwc->dwc3);
 }
 
 static const struct pci_device_id dwc3_pci_id_table[] = {
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_BSW),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_BYT),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_MRFLD),
-	  (kernel_ulong_t) &dwc3_pci_mrfld_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_mrfld_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CMLLP),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CMLH),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_SPTLP),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_SPTH),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_BXT),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_pm_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_BXT_M),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_pm_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_APL),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_KBP),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_GLK),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CNPLP),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CNPH),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CNPV),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ICLLP),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_EHLLP),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_pm_swnode },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGPLP),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_TGPH),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_JSP),
-	  (kernel_ulong_t) &dwc3_pci_intel_properties, },
+	  (kernel_ulong_t) &dwc3_pci_intel_swnode, },
 
 	{ PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_NL_USB),
-	  (kernel_ulong_t) &dwc3_pci_amd_properties, },
+	  (kernel_ulong_t) &dwc3_pci_amd_swnode, },
 	{  }	/* Terminating Entry */
 };
 MODULE_DEVICE_TABLE(pci, dwc3_pci_id_table);
 
-#if defined(CONFIG_PM) || defined(CONFIG_PM_SLEEP)
-static int dwc3_pci_dsm(struct dwc3_pci *dwc, int param)
-{
-	union acpi_object *obj;
-	union acpi_object tmp;
-	union acpi_object argv4 = ACPI_INIT_DSM_ARGV4(1, &tmp);
-
-	if (!dwc->has_dsm_for_pm)
-		return 0;
-
-	tmp.type = ACPI_TYPE_INTEGER;
-	tmp.integer.value = param;
-
-	obj = acpi_evaluate_dsm(ACPI_HANDLE(&dwc->pci->dev), &dwc->guid,
-			1, PCI_INTEL_BXT_FUNC_PMU_PWR, &argv4);
-	if (!obj) {
-		dev_err(&dwc->pci->dev, "failed to evaluate _DSM\n");
-		return -EIO;
-	}
-
-	ACPI_FREE(obj);
-
-	return 0;
-}
-#endif /* CONFIG_PM || CONFIG_PM_SLEEP */
-
 #ifdef CONFIG_PM
 static int dwc3_pci_runtime_suspend(struct device *dev)
 {
-	struct dwc3_pci		*dwc = dev_get_drvdata(dev);
-
-	if (device_can_wakeup(dev))
-		return dwc3_pci_dsm(dwc, PCI_INTEL_BXT_STATE_D3);
-
-	return -EBUSY;
+	return device_can_wakeup(dev) ? 0 : -EBUSY;
 }
 
 static int dwc3_pci_runtime_resume(struct device *dev)
 {
 	struct dwc3_pci		*dwc = dev_get_drvdata(dev);
-	int			ret;
-
-	ret = dwc3_pci_dsm(dwc, PCI_INTEL_BXT_STATE_D0);
-	if (ret)
-		return ret;
 
 	queue_work(pm_wq, &dwc->wakeup_work);
 
@@ -425,24 +439,7 @@ static int dwc3_pci_runtime_resume(struct device *dev)
 }
 #endif /* CONFIG_PM */
 
-#ifdef CONFIG_PM_SLEEP
-static int dwc3_pci_suspend(struct device *dev)
-{
-	struct dwc3_pci		*dwc = dev_get_drvdata(dev);
-
-	return dwc3_pci_dsm(dwc, PCI_INTEL_BXT_STATE_D3);
-}
-
-static int dwc3_pci_resume(struct device *dev)
-{
-	struct dwc3_pci		*dwc = dev_get_drvdata(dev);
-
-	return dwc3_pci_dsm(dwc, PCI_INTEL_BXT_STATE_D0);
-}
-#endif /* CONFIG_PM_SLEEP */
-
 static const struct dev_pm_ops dwc3_pci_dev_pm_ops = {
-	SET_SYSTEM_SLEEP_PM_OPS(dwc3_pci_suspend, dwc3_pci_resume)
 	SET_RUNTIME_PM_OPS(dwc3_pci_runtime_suspend, dwc3_pci_runtime_resume,
 		NULL)
 };
-- 
2.28.0

Re: [PATCHv2 1/3] software node: Power management operations for software nodes

[Sakari Ailus]

