From 0ebf2f1556d59fd88aa5d78f37b9155431e9967e Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Fri, 27 Jul 2012 22:14:59 +0200
Subject: [PATCH] --- yaml --- r: 324359 b: refs/heads/master c:
 689ae231afbac8979f96100b372a5a73458baaa9 h: refs/heads/master i:   324357:
 2057cefc77a88741a1a0a09925816c4d63f56b7e   324355:
 3aad788db1ae572b8dd702a31ccf9c7b0cbcb80b   324351:
 1bcfbc7da019ee6f787e158b3b6b0ffcb0d4906a v: v3

---
 [refs]                                |  2 +-
 trunk/drivers/base/platform.c         | 38 ++++++++++++++++++++++++---
 trunk/include/linux/platform_device.h |  4 +++
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index 53b88d2aacf6..ed4169eff465 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: a525a3ddeaca69f405d98442ab3c0746e53168dc
+refs/heads/master: 689ae231afbac8979f96100b372a5a73458baaa9
diff --git a/trunk/drivers/base/platform.c b/trunk/drivers/base/platform.c
index a1a722502587..3f8077ce585c 100644
--- a/trunk/drivers/base/platform.c
+++ b/trunk/drivers/base/platform.c
@@ -20,9 +20,13 @@
 #include <linux/err.h>
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>
+#include <linux/idr.h>
 
 #include "base.h"
 
+/* For automatically allocated device IDs */
+static DEFINE_IDA(platform_devid_ida);
+
 #define to_platform_driver(drv)	(container_of((drv), struct platform_driver, \
 				 driver))
 
@@ -263,7 +267,7 @@ EXPORT_SYMBOL_GPL(platform_device_add_data);
  */
 int platform_device_add(struct platform_device *pdev)
 {
-	int i, ret = 0;
+	int i, ret;
 
 	if (!pdev)
 		return -EINVAL;
@@ -273,10 +277,27 @@ int platform_device_add(struct platform_device *pdev)
 
 	pdev->dev.bus = &platform_bus_type;
 
-	if (pdev->id != -1)
+	switch (pdev->id) {
+	default:
 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
-	else
+		break;
+	case PLATFORM_DEVID_NONE:
 		dev_set_name(&pdev->dev, "%s", pdev->name);
+		break;
+	case PLATFORM_DEVID_AUTO:
+		/*
+		 * Automatically allocated device ID. We mark it as such so
+		 * that we remember it must be freed, and we append a suffix
+		 * to avoid namespace collision with explicit IDs.
+		 */
+		ret = ida_simple_get(&platform_devid_ida, 0, 0, GFP_KERNEL);
+		if (ret < 0)
+			goto err_out;
+		pdev->id = ret;
+		pdev->id_auto = true;
+		dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
+		break;
+	}
 
 	for (i = 0; i < pdev->num_resources; i++) {
 		struct resource *p, *r = &pdev->resource[i];
@@ -309,6 +330,11 @@ int platform_device_add(struct platform_device *pdev)
 		return ret;
 
  failed:
+	if (pdev->id_auto) {
+		ida_simple_remove(&platform_devid_ida, pdev->id);
+		pdev->id = PLATFORM_DEVID_AUTO;
+	}
+
 	while (--i >= 0) {
 		struct resource *r = &pdev->resource[i];
 		unsigned long type = resource_type(r);
@@ -317,6 +343,7 @@ int platform_device_add(struct platform_device *pdev)
 			release_resource(r);
 	}
 
+ err_out:
 	return ret;
 }
 EXPORT_SYMBOL_GPL(platform_device_add);
@@ -336,6 +363,11 @@ void platform_device_del(struct platform_device *pdev)
 	if (pdev) {
 		device_del(&pdev->dev);
 
+		if (pdev->id_auto) {
+			ida_simple_remove(&platform_devid_ida, pdev->id);
+			pdev->id = PLATFORM_DEVID_AUTO;
+		}
+
 		for (i = 0; i < pdev->num_resources; i++) {
 			struct resource *r = &pdev->resource[i];
 			unsigned long type = resource_type(r);
diff --git a/trunk/include/linux/platform_device.h b/trunk/include/linux/platform_device.h
index 60e9994ef405..5711e9525a2a 100644
--- a/trunk/include/linux/platform_device.h
+++ b/trunk/include/linux/platform_device.h
@@ -14,11 +14,15 @@
 #include <linux/device.h>
 #include <linux/mod_devicetable.h>
 
+#define PLATFORM_DEVID_NONE	(-1)
+#define PLATFORM_DEVID_AUTO	(-2)
+
 struct mfd_cell;
 
 struct platform_device {
 	const char	* name;
 	int		id;
+	bool		id_auto;
 	struct device	dev;
 	u32		num_resources;
 	struct resource	* resource;