xref: /openbmc/qemu/include/hw/stream.h (revision fcf5ef2a)
1 #ifndef STREAM_H
2 #define STREAM_H
3 
4 #include "qemu-common.h"
5 #include "qom/object.h"
6 
7 /* stream slave. Used until qdev provides a generic way.  */
8 #define TYPE_STREAM_SLAVE "stream-slave"
9 
10 #define STREAM_SLAVE_CLASS(klass) \
11      OBJECT_CLASS_CHECK(StreamSlaveClass, (klass), TYPE_STREAM_SLAVE)
12 #define STREAM_SLAVE_GET_CLASS(obj) \
13     OBJECT_GET_CLASS(StreamSlaveClass, (obj), TYPE_STREAM_SLAVE)
14 #define STREAM_SLAVE(obj) \
15      INTERFACE_CHECK(StreamSlave, (obj), TYPE_STREAM_SLAVE)
16 
17 typedef struct StreamSlave {
18     Object Parent;
19 } StreamSlave;
20 
21 typedef void (*StreamCanPushNotifyFn)(void *opaque);
22 
23 typedef struct StreamSlaveClass {
24     InterfaceClass parent;
25     /**
26      * can push - determine if a stream slave is capable of accepting at least
27      * one byte of data. Returns false if cannot accept. If not implemented, the
28      * slave is assumed to always be capable of receiving.
29      * @notify: Optional callback that the slave will call when the slave is
30      * capable of receiving again. Only called if false is returned.
31      * @notify_opaque: opaque data to pass to notify call.
32      */
33     bool (*can_push)(StreamSlave *obj, StreamCanPushNotifyFn notify,
34                      void *notify_opaque);
35     /**
36      * push - push data to a Stream slave. The number of bytes pushed is
37      * returned. If the slave short returns, the master must wait before trying
38      * again, the slave may continue to just return 0 waiting for the vm time to
39      * advance. The can_push() function can be used to trap the point in time
40      * where the slave is ready to receive again, otherwise polling on a QEMU
41      * timer will work.
42      * @obj: Stream slave to push to
43      * @buf: Data to write
44      * @len: Maximum number of bytes to write
45      */
46     size_t (*push)(StreamSlave *obj, unsigned char *buf, size_t len);
47 } StreamSlaveClass;
48 
49 size_t
50 stream_push(StreamSlave *sink, uint8_t *buf, size_t len);
51 
52 bool
53 stream_can_push(StreamSlave *sink, StreamCanPushNotifyFn notify,
54                 void *notify_opaque);
55 
56 
57 #endif /* STREAM_H */
58