Moi Heikki,

On Thu, Oct 29, 2020 at 01:59:39PM +0300, Heikki Krogerus wrote:
> The software node specific PM operations make it possible to
> handle most PM related quirks separately in their own
> functions instead of conditionally in the device driver's
> generic PM functions (and in some cases all over the
> driver). The software node specific PM operations will also
> reduce the need to pass platform data in some cases, for
> example from a core MFD driver to the child device drivers,
> as from now on the core MFD driver will be able to implement
> the PM quirks directly for the child devices without the
> need to touch the drivers of those child devices.
> 
> If a software node includes the PM operations, those PM
> operations are always executed separately on top of the
> other PM operations of the device, so the software node will
> never replace any of the "normal" PM operations of the
> device (including the PM domain's operations, class's or
> bus's PM operations, the device drivers own operations, or
> any other).
> 
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> ---
>  drivers/base/power/common.c |   8 +-
>  drivers/base/swnode.c       | 693 +++++++++++++++++++++++++++++++++++-
>  include/linux/property.h    |  10 +
>  3 files changed, 701 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
> index bbddb267c2e69..b64cd4690ac63 100644
> --- a/drivers/base/power/common.c
> +++ b/drivers/base/power/common.c
> @@ -109,8 +109,14 @@ int dev_pm_domain_attach(struct device *dev, bool power_on)
>  	ret = acpi_dev_pm_attach(dev, power_on);
>  	if (!ret)
>  		ret = genpd_dev_pm_attach(dev);
> +	if (ret < 0)
> +		return ret;
>  
> -	return ret < 0 ? ret : 0;
> +	ret = software_node_dev_pm_attach(dev, power_on);
> +	if (ret)
> +		dev_pm_domain_detach(dev, power_on);
> +
> +	return ret;
>  }
>  EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
>  
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index 010828fc785bc..595a9c240fede 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -8,6 +8,8 @@
>  
>  #include <linux/device.h>
>  #include <linux/kernel.h>
> +#include <linux/pm_domain.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/property.h>
>  #include <linux/slab.h>
>  
> @@ -48,6 +50,19 @@ EXPORT_SYMBOL_GPL(is_software_node);
>  				     struct swnode, fwnode) : NULL;	\
>  	})
>  
> +static inline struct swnode *dev_to_swnode(struct device *dev)
> +{
> +	struct fwnode_handle *fwnode = dev_fwnode(dev);
> +
> +	if (!fwnode)
> +		return NULL;
> +
> +	if (!is_software_node(fwnode))
> +		fwnode = fwnode->secondary;
> +
> +	return to_swnode(fwnode);
> +}
> +
>  static struct swnode *
>  software_node_to_swnode(const struct software_node *node)
>  {
> @@ -344,6 +359,673 @@ void property_entries_free(const struct property_entry *properties)
>  }
>  EXPORT_SYMBOL_GPL(property_entries_free);
>  
> +/* -------------------------------------------------------------------------- */
> +/* Power management operations */
> +
> +/*
> + * The power management operations in software nodes are handled with a power
> + * management domain - a "wrapper" PM domain:
> + *
> + *   When PM operations are supplied as part of the software node, the primary
> + *   PM domain of the device is stored and replaced with a device specific
> + *   software node PM domain. The software node PM domain's PM operations, which
> + *   are implemented below, will then always call the matching PM operation of
> + *   the primary PM domain (which was stored) on top of the software node's own
> + *   operation.
> + *
> + * If the device does not have primary PM domain, the software node PM wrapper
> + * operations below will also call the classes, buses and device type's PM
> + * operations, and of course the device driver's own PM operations if they are
> + * implemented. The priority of those calls follows drivers/base/power/domain.c:
> + *
> + * 1) device type
> + * 2) class
> + * 3) bus
> + * 4) driver
> + *
> + * NOTE. The software node PM operation is always called before the primary
> + * PM domain with resume/on callbacks, and after the primary PM domain with
> + * suspend/off callbacks. This order is used because the software node PM
> + * operations are primarily meant to be used to implement quirks, quirks that
> + * may be needed to power on the device to a point where it is even possible to
> + * execute the primary PM domain's resume/on routines.
> + */
> +
> +#ifdef CONFIG_PM
> +struct swnode_pm_domain {
> +	struct dev_pm_domain pm_domain;
> +	struct dev_pm_domain *primary;
> +};
> +
> +#define to_swnode_pm_domain(d) \
> +		container_of(d, struct swnode_pm_domain, pm_domain)
> +
> +static int software_node_runtime_suspend(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.runtime_suspend)
> +		ret = domain->primary->ops.runtime_suspend(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->runtime_suspend)
> +		ret = dev->type->pm->runtime_suspend(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->runtime_suspend)
> +		ret = dev->class->pm->runtime_suspend(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
> +		ret = dev->bus->pm->runtime_suspend(dev);
> +	else
> +		ret = pm_generic_runtime_suspend(dev);
> +
> +	if (ret || !swnode->node->pm->runtime_suspend)
> +		return ret;
> +
> +	return swnode->node->pm->runtime_suspend(dev);
> +}
> +
> +static int software_node_runtime_resume(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->runtime_resume) {
> +		ret = swnode->node->pm->runtime_resume(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.runtime_resume)
> +		ret = domain->primary->ops.runtime_resume(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->runtime_resume)
> +		ret = dev->type->pm->runtime_resume(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->runtime_resume)
> +		ret = dev->class->pm->runtime_resume(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_resume)
> +		ret = dev->bus->pm->runtime_resume(dev);
> +	else
> +		ret = pm_generic_runtime_resume(dev);
> +
> +	return ret;
> +}
> +
> +static int software_node_runtime_idle(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret = 0;
> +
> +	if (domain->primary && domain->primary->ops.runtime_idle)
> +		ret = domain->primary->ops.runtime_idle(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->runtime_idle)
> +		ret = dev->type->pm->runtime_idle(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->runtime_idle)
> +		ret = dev->class->pm->runtime_idle(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_idle)
> +		ret = dev->bus->pm->runtime_idle(dev);
> +	else if (dev->driver && dev->driver->pm && dev->driver->pm->runtime_idle)
> +		ret = dev->driver->pm->runtime_idle(dev);
> +
> +	if (ret || !swnode->node->pm->runtime_idle)
> +		return ret;
> +
> +	return swnode->node->pm->runtime_idle(dev);
> +}

