ALSA: xen-front: Implement ALSA virtual sound driver
Implement essential initialization of the sound driver:
- introduce required data structures
- handle driver registration
- handle sound card registration
- register sound driver on backend connection
- remove sound driver on backend disconnect
Initialize virtual sound card with streams according to the
Xen store configuration.
Implement ALSA driver operations including:
- manage frontend/backend shared buffers
- manage Xen bus event channel states
Implement requests from front to back for ALSA
PCM operations.
- report ALSA period elapsed event: handle XENSND_EVT_CUR_POS
notifications from the backend when stream position advances
during playback/capture. The event carries a value of how
many octets were played/captured at the time of the event.
- implement explicit stream parameter negotiation between
backend and frontend: handle XENSND_OP_HW_PARAM_QUERY request
to read/update configuration space for the parameter given:
request passes desired parameter interval and the response to
this request returns min/max interval for the parameter to be used.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/xen/xen_snd_front.c b/sound/xen/xen_snd_front.c
index cdf66ea..c18973a 100644
--- a/sound/xen/xen_snd_front.c
+++ b/sound/xen/xen_snd_front.c
@@ -19,10 +19,189 @@
#include <xen/interface/io/sndif.h>
#include "xen_snd_front.h"
+#include "xen_snd_front_alsa.h"
#include "xen_snd_front_evtchnl.h"
+#include "xen_snd_front_shbuf.h"
+
+static struct xensnd_req *
+be_stream_prepare_req(struct xen_snd_front_evtchnl *evtchnl, u8 operation)
+{
+ struct xensnd_req *req;
+
+ req = RING_GET_REQUEST(&evtchnl->u.req.ring,
+ evtchnl->u.req.ring.req_prod_pvt);
+ req->operation = operation;
+ req->id = evtchnl->evt_next_id++;
+ evtchnl->evt_id = req->id;
+ return req;
+}
+
+static int be_stream_do_io(struct xen_snd_front_evtchnl *evtchnl)
+{
+ if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED))
+ return -EIO;
+
+ reinit_completion(&evtchnl->u.req.completion);
+ xen_snd_front_evtchnl_flush(evtchnl);
+ return 0;
+}
+
+static int be_stream_wait_io(struct xen_snd_front_evtchnl *evtchnl)
+{
+ if (wait_for_completion_timeout(&evtchnl->u.req.completion,
+ msecs_to_jiffies(VSND_WAIT_BACK_MS)) <= 0)
+ return -ETIMEDOUT;
+
+ return evtchnl->u.req.resp_status;
+}
+
+int xen_snd_front_stream_query_hw_param(struct xen_snd_front_evtchnl *evtchnl,
+ struct xensnd_query_hw_param *hw_param_req,
+ struct xensnd_query_hw_param *hw_param_resp)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_HW_PARAM_QUERY);
+ req->op.hw_param = *hw_param_req;
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ if (ret == 0)
+ *hw_param_resp = evtchnl->u.req.resp.hw_param;
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_prepare(struct xen_snd_front_evtchnl *evtchnl,
+ struct xen_snd_front_shbuf *sh_buf,
+ u8 format, unsigned int channels,
+ unsigned int rate, u32 buffer_sz,
+ u32 period_sz)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_OPEN);
+ req->op.open.pcm_format = format;
+ req->op.open.pcm_channels = channels;
+ req->op.open.pcm_rate = rate;
+ req->op.open.buffer_sz = buffer_sz;
+ req->op.open.period_sz = period_sz;
+ req->op.open.gref_directory = xen_snd_front_shbuf_get_dir_start(sh_buf);
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_close(struct xen_snd_front_evtchnl *evtchnl)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_CLOSE);
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_write(struct xen_snd_front_evtchnl *evtchnl,
+ unsigned long pos, unsigned long count)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_WRITE);
+ req->op.rw.length = count;
+ req->op.rw.offset = pos;
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_read(struct xen_snd_front_evtchnl *evtchnl,
+ unsigned long pos, unsigned long count)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_READ);
+ req->op.rw.length = count;
+ req->op.rw.offset = pos;
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
+
+int xen_snd_front_stream_trigger(struct xen_snd_front_evtchnl *evtchnl,
+ int type)
+{
+ struct xensnd_req *req;
+ int ret;
+
+ mutex_lock(&evtchnl->u.req.req_io_lock);
+
+ mutex_lock(&evtchnl->ring_io_lock);
+ req = be_stream_prepare_req(evtchnl, XENSND_OP_TRIGGER);
+ req->op.trigger.type = type;
+ mutex_unlock(&evtchnl->ring_io_lock);
+
+ ret = be_stream_do_io(evtchnl);
+
+ if (ret == 0)
+ ret = be_stream_wait_io(evtchnl);
+
+ mutex_unlock(&evtchnl->u.req.req_io_lock);
+ return ret;
+}
static void xen_snd_drv_fini(struct xen_snd_front_info *front_info)
{
+ xen_snd_front_alsa_fini(front_info);
xen_snd_front_evtchnl_free_all(front_info);
}
@@ -45,7 +224,7 @@ static int sndback_initwait(struct xen_snd_front_info *front_info)
static int sndback_connect(struct xen_snd_front_info *front_info)
{
- return 0;
+ return xen_snd_front_alsa_init(front_info);
}
static void sndback_disconnect(struct xen_snd_front_info *front_info)
