ASoC: imx-pcm: Request DMA channel early

Request the DMA channel in the pcm open callback. This allows us to let open
fail if there is no dma channel available.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --git a/sound/soc/imx/imx-pcm-dma-mx2.c b/sound/soc/imx/imx-pcm-dma-mx2.c
index ec1394415526dea0576f8184bb86257492bfea67..f974e61fa68c2196a97ba6e8692177de3cd00516 100644 (file)
--- a/sound/soc/imx/imx-pcm-dma-mx2.c
+++ b/sound/soc/imx/imx-pcm-dma-mx2.c
@@ -65,17 +65,13 @@ static bool filter(struct dma_chan *chan, void *param)
         return true;
 }
 
-static int imx_ssi_dma_alloc(struct snd_pcm_substream *substream,
-                               struct snd_pcm_hw_params *params)
+static int imx_ssi_dma_alloc(struct snd_pcm_substream *substream)
 {
        struct snd_soc_pcm_runtime *rtd = substream->private_data;
        struct imx_pcm_dma_params *dma_params;
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct imx_pcm_runtime_data *iprtd = runtime->private_data;
-       struct dma_slave_config slave_config;
        dma_cap_mask_t mask;
-       enum dma_slave_buswidth buswidth;
-       int ret;
 
        dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 
@@ -84,13 +80,29 @@ static int imx_ssi_dma_alloc(struct snd_pcm_substream *substream,
        iprtd->dma_data.dma_request = dma_params->dma;
 
        /* Try to grab a DMA channel */
-       if (!iprtd->dma_chan) {
-               dma_cap_zero(mask);
-               dma_cap_set(DMA_SLAVE, mask);
-               iprtd->dma_chan = dma_request_channel(mask, filter, iprtd);
-               if (!iprtd->dma_chan)
-                       return -EINVAL;
-       }
+       dma_cap_zero(mask);
+       dma_cap_set(DMA_SLAVE, mask);
+       iprtd->dma_chan = dma_request_channel(mask, filter, iprtd);
+       if (!iprtd->dma_chan)
+               return -EINVAL;
+
+       return 0;
+}
+
+static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
+                               struct snd_pcm_hw_params *params)
+{
+       struct snd_soc_pcm_runtime *rtd = substream->private_data;
+       struct snd_pcm_runtime *runtime = substream->runtime;
+       struct imx_pcm_runtime_data *iprtd = runtime->private_data;
+       struct dma_chan *chan = iprtd->dma_chan;
+       struct imx_pcm_dma_params *dma_params;
+       struct dma_slave_config slave_config;
+       enum dma_slave_buswidth buswidth;
+       unsigned long dma_addr;
+       int ret;
+
+       dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
 
        switch (params_format(params)) {
        case SNDRV_PCM_FORMAT_S16_LE:
@@ -116,29 +128,10 @@ static int imx_ssi_dma_alloc(struct snd_pcm_substream *substream,
                slave_config.src_maxburst = dma_params->burstsize;
        }
 
-       ret = dmaengine_slave_config(iprtd->dma_chan, &slave_config);
+       ret = dmaengine_slave_config(chan, &slave_config);
        if (ret)
                return ret;
 
-       return 0;
-}
-
-static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
-                               struct snd_pcm_hw_params *params)
-{
-       struct snd_soc_pcm_runtime *rtd = substream->private_data;
-       struct snd_pcm_runtime *runtime = substream->runtime;
-       struct imx_pcm_runtime_data *iprtd = runtime->private_data;
-       unsigned long dma_addr;
-       struct dma_chan *chan;
-       struct imx_pcm_dma_params *dma_params;
-       int ret;
-
-       dma_params = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
-       ret = imx_ssi_dma_alloc(substream, params);
-       if (ret)
-               return ret;
-       chan = iprtd->dma_chan;
 
        iprtd->periods = params_periods(params);
        iprtd->period_bytes = params_period_bytes(params);
@@ -164,19 +157,6 @@ static int snd_imx_pcm_hw_params(struct snd_pcm_substream *substream,
        return 0;
 }
 
-static int snd_imx_pcm_hw_free(struct snd_pcm_substream *substream)
-{
-       struct snd_pcm_runtime *runtime = substream->runtime;
-       struct imx_pcm_runtime_data *iprtd = runtime->private_data;
-
-       if (iprtd->dma_chan) {
-               dma_release_channel(iprtd->dma_chan);
-               iprtd->dma_chan = NULL;
-       }
-
-       return 0;
-}
-
 static int snd_imx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 {
        struct snd_pcm_runtime *runtime = substream->runtime;
@@ -251,6 +231,12 @@ static int snd_imx_open(struct snd_pcm_substream *substream)
                return ret;
        }
 
+       ret = imx_ssi_dma_alloc(substream);
+       if (ret < 0) {
+               kfree(iprtd);
+               return ret;
+       }
+
        snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);
 
        return 0;
@@ -261,6 +247,7 @@ static int snd_imx_close(struct snd_pcm_substream *substream)
        struct snd_pcm_runtime *runtime = substream->runtime;
        struct imx_pcm_runtime_data *iprtd = runtime->private_data;
 
+       dma_release_channel(iprtd->dma_chan);
        kfree(iprtd);
 
        return 0;
@@ -271,7 +258,6 @@ static struct snd_pcm_ops imx_pcm_ops = {
        .close          = snd_imx_close,
        .ioctl          = snd_pcm_lib_ioctl,
        .hw_params      = snd_imx_pcm_hw_params,
-       .hw_free        = snd_imx_pcm_hw_free,
        .trigger        = snd_imx_pcm_trigger,
        .pointer        = snd_imx_pcm_pointer,
        .mmap           = snd_imx_pcm_mmap,