summaryrefslogtreecommitdiffstats
path: root/drivers/base/platform.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/base/platform.c')
-rw-r--r--drivers/base/platform.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 940ce41..d1df4a0 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -388,6 +388,11 @@ static int platform_drv_probe(struct device *_dev)
return drv->probe(dev);
}
+static int platform_drv_probe_fail(struct device *_dev)
+{
+ return -ENXIO;
+}
+
static int platform_drv_remove(struct device *_dev)
{
struct platform_driver *drv = to_platform_driver(_dev->driver);
@@ -451,6 +456,49 @@ void platform_driver_unregister(struct platform_driver *drv)
}
EXPORT_SYMBOL_GPL(platform_driver_unregister);
+/**
+ * platform_driver_probe - register driver for non-hotpluggable device
+ * @drv: platform driver structure
+ * @probe: the driver probe routine, probably from an __init section
+ *
+ * Use this instead of platform_driver_register() when you know the device
+ * is not hotpluggable and has already been registered, and you want to
+ * remove its run-once probe() infrastructure from memory after the driver
+ * has bound to the device.
+ *
+ * One typical use for this would be with drivers for controllers integrated
+ * into system-on-chip processors, where the controller devices have been
+ * configured as part of board setup.
+ *
+ * Returns zero if the driver registered and bound to a device, else returns
+ * a negative error code and with the driver not registered.
+ */
+int platform_driver_probe(struct platform_driver *drv,
+ int (*probe)(struct platform_device *))
+{
+ int retval, code;
+
+ /* temporary section violation during probe() */
+ drv->probe = probe;
+ retval = code = platform_driver_register(drv);
+
+ /* Fixup that section violation, being paranoid about code scanning
+ * the list of drivers in order to probe new devices. Check to see
+ * if the probe was successful, and make sure any forced probes of
+ * new devices fail.
+ */
+ spin_lock(&platform_bus_type.klist_drivers.k_lock);
+ drv->probe = NULL;
+ if (code == 0 && list_empty(&drv->driver.klist_devices.k_list))
+ retval = -ENODEV;
+ drv->driver.probe = platform_drv_probe_fail;
+ spin_unlock(&platform_bus_type.klist_drivers.k_lock);
+
+ if (code != retval)
+ platform_driver_unregister(drv);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(platform_driver_probe);
/* modalias support enables more hands-off userspace setup:
* (a) environment variable lets new-style hotplug events work once system is
OpenPOWER on IntegriCloud