sound/xen/xen_snd_front_evtchnl.h

   1 /* SPDX-License-Identifier: GPL-2.0 OR MIT */
   2
   3 /*
   4  * Xen para-virtual sound device
   5  *
   6  * Copyright (C) 2016-2018 EPAM Systems Inc.
   7  *
   8  * Author: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
   9  */
  10
  11 #ifndef __XEN_SND_FRONT_EVTCHNL_H
  12 #define __XEN_SND_FRONT_EVTCHNL_H
  13
  14 #include <xen/interface/io/sndif.h>
  15
  16 struct xen_snd_front_info;
  17
  18 /* Timeout in ms to wait for backend to respond. */
  19 #define VSND_WAIT_BACK_MS       3000
  20
  21 enum xen_snd_front_evtchnl_state {
  22         EVTCHNL_STATE_DISCONNECTED,
  23         EVTCHNL_STATE_CONNECTED,
  24 };
  25
  26 enum xen_snd_front_evtchnl_type {
  27         EVTCHNL_TYPE_REQ,
  28         EVTCHNL_TYPE_EVT,
  29 };
  30
  31 struct xen_snd_front_evtchnl {
  32         struct xen_snd_front_info *front_info;
  33         int gref;
  34         int port;
  35         int irq;
  36         int index;
  37         /* State of the event channel. */
  38         enum xen_snd_front_evtchnl_state state;
  39         enum xen_snd_front_evtchnl_type type;
  40         /* Either response id or incoming event id. */
  41         u16 evt_id;
  42         /* Next request id or next expected event id. */
  43         u16 evt_next_id;
  44         /* Shared ring access lock. */
  45         struct mutex ring_io_lock;
  46         union {
  47                 struct {
  48                         struct xen_sndif_front_ring ring;
  49                         struct completion completion;
  50                         /* Serializer for backend IO: request/response. */
  51                         struct mutex req_io_lock;
  52
  53                         /* Latest response status. */
  54                         int resp_status;
  55                         union {
  56                                 struct xensnd_query_hw_param hw_param;
  57                         } resp;
  58                 } req;
  59                 struct {
  60                         struct xensnd_event_page *page;
  61                         /* This is needed to handle XENSND_EVT_CUR_POS event. */
  62                         struct snd_pcm_substream *substream;
  63                 } evt;
  64         } u;
  65 };
  66
  67 struct xen_snd_front_evtchnl_pair {
  68         struct xen_snd_front_evtchnl req;
  69         struct xen_snd_front_evtchnl evt;
  70 };
  71
  72 int xen_snd_front_evtchnl_create_all(struct xen_snd_front_info *front_info,
  73                                      int num_streams);
  74
  75 void xen_snd_front_evtchnl_free_all(struct xen_snd_front_info *front_info);
  76
  77 int xen_snd_front_evtchnl_publish_all(struct xen_snd_front_info *front_info);
  78
  79 void xen_snd_front_evtchnl_flush(struct xen_snd_front_evtchnl *evtchnl);
  80
  81 void xen_snd_front_evtchnl_pair_set_connected(struct xen_snd_front_evtchnl_pair *evt_pair,
  82                                               bool is_connected);
  83
  84 void xen_snd_front_evtchnl_pair_clear(struct xen_snd_front_evtchnl_pair *evt_pair);
  85
  86 #endif /* __XEN_SND_FRONT_EVTCHNL_H */