void (*tx_done)(struct mbox_client *cl, void *mssg, int r);
};
+struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl,
+ const char *name);
struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index);
int mbox_send_message(struct mbox_chan *chan, void *mssg);
void mbox_client_txdone(struct mbox_chan *chan, int r); /* atomic */