From: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
Add OF notifier handler needed for creating/destroying platform devices
according to dynamic runtime changes in the DT live tree.
Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
Signed-off-by: Grant Likely <grant.likely@xxxxxxxxxx>
---
drivers/base/platform.c | 1 +
drivers/of/platform.c | 55 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/of_platform.h | 6 +++++
3 files changed, 62 insertions(+)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index b2afc29403f9..233ececd15a3 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1006,6 +1006,7 @@ int __init platform_bus_init(void)
error = bus_register(&platform_bus_type);
if (error)
device_unregister(&platform_bus);
+ of_platform_register_reconfig_notifier();
return error;
}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 656cccf0e680..cd87a36495be 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -550,4 +550,59 @@ void of_platform_depopulate(struct device *parent)
}
EXPORT_SYMBOL_GPL(of_platform_depopulate);
+#ifdef CONFIG_OF_DYNAMIC
+static int of_platform_notify(struct notifier_block *nb,
+ unsigned long action, void *arg)
+{
+ struct of_reconfig_data *rd = arg;
+ struct platform_device *pdev_parent, *pdev;
+ bool children_left;
+
+ switch (of_reconfig_get_state_change(action, rd)) {
+ case OF_RECONFIG_CHANGE_ADD:
+ /* verify that the parent is a bus */
+ if (!of_node_check_flag(rd->dn->parent, OF_POPULATED_BUS))
+ return NOTIFY_OK; /* not for us */
+
+ /* pdev_parent may be NULL when no bus platform device */
+ pdev_parent = of_find_device_by_node(rd->dn->parent);
+ pdev = of_platform_device_create(rd->dn, NULL,
+ pdev_parent ? &pdev_parent->dev : NULL);
+ of_dev_put(pdev_parent);
+
+ if (pdev == NULL) {
+ pr_err("%s: failed to create for '%s'\n",
+ __func__, rd->dn->full_name);
+ /* of_platform_device_create tosses the error code */
+ return notifier_from_errno(-EINVAL);
+ }
+ break;
+
+ case OF_RECONFIG_CHANGE_REMOVE:
+ /* find our device by node */
+ pdev = of_find_device_by_node(rd->dn);
+ if (pdev == NULL)
+ return NOTIFY_OK; /* no? not meant for us */
+
+ /* unregister takes one ref away */
+ of_platform_device_destroy(&pdev->dev, &children_left);
+
+ /* and put the reference of the find */
+ of_dev_put(pdev);
+ break;
+ }
+
+ return NOTIFY_OK;
+}
+
+static struct notifier_block platform_of_notifier = {
+ .notifier_call = of_platform_notify,
+};
+
+void of_platform_register_reconfig_notifier(void)
+{
+ WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
#endif /* CONFIG_OF_ADDRESS */
diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
index c2b0627a2317..8a860f096c35 100644
--- a/include/linux/of_platform.h
+++ b/include/linux/of_platform.h
@@ -84,4 +84,10 @@ static inline int of_platform_populate(struct device_node *root,
static inline void of_platform_depopulate(struct device *parent) { }
#endif
+#ifdef CONFIG_OF_DYNAMIC
+extern void of_platform_register_reconfig_notifier(void);
+#else
+static inline void of_platform_register_reconfig_notifier(void) { }
+#endif
+
#endif /* _LINUX_OF_PLATFORM_H */
--
1.9.1
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