xref: /linux/sound/firewire/cmp.h (revision e21f9e2e862e9eb3dd64eaddb6256b3e5098660f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef SOUND_FIREWIRE_CMP_H_INCLUDED
3 #define SOUND_FIREWIRE_CMP_H_INCLUDED
4 
5 #include <linux/mutex.h>
6 #include <linux/types.h>
7 #include "iso-resources.h"
8 
9 struct fw_unit;
10 
11 enum cmp_direction {
12 	CMP_INPUT = 0,
13 	CMP_OUTPUT,
14 };
15 
16 /**
17  * struct cmp_connection - manages an isochronous connection to a device
18  * @speed: the connection's actual speed
19  *
20  * This structure manages (using CMP) an isochronous stream between the local
21  * computer and a device's input plug (iPCR) and output plug (oPCR).
22  *
23  * There is no corresponding oPCR created on the local computer, so it is not
24  * possible to overlay connections on top of this one.
25  */
26 struct cmp_connection {
27 	int speed;
28 	/* private: */
29 	bool connected;
30 	struct mutex mutex;
31 	struct fw_iso_resources resources;
32 	__be32 last_pcr_value;
33 	unsigned int pcr_index;
34 	unsigned int max_speed;
35 	enum cmp_direction direction;
36 };
37 
38 int cmp_connection_init(struct cmp_connection *connection,
39 			struct fw_unit *unit,
40 			enum cmp_direction direction,
41 			unsigned int pcr_index);
42 int cmp_connection_check_used(struct cmp_connection *connection, bool *used);
43 void cmp_connection_destroy(struct cmp_connection *connection);
44 
45 int cmp_connection_establish(struct cmp_connection *connection,
46 			     unsigned int max_payload);
47 int cmp_connection_update(struct cmp_connection *connection);
48 void cmp_connection_break(struct cmp_connection *connection);
49 
50 #endif
51