ASoC: davinci-mcasp: Add set_tdm_slots() support

Implements set_tdm_slot() callback for mcasp. Channel constraints are
updated according to the configured tdm mask and slots each time
set_tdm_slot() is called. The special case when slot width is set to
zero is allowed and it means that slot width is the same as the sample
width.

Signed-off-by: Jyri Sarha <jsarha@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 174 insertions, 81 deletions

diff --git a/sound/soc/davinci/davinci-mcasp.c b/sound/soc/davinci/davinci-mcasp.c
index add6bb99661d..fa47a39fac86 100644
--- a/sound/soc/davinci/davinci-mcasp.c
+++ b/sound/soc/davinci/davinci-mcasp.c
@@ -80,6 +80,8 @@ struct davinci_mcasp {
 
         /* McASP specific data */
         int     tdm_slots;
+        u32     tdm_mask[2];
+        int     slot_width;
         u8      op_mode;
         u8      num_serializer;
         u8      *serial_dir;
@@ -596,6 +598,84 @@ static int davinci_mcasp_set_sysclk(struct snd_soc_dai *dai, int clk_id,
         return 0;
 }
 
+/* All serializers must have equal number of channels */
+static int davinci_mcasp_ch_constraint(struct davinci_mcasp *mcasp, int stream,
+                                       int serializers)
+{
+        struct snd_pcm_hw_constraint_list *cl = &mcasp->chconstr[stream];
+        unsigned int *list = (unsigned int *) cl->list;
+        int slots = mcasp->tdm_slots;
+        int i, count = 0;
+
+        if (mcasp->tdm_mask[stream])
+                slots = hweight32(mcasp->tdm_mask[stream]);
+
+        for (i = 2; i <= slots; i++)
+                list[count++] = i;
+
+        for (i = 2; i <= serializers; i++)
+                list[count++] = i*slots;
+
+        cl->count = count;
+
+        return 0;
+}
+
+static int davinci_mcasp_set_ch_constraints(struct davinci_mcasp *mcasp)
+{
+        int rx_serializers = 0, tx_serializers = 0, ret, i;
+
+        for (i = 0; i < mcasp->num_serializer; i++)
+                if (mcasp->serial_dir[i] == TX_MODE)
+                        tx_serializers++;
+                else if (mcasp->serial_dir[i] == RX_MODE)
+                        rx_serializers++;
+
+        ret = davinci_mcasp_ch_constraint(mcasp, SNDRV_PCM_STREAM_PLAYBACK,
+                                          tx_serializers);
+        if (ret)
+                return ret;
+
+        ret = davinci_mcasp_ch_constraint(mcasp, SNDRV_PCM_STREAM_CAPTURE,
+                                          rx_serializers);
+
+        return ret;
+}
+
+
+static int davinci_mcasp_set_tdm_slot(struct snd_soc_dai *dai,
+                                      unsigned int tx_mask,
+                                      unsigned int rx_mask,
+                                      int slots, int slot_width)
+{
+        struct davinci_mcasp *mcasp = snd_soc_dai_get_drvdata(dai);
+
+        dev_dbg(mcasp->dev,
+                 "%s() tx_mask 0x%08x rx_mask 0x%08x slots %d width %d\n",
+                 __func__, tx_mask, rx_mask, slots, slot_width);
+
+        if (tx_mask >= (1<<slots) || rx_mask >= (1<<slots)) {
+                dev_err(mcasp->dev,
+                        "Bad tdm mask tx: 0x%08x rx: 0x%08x slots %d\n",
+                        tx_mask, rx_mask, slots);
+                return -EINVAL;
+        }
+
+        if (slot_width &&
+            (slot_width < 8 || slot_width > 32 || slot_width % 4 != 0)) {
+                dev_err(mcasp->dev, "%s: Unsupported slot_width %d\n",
+                        __func__, slot_width);
+                return -EINVAL;
+        }
+
+        mcasp->tdm_slots = slots;
+        mcasp->tdm_mask[SNDRV_PCM_STREAM_PLAYBACK] = rx_mask;
+        mcasp->tdm_mask[SNDRV_PCM_STREAM_CAPTURE] = tx_mask;
+        mcasp->slot_width = slot_width;
+
+        return davinci_mcasp_set_ch_constraints(mcasp);
+}
+
 static int davinci_config_channel_size(struct davinci_mcasp *mcasp,
                                        int word_length)
 {
@@ -632,6 +712,9 @@ static int davinci_config_channel_size(struct davinci_mcasp *mcasp,
                  */
                 rx_rotate = (slot_length - word_length) / 4;
                 word_length = slot_length;
+        } else if (mcasp->slot_width) {
+                rx_rotate = (mcasp->slot_width - word_length) / 4;
+                word_length = mcasp->slot_width;
         }
 
