firewire: cdev: add ioctl for broadcast write requests

Write transactions to the broadcast node ID are a convenient way to
trigger functions of multiple nodes at once.  IIDC is a protocol which
can make use of this if multiple cameras with same command_regs_base are
connected at the same bus.

Based on
    Date: Wed, 10 Sep 2008 11:32:16 -0400
    From: Jay Fenlason <fenlason@redhat.com>
    Subject: [patch] SEND_BROADCAST_REQUEST
Changes:  ioctl_send_request() and ioctl_send_broadcast_request() now
share code.  Broadcast speed corrected to S100.  Check for proper tcode.

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

1 files changed, 47 insertions, 27 deletions

diff --git a/drivers/firewire/fw-cdev.c b/drivers/firewire/fw-cdev.c
index 05ad2a8f286c..a1637a86da3d 100644
--- a/drivers/firewire/fw-cdev.c
+++ b/drivers/firewire/fw-cdev.c
@@ -518,10 +518,10 @@ static void complete_transaction(struct fw_card *card, int rcode,
         client_put(client);
 }
 
-static int ioctl_send_request(struct client *client, void *buffer)
+static int init_request(struct client *client,
+                        struct fw_cdev_send_request *request,
+                        int destination_id, int speed)
 {
-        struct fw_device *device = client->device;
-        struct fw_cdev_send_request *request = buffer;
         struct outbound_transaction_event *e;
         int ret;
 
@@ -544,24 +544,6 @@ static int ioctl_send_request(struct client *client, void *buffer)
                 goto failed;
         }
 
-        switch (request->tcode) {
-        case TCODE_WRITE_QUADLET_REQUEST:
-        case TCODE_WRITE_BLOCK_REQUEST:
-        case TCODE_READ_QUADLET_REQUEST:
-        case TCODE_READ_BLOCK_REQUEST:
-        case TCODE_LOCK_MASK_SWAP:
-        case TCODE_LOCK_COMPARE_SWAP:
-        case TCODE_LOCK_FETCH_ADD:
-        case TCODE_LOCK_LITTLE_ADD:
-        case TCODE_LOCK_BOUNDED_ADD:
-        case TCODE_LOCK_WRAP_ADD:
-        case TCODE_LOCK_VENDOR_DEPENDENT:
-                break;
-        default:
-                ret = -EINVAL;
-                goto failed;
-        }
-
         e->r.resource.release = release_transaction;
         ret = add_client_resource(client, &e->r.resource, GFP_KERNEL);
         if (ret < 0)
@@ -570,12 +552,9 @@ static int ioctl_send_request(struct client *client, void *buffer)
         /* Get a reference for the transaction callback */
         client_get(client);
 
-        fw_send_request(device->card, &e->r.transaction,
-                        request->tcode & 0x1f,
-                        device->node->node_id,
-                        request->generation,
-                        device->max_speed,
-                        request->offset,
+        fw_send_request(client->device->card, &e->r.transaction,
+                        request->tcode & 0x1f, destination_id,
+                        request->generation, speed, request->offset,
                         e->response.data, request->length,
                         complete_transaction, e);
 
@@ -589,6 +568,31 @@ static int ioctl_send_request(struct client *client, void *buffer)
         return ret;
 }
 
+static int ioctl_send_request(struct client *client, void *buffer)
+{
+        struct fw_cdev_send_request *request = buffer;
+
+        switch (request->tcode) {
+        case TCODE_WRITE_QUADLET_REQUEST:
+        case TCODE_WRITE_BLOCK_REQUEST:
+        case TCODE_READ_QUADLET_REQUEST:
+        case TCODE_READ_BLOCK_REQUEST:
+        case TCODE_LOCK_MASK_SWAP:
+        case TCODE_LOCK_COMPARE_SWAP:
+        case TCODE_LOCK_FETCH_ADD:
+        case TCODE_LOCK_LITTLE_ADD:
+        case TCODE_LOCK_BOUNDED_ADD:
+        case TCODE_LOCK_WRAP_ADD:
+        case TCODE_LOCK_VENDOR_DEPENDENT:
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return init_request(client, request, client->device->node->node_id,
+                            client->device->max_speed);
+}
+
 static void release_request(struct client *client,
                             struct client_resource *resource)
 {
@@ -1229,6 +1233,21 @@ static int ioctl_get_speed(struct client *client, void *buffer)
         return 0;
 }
 
+static int ioctl_send_broadcast_request(struct client *client, void *buffer)
+{
+        struct fw_cdev_send_request *request = buffer;
+
+        switch (request->tcode) {
+        case TCODE_WRITE_QUADLET_REQUEST:
+        case TCODE_WRITE_BLOCK_REQUEST:
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return init_request(client, request, LOCAL_BUS | 0x3f, SCODE_100);
+}
+
 static int (* const ioctl_handlers[])(struct client *client, void *buffer) = {
         ioctl_get_info,
         ioctl_send_request,
@@ -1248,6 +1267,7 @@ static int (* const ioctl_handlers[])(struct client *client, void *buffer) = {
         ioctl_allocate_iso_resource_once,
         ioctl_deallocate_iso_resource_once,
         ioctl_get_speed,
+        ioctl_send_broadcast_request,
 };
 
 static int dispatch_ioctl(struct client *client,