[PATCH 09/11] ALSA: vsnd: Implement ALSA PCM operations

Oleksandr Andrushchenko
2017-08-07T07:44:32Z

Implement ALSA driver operations including:
- start/stop period interrupt emulation
- manage frontend/backend shraed buffers
- manage Xen bus event channel state

Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
---
sound/drivers/xen-front.c | 175 ++++++++++++++++++++++++++++++++++++++++++----
1 file changed, 163 insertions(+), 12 deletions(-)

diff --git a/sound/drivers/xen-front.c b/sound/drivers/xen-front.c
index 507c5eb343c8..7275e9cb38c0 100644
--- a/sound/drivers/xen-front.c
+++ b/sound/drivers/xen-front.c
@@ -151,6 +151,11 @@ struct xdrv_info {
struct sdev_card_plat_data cfg_plat_data;
};

+static inline void sh_buf_clear(struct sh_buf_info *buf);
+static void sh_buf_free(struct sh_buf_info *buf);
+static int sh_buf_alloc(struct xenbus_device *xb_dev, struct sh_buf_info *buf,
+ unsigned int buffer_size);
+
static struct sdev_pcm_stream_info *sdrv_stream_get(
struct snd_pcm_substream *substream)
{
@@ -311,71 +316,217 @@ static void sdrv_copy_pcm_hw(struct snd_pcm_hardware *dst,

static int sdrv_alsa_open(struct snd_pcm_substream *substream)
{
- return 0;
+ struct sdev_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ struct xdrv_info *xdrv_info;
+ unsigned long flags;
+ int ret;
+
+ sdrv_copy_pcm_hw(&runtime->hw, &stream->pcm_hw, &pcm_instance->pcm_hw);
+ runtime->hw.info &= ~(SNDRV_PCM_INFO_MMAP |
+ SNDRV_PCM_INFO_MMAP_VALID |
+ SNDRV_PCM_INFO_DOUBLE |
+ SNDRV_PCM_INFO_BATCH |
+ SNDRV_PCM_INFO_NONINTERLEAVED |
+ SNDRV_PCM_INFO_RESUME |
+ SNDRV_PCM_INFO_PAUSE);
+ runtime->hw.info |= SNDRV_PCM_INFO_INTERLEAVED;
+
+ xdrv_info = pcm_instance->card_info->xdrv_info;
+
+ ret = sdrv_alsa_timer_create(substream);
+
+ spin_lock_irqsave(&xdrv_info->io_lock, flags);
+ sh_buf_clear(&stream->sh_buf);
+ stream->evt_chnl = &xdrv_info->evt_chnls[stream->unique_id];
+ if (ret < 0)
+ stream->evt_chnl->state = EVTCHNL_STATE_DISCONNECTED;
+ else
+ stream->evt_chnl->state = EVTCHNL_STATE_CONNECTED;
+ spin_unlock_irqrestore(&xdrv_info->io_lock, flags);
+ return ret;
}

static int sdrv_alsa_close(struct snd_pcm_substream *substream)
{
+ struct sdev_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+ struct xdrv_info *xdrv_info;
+ unsigned long flags;
+
+ xdrv_info = pcm_instance->card_info->xdrv_info;
+
+ sdrv_alsa_timer_stop(substream);
+
+ spin_lock_irqsave(&xdrv_info->io_lock, flags);
+ stream->evt_chnl->state = EVTCHNL_STATE_DISCONNECTED;
+ spin_unlock_irqrestore(&xdrv_info->io_lock, flags);
return 0;
}

static int sdrv_alsa_hw_params(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params)
{
+ struct sdev_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+ struct xdrv_info *xdrv_info;
+ unsigned int buffer_size;
+ int ret;
+
+ buffer_size = params_buffer_bytes(params);
+ sh_buf_clear(&stream->sh_buf);
+ xdrv_info = pcm_instance->card_info->xdrv_info;
+ ret = sh_buf_alloc(xdrv_info->xb_dev,
+ &stream->sh_buf, buffer_size);
+ if (ret < 0)
+ goto fail;
return 0;
+
+fail:
+ dev_err(&xdrv_info->xb_dev->dev,
+ "Failed to allocate buffers for stream idx %d\n",
+ stream->unique_id);
+ return ret;
}

