Commit a0245f7a authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman

[PATCH] platform_bus learns about modalias

This patch adds modalias support to platform devices, for simpler
hotplug/coldplug driven driver setup.
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 05967118
...@@ -452,6 +452,37 @@ void platform_driver_unregister(struct platform_driver *drv) ...@@ -452,6 +452,37 @@ void platform_driver_unregister(struct platform_driver *drv)
EXPORT_SYMBOL_GPL(platform_driver_unregister); 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. * platform_match - bind platform device to platform driver.
* @dev: device. * @dev: device.
...@@ -496,7 +527,9 @@ static int platform_resume(struct device * dev) ...@@ -496,7 +527,9 @@ static int platform_resume(struct device * dev)
struct bus_type platform_bus_type = { struct bus_type platform_bus_type = {
.name = "platform", .name = "platform",
.dev_attrs = platform_dev_attrs,
.match = platform_match, .match = platform_match,
.uevent = platform_uevent,
.suspend = platform_suspend, .suspend = platform_suspend,
.resume = platform_resume, .resume = platform_resume,
}; };
......
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