These functions are doing pretty much the same thing but with different
parameters. How about implementing a macro or a few, which would take all
the parameters as arguments and return the function to call? A few variants
may be needed. Individual functions performing different tasks would become
very simple.

> +
> +#ifdef CONFIG_PM_SLEEP
> +static int software_node_prepare(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.prepare)
> +		ret = domain->primary->ops.prepare(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->prepare)
> +		ret = dev->type->pm->prepare(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->prepare)
> +		ret = dev->class->pm->prepare(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->prepare)
> +		ret = dev->bus->pm->prepare(dev);
> +	else
> +		ret = pm_generic_prepare(dev);
> +
> +	if (ret || !swnode->node->pm->prepare)
> +		return ret;
> +
> +	return swnode->node->pm->prepare(dev);
> +}
> +
> +static void software_node_complete(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +
> +	if (swnode->node->pm->complete)
> +		swnode->node->pm->complete(dev);
> +
> +	if (domain->primary && domain->primary->ops.complete)
> +		domain->primary->ops.complete(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->complete)
> +		dev->type->pm->complete(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->complete)
> +		dev->class->pm->complete(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->complete)
> +		dev->bus->pm->complete(dev);
> +	else
> +		pm_generic_complete(dev);
> +}
> +
> +static int software_node_suspend(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.suspend)
> +		ret = domain->primary->ops.suspend(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->suspend)
> +		ret = dev->type->pm->suspend(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->suspend)
> +		ret = dev->class->pm->suspend(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->suspend)
> +		ret = dev->bus->pm->suspend(dev);
> +	else
> +		ret = pm_generic_suspend(dev);
> +
> +	if (ret || !swnode->node->pm->suspend)
> +		return ret;
> +
> +	return swnode->node->pm->suspend(dev);
> +}
> +
> +static int software_node_resume(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->resume) {
> +		ret = swnode->node->pm->resume(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.resume)
> +		ret = domain->primary->ops.resume(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->resume)
> +		ret = dev->type->pm->resume(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->resume)
> +		ret = dev->class->pm->resume(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->resume)
> +		ret = dev->bus->pm->resume(dev);
> +	else
> +		ret = pm_generic_resume(dev);
> +
> +	return ret;
> +}
> +
> +static int software_node_freeze(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.freeze)
> +		ret = domain->primary->ops.freeze(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->freeze)
> +		ret = dev->type->pm->freeze(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->freeze)
> +		ret = dev->class->pm->freeze(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->freeze)
> +		ret = dev->bus->pm->freeze(dev);
> +	else
> +		ret = pm_generic_freeze(dev);
> +
> +	if (ret || !swnode->node->pm->freeze)
> +		return ret;
> +
> +	return swnode->node->pm->freeze(dev);
> +}
> +
> +static int software_node_thaw(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->thaw) {
> +		ret = swnode->node->pm->thaw(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.thaw)
> +		ret = domain->primary->ops.thaw(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->thaw)
> +		ret = dev->type->pm->thaw(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->thaw)
> +		ret = dev->class->pm->thaw(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->thaw)
> +		ret = dev->bus->pm->thaw(dev);
> +	else
> +		ret = pm_generic_thaw(dev);
> +
> +	return ret;
> +}
> +
> +static int software_node_poweroff(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.poweroff)
> +		ret = domain->primary->ops.poweroff(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->poweroff)
> +		ret = dev->type->pm->poweroff(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->poweroff)
> +		ret = dev->class->pm->poweroff(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->poweroff)
> +		ret = dev->bus->pm->poweroff(dev);
> +	else
> +		ret = pm_generic_poweroff(dev);
> +
> +	if (ret || !swnode->node->pm->poweroff)
> +		return ret;
> +
> +	return swnode->node->pm->poweroff(dev);
> +}
> +
> +static int software_node_restore(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->restore) {
> +		ret = swnode->node->pm->restore(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.restore)
> +		ret = domain->primary->ops.restore(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->restore)
> +		ret = dev->type->pm->restore(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->restore)
> +		ret = dev->class->pm->restore(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->restore)
> +		ret = dev->bus->pm->restore(dev);
> +	else
> +		ret = pm_generic_restore(dev);
> +
> +	return ret;
> +}
> +
> +static int software_node_suspend_late(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.suspend_late)
> +		ret = domain->primary->ops.suspend_late(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->suspend_late)
> +		ret = dev->type->pm->suspend_late(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->suspend_late)
> +		ret = dev->class->pm->suspend_late(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->suspend_late)
> +		ret = dev->bus->pm->suspend_late(dev);
> +	else
> +		ret = pm_generic_suspend_late(dev);
> +
> +	if (ret || !swnode->node->pm->suspend_late)
> +		return ret;
> +
> +	return swnode->node->pm->suspend_late(dev);
> +}
> +
