xref: /openbmc/qemu/include/hw/stream.h (revision 09a274d8)
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 StreamSlave;
18 
19 typedef void (*StreamCanPushNotifyFn)(void *opaque);
20 
21 typedef struct StreamSlaveClass {
22     InterfaceClass parent;
23     /**
24      * can push - determine if a stream slave is capable of accepting at least
25      * one byte of data. Returns false if cannot accept. If not implemented, the
26      * slave is assumed to always be capable of receiving.
27      * @notify: Optional callback that the slave will call when the slave is
28      * capable of receiving again. Only called if false is returned.
29      * @notify_opaque: opaque data to pass to notify call.
30      */
31     bool (*can_push)(StreamSlave *obj, StreamCanPushNotifyFn notify,
32                      void *notify_opaque);
33     /**
34      * push - push data to a Stream slave. The number of bytes pushed is
35      * returned. If the slave short returns, the master must wait before trying
36      * again, the slave may continue to just return 0 waiting for the vm time to
37      * advance. The can_push() function can be used to trap the point in time
38      * where the slave is ready to receive again, otherwise polling on a QEMU
39      * timer will work.
40      * @obj: Stream slave to push to
41      * @buf: Data to write
42      * @len: Maximum number of bytes to write
43      */
44     size_t (*push)(StreamSlave *obj, unsigned char *buf, size_t len);
45 } StreamSlaveClass;
46 
47 size_t
48 stream_push(StreamSlave *sink, uint8_t *buf, size_t len);
49 
50 bool
51 stream_can_push(StreamSlave *sink, StreamCanPushNotifyFn notify,
52                 void *notify_opaque);
53 
54 
55 #endif /* STREAM_H */
56