1 files changed, 125 insertions, 50 deletions

diff --git a/sound/soc/omap/omap-mcbsp.c b/sound/soc/omap/omap-mcbsp.c
index 6f44cb4d30b8..86f213905e2c 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)
@@ -154,20 +155,51 @@ static void omap_mcbsp_set_threshold(struct snd_pcm_substream *substream)
         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 omap_pcm_dma_data *dma_data;
         int dma_op_mode = omap_mcbsp_get_dma_op_mode(mcbsp_data->bus_id);
-        int samples;
+        int words;
+
+        dma_data = snd_soc_dai_get_dma_data(rtd->dai->cpu_dai, substream);
 
         /* TODO: Currently, MODE_ELEMENT == MODE_FRAME */
         if (dma_op_mode == MCBSP_DMA_MODE_THRESHOLD)
-                samples = snd_pcm_lib_period_bytes(substream) >> 1;
+                /*
+                 * Configure McBSP threshold based on either:
+                 * packet_size, when the sDMA is in packet mode, or
+                 * based on the period size.
+                 */
+                if (dma_data->packet_size)
+                        words = dma_data->packet_size;
+                else
+                        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_dai_startup(struct snd_pcm_substream *substream,
@@ -182,33 +214,35 @@ 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;
-
-                if (dma_op_mode == MCBSP_DMA_MODE_THRESHOLD)
-                        snd_pcm_hw_constraint_minmax(substream->runtime,
-                                                SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
-                                                32, max_period);
+                * Rule 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);
+
+                /* Make sure, that the period size is always even */
+                snd_pcm_hw_constraint_step(substream->runtime, 0,
+                                           SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 2);
         }
 
         return err;
@@ -289,11 +323,14 @@ static int omap_mcbsp_dai_hw_params(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);
         struct omap_mcbsp_reg_cfg *regs = &mcbsp_data->regs;
-        int dma, bus_id = mcbsp_data->bus_id, id = cpu_dai->id;
+        struct omap_pcm_dma_data *dma_data;
+        int dma, bus_id = mcbsp_data->bus_id;
         int wlen, channels, wpf, sync_mode = OMAP_DMA_SYNC_ELEMENT;
+        int pkt_size = 0;
         unsigned long port;
         unsigned int format, div, framesize, master;
 