         /* mapping of the XSSZ bit-field as described in the datasheet */
@@ -777,33 +860,50 @@ static int mcasp_i2s_hw_param(struct davinci_mcasp *mcasp, int stream,
 
         /*
          * If more than one serializer is needed, then use them with
-         * their specified tdm_slots count. Otherwise, one serializer
-         * can cope with the transaction using as many slots as channels
-         * in the stream, requires channels symmetry
+         * all the specified tdm_slots. Otherwise, one serializer can
+         * cope with the transaction using just as many slots as there
+         * are channels in the stream.
          */
-        active_serializers = (channels + total_slots - 1) / total_slots;
-        if (active_serializers == 1)
-                active_slots = channels;
-        else
-                active_slots = total_slots;
-
-        for (i = 0; i < active_slots; i++)
-                mask |= (1 << i);
+        if (mcasp->tdm_mask[stream]) {
+                active_slots = hweight32(mcasp->tdm_mask[stream]);
+                active_serializers = (channels + active_slots - 1) /
+                        active_slots;
+                if (active_serializers == 1) {
+                        active_slots = channels;
+                        for (i = 0; i < total_slots; i++) {
+                                if ((1 << i) & mcasp->tdm_mask[stream]) {
+                                        mask |= (1 << i);
+                                        if (--active_slots <= 0)
+                                                break;
+                                }
+                        }
+                }
+        } else {
+                active_serializers = (channels + total_slots - 1) / total_slots;
+                if (active_serializers == 1)
+                        active_slots = channels;
+                else
+                        active_slots = total_slots;
 
+                for (i = 0; i < active_slots; i++)
+                        mask |= (1 << i);
+        }
         mcasp_clr_bits(mcasp, DAVINCI_MCASP_ACLKXCTL_REG, TX_ASYNC);
 
         if (!mcasp->dat_port)
                 busel = TXSEL;
 
-        mcasp_set_reg(mcasp, DAVINCI_MCASP_TXTDM_REG, mask);
-        mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMT_REG, busel | TXORD);
-        mcasp_mod_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG,
-                       FSXMOD(total_slots), FSXMOD(0x1FF));
-
-        mcasp_set_reg(mcasp, DAVINCI_MCASP_RXTDM_REG, mask);
-        mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, busel | RXORD);
-        mcasp_mod_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG,
-                       FSRMOD(total_slots), FSRMOD(0x1FF));
+        if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+                mcasp_set_reg(mcasp, DAVINCI_MCASP_TXTDM_REG, mask);
+                mcasp_set_bits(mcasp, DAVINCI_MCASP_TXFMT_REG, busel | TXORD);
+                mcasp_mod_bits(mcasp, DAVINCI_MCASP_TXFMCTL_REG,
+                               FSXMOD(total_slots), FSXMOD(0x1FF));
+        } else if (stream == SNDRV_PCM_STREAM_CAPTURE) {
+                mcasp_set_reg(mcasp, DAVINCI_MCASP_RXTDM_REG, mask);
+                mcasp_set_bits(mcasp, DAVINCI_MCASP_RXFMT_REG, busel | RXORD);
+                mcasp_mod_bits(mcasp, DAVINCI_MCASP_RXFMCTL_REG,
+                               FSRMOD(total_slots), FSRMOD(0x1FF));
+        }
 
         return 0;
 }
@@ -923,6 +1023,9 @@ static int davinci_mcasp_hw_params(struct snd_pcm_substream *substream,
                 int sbits = params_width(params);
                 int ppm, div;
 
