of/reconfig: Add OF_DYNAMIC notifier for platform_bus_type

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@konsulko.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
(cherry picked from commit 801d728c10db4b28e01590b46bf1f0df930760cc)
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 9eda84246ffd5eda7d1d6947ef27a5ba05a75951..2fb6e9888f3661ca1ab4b83957e1c88db7952fd5 100644 (file)
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -913,6 +913,7 @@ 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 eb6e20597e82a6cc5ada5b70f78c14cd14d3377b..6523eb5bb4eb4eb237e51711cdf0d0153c23c9e5 100644 (file)
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -526,4 +526,59 @@ 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 3e989ed04e3fc12cdea36298eaca5da371920ebb..30ebd762063a07e8bfc4f75d41e79b4040456fce 100644 (file)
--- a/include/linux/of_platform.h
+++ b/include/linux/of_platform.h
@@ -113,4 +113,10 @@ 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 */