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[PATCH] platform_bus learns about modalias 

This patch adds modalias support to platform devices, for simpler
hotplug/coldplug driven driver setup.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
David Brownell 2006-05-29 10:37:33 -07:00 committed by Greg Kroah-Hartman
parent 05967118a6
commit a0245f7ad5
1 changed files with 33 additions and 0 deletions
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33
drivers/base/platform.c
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@ -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,
};