of/device: Rework to use common platform_device_alloc() for allocating devices

The current code allocates and manages platform_devices created from
the device tree manually.  It also uses an unsafe shortcut for
allocating the platform_device and the resource table at the same
time. (which I added in the last rework; sorry).

This patch refactors the code to use platform_device_alloc() for
allocating new devices.  This reduces the amount of custom code
implemented by of_platform, eliminates the unsafe alloc trick, and has
the side benefit of letting the platform_bus code manage freeing the
device data and resources when the device is freed.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michal Simek <monstr@monstr.eu>

2 files changed, 20 insertions, 31 deletions

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 92de0eb74aea..45d86530799f 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -81,29 +81,10 @@ struct device_attribute of_platform_device_attrs[] = {
         __ATTR_NULL
 };
 
-/**
- * of_release_dev - free an of device structure when all users of it are finished.
- * @dev: device that's been disconnected
- *
- * Will be called only by the device core when all users of this of device are
- * done.
- */
-void of_release_dev(struct device *dev)
-{
-        struct platform_device *ofdev;
-
-        ofdev = to_platform_device(dev);
-        of_node_put(ofdev->dev.of_node);
-        kfree(ofdev);
-}
-EXPORT_SYMBOL(of_release_dev);
-
-int of_device_register(struct platform_device *ofdev)
+int of_device_add(struct platform_device *ofdev)
 {
         BUG_ON(ofdev->dev.of_node == NULL);
 
-        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);
@@ -117,6 +98,12 @@ int of_device_register(struct platform_device *ofdev)
 
         return device_add(&ofdev->dev);
 }
+
+int of_device_register(struct platform_device *pdev)
+{
+        device_initialize(&pdev->dev);
+        return of_device_add(pdev);
+}
 EXPORT_SYMBOL(of_device_register);
 
 void of_device_unregister(struct platform_device *ofdev)
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 30726c8b0693..5b4a07f1220e 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -587,20 +587,23 @@ struct platform_device *of_device_alloc(struct device_node *np,
         int rc, i, num_reg = 0, num_irq;
         struct resource *res, temp_res;
 
-        /* First count how many resources are needed */
+        dev = platform_device_alloc("", -1);
+        if (!dev)
+                return NULL;
+
+        /* count the io and irq resources */
         while (of_address_to_resource(np, num_reg, &temp_res) == 0)
                 num_reg++;
         num_irq = of_irq_count(np);
 
-        /* Allocate memory for both the struct device and the resource table */
-        dev = kzalloc(sizeof(*dev) + (sizeof(*res) * (num_reg + num_irq)),
-                      GFP_KERNEL);
-        if (!dev)
-                return NULL;
-        res = (struct resource *) &dev[1];
-
         /* Populate the resource table */
         if (num_irq || num_reg) {
+                res = kzalloc(sizeof(*res) * (num_irq + num_reg), GFP_KERNEL);
+                if (!res) {
+                        platform_device_put(dev);
+                        return NULL;
+                }
+
                 dev->num_resources = num_reg + num_irq;
                 dev->resource = res;
                 for (i = 0; i < num_reg; i++, res++) {
@@ -615,7 +618,6 @@ struct platform_device *of_device_alloc(struct device_node *np,
         dev->dev.dma_mask = &dev->archdata.dma_mask;
 #endif
         dev->dev.parent = parent;
-        dev->dev.release = of_release_dev;
 
         if (bus_id)
                 dev_set_name(&dev->dev, "%s", bus_id);
@@ -653,8 +655,8 @@ struct platform_device *of_platform_device_create(struct device_node *np,
          * to do such, possibly using a device notifier
          */
 
-        if (of_device_register(dev) != 0) {
-                of_device_free(dev);
+        if (of_device_add(dev) != 0) {
+                platform_device_put(dev);
                 return NULL;
         }