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path: root/sound/soc/omap/omap-mcpdm.c
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Diffstat (limited to 'sound/soc/omap/omap-mcpdm.c')
-rw-r--r--sound/soc/omap/omap-mcpdm.c43
1 files changed, 42 insertions, 1 deletions
diff --git a/sound/soc/omap/omap-mcpdm.c b/sound/soc/omap/omap-mcpdm.c
index 64609c77a79d..44ffeb71cd1d 100644
--- a/sound/soc/omap/omap-mcpdm.c
+++ b/sound/soc/omap/omap-mcpdm.c
@@ -54,6 +54,8 @@ struct omap_mcpdm {
unsigned long phys_base;
void __iomem *io_base;
int irq;
+ struct pm_qos_request pm_qos_req;
+ int latency[2];
struct mutex mutex;
@@ -277,6 +279,9 @@ static void omap_mcpdm_dai_shutdown(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
struct omap_mcpdm *mcpdm = snd_soc_dai_get_drvdata(dai);
+ int tx = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
+ int stream1 = tx ? SNDRV_PCM_STREAM_PLAYBACK : SNDRV_PCM_STREAM_CAPTURE;
+ int stream2 = tx ? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
mutex_lock(&mcpdm->mutex);
@@ -289,6 +294,14 @@ static void omap_mcpdm_dai_shutdown(struct snd_pcm_substream *substream,
}
}
+ if (mcpdm->latency[stream2])
+ pm_qos_update_request(&mcpdm->pm_qos_req,
+ mcpdm->latency[stream2]);
+ else if (mcpdm->latency[stream1])
+ pm_qos_remove_request(&mcpdm->pm_qos_req);
+
+ mcpdm->latency[stream1] = 0;
+
mutex_unlock(&mcpdm->mutex);
}
@@ -300,7 +313,7 @@ static int omap_mcpdm_dai_hw_params(struct snd_pcm_substream *substream,
int stream = substream->stream;
struct snd_dmaengine_dai_dma_data *dma_data;
u32 threshold;
- int channels;
+ int channels, latency;
int link_mask = 0;
channels = params_channels(params);
@@ -340,14 +353,25 @@ static int omap_mcpdm_dai_hw_params(struct snd_pcm_substream *substream,
dma_data->maxburst =
(MCPDM_DN_THRES_MAX - threshold) * channels;
+ latency = threshold;
} else {
/* If playback is not running assume a stereo stream to come */
if (!mcpdm->config[!stream].link_mask)
mcpdm->config[!stream].link_mask = (0x3 << 3);
dma_data->maxburst = threshold * channels;
+ latency = (MCPDM_DN_THRES_MAX - threshold);
}
+ /*
+ * The DMA must act to a DMA request within latency time (usec) to avoid
+ * under/overflow
+ */
+ mcpdm->latency[stream] = latency * USEC_PER_SEC / params_rate(params);
+
+ if (!mcpdm->latency[stream])
+ mcpdm->latency[stream] = 10;
+
/* Check if we need to restart McPDM with this stream */
if (mcpdm->config[stream].link_mask &&
mcpdm->config[stream].link_mask != link_mask)
@@ -362,6 +386,20 @@ static int omap_mcpdm_prepare(struct snd_pcm_substream *substream,
struct snd_soc_dai *dai)
{
struct omap_mcpdm *mcpdm = snd_soc_dai_get_drvdata(dai);
+ struct pm_qos_request *pm_qos_req = &mcpdm->pm_qos_req;
+ int tx = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
+ int stream1 = tx ? SNDRV_PCM_STREAM_PLAYBACK : SNDRV_PCM_STREAM_CAPTURE;
+ int stream2 = tx ? SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
+ int latency = mcpdm->latency[stream2];
+
+ /* Prevent omap hardware from hitting off between FIFO fills */
+ if (!latency || mcpdm->latency[stream1] < latency)
+ latency = mcpdm->latency[stream1];
+
+ if (pm_qos_request_active(pm_qos_req))
+ pm_qos_update_request(pm_qos_req, latency);
+ else if (latency)
+ pm_qos_add_request(pm_qos_req, PM_QOS_CPU_DMA_LATENCY, latency);
if (!omap_mcpdm_active(mcpdm)) {
omap_mcpdm_start(mcpdm);
@@ -423,6 +461,9 @@ static int omap_mcpdm_remove(struct snd_soc_dai *dai)
free_irq(mcpdm->irq, (void *)mcpdm);
pm_runtime_disable(mcpdm->dev);
+ if (pm_qos_request_active(&mcpdm->pm_qos_req))
+ pm_qos_remove_request(&mcpdm->pm_qos_req);
+
return 0;
}