> +static int software_node_resume_early(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->resume_early) {
> +		ret = swnode->node->pm->resume_early(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.resume_early)
> +		ret = domain->primary->ops.resume_early(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->resume_early)
> +		ret = dev->type->pm->resume_early(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->resume_early)
> +		ret = dev->class->pm->resume_early(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->resume_early)
> +		ret = dev->bus->pm->resume_early(dev);
> +	else
> +		pm_generic_resume_early(dev);
> +
> +	return 0;
> +}
> +
> +static int software_node_freeze_late(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.freeze_late)
> +		ret = domain->primary->ops.freeze_late(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->freeze_late)
> +		ret = dev->type->pm->freeze_late(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->freeze_late)
> +		ret = dev->class->pm->freeze_late(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->freeze_late)
> +		ret = dev->bus->pm->freeze_late(dev);
> +	else
> +		ret = pm_generic_freeze_late(dev);
> +
> +	if (ret || !swnode->node->pm->freeze_late)
> +		return ret;
> +
> +	return swnode->node->pm->freeze_late(dev);
> +}
> +
> +static int software_node_thaw_early(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->thaw_early) {
> +		ret = swnode->node->pm->thaw_early(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.thaw_early)
> +		ret = domain->primary->ops.thaw_early(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->thaw_early)
> +		ret = dev->type->pm->thaw_early(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->thaw_early)
> +		ret = dev->class->pm->thaw_early(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->thaw_early)
> +		ret = dev->bus->pm->thaw_early(dev);
> +	else
> +		ret = pm_generic_thaw_early(dev);
> +
> +	return ret;
> +}
> +
> +static int software_node_poweroff_late(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.poweroff_late)
> +		ret = domain->primary->ops.poweroff_late(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->poweroff_late)
> +		ret = dev->type->pm->poweroff_late(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->poweroff_late)
> +		ret = dev->class->pm->poweroff_late(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->poweroff_late)
> +		ret = dev->bus->pm->poweroff_late(dev);
> +	else
> +		ret = pm_generic_poweroff_late(dev);
> +
> +	if (ret || !swnode->node->pm->poweroff_late)
> +		return ret;
> +
> +	return swnode->node->pm->poweroff(dev);
> +}
> +
> +static int software_node_restore_early(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->restore_early) {
> +		ret = swnode->node->pm->restore_early(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.restore_early)
> +		ret = domain->primary->ops.restore_early(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->restore_early)
> +		ret = dev->type->pm->restore_early(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->restore_early)
> +		ret = dev->class->pm->restore_early(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->restore_early)
> +		ret = dev->bus->pm->restore_early(dev);
> +	else
> +		ret = pm_generic_restore_early(dev);
> +
> +	return ret;
> +}
> +
> +static int software_node_suspend_noirq(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.suspend_noirq)
> +		ret = domain->primary->ops.suspend_noirq(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->suspend_noirq)
> +		ret = dev->type->pm->suspend_noirq(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->suspend_noirq)
> +		ret = dev->class->pm->suspend_noirq(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->suspend_noirq)
> +		ret = dev->bus->pm->suspend_noirq(dev);
> +	else
> +		ret = pm_generic_suspend_noirq(dev);
> +
> +	if (ret || !swnode->node->pm->suspend_noirq)
> +		return ret;
> +
> +	return swnode->node->pm->suspend_noirq(dev);
> +}
> +
> +static int software_node_resume_noirq(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->resume_noirq) {
> +		ret = swnode->node->pm->resume_noirq(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.resume_noirq)
> +		ret = domain->primary->ops.resume_noirq(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->resume_noirq)
> +		ret = dev->type->pm->resume_noirq(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->resume_noirq)
> +		ret = dev->class->pm->resume_noirq(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->resume_noirq)
> +		ret = dev->bus->pm->resume_noirq(dev);
> +	else
> +		ret = pm_generic_resume_noirq(dev);
> +
> +	return ret;
> +}
> +
> +static int software_node_freeze_noirq(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.freeze_noirq)
> +		ret = domain->primary->ops.freeze_noirq(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->freeze_noirq)
> +		ret = dev->type->pm->freeze_noirq(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->freeze_noirq)
> +		ret = dev->class->pm->freeze_noirq(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->freeze_noirq)
> +		ret = dev->bus->pm->freeze_noirq(dev);
> +	else
> +		ret = pm_generic_freeze_noirq(dev);
> +
> +	if (ret || !swnode->node->pm->freeze_noirq)
> +		return ret;
> +
> +	return swnode->node->pm->freeze_noirq(dev);
> +}
> +
> +static int software_node_thaw_noirq(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->thaw_noirq) {
> +		ret = swnode->node->pm->thaw_noirq(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.thaw_noirq)
> +		ret = domain->primary->ops.thaw_noirq(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->thaw_noirq)
> +		ret = dev->type->pm->thaw_noirq(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->thaw_noirq)