static int sdrv_alsa_hw_free(struct snd_pcm_substream *substream)
{
+ struct sdev_pcm_instance_info *pcm_instance =
+ snd_pcm_substream_chip(substream);
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+ struct xdrv_info *xdrv_info;
+ unsigned long flags;
+
+ xdrv_info = pcm_instance->card_info->xdrv_info;
+ spin_lock_irqsave(&xdrv_info->io_lock, flags);
+ sh_buf_free(&stream->sh_buf);
+ spin_unlock_irqrestore(&xdrv_info->io_lock, flags);
return 0;
}

static int sdrv_alsa_prepare(struct snd_pcm_substream *substream)
{
- return 0;
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+ int ret = 0;
+
+ if (!stream->is_open)
+ ret = sdrv_alsa_timer_prepare(substream);
+ return ret;
}

static int sdrv_alsa_trigger(struct snd_pcm_substream *substream, int cmd)
{
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ /* fall through */
+ case SNDRV_PCM_TRIGGER_RESUME:
+ return sdrv_alsa_timer_start(substream);
+
+ case SNDRV_PCM_TRIGGER_STOP:
+ /* fall through */
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ return sdrv_alsa_timer_stop(substream);
+
+ default:
+ break;
+ }
return 0;
}

static inline snd_pcm_uframes_t sdrv_alsa_pointer(
struct snd_pcm_substream *substream)
{
+ return sdrv_alsa_timer_pointer(substream);
+}
+
+static int sdrv_alsa_playback_do_write(struct snd_pcm_substream *substream,
+ unsigned long pos, unsigned long count)
+{
return 0;
}

static int sdrv_alsa_playback_copy_user(struct snd_pcm_substream *substream,
- int channel, unsigned long pos, void __user *buf,
- unsigned long bytes)
+ int channel, unsigned long pos, void __user *src,
+ unsigned long count)
{
- return 0;
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+
+ if (unlikely(pos + count > stream->sh_buf.vbuffer_sz))
+ return -EINVAL;
+
+ if (copy_from_user(stream->sh_buf.vbuffer + pos, src, count))
+ return -EFAULT;
+
+ return sdrv_alsa_playback_do_write(substream, pos, count);
}

static int sdrv_alsa_playback_copy_kernel(struct snd_pcm_substream *substream,
- int channel, unsigned long pos, void *buf, unsigned long bytes)
+ int channel, unsigned long pos, void *src, unsigned long count)
+{
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+
+ if (unlikely(pos + count > stream->sh_buf.vbuffer_sz))
+ return -EINVAL;
+
+ memcpy(stream->sh_buf.vbuffer + pos, src, count);
+ return sdrv_alsa_playback_do_write(substream, pos, count);
+}
+
+static int sdrv_alsa_playback_do_read(struct snd_pcm_substream *substream,
+ unsigned long pos, unsigned long count)
{
return 0;
}

static int sdrv_alsa_capture_copy_user(struct snd_pcm_substream *substream,
- int channel, unsigned long pos, void __user *buf,
- unsigned long bytes)
+ int channel, unsigned long pos, void __user *dst,
+ unsigned long count)
{
- return 0;
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+ int ret;
+
+ if (unlikely(pos + count > stream->sh_buf.vbuffer_sz))
+ return -EINVAL;
+
+ ret = sdrv_alsa_playback_do_read(substream, pos, count);
+ if (ret < 0)
+ return ret;
+
+ return copy_to_user(dst, stream->sh_buf.vbuffer + pos, count) ?
+ -EFAULT : 0;
}

static int sdrv_alsa_capture_copy_kernel(struct snd_pcm_substream *substream,
- int channel, unsigned long pos, void *buf, unsigned long bytes)
+ int channel, unsigned long pos, void *dst, unsigned long count)
{
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+ int ret;
+
+ if (unlikely(pos + count > stream->sh_buf.vbuffer_sz))
+ return -EINVAL;
+
+ ret = sdrv_alsa_playback_do_read(substream, pos, count);
+ if (ret < 0)
+ return ret;
+
+ memcpy(dst, stream->sh_buf.vbuffer + pos, count);
return 0;
}

static int sdrv_alsa_playback_fill_silence(struct snd_pcm_substream *substream,
- int channel, unsigned long pos, unsigned long bytes)
+ int channel, unsigned long pos, unsigned long count)
{
- return 0;
+ struct sdev_pcm_stream_info *stream = sdrv_stream_get(substream);
+
+ if (unlikely(pos + count > stream->sh_buf.vbuffer_sz))
+ return -EINVAL;
+
+ memset(stream->sh_buf.vbuffer + pos, 0, count);
+ return sdrv_alsa_playback_do_write(substream, pos, count);
}

#define MAX_XEN_BUFFER_SIZE (64 * 1024)
--
2.7.4