In "Device Tree powered" systems, platform devices are usually
massively populated with of_platform_populate() call, executed
at some level of initcalls, either by generic architecture
or by platform-specific code.
There are situations though where certain devices must be
created (and bound with drivers) before all the others.
This presents small challenge in DT-driven systems, as
devices explicitly created in early code would be created
again by of_platform_populate().
This patch tries to solve that issue in a generic way,
adding a "populated" flag which is set in the device_node
structure when a device is being created in the core.
Later, of_platform_populate() skips such nodes (and
its children) in a similar way to the non-available ones.
Signed-off-by: Pawel Moll <pawel.moll@xxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Grant Likely <grant.likely@xxxxxxxxxx>
Cc: Rob Herring <rob.herring@xxxxxxxxxxx>
Cc: devicetree@xxxxxxxxxxxxxxx
---
drivers/base/core.c | 4 ++++
drivers/of/device.c | 16 ++++++++++++++++
drivers/of/platform.c | 6 ++++--
include/linux/of.h | 6 ++++++
include/linux/of_device.h | 11 +++++++++++
5 files changed, 41 insertions(+), 2 deletions(-)
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 67b180d..50dd8f3 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1086,6 +1086,8 @@ int device_add(struct device *dev)
class_intf->add_dev(dev, class_intf);
mutex_unlock(&dev->class->p->mutex);
}
+
+ of_device_populate(dev);
done:
put_device(dev);
return error;
@@ -1188,6 +1190,8 @@ void device_del(struct device *dev)
struct device *parent = dev->parent;
struct class_interface *class_intf;
+ of_device_depopulate(dev);
+
/* Notify clients of device removal. This call must come
* before dpm_sysfs_remove().
*/
diff --git a/drivers/of/device.c b/drivers/of/device.c
index f685e55..dae092a 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -187,3 +187,19 @@ int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
return 0;
}
+
+void of_device_populate(struct device *dev)
+{
+ if ((!dev) || (!dev->of_node))
+ return;
+
+ of_node_set_flag(dev->of_node, OF_POPULATED);
+}
+
+void of_device_depopulate(struct device *dev)
+{
+ if ((!dev) || (!dev->of_node))
+ return;
+
+ of_node_clear_flag(dev->of_node, OF_POPULATED);
+}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 404d1da..ad43ee0 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -204,7 +204,8 @@ static struct platform_device *of_platform_device_create_pdata(
{
struct platform_device *dev;
- if (!of_device_is_available(np))
+ if (!of_device_is_available(np) ||
+ of_node_check_flag(np, OF_POPULATED))
return NULL;
dev = of_device_alloc(np, bus_id, parent);
@@ -262,7 +263,8 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
pr_debug("Creating amba device %s\n", node->full_name);
- if (!of_device_is_available(node))
+ if (!of_device_is_available(node) ||
+ of_node_check_flag(node, OF_POPULATED))
return NULL;
dev = amba_device_alloc(NULL, 0, 0);
diff --git a/include/linux/of.h b/include/linux/of.h
index 276c546..53989cf 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -114,6 +114,11 @@ static inline void of_node_set_flag(struct device_node *n, unsigned long flag)
set_bit(flag, &n->_flags);
}
+static inline void of_node_clear_flag(struct device_node *n, unsigned long flag)
+{
+ clear_bit(flag, &n->_flags);
+}
+
extern struct device_node *of_find_all_nodes(struct device_node *prev);
/*
@@ -156,6 +161,7 @@ static inline unsigned long of_read_ulong(const __be32 *cell, int size)
/* flag descriptions */
#define OF_DYNAMIC 1 /* node and properties were allocated via kmalloc */
#define OF_DETACHED 2 /* node has been detached from the device tree */
+#define OF_POPULATED 3 /* device already created for the node */
#define OF_IS_DYNAMIC(x) test_bit(OF_DYNAMIC, &x->_flags)
#define OF_MARK_DYNAMIC(x) set_bit(OF_DYNAMIC, &x->_flags)
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index 82ce324..bfb4a48 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -44,6 +44,9 @@ static inline void of_device_node_put(struct device *dev)
of_node_put(dev->of_node);
}
+extern void of_device_populate(struct device *dev);
+extern void of_device_depopulate(struct device *dev);
+
static inline struct device_node *of_cpu_device_node_get(int cpu)
{
struct device *cpu_dev;
@@ -78,6 +81,14 @@ static inline const struct of_device_id *of_match_device(
return NULL;
}
+static inline void of_device_populate(struct device *dev)
+{
+}
+
+static inline void of_device_depopulate(struct device *dev)
+{
+}
+
static inline struct device_node *of_cpu_device_node_get(int cpu)
{
return NULL;
--
1.8.3.2
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