> +		ret = dev->class->pm->thaw_noirq(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->thaw_noirq)
> +		ret = dev->bus->pm->thaw_noirq(dev);
> +	else
> +		ret = pm_generic_thaw_noirq(dev);
> +
> +	return ret;
> +}
> +
> +static int software_node_poweroff_noirq(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.poweroff_noirq)
> +		ret = domain->primary->ops.poweroff_noirq(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->poweroff_noirq)
> +		ret = dev->type->pm->poweroff_noirq(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->poweroff_noirq)
> +		ret = dev->class->pm->poweroff_noirq(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->poweroff_noirq)
> +		ret = dev->bus->pm->poweroff_noirq(dev);
> +	else
> +		ret = pm_generic_poweroff_noirq(dev);
> +
> +	if (ret || !swnode->node->pm->poweroff)
> +		return ret;
> +
> +	return swnode->node->pm->poweroff_noirq(dev);
> +}
> +
> +static int software_node_restore_noirq(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (swnode->node->pm->restore_noirq) {
> +		ret = swnode->node->pm->restore_noirq(dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	if (domain->primary && domain->primary->ops.restore_noirq)
> +		ret = domain->primary->ops.restore_noirq(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->restore_noirq)
> +		ret = dev->type->pm->restore_noirq(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->restore_noirq)
> +		ret = dev->class->pm->restore_noirq(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->restore_noirq)
> +		ret = dev->bus->pm->restore_noirq(dev);
> +	else
> +		ret = pm_generic_restore_noirq(dev);
> +
> +	return ret;
> +}
> +#endif /* CONFIG_PM_SLEEP */
> +
> +static const struct dev_pm_ops software_node_pm_ops = {
> +	.runtime_suspend = software_node_runtime_suspend,
> +	.runtime_resume = software_node_runtime_resume,
> +	.runtime_idle = software_node_runtime_idle,
> +#ifdef CONFIG_PM_SLEEP
> +	.prepare = software_node_prepare,
> +	.complete = software_node_complete,
> +	.suspend = software_node_suspend,
> +	.resume = software_node_resume,
> +	.freeze = software_node_freeze,
> +	.thaw = software_node_thaw,
> +	.poweroff = software_node_poweroff,
> +	.restore = software_node_restore,
> +	.suspend_late = software_node_suspend_late,
> +	.resume_early = software_node_resume_early,
> +	.freeze_late = software_node_freeze_late,
> +	.thaw_early = software_node_thaw_early,
> +	.poweroff_late = software_node_poweroff_late,
> +	.restore_early = software_node_restore_early,
> +	.suspend_noirq = software_node_suspend_noirq,
> +	.resume_noirq = software_node_resume_noirq,
> +	.freeze_noirq = software_node_freeze_noirq,
> +	.thaw_noirq = software_node_thaw_noirq,
> +	.poweroff_noirq = software_node_poweroff_noirq,
> +	.restore_noirq = software_node_restore_noirq,
> +#endif /* CONFIG_PM_SLEEP */
> +};
> +
> +static void software_node_dev_pm_detach(struct device *dev, bool power_off)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +
> +	if (domain->primary && domain->primary->detach) {
> +		dev->pm_domain = domain->primary;
> +		domain->primary->detach(dev, power_off);
> +	} else {
> +		dev_pm_domain_set(dev, NULL);
> +	}
> +
> +	kfree(domain);
> +}
> +
> +int software_node_dev_pm_attach(struct device *dev, bool power_on)
> +{
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	struct swnode_pm_domain *domain;
> +
> +	if (!swnode || !swnode->node->pm)
> +		return 0;
> +
> +	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
> +	if (!domain)
> +		return -ENOMEM;
> +
> +	if (dev->pm_domain)
> +		domain->pm_domain = *dev->pm_domain;
> +
> +	domain->primary = dev->pm_domain;
> +	domain->pm_domain.ops = software_node_pm_ops;
> +	domain->pm_domain.detach = software_node_dev_pm_detach;
> +
> +	dev_pm_domain_set(dev, &domain->pm_domain);
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(software_node_dev_pm_attach);
> +#endif /* CONFIG_PM */
> +
>  /* -------------------------------------------------------------------------- */
>  /* fwnode operations */
>  
> @@ -845,20 +1527,13 @@ EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
>  
>  int software_node_notify(struct device *dev, unsigned long action)
>  {
> -	struct fwnode_handle *fwnode = dev_fwnode(dev);
>  	struct swnode *swnode;
>  	int ret;
>  
> -	if (!fwnode)
> -		return 0;
> -
> -	if (!is_software_node(fwnode))
> -		fwnode = fwnode->secondary;
> -	if (!is_software_node(fwnode))
> +	swnode = dev_to_swnode(dev);
> +	if (!swnode)
>  		return 0;
>  
> -	swnode = to_swnode(fwnode);
> -
>  	switch (action) {
>  	case KOBJ_ADD:
>  		ret = sysfs_create_link(&dev->kobj, &swnode->kobj,
> diff --git a/include/linux/property.h b/include/linux/property.h
> index 2d4542629d80b..33b25c8bd4052 100644
> --- a/include/linux/property.h
> +++ b/include/linux/property.h
> @@ -453,11 +453,13 @@ static inline void *device_connection_find_match(struct device *dev,
>   * @name: Name of the software node
>   * @parent: Parent of the software node
>   * @properties: Array of device properties
> + * @pm: Power management operations
>   */
>  struct software_node {
>  	const char *name;
>  	const struct software_node *parent;
>  	const struct property_entry *properties;
> +	const struct dev_pm_ops *pm;
>  };
>  
>  bool is_software_node(const struct fwnode_handle *fwnode);
> @@ -479,6 +481,14 @@ int software_node_register(const struct software_node *node);
>  void software_node_unregister(const struct software_node *node);
>  
>  int software_node_notify(struct device *dev, unsigned long action);
> +#ifdef CONFIG_PM
> +int software_node_dev_pm_attach(struct device *dev, bool power_on);
> +#else
> +static inline int software_node_dev_pm_attach(struct device *dev, bool power_on)
> +{
> +	return 0;
> +}
> +#endif /* CONFIG_PM */
>  
>  struct fwnode_handle *
>  fwnode_create_software_node(const struct property_entry *properties,

