From 0edb586049e57c56e625536476931117a57671e9 Mon Sep 17 00:00:00 2001 From: Cornelia Huck Date: Wed, 22 Jun 2005 16:59:51 +0200 Subject: [PATCH] [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 Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 34 ++++++++++++++++++++++++++++++++++ drivers/base/driver.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/device.h | 5 +++++ 3 files changed, 74 insertions(+) diff --git a/drivers/base/bus.c b/drivers/base/bus.c index c3fac7fd555e..2c64b792d074 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -177,6 +177,39 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start, 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 index 1b645886e9eb..291c5954a3af 100644 --- a/drivers/base/driver.c +++ b/drivers/base/driver.c @@ -55,6 +55,41 @@ int driver_for_each_device(struct device_driver * drv, struct device * start, 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. diff --git a/include/linux/device.h b/include/linux/device.h index 7b781a72b293..07222c531d37 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -80,6 +80,8 @@ extern struct bus_type * find_bus(char * name); 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 device_driver *, struct driver_attribute * 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 *)); /* -- 2.30.2