of: Merge of_platform_bus_type with platform_bus_type

of_platform_bus was being used in the same manner as the platform_bus.
The only difference being that of_platform_bus devices are generated
from data in the device tree, and platform_bus devices are usually
statically allocated in platform code.  Having them separate causes
the problem of device drivers having to be registered twice if it
was possible for the same device to appear on either bus.

This patch removes of_platform_bus_type and registers all of_platform
bus devices and drivers on the platform bus instead.  A previous patch
made the of_device structure an alias for the platform_device structure,
and a shim is used to adapt of_platform_drivers to the platform bus.

After all of of_platform_bus drivers are converted to be normal platform
drivers, the shim code can be removed.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: David S. Miller <davem@davemloft.net>

2 files changed, 69 insertions, 3 deletions

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 5282a20..12a44b4 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -104,6 +104,11 @@ int of_device_register(struct of_device *ofdev)
 
 	device_initialize(&ofdev->dev);
 
+	/* name and id have to be set so that the platform bus doesn't get
+	 * confused on matching */
+	ofdev->name = dev_name(&ofdev->dev);
+	ofdev->id = -1;
+
 	/* device_add will assume that this device is on the same node as
 	 * the parent. If there is no parent defined, set the node
 	 * explicitly */
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 9d3d932..712dfd8 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -20,6 +20,54 @@
 #include <linux/of_device.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+static int platform_driver_probe_shim(struct platform_device *pdev)
+{
+	struct platform_driver *pdrv;
+	struct of_platform_driver *ofpdrv;
+	const struct of_device_id *match;
+
+	pdrv = container_of(pdev->dev.driver, struct platform_driver, driver);
+	ofpdrv = container_of(pdrv, struct of_platform_driver, platform_driver);
+	match = of_match_device(pdev->dev.driver->of_match_table, &pdev->dev);
+	return ofpdrv->probe(pdev, match);
+}
+
+static void platform_driver_shutdown_shim(struct platform_device *pdev)
+{
+	struct platform_driver *pdrv;
+	struct of_platform_driver *ofpdrv;
+
+	pdrv = container_of(pdev->dev.driver, struct platform_driver, driver);
+	ofpdrv = container_of(pdrv, struct of_platform_driver, platform_driver);
+	ofpdrv->shutdown(pdev);
+}
+
+/**
+ * of_register_platform_driver
+ */
+int of_register_platform_driver(struct of_platform_driver *drv)
+{
+	/* setup of_platform_driver to platform_driver adaptors */
+	drv->platform_driver.driver = drv->driver;
+	if (drv->probe)
+		drv->platform_driver.probe = platform_driver_probe_shim;
+	drv->platform_driver.remove = drv->remove;
+	if (drv->shutdown)
+		drv->platform_driver.shutdown = platform_driver_shutdown_shim;
+	drv->platform_driver.suspend = drv->suspend;
+	drv->platform_driver.resume = drv->resume;
+
+	return platform_driver_register(&drv->platform_driver);
+}
+EXPORT_SYMBOL(of_register_platform_driver);
+
+void of_unregister_platform_driver(struct of_platform_driver *drv)
+{
+	platform_driver_unregister(&drv->platform_driver);
+}
+EXPORT_SYMBOL(of_unregister_platform_driver);
 
 #if defined(CONFIG_PPC_DCR)
 #include <asm/dcr.h>
@@ -392,16 +440,29 @@ int of_bus_type_init(struct bus_type *bus, const char *name)
 
 int of_register_driver(struct of_platform_driver *drv, struct bus_type *bus)
 {
-	drv->driver.bus = bus;
+	/*
+	 * Temporary: of_platform_bus used to be distinct from the platform
+	 * bus.  It isn't anymore, and so drivers on the platform bus need
+	 * to be registered in a special way.
+	 *
+	 * After all of_platform_bus_type drivers are converted to
+	 * platform_drivers, this exception can be removed.
+	 */
+	if (bus == &platform_bus_type)
+		return of_register_platform_driver(drv);
 
 	/* register with core */
+	drv->driver.bus = bus;
 	return driver_register(&drv->driver);
 }
 EXPORT_SYMBOL(of_register_driver);
 
 void of_unregister_driver(struct of_platform_driver *drv)
 {
-	driver_unregister(&drv->driver);
+	if (drv->driver.bus == &platform_bus_type)
+		of_unregister_platform_driver(drv);
+	else
+		driver_unregister(&drv->driver);
 }
 EXPORT_SYMBOL(of_unregister_driver);
 
@@ -548,7 +609,7 @@ struct of_device *of_platform_device_create(struct device_node *np,
 	dev->archdata.dma_mask = 0xffffffffUL;
 #endif
 	dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
-	dev->dev.bus = &of_platform_bus_type;
+	dev->dev.bus = &platform_bus_type;
 
 	/* We do not fill the DMA ops for platform devices by default.
 	 * This is currently the responsibility of the platform code