[PATCH v4 4/8] OF: platform: Add overlay bus handler

From: Pantelis Antoniou
Date: Fri Apr 04 2014 - 08:46:42 EST


Add the bus handler registration needed for performing overlays
containing platform devices.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@xxxxxxxxxxxx>
---
drivers/base/platform.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 95 insertions(+), 3 deletions(-)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index e714709..bf5b429 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -922,6 +922,86 @@ struct bus_type platform_bus_type = {
};
EXPORT_SYMBOL_GPL(platform_bus_type);

+#ifdef CONFIG_OF_OVERLAY
+
+static int platform_handler_create(struct of_overlay_device_entry *de,
+ int revert)
+{
+ struct device_node *dn;
+ struct platform_device *pdev_parent, *pdev;
+
+ if (!de || !de->np)
+ return -ENOTSUPP;
+
+ dn = de->np;
+
+ /* verify that the parent is a bus */
+ if (!of_match_node(of_default_bus_match_table, dn->parent))
+ return -ENOTSUPP;
+
+ /* pdev_parent may be NULL when there is 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 platform device "
+ "for '%s'\n",
+ __func__, dn->full_name);
+ /* of_platform_device_create tosses the real error code */
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int platform_handler_remove(struct of_overlay_device_entry *de,
+ int revert)
+{
+ struct device_node *dn;
+ struct platform_device *pdev;
+
+ if (!de || !de->np)
+ return -ENOTSUPP;
+
+ dn = de->np;
+
+ pdev = of_find_device_by_node(dn);
+ if (pdev == NULL)
+ return -ENOTSUPP;
+
+ /* unregister takes one ref away */
+ platform_device_unregister(pdev);
+
+ /* and put the reference of the find */
+ of_dev_put(pdev);
+
+ return 0;
+}
+
+static const struct of_overlay_handler_ops platform_handler_ops = {
+ .create = platform_handler_create,
+ .remove = platform_handler_remove,
+};
+
+static struct of_overlay_handler platform_handler = {
+ .name = "platform",
+ .ops = &platform_handler_ops,
+};
+
+static int __init platform_bus_handler_register(void)
+{
+ return of_overlay_handler_register(&platform_handler);
+}
+
+#else
+static inline int platform_bus_handler_register(void)
+{
+ return 0;
+}
+#endif
+
int __init platform_bus_init(void)
{
int error;
@@ -930,10 +1010,22 @@ 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)
- device_unregister(&platform_bus);
+ goto err_unreg_dev;
+
+ error = platform_bus_handler_register();
+ if (error)
+ 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;
}

--
1.7.12

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