+                if (mcasp->slot_width)
+                        sbits = mcasp->slot_width;
+
                 div = davinci_mcasp_calc_clk_div(mcasp, rate*sbits*slots,
                                                  &ppm);
                 if (ppm)
@@ -1028,6 +1131,9 @@ static int davinci_mcasp_hw_rule_rate(struct snd_pcm_hw_params *params,
         struct snd_interval range;
         int i;
 
+        if (rd->mcasp->slot_width)
+                sbits = rd->mcasp->slot_width;
+
         snd_interval_any(&range);
         range.empty = 1;
 
@@ -1070,10 +1176,14 @@ static int davinci_mcasp_hw_rule_format(struct snd_pcm_hw_params *params,
 
         for (i = 0; i < SNDRV_PCM_FORMAT_LAST; i++) {
                 if (snd_mask_test(fmt, i)) {
-                        uint bclk_freq = snd_pcm_format_width(i)*slots*rate;
+                        uint sbits = snd_pcm_format_width(i);
                         int ppm;
 
-                        davinci_mcasp_calc_clk_div(rd->mcasp, bclk_freq, &ppm);
+                        if (rd->mcasp->slot_width)
+                                sbits = rd->mcasp->slot_width;
+
+                        davinci_mcasp_calc_clk_div(rd->mcasp, sbits*slots*rate,
+                                                   &ppm);
                         if (abs(ppm) < DAVINCI_MAX_RATE_ERROR_PPM) {
                                 snd_mask_set(&nfmt, i);
                                 count++;
@@ -1095,6 +1205,10 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
                                         &mcasp->ruledata[substream->stream];
         u32 max_channels = 0;
         int i, dir;
+        int tdm_slots = mcasp->tdm_slots;
+
+        if (mcasp->tdm_mask[substream->stream])
+                tdm_slots = hweight32(mcasp->tdm_mask[substream->stream]);
 
         mcasp->substreams[substream->stream] = substream;
 
@@ -1115,7 +1229,7 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
                         max_channels++;
         }
         ruledata->serializers = max_channels;
-        max_channels *= mcasp->tdm_slots;
+        max_channels *= tdm_slots;
         /*
          * If the already active stream has less channels than the calculated
          * limnit based on the seirializers * tdm_slots, we need to use that as
@@ -1125,15 +1239,25 @@ static int davinci_mcasp_startup(struct snd_pcm_substream *substream,
          */
         if (mcasp->channels && mcasp->channels < max_channels)
                 max_channels = mcasp->channels;
+        /*
+         * But we can always allow channels upto the amount of
+         * the available tdm_slots.
+         */
+        if (max_channels < tdm_slots)
+                max_channels = tdm_slots;
 
         snd_pcm_hw_constraint_minmax(substream->runtime,
                                      SNDRV_PCM_HW_PARAM_CHANNELS,
                                      2, max_channels);
 
-        if (mcasp->chconstr[substream->stream].count)
-                snd_pcm_hw_constraint_list(substream->runtime,
-                                           0, SNDRV_PCM_HW_PARAM_CHANNELS,
-                                           &mcasp->chconstr[substream->stream]);
+        snd_pcm_hw_constraint_list(substream->runtime,
+                                   0, SNDRV_PCM_HW_PARAM_CHANNELS,
+                                   &mcasp->chconstr[substream->stream]);
+
+        if (mcasp->slot_width)
+                snd_pcm_hw_constraint_minmax(substream->runtime,
+                                             SNDRV_PCM_HW_PARAM_SAMPLE_BITS,
+                                             8, mcasp->slot_width);
 
