firewire: move fw_device reference counting from drivers to core

fw_unit device drivers invariably need to talk to the fw_unit's parent
(an fw_device) and grandparent (an fw_card).  firewire-core already
maintains an fw_card reference for the entire lifetime of an fw_device.
Likewise, let firewire-core maintain an fw_device reference for the
entire lifetime of an fw_unit so that fw_unit drivers don't have to.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/firewire/core-device.c

@@ -641,6 +641,7 @@ static void fw_unit_release(struct device *dev)
 {
 	struct fw_unit *unit = fw_unit(dev);
 
+	fw_device_put(fw_parent_device(unit));
 	kfree(unit);
 }
 
@@ -692,6 +693,7 @@ static void create_units(struct fw_device *device)
 		if (device_register(&unit->device) < 0)
 			goto skip_unit;
 
+		fw_device_get(device);
 		continue;
 
 	skip_unit:

drivers/firewire/core.h

@@ -1,6 +1,7 @@
 #ifndef _FIREWIRE_CORE_H
 #define _FIREWIRE_CORE_H
 
+#include <linux/device.h>
 #include <linux/fs.h>
 #include <linux/list.h>
 #include <linux/idr.h>
@@ -141,6 +142,18 @@ extern struct rw_semaphore fw_device_rwsem;
 extern struct idr fw_device_idr;
 extern int fw_cdev_major;
 
+static inline struct fw_device *fw_device_get(struct fw_device *device)
+{
+	get_device(&device->device);
+
+	return device;
+}
+
+static inline void fw_device_put(struct fw_device *device)
+{
+	put_device(&device->device);
+}
+
 struct fw_device *fw_device_get_by_devt(dev_t devt);
 int fw_device_set_broadcast_channel(struct device *dev, void *gen);
 void fw_node_event(struct fw_card *card, struct fw_node *node, int event);

include/linux/firewire.h

@@ -203,18 +203,6 @@ static inline int fw_device_is_shutdown(struct fw_device *device)
 	return atomic_read(&device->state) == FW_DEVICE_SHUTDOWN;
 }
 
-static inline struct fw_device *fw_device_get(struct fw_device *device)
-{
-	get_device(&device->device);
-
-	return device;
-}
-
-static inline void fw_device_put(struct fw_device *device)
-{
-	put_device(&device->device);
-}
-
 int fw_device_enable_phys_dma(struct fw_device *device);
 
 /*

sound/firewire/isight.c

@@ -612,7 +612,6 @@ static void isight_card_free(struct snd_card *card)
 
 	fw_iso_resources_destroy(&isight->resources);
 	fw_unit_put(isight->unit);
-	fw_device_put(isight->device);
 	mutex_destroy(&isight->mutex);
 }
 
@@ -645,7 +644,7 @@ static int isight_probe(struct device *unit_dev)
 	isight->card = card;
 	mutex_init(&isight->mutex);
 	isight->unit = fw_unit_get(unit);
-	isight->device = fw_device_get(fw_dev);
+	isight->device = fw_dev;
 	isight->audio_base = get_unit_base(unit);
 	if (!isight->audio_base) {
 		dev_err(&unit->device, "audio unit base not found\n");
@@ -682,7 +681,6 @@ static int isight_probe(struct device *unit_dev)
 
 err_unit:
 	fw_unit_put(isight->unit);
-	fw_device_put(isight->device);
 	mutex_destroy(&isight->mutex);
 error:
 	snd_card_free(card);

sound/firewire/speakers.c

@@ -656,12 +656,10 @@ static u32 fwspk_read_firmware_version(struct fw_unit *unit)
 static void fwspk_card_free(struct snd_card *card)
 {
 	struct fwspk *fwspk = card->private_data;
-	struct fw_device *dev = fw_parent_device(fwspk->unit);
 
 	amdtp_out_stream_destroy(&fwspk->stream);
 	cmp_connection_destroy(&fwspk->connection);
 	fw_unit_put(fwspk->unit);
-	fw_device_put(dev);
 	mutex_destroy(&fwspk->mutex);
 }
 
@@ -718,7 +716,6 @@ static int __devinit fwspk_probe(struct device *unit_dev)
 	fwspk = card->private_data;
 	fwspk->card = card;
 	mutex_init(&fwspk->mutex);
-	fw_device_get(fw_dev);
 	fwspk->unit = fw_unit_get(unit);
 	fwspk->device_info = fwspk_detect(fw_dev);
 	if (!fwspk->device_info) {
@@ -767,7 +764,6 @@ err_connection:
 	cmp_connection_destroy(&fwspk->connection);
 err_unit:
 	fw_unit_put(fwspk->unit);
-	fw_device_put(fw_dev);
 	mutex_destroy(&fwspk->mutex);
 error:
 	snd_card_free(card);