xref: /openbmc/qemu/include/hw/stream.h (revision f363d039)
1 #ifndef STREAM_H
2 #define STREAM_H
3 
4 #include "qom/object.h"
5 
6 /* stream slave. Used until qdev provides a generic way.  */
7 #define TYPE_STREAM_SLAVE "stream-slave"
8 
9 #define STREAM_SLAVE_CLASS(klass) \
10      OBJECT_CLASS_CHECK(StreamSlaveClass, (klass), TYPE_STREAM_SLAVE)
11 #define STREAM_SLAVE_GET_CLASS(obj) \
12     OBJECT_GET_CLASS(StreamSlaveClass, (obj), TYPE_STREAM_SLAVE)
13 #define STREAM_SLAVE(obj) \
14      INTERFACE_CHECK(StreamSlave, (obj), TYPE_STREAM_SLAVE)
15 
16 typedef struct StreamSlave StreamSlave;
17 
18 typedef void (*StreamCanPushNotifyFn)(void *opaque);
19 
20 typedef struct StreamSlaveClass {
21     InterfaceClass parent;
22     /**
23      * can push - determine if a stream slave is capable of accepting at least
24      * one byte of data. Returns false if cannot accept. If not implemented, the
25      * slave is assumed to always be capable of receiving.
26      * @notify: Optional callback that the slave will call when the slave is
27      * capable of receiving again. Only called if false is returned.
28      * @notify_opaque: opaque data to pass to notify call.
29      */
30     bool (*can_push)(StreamSlave *obj, StreamCanPushNotifyFn notify,
31                      void *notify_opaque);
32     /**
33      * push - push data to a Stream slave. The number of bytes pushed is
34      * returned. If the slave short returns, the master must wait before trying
35      * again, the slave may continue to just return 0 waiting for the vm time to
36      * advance. The can_push() function can be used to trap the point in time
37      * where the slave is ready to receive again, otherwise polling on a QEMU
38      * timer will work.
39      * @obj: Stream slave to push to
40      * @buf: Data to write
41      * @len: Maximum number of bytes to write
42      */
43     size_t (*push)(StreamSlave *obj, unsigned char *buf, size_t len);
44 } StreamSlaveClass;
45 
46 size_t
47 stream_push(StreamSlave *sink, uint8_t *buf, size_t len);
48 
49 bool
50 stream_can_push(StreamSlave *sink, StreamCanPushNotifyFn notify,
51                 void *notify_opaque);
52 
53 
54 #endif /* STREAM_H */
55