sound/firewire/cmp.h

   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