[PATCH 4/5] Driver core: add bus_find_device_by_name function

Greg Kroah-Hartman
2008-01-27T23:41:13Z

The driver core, and some other parts of the kernel just want to find a
device based on a name for a specific bus. Give them a simple wrapper
to prevent them from having to always roll their own.

This will be used in the PPC patch later in this series.

Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
drivers/base/bus.c | 41 +++++++++++++++++++++++++++++------------
include/linux/device.h | 3 +++
2 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index f484495..055989e 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -163,15 +163,6 @@ static struct kset *bus_kset;

#ifdef CONFIG_HOTPLUG
/* Manually detach a device from its associated driver. */
-static int driver_helper(struct device *dev, void *data)
-{
- const char *name = data;
-
- if (strcmp(name, dev->bus_id) == 0)
- return 1;
- return 0;
-}
-
static ssize_t driver_unbind(struct device_driver *drv,
const char *buf, size_t count)
{
@@ -179,7 +170,7 @@ static ssize_t driver_unbind(struct device_driver *drv,
struct device *dev;
int err = -ENODEV;

- dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
+ dev = bus_find_device_by_name(bus, NULL, buf);
if (dev && dev->driver == drv) {
if (dev->parent) /* Needed for USB */
down(&dev->parent->sem);
@@ -206,7 +197,7 @@ static ssize_t driver_bind(struct device_driver *drv,
struct device *dev;
int err = -ENODEV;

- dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
+ dev = bus_find_device_by_name(bus, NULL, buf);
if (dev && dev->driver == NULL) {
if (dev->parent) /* Needed for USB */
down(&dev->parent->sem);
@@ -250,7 +241,7 @@ static ssize_t store_drivers_probe(struct bus_type *bus,
{
struct device *dev;

- dev = bus_find_device(bus, NULL, (void *)buf, driver_helper);
+ dev = bus_find_device_by_name(bus, NULL, buf);
if (!dev)
return -ENODEV;
if (bus_rescan_devices_helper(dev, NULL) != 0)
@@ -338,6 +329,32 @@ struct device *bus_find_device(struct bus_type *bus,
}
EXPORT_SYMBOL_GPL(bus_find_device);

+static int match_name(struct device *dev, void *data)
+{
+ const char *name = data;
+
+ if (strcmp(name, dev->bus_id) == 0)
+ return 1;
+ return 0;
+}
+
+/**
+ * bus_find_device_by_name - device iterator for locating a particular device of a specific name
+ * @bus: bus type
+ * @start: Device to begin with
+ * @name: name of the device to match
+ *
+ * This is similar to the bus_find_device() function above, but it handles
+ * searching by a name automatically, no need to write another strcmp matching
+ * function.
+ */
+struct device *bus_find_device_by_name(struct bus_type *bus,
+ struct device *start, const char *name)
+{
+ return bus_find_device(bus, start, (void *)name, match_name);
+}
+EXPORT_SYMBOL_GPL(bus_find_device_by_name);
+
static struct device_driver *next_driver(struct klist_iter *i)
{
struct klist_node *n = klist_next(i);
diff --git a/include/linux/device.h b/include/linux/device.h
index 1880208..db375be 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -84,6 +84,9 @@ int bus_for_each_dev(struct bus_type *bus, struct device *start, void *data,
struct device *bus_find_device(struct bus_type *bus, struct device *start,
void *data,
int (*match)(struct device *dev, void *data));
+struct device *bus_find_device_by_name(struct bus_type *bus,
+ struct device *start,
+ const char *name);

int __must_check bus_for_each_drv(struct bus_type *bus,
struct device_driver *start, void *data,
--
1.5.3.8