         /*
          * If we rely on implicit BCLK divider setting we should
@@ -1185,6 +1309,7 @@ static const struct snd_soc_dai_ops davinci_mcasp_dai_ops = {
         .set_fmt        = davinci_mcasp_set_dai_fmt,
         .set_clkdiv     = davinci_mcasp_set_clkdiv,
         .set_sysclk     = davinci_mcasp_set_sysclk,
+        .set_tdm_slot   = davinci_mcasp_set_tdm_slot,
 };
 
 static int davinci_mcasp_dai_probe(struct snd_soc_dai *dai)
@@ -1514,59 +1639,6 @@ nodata:
         return  pdata;
 }
 
-/* All serializers must have equal number of channels */
-static int davinci_mcasp_ch_constraint(struct davinci_mcasp *mcasp,
-                                       struct snd_pcm_hw_constraint_list *cl,
-                                       int serializers)
-{
-        unsigned int *list;
-        int i, count = 0;
-
-        if (serializers <= 1)
-                return 0;
-
-        list = devm_kzalloc(mcasp->dev, sizeof(unsigned int) *
-                            (mcasp->tdm_slots + serializers - 2),
-                            GFP_KERNEL);
-        if (!list)
-                return -ENOMEM;
-
-        for (i = 2; i <= mcasp->tdm_slots; i++)
-                list[count++] = i;
-
-        for (i = 2; i <= serializers; i++)
-                list[count++] = i*mcasp->tdm_slots;
-
-        cl->count = count;
-        cl->list = list;
-
-        return 0;
-}
-
-
-static int davinci_mcasp_init_ch_constraints(struct davinci_mcasp *mcasp)
-{
-        int rx_serializers = 0, tx_serializers = 0, ret, i;
-
-        for (i = 0; i < mcasp->num_serializer; i++)
-                if (mcasp->serial_dir[i] == TX_MODE)
-                        tx_serializers++;
-                else if (mcasp->serial_dir[i] == RX_MODE)
-                        rx_serializers++;
-
-        ret = davinci_mcasp_ch_constraint(mcasp, &mcasp->chconstr[
-                                                  SNDRV_PCM_STREAM_PLAYBACK],
-                                          tx_serializers);
-        if (ret)
-                return ret;
-
-        ret = davinci_mcasp_ch_constraint(mcasp, &mcasp->chconstr[
-                                                  SNDRV_PCM_STREAM_CAPTURE],
-                                          rx_serializers);
-
-        return ret;
-}
-
 enum {
         PCM_EDMA,
         PCM_SDMA,
@@ -1783,7 +1855,28 @@ static int davinci_mcasp_probe(struct platform_device *pdev)
                 mcasp->fifo_base = DAVINCI_MCASP_V3_AFIFO_BASE;
         }
 
-        ret = davinci_mcasp_init_ch_constraints(mcasp);
+        /* Allocate memory for long enough list for all possible
+         * scenarios. Maximum number tdm slots is 32 and there cannot
+         * be more serializers than given in the configuration.  The
+         * serializer directions could be taken into account, but it
+         * would make code much more complex and save only couple of
+         * bytes.
+         */
+        mcasp->chconstr[SNDRV_PCM_STREAM_PLAYBACK].list =
+                devm_kzalloc(mcasp->dev, sizeof(unsigned int) *
+                             (32 + mcasp->num_serializer - 2),
+                             GFP_KERNEL);
+
+        mcasp->chconstr[SNDRV_PCM_STREAM_CAPTURE].list =
+                devm_kzalloc(mcasp->dev, sizeof(unsigned int) *
+                             (32 + mcasp->num_serializer - 2),
+                             GFP_KERNEL);
+
+        if (!mcasp->chconstr[SNDRV_PCM_STREAM_PLAYBACK].list ||
+            !mcasp->chconstr[SNDRV_PCM_STREAM_CAPTURE].list)
+                return -ENOMEM;
+
+        ret = davinci_mcasp_set_ch_constraints(mcasp);
         if (ret)
                 goto err;