-- 
Terveisin,

Sakari Ailus

Re: [PATCHv2 1/3] software node: Power management operations for software nodes

[Heikki Krogerus]

On Thu, Oct 29, 2020 at 01:13:03PM +0200, Sakari Ailus wrote:
> These functions are doing pretty much the same thing but with different
> parameters. How about implementing a macro or a few, which would take all
> the parameters as arguments and return the function to call? A few variants
> may be needed. Individual functions performing different tasks would become
> very simple.

I would prefer to do that as the second step, if you guys don't mind.
I think this was already talked about, but maybe only internally.
Those macros should then be used also in other places where the same
steps are being executed, for example in drivers/base/power/domain.c.

thanks,

-- 
heikki

Re: [PATCHv2 1/3] software node: Power management operations for software nodes

[Andy Shevchenko]

On Thu, Oct 29, 2020 at 01:51:13PM +0200, Heikki Krogerus wrote:
> On Thu, Oct 29, 2020 at 01:13:03PM +0200, Sakari Ailus wrote:
> > These functions are doing pretty much the same thing but with different
> > parameters. How about implementing a macro or a few, which would take all
> > the parameters as arguments and return the function to call? A few variants
> > may be needed. Individual functions performing different tasks would become
> > very simple.
> 
> I would prefer to do that as the second step, if you guys don't mind.
> I think this was already talked about, but maybe only internally.
> Those macros should then be used also in other places where the same
> steps are being executed, for example in drivers/base/power/domain.c.

I agree.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCHv2 0/3] PM operations for software nodes

[Andy Shevchenko]

On Thu, Oct 29, 2020 at 01:59:38PM +0300, Heikki Krogerus wrote:
> Hi,
> 
> This is the second version of this series. Rafael pointed out in v1
> that I was not handling bus PM ops correctly. He also requested that I
> put a comment to the code explaining things a little.
> 
> The original v1 series:
> https://lore.kernel.org/linux-acpi/20200825135951.53340-1-heikki.krogerus@linux.intel.com/

I have tested this on Intel Edison and found no regressions.
Feel free to add my
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> Heikki Krogerus (3):
>   software node: Power management operations for software nodes
>   software node: Introduce device_add_software_node()
>   usb: dwc3: pci: Register a software node for the dwc3 platform device
> 
>  drivers/base/power/common.c |   8 +-
>  drivers/base/swnode.c       | 738 +++++++++++++++++++++++++++++++++++-
>  drivers/usb/dwc3/dwc3-pci.c | 175 +++++----
>  include/linux/property.h    |  13 +
>  4 files changed, 835 insertions(+), 99 deletions(-)
> 
> -- 
> 2.28.0
> 

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCHv2 1/3] software node: Power management operations for software nodes

[Sakari Ailus]

On Thu, Oct 29, 2020 at 01:51:13PM +0200, Heikki Krogerus wrote:
> On Thu, Oct 29, 2020 at 01:13:03PM +0200, Sakari Ailus wrote:
> > These functions are doing pretty much the same thing but with different
> > parameters. How about implementing a macro or a few, which would take all
> > the parameters as arguments and return the function to call? A few variants
> > may be needed. Individual functions performing different tasks would become
> > very simple.
> 
> I would prefer to do that as the second step, if you guys don't mind.
> I think this was already talked about, but maybe only internally.
> Those macros should then be used also in other places where the same
> steps are being executed, for example in drivers/base/power/domain.c.

