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Diffstat (limited to 'drivers/base/platform.c')
-rw-r--r--drivers/base/platform.c35
1 files changed, 34 insertions, 1 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 83f5c5984d1..2b8755db76c 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -275,7 +275,7 @@ int platform_device_add(struct platform_device *pdev)
pr_debug("Registering platform device '%s'. Parent at %s\n",
pdev->dev.bus_id, pdev->dev.parent->bus_id);
- ret = device_register(&pdev->dev);
+ ret = device_add(&pdev->dev);
if (ret == 0)
return ret;
@@ -452,6 +452,37 @@ void platform_driver_unregister(struct platform_driver *drv)
EXPORT_SYMBOL_GPL(platform_driver_unregister);
+/* modalias support enables more hands-off userspace setup:
+ * (a) environment variable lets new-style hotplug events work once system is
+ * fully running: "modprobe $MODALIAS"
+ * (b) sysfs attribute lets new-style coldplug recover from hotplug events
+ * mishandled before system is fully running: "modprobe $(cat modalias)"
+ */
+static ssize_t
+modalias_show(struct device *dev, struct device_attribute *a, char *buf)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ int len = snprintf(buf, PAGE_SIZE, "%s\n", pdev->name);
+
+ return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
+}
+
+static struct device_attribute platform_dev_attrs[] = {
+ __ATTR_RO(modalias),
+ __ATTR_NULL,
+};
+
+static int platform_uevent(struct device *dev, char **envp, int num_envp,
+ char *buffer, int buffer_size)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+
+ envp[0] = buffer;
+ snprintf(buffer, buffer_size, "MODALIAS=%s", pdev->name);
+ return 0;
+}
+
+
/**
* platform_match - bind platform device to platform driver.
* @dev: device.
@@ -496,7 +527,9 @@ static int platform_resume(struct device * dev)
struct bus_type platform_bus_type = {
.name = "platform",
+ .dev_attrs = platform_dev_attrs,
.match = platform_match,
+ .uevent = platform_uevent,
.suspend = platform_suspend,
.resume = platform_resume,
};