Greg KH
2005-06-30T06:06:56Z

[PATCH] driver core: add bus_find_device & driver_find_device functions

Add bus_find_device() and driver_find_device() which allow searching for a
device in the bus's resp. the driver's klist and obtain a reference on it.

Signed-off-by: Cornelia Huck <cohuck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
commit 0edb586049e57c56e625536476931117a57671e9
tree 9d92bb9821d134d199d62de1ff3096ff2b73fdc7
parent fd782a4a99d2d3e818b9465c427b10f7f027d7da
author Cornelia Huck <cohuck@de.ibm.com> Wed, 22 Jun 2005 16:59:51 +0200
committer Greg Kroah-Hartman <gregkh@suse.de> Wed, 29 Jun 2005 22:48:03 -0700

drivers/base/bus.c | 34 ++++++++++++++++++++++++++++++++++
drivers/base/driver.c | 35 +++++++++++++++++++++++++++++++++++
include/linux/device.h | 5 +++++
3 files changed, 74 insertions(+), 0 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -177,6 +177,39 @@ int bus_for_each_dev(struct bus_type * b
return error;
}

+/**
+ * bus_find_device - device iterator for locating a particular device.
+ * @bus: bus type
+ * @start: Device to begin with
+ * @data: Data to pass to match function
+ * @match: Callback function to check device
+ *
+ * This is similar to the bus_for_each_dev() function above, but it
+ * returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
+ *
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does. If the callback returns non-zero, this function will
+ * return to the caller and not iterate over any more devices.
+ */
+struct device * bus_find_device(struct bus_type *bus,
+ struct device *start, void *data,
+ int (*match)(struct device *, void *))
+{
+ struct klist_iter i;
+ struct device *dev;
+
+ if (!bus)
+ return NULL;
+
+ klist_iter_init_node(&bus->klist_devices, &i,
+ (start ? &start->knode_bus : NULL));
+ while ((dev = next_device(&i)))
+ if (match(dev, data) && get_device(dev))
+ break;
+ klist_iter_exit(&i);
+ return dev;
+}

static struct device_driver * next_driver(struct klist_iter * i)
@@ -557,6 +590,7 @@ int __init buses_init(void)

EXPORT_SYMBOL_GPL(bus_for_each_dev);
+EXPORT_SYMBOL_GPL(bus_find_device);
EXPORT_SYMBOL_GPL(bus_for_each_drv);

EXPORT_SYMBOL_GPL(bus_add_device);
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -56,6 +56,41 @@ EXPORT_SYMBOL_GPL(driver_for_each_device

/**
+ * driver_find_device - device iterator for locating a particular device.
+ * @driver: The device's driver
+ * @start: Device to begin with
+ * @data: Data to pass to match function
+ * @match: Callback function to check device
+ *
+ * This is similar to the driver_for_each_device() function above, but
+ * it returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
+ *
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does. If the callback returns non-zero, this function will
+ * return to the caller and not iterate over any more devices.
+ */
+struct device * driver_find_device(struct device_driver *drv,
+ struct device * start, void * data,
+ int (*match)(struct device *, void *))
+{
+ struct klist_iter i;
+ struct device *dev;
+
+ if (!drv)
+ return NULL;
+
+ klist_iter_init_node(&drv->klist_devices, &i,
+ (start ? &start->knode_driver : NULL));
+ while ((dev = next_device(&i)))
+ if (match(dev, data) && get_device(dev))
+ break;
+ klist_iter_exit(&i);
+ return dev;
+}
+EXPORT_SYMBOL_GPL(driver_find_device);
+
+/**
* driver_create_file - create sysfs file for driver.
* @drv: driver.
* @attr: driver attribute descriptor.
diff --git a/include/linux/device.h b/include/linux/device.h
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -80,6 +80,8 @@ extern struct bus_type * find_bus(char *

int bus_for_each_dev(struct bus_type * bus, struct device * start, void * data,
int (*fn)(struct device *, void *));
+struct device * bus_find_device(struct bus_type *bus, struct device *start,
+ void *data, int (*match)(struct device *, void *));

int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,
void * data, int (*fn)(struct device_driver *, void *));
@@ -142,6 +144,9 @@ extern void driver_remove_file(struct de

extern int driver_for_each_device(struct device_driver * drv, struct device * start,
void * data, int (*fn)(struct device *, void *));
+struct device * driver_find_device(struct device_driver *drv,
+ struct device *start, void *data,
+ int (*match)(struct device *, void *));

/*