Works for me.

For the set:

Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>

-- 
Sakari Ailus

Re: [PATCHv2 1/3] software node: Power management operations for software nodes

[Rafael J. Wysocki]

On Thu, Oct 29, 2020 at 11:59 AM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
>
> The software node specific PM operations make it possible to
> handle most PM related quirks separately in their own
> functions instead of conditionally in the device driver's
> generic PM functions (and in some cases all over the
> driver). The software node specific PM operations will also
> reduce the need to pass platform data in some cases, for
> example from a core MFD driver to the child device drivers,
> as from now on the core MFD driver will be able to implement
> the PM quirks directly for the child devices without the
> need to touch the drivers of those child devices.
>
> If a software node includes the PM operations, those PM
> operations are always executed separately on top of the
> other PM operations of the device, so the software node will
> never replace any of the "normal" PM operations of the
> device (including the PM domain's operations, class's or
> bus's PM operations, the device drivers own operations, or
> any other).
>
> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> ---
>  drivers/base/power/common.c |   8 +-
>  drivers/base/swnode.c       | 693 +++++++++++++++++++++++++++++++++++-
>  include/linux/property.h    |  10 +
>  3 files changed, 701 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/base/power/common.c b/drivers/base/power/common.c
> index bbddb267c2e69..b64cd4690ac63 100644
> --- a/drivers/base/power/common.c
> +++ b/drivers/base/power/common.c
> @@ -109,8 +109,14 @@ int dev_pm_domain_attach(struct device *dev, bool power_on)
>         ret = acpi_dev_pm_attach(dev, power_on);
>         if (!ret)
>                 ret = genpd_dev_pm_attach(dev);
> +       if (ret < 0)
> +               return ret;
>
> -       return ret < 0 ? ret : 0;
> +       ret = software_node_dev_pm_attach(dev, power_on);
> +       if (ret)
> +               dev_pm_domain_detach(dev, power_on);
> +
> +       return ret;
>  }
>  EXPORT_SYMBOL_GPL(dev_pm_domain_attach);
>
> diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c
> index 010828fc785bc..595a9c240fede 100644
> --- a/drivers/base/swnode.c
> +++ b/drivers/base/swnode.c
> @@ -8,6 +8,8 @@
>
>  #include <linux/device.h>
>  #include <linux/kernel.h>
> +#include <linux/pm_domain.h>
> +#include <linux/pm_runtime.h>
>  #include <linux/property.h>
>  #include <linux/slab.h>
>
> @@ -48,6 +50,19 @@ EXPORT_SYMBOL_GPL(is_software_node);
>                                      struct swnode, fwnode) : NULL;     \
>         })
>
> +static inline struct swnode *dev_to_swnode(struct device *dev)
> +{
> +       struct fwnode_handle *fwnode = dev_fwnode(dev);
> +
> +       if (!fwnode)
> +               return NULL;
> +
> +       if (!is_software_node(fwnode))
> +               fwnode = fwnode->secondary;
> +
> +       return to_swnode(fwnode);
> +}
> +
>  static struct swnode *
>  software_node_to_swnode(const struct software_node *node)
>  {
> @@ -344,6 +359,673 @@ void property_entries_free(const struct property_entry *properties)
>  }
>  EXPORT_SYMBOL_GPL(property_entries_free);
>
> +/* -------------------------------------------------------------------------- */
> +/* Power management operations */
> +
> +/*
> + * The power management operations in software nodes are handled with a power
> + * management domain - a "wrapper" PM domain:
> + *
> + *   When PM operations are supplied as part of the software node, the primary
> + *   PM domain of the device is stored and replaced with a device specific
> + *   software node PM domain. The software node PM domain's PM operations, which
> + *   are implemented below, will then always call the matching PM operation of
> + *   the primary PM domain (which was stored) on top of the software node's own
> + *   operation.
> + *
> + * If the device does not have primary PM domain, the software node PM wrapper
> + * operations below will also call the classes, buses and device type's PM
> + * operations, and of course the device driver's own PM operations if they are
> + * implemented. The priority of those calls follows drivers/base/power/domain.c:
> + *
> + * 1) device type
> + * 2) class
> + * 3) bus
> + * 4) driver
> + *
> + * NOTE. The software node PM operation is always called before the primary
> + * PM domain with resume/on callbacks, and after the primary PM domain with
> + * suspend/off callbacks. This order is used because the software node PM
> + * operations are primarily meant to be used to implement quirks, quirks that
> + * may be needed to power on the device to a point where it is even possible to
> + * execute the primary PM domain's resume/on routines.
> + */

Well, this basically implements a wrapper PM domain that is somewhat
more generic, as a concept, then software nodes PM.

At least it is not specific to software nodes, so I'd prefer it to be
defined generically.

Moreover, IIUC, this breaks if the "primary" PM domain callbacks try
to get to the original PM domain via the dev->pm_domain pointer, which
the genpd callbacks do.

