diff options
Diffstat (limited to 'sound/soc/omap/omap-mcbsp.c')
| -rw-r--r-- | sound/soc/omap/omap-mcbsp.c | 112 |
1 files changed, 86 insertions, 26 deletions
diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c index 6f44cb4..aebd3af 100644 --- a/sound/soc/omap/omap-mcbsp.c +++ b/sound/soc/omap/omap-mcbsp.c @@ -59,6 +59,7 @@ struct omap_mcbsp_data { int configured; unsigned int in_freq; int clk_div; + int wlen; }; #define to_mcbsp(priv) container_of((priv), struct omap_mcbsp_data, bus_id) @@ -155,19 +156,65 @@ static void omap_mcbsp_set_threshold(struct snd_pcm_substream *substream) struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai; struct omap_mcbsp_data *mcbsp_data = to_mcbsp(cpu_dai->private_data); int dma_op_mode = omap_mcbsp_get_dma_op_mode(mcbsp_data->bus_id); - int samples; + int words; /* TODO: Currently, MODE_ELEMENT == MODE_FRAME */ if (dma_op_mode == MCBSP_DMA_MODE_THRESHOLD) - samples = snd_pcm_lib_period_bytes(substream) >> 1; + /* The FIFO size depends on the McBSP word configuration */ + words = snd_pcm_lib_period_bytes(substream) / + (mcbsp_data->wlen / 8); else - samples = 1; + words = 1; /* Configure McBSP internal buffer usage */ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) - omap_mcbsp_set_tx_threshold(mcbsp_data->bus_id, samples - 1); + omap_mcbsp_set_tx_threshold(mcbsp_data->bus_id, words); else - omap_mcbsp_set_rx_threshold(mcbsp_data->bus_id, samples - 1); + omap_mcbsp_set_rx_threshold(mcbsp_data->bus_id, words); +} + +static int omap_mcbsp_hwrule_min_buffersize(struct snd_pcm_hw_params *params, + struct snd_pcm_hw_rule *rule) +{ + struct snd_interval *buffer_size = hw_param_interval(params, + SNDRV_PCM_HW_PARAM_BUFFER_SIZE); + struct snd_interval *channels = hw_param_interval(params, + SNDRV_PCM_HW_PARAM_CHANNELS); + struct omap_mcbsp_data *mcbsp_data = rule->private; + struct snd_interval frames; + int size; + + snd_interval_any(&frames); + size = omap_mcbsp_get_fifo_size(mcbsp_data->bus_id); + + frames.min = size / channels->min; + frames.integer = 1; + return snd_interval_refine(buffer_size, &frames); +} + +static int omap_mcbsp_hwrule_max_periodsize(struct snd_pcm_hw_params *params, + struct snd_pcm_hw_rule *rule) +{ + struct snd_interval *period_size = hw_param_interval(params, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE); + struct snd_interval *channels = hw_param_interval(params, + SNDRV_PCM_HW_PARAM_CHANNELS); + struct snd_pcm_substream *substream = rule->private; + struct snd_soc_pcm_runtime *rtd = substream->private_data; + struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai; + struct omap_mcbsp_data *mcbsp_data = to_mcbsp(cpu_dai->private_data); + struct snd_interval frames; + int size; + + snd_interval_any(&frames); + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + size = omap_mcbsp_get_max_tx_threshold(mcbsp_data->bus_id); + else + size = omap_mcbsp_get_max_rx_threshold(mcbsp_data->bus_id); + + frames.max = size / channels->min; + frames.integer = 1; + return snd_interval_refine(period_size, &frames); } static int omap_mcbsp_dai_startup(struct snd_pcm_substream *substream, @@ -182,33 +229,45 @@ static int omap_mcbsp_dai_startup(struct snd_pcm_substream *substream, if (!cpu_dai->active) err = omap_mcbsp_request(bus_id); + /* + * OMAP3 McBSP FIFO is word structured. + * McBSP2 has 1024 + 256 = 1280 word long buffer, + * McBSP1,3,4,5 has 128 word long buffer + * This means that the size of the FIFO depends on the sample format. + * For example on McBSP3: + * 16bit samples: size is 128 * 2 = 256 bytes + * 32bit samples: size is 128 * 4 = 512 bytes + * It is simpler to place constraint for buffer and period based on + * channels. + * McBSP3 as example again (16 or 32 bit samples): + * 1 channel (mono): size is 128 frames (128 words) + * 2 channels (stereo): size is 128 / 2 = 64 frames (2 * 64 words) + * 4 channels: size is 128 / 4 = 32 frames (4 * 32 words) + */ if (cpu_is_omap343x()) { int dma_op_mode = omap_mcbsp_get_dma_op_mode(bus_id); - int max_period; /* - * McBSP2 in OMAP3 has 1024 * 32-bit internal audio buffer. - * Set constraint for minimum buffer size to the same than FIFO - * size in order to avoid underruns in playback startup because - * HW is keeping the DMA request active until FIFO is filled. - */ - if (bus_id == 1) - snd_pcm_hw_constraint_minmax(substream->runtime, - SNDRV_PCM_HW_PARAM_BUFFER_BYTES, - 4096, UINT_MAX); - - if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) - max_period = omap_mcbsp_get_max_tx_threshold(bus_id); - else - max_period = omap_mcbsp_get_max_rx_threshold(bus_id); - - max_period++; - max_period <<= 1; + * The first rule is for the buffer size, we should not allow + * smaller buffer than the FIFO size to avoid underruns + */ + snd_pcm_hw_rule_add(substream->runtime, 0, + SNDRV_PCM_HW_PARAM_CHANNELS, + omap_mcbsp_hwrule_min_buffersize, + mcbsp_data, + SNDRV_PCM_HW_PARAM_BUFFER_SIZE, -1); + /* + * In case of threshold mode, the rule will ensure, that the + * period size is not bigger than the maximum allowed threshold + * value. + */ if (dma_op_mode == MCBSP_DMA_MODE_THRESHOLD) - snd_pcm_hw_constraint_minmax(substream->runtime, - SNDRV_PCM_HW_PARAM_PERIOD_BYTES, - 32, max_period); + snd_pcm_hw_rule_add(substream->runtime, 0, + SNDRV_PCM_HW_PARAM_CHANNELS, + omap_mcbsp_hwrule_max_periodsize, + substream, + SNDRV_PCM_HW_PARAM_PERIOD_SIZE, -1); } return err; @@ -409,6 +468,7 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream, } omap_mcbsp_config(bus_id, &mcbsp_data->regs); + mcbsp_data->wlen = wlen; mcbsp_data->configured = 1; return 0; |