+        dma_data = &omap_mcbsp_dai_dma_params[cpu_dai->id][substream->stream];
         if (cpu_class_is_omap1()) {
                 dma = omap1_dma_reqs[bus_id][substream->stream];
                 port = omap1_mcbsp_port[bus_id][substream->stream];
@@ -306,35 +343,74 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream,
         } else if (cpu_is_omap343x()) {
                 dma = omap24xx_dma_reqs[bus_id][substream->stream];
                 port = omap34xx_mcbsp_port[bus_id][substream->stream];
-                omap_mcbsp_dai_dma_params[id][substream->stream].set_threshold =
-                                                omap_mcbsp_set_threshold;
-                /* TODO: Currently, MODE_ELEMENT == MODE_FRAME */
-                if (omap_mcbsp_get_dma_op_mode(bus_id) ==
-                                                MCBSP_DMA_MODE_THRESHOLD)
-                        sync_mode = OMAP_DMA_SYNC_FRAME;
         } else {
                 return -ENODEV;
         }
-        omap_mcbsp_dai_dma_params[id][substream->stream].name =
-                substream->stream ? "Audio Capture" : "Audio Playback";
-        omap_mcbsp_dai_dma_params[id][substream->stream].dma_req = dma;
-        omap_mcbsp_dai_dma_params[id][substream->stream].port_addr = port;
-        omap_mcbsp_dai_dma_params[id][substream->stream].sync_mode = sync_mode;
         switch (params_format(params)) {
         case SNDRV_PCM_FORMAT_S16_LE:
-                omap_mcbsp_dai_dma_params[id][substream->stream].data_type =
-                         OMAP_DMA_DATA_TYPE_S16;
+                dma_data->data_type = OMAP_DMA_DATA_TYPE_S16;
+                wlen = 16;
                 break;
         case SNDRV_PCM_FORMAT_S32_LE:
-                omap_mcbsp_dai_dma_params[id][substream->stream].data_type =
-                         OMAP_DMA_DATA_TYPE_S32;
+                dma_data->data_type = OMAP_DMA_DATA_TYPE_S32;
+                wlen = 32;
                 break;
         default:
                 return -EINVAL;
         }
+        if (cpu_is_omap343x()) {
+                dma_data->set_threshold = omap_mcbsp_set_threshold;
+                /* TODO: Currently, MODE_ELEMENT == MODE_FRAME */
+                if (omap_mcbsp_get_dma_op_mode(bus_id) ==
+                                                MCBSP_DMA_MODE_THRESHOLD) {
+                        int period_words, max_thrsh;
+
+                        period_words = params_period_bytes(params) / (wlen / 8);
+                        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+                                max_thrsh = omap_mcbsp_get_max_tx_threshold(
+                                                            mcbsp_data->bus_id);
+                        else
+                                max_thrsh = omap_mcbsp_get_max_rx_threshold(
+                                                            mcbsp_data->bus_id);
+                        /*
+                         * If the period contains less or equal number of words,
+                         * we are using the original threshold mode setup:
+                         * McBSP threshold = sDMA frame size = period_size
+                         * Otherwise we switch to sDMA packet mode:
+                         * McBSP threshold = sDMA packet size
+                         * sDMA frame size = period size
+                         */
+                        if (period_words > max_thrsh) {
+                                int divider = 0;
+
+                                /*
+                                 * Look for the biggest threshold value, which
+                                 * divides the period size evenly.
+                                 */
+                                divider = period_words / max_thrsh;
+                                if (period_words % max_thrsh)
+                                        divider++;
+                                while (period_words % divider &&
+                                        divider < period_words)
+                                        divider++;
+                                if (divider == period_words)
+                                        return -EINVAL;
+
+                                pkt_size = period_words / divider;
+                                sync_mode = OMAP_DMA_SYNC_PACKET;
+                        } else {
+                                sync_mode = OMAP_DMA_SYNC_FRAME;
+                        }
+                }
+        }
 
-        snd_soc_dai_set_dma_data(cpu_dai, substream,
-                &omap_mcbsp_dai_dma_params[id][substream->stream]);
+        dma_data->name = substream->stream ? "Audio Capture" : "Audio Playback";
+        dma_data->dma_req = dma;
+        dma_data->port_addr = port;
+        dma_data->sync_mode = sync_mode;
+        dma_data->packet_size = pkt_size;
+
+        snd_soc_dai_set_dma_data(cpu_dai, substream, dma_data);
 
         if (mcbsp_data->configured) {
                 /* McBSP already configured by another stream */
@@ -360,7 +436,6 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream,
         switch (params_format(params)) {
         case SNDRV_PCM_FORMAT_S16_LE:
                 /* Set word lengths */
-                wlen = 16;
                 regs->rcr2      |= RWDLEN2(OMAP_MCBSP_WORD_16);
                 regs->rcr1      |= RWDLEN1(OMAP_MCBSP_WORD_16);
                 regs->xcr2      |= XWDLEN2(OMAP_MCBSP_WORD_16);
@@ -368,7 +443,6 @@ static int omap_mcbsp_dai_hw_params(struct snd_pcm_substream *substream,
                 break;
         case SNDRV_PCM_FORMAT_S32_LE:
                 /* Set word lengths */
-                wlen = 32;
                 regs->rcr2      |= RWDLEN2(OMAP_MCBSP_WORD_32);
                 regs->rcr1      |= RWDLEN1(OMAP_MCBSP_WORD_32);
                 regs->xcr2      |= XWDLEN2(OMAP_MCBSP_WORD_32);
@@ -409,6 +483,7 @@ 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;