Do we want to wrap the ACPI PM domain only, by any chance?  If so, it
may be more straightforward to invoke swnode callbacks directly from
there, if any.

Re: [PATCHv2 1/3] software node: Power management operations for software nodes

[Heikki Krogerus]

Hi Rafael,

On Thu, Oct 29, 2020 at 06:10:59PM +0100, Rafael J. Wysocki wrote:
> Well, this basically implements a wrapper PM domain that is somewhat
> more generic, as a concept, then software nodes PM.
> 
> At least it is not specific to software nodes, so I'd prefer it to be
> defined generically.

I don't think we should generalize it like that. I do not think the
power domains should have any links between each other at the general
level (just like we probable should not link fwnodes together anymore
like we do now with the "secondary" fwnode). That is why I have
confined this to software nodes only for now.

I think ideally devices could belong to multiple power domains. That
would be the general solution. I did not think that trying to figure
out how to do that would be reasonable as the first approach (maybe I
should have done exactly that?). But would it be acceptable to allow
devices to belong to multiple power domains?

> Moreover, IIUC, this breaks if the "primary" PM domain callbacks try
> to get to the original PM domain via the dev->pm_domain pointer, which
> the genpd callbacks do.

Ouch, that is true.

> Do we want to wrap the ACPI PM domain only, by any chance?  If so, it
> may be more straightforward to invoke swnode callbacks directly from
> there, if any.

The software node can still be the only "primary" fwnode. I don't
think we should limit this to only platforms (and kernels) that
support ACPI.


thanks,

-- 
heikki

Re: [PATCHv2 1/3] software node: Power management operations for software nodes

[Lukas Wunner]

Hi Heikki,

saw this linked in your WSR and felt compelled to reply... ;)

On Thu, Oct 29, 2020 at 01:59:39PM +0300, Heikki Krogerus wrote:
> +static int software_node_runtime_suspend(struct device *dev)
> +{
> +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> +	struct swnode *swnode = dev_to_swnode(dev);
> +	int ret;
> +
> +	if (domain->primary && domain->primary->ops.runtime_suspend)
> +		ret = domain->primary->ops.runtime_suspend(dev);
> +	else if (dev->type && dev->type->pm && dev->type->pm->runtime_suspend)
> +		ret = dev->type->pm->runtime_suspend(dev);
> +	else if (dev->class && dev->class->pm && dev->class->pm->runtime_suspend)
> +		ret = dev->class->pm->runtime_suspend(dev);
> +	else if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
> +		ret = dev->bus->pm->runtime_suspend(dev);
> +	else
> +		ret = pm_generic_runtime_suspend(dev);

This if/else ladder seems to be duplicated for every single PM callback
in this patch.

Code size can be reduced significantly if you use offsetof() to determine
the offset of the given callback in struct pm_ops, then pass that offset
to a helper which contains the above-quoted if/else ladder and retrieves
the callback.  Finally invoke the callback you've just retrieved.

That way you only need the if/else ladder once in your patch.

For an example, see pcie_port_device_iter() and its callers
pcie_port_device_suspend() and so on:

https://elixir.bootlin.com/linux/latest/source/drivers/pci/pcie/portdrv_core.c#L372

Thanks,

Lukas

Re: [PATCHv2 1/3] software node: Power management operations for software nodes

[Heikki Krogerus]

Hi Lukas,

On Fri, Mar 25, 2022 at 05:42:55PM +0100, Lukas Wunner wrote:
> Hi Heikki,
> 
> saw this linked in your WSR and felt compelled to reply... ;)
> 
> On Thu, Oct 29, 2020 at 01:59:39PM +0300, Heikki Krogerus wrote:
> > +static int software_node_runtime_suspend(struct device *dev)
> > +{
> > +	struct swnode_pm_domain *domain = to_swnode_pm_domain(dev->pm_domain);
> > +	struct swnode *swnode = dev_to_swnode(dev);
> > +	int ret;
> > +
> > +	if (domain->primary && domain->primary->ops.runtime_suspend)
> > +		ret = domain->primary->ops.runtime_suspend(dev);
> > +	else if (dev->type && dev->type->pm && dev->type->pm->runtime_suspend)
> > +		ret = dev->type->pm->runtime_suspend(dev);
> > +	else if (dev->class && dev->class->pm && dev->class->pm->runtime_suspend)
> > +		ret = dev->class->pm->runtime_suspend(dev);
> > +	else if (dev->bus && dev->bus->pm && dev->bus->pm->runtime_suspend)
> > +		ret = dev->bus->pm->runtime_suspend(dev);
> > +	else
> > +		ret = pm_generic_runtime_suspend(dev);
> 
> This if/else ladder seems to be duplicated for every single PM callback
> in this patch.
> 
> Code size can be reduced significantly if you use offsetof() to determine
> the offset of the given callback in struct pm_ops, then pass that offset
> to a helper which contains the above-quoted if/else ladder and retrieves
> the callback.  Finally invoke the callback you've just retrieved.

I think Sakari already suggested that. I'll improve this part in the
next version.

thanks,

-- 
heikki