xref: /openbmc/linux/sound/firewire/cmp.h (revision 588b48ca)
1 #ifndef SOUND_FIREWIRE_CMP_H_INCLUDED
2 #define SOUND_FIREWIRE_CMP_H_INCLUDED
3 
4 #include <linux/mutex.h>
5 #include <linux/types.h>
6 #include "iso-resources.h"
7 
8 struct fw_unit;
9 
10 enum cmp_direction {
11 	CMP_INPUT = 0,
12 	CMP_OUTPUT,
13 };
14 
15 /**
16  * struct cmp_connection - manages an isochronous connection to a device
17  * @speed: the connection's actual speed
18  *
19  * This structure manages (using CMP) an isochronous stream between the local
20  * computer and a device's input plug (iPCR) and output plug (oPCR).
21  *
22  * There is no corresponding oPCR created on the local computer, so it is not
23  * possible to overlay connections on top of this one.
24  */
25 struct cmp_connection {
26 	int speed;
27 	/* private: */
28 	bool connected;
29 	struct mutex mutex;
30 	struct fw_iso_resources resources;
31 	__be32 last_pcr_value;
32 	unsigned int pcr_index;
33 	unsigned int max_speed;
34 	enum cmp_direction direction;
35 };
36 
37 int cmp_connection_init(struct cmp_connection *connection,
38 			struct fw_unit *unit,
39 			enum cmp_direction direction,
40 			unsigned int pcr_index);
41 int cmp_connection_check_used(struct cmp_connection *connection, bool *used);
42 void cmp_connection_destroy(struct cmp_connection *connection);
43 
44 int cmp_connection_establish(struct cmp_connection *connection,
45 			     unsigned int max_payload);
46 int cmp_connection_update(struct cmp_connection *connection);
47 void cmp_connection_break(struct cmp_connection *connection);
48 
49 #endif
50