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.anton...@konsulko.com>
---
 drivers/base/platform.c     | 18 +++++++++--
 drivers/of/platform.c       | 78 +++++++++++++++++++++++++++++++++++++++++++++
 include/linux/of_platform.h | 10 ++++++
 3 files changed, 103 insertions(+), 3 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index b2afc29..282bfec 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -1002,10 +1002,22 @@ int __init platform_bus_init(void)
 
        error = device_register(&platform_bus);
        if (error)
-               return error;
-       error =  bus_register(&platform_bus_type);
+               goto err_out;
+
+       error = bus_register(&platform_bus_type);
+       if (error)
+               goto err_unreg_dev;
+
+       error = of_platform_register_reconfig_notifier();
        if (error)
-               device_unregister(&platform_bus);
+               goto err_unreg_bus;
+
+       return 0;
+err_unreg_bus:
+       bus_unregister(&platform_bus_type);
+err_unreg_dev:
+       device_unregister(&platform_bus);
+err_out:
        return error;
 }
 
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 3b64d0b..aa8db92 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -546,4 +546,82 @@ void of_platform_depopulate(struct device *parent)
 }
 EXPORT_SYMBOL_GPL(of_platform_depopulate);
 
+#ifdef CONFIG_OF_DYNAMIC
+
+static struct notifier_block platform_of_notifier;
+
+static int of_platform_notify(struct notifier_block *nb,
+                               unsigned long action, void *arg)
+{
+       struct platform_device *pdev_parent, *pdev;
+       struct device_node *dn;
+       int state;
+       bool children_left;
+
+       state = of_reconfig_get_state_change(action, arg);
+
+       /* no change? */
+       if (state == -1)
+               return NOTIFY_OK;
+
+       switch (action) {
+       case OF_RECONFIG_ATTACH_NODE:
+       case OF_RECONFIG_DETACH_NODE:
+               dn = arg;
+               break;
+       case OF_RECONFIG_ADD_PROPERTY:
+       case OF_RECONFIG_REMOVE_PROPERTY:
+       case OF_RECONFIG_UPDATE_PROPERTY:
+               dn = ((struct of_prop_reconfig *)arg)->dn;
+               break;
+       default:
+               return NOTIFY_OK;
+       }
+
+       if (state) {
+
+               /* verify that the parent is a bus */
+               if (!of_match_node(of_default_bus_match_table, dn->parent))
+                       return NOTIFY_OK;       /* not for us */
+
+               /* pdev_parent may be NULL when no bus platform device */
+               pdev_parent = of_find_device_by_node(dn->parent);
+               pdev = of_platform_device_create(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__, dn->full_name);
+                       /* of_platform_device_create tosses the error code */
+                       return notifier_from_errno(-EINVAL);
+               }
+
+       } else {
+
+               /* find our device by node */
+               pdev = of_find_device_by_node(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);
+
+       }
+
+       return NOTIFY_OK;
+}
+
+int of_platform_register_reconfig_notifier(void)
+{
+       platform_of_notifier.notifier_call = of_platform_notify;
+       return of_reconfig_notifier_register(&platform_of_notifier);
+}
+EXPORT_SYMBOL_GPL(of_platform_register_reconfig_notifier);
+
+#endif
+
 #endif /* CONFIG_OF_ADDRESS */
diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
index c2b0627..01fe5d6 100644
--- a/include/linux/of_platform.h
+++ b/include/linux/of_platform.h
@@ -84,4 +84,14 @@ 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 int of_platform_register_reconfig_notifier(void);
+#else
+static inline int of_platform_register_reconfig_notifier(void)
+{
+       return 0;
+}
+#endif
+
+
 #endif /* _LINUX_OF_PLATFORM_H */
-- 
1.7.12

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to