--- /dev/null
+/*
+ * ff-pcm.c - a part of driver for RME Fireface series
+ *
+ * Copyright (c) 2015-2017 Takashi Sakamoto
+ *
+ * Licensed under the terms of the GNU General Public License, version 2.
+ */
+
+#include "ff.h"
+
+static inline unsigned int get_multiplier_mode_with_index(unsigned int index)
+{
+       return ((int)index - 1) / 2;
+}
+
+static int hw_rule_rate(struct snd_pcm_hw_params *params,
+                       struct snd_pcm_hw_rule *rule)
+{
+       const unsigned int *pcm_channels = rule->private;
+       struct snd_interval *r =
+               hw_param_interval(params, SNDRV_PCM_HW_PARAM_RATE);
+       const struct snd_interval *c =
+               hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_CHANNELS);
+       struct snd_interval t = {
+               .min = UINT_MAX, .max = 0, .integer = 1
+       };
+       unsigned int i, mode;
+
+       for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
+               mode = get_multiplier_mode_with_index(i);
+               if (!snd_interval_test(c, pcm_channels[mode]))
+                       continue;
+
+               t.min = min(t.min, amdtp_rate_table[i]);
+               t.max = max(t.max, amdtp_rate_table[i]);
+       }
+
+       return snd_interval_refine(r, &t);
+}
+
+static int hw_rule_channels(struct snd_pcm_hw_params *params,
+                           struct snd_pcm_hw_rule *rule)
+{
+       const unsigned int *pcm_channels = rule->private;
+       struct snd_interval *c =
+               hw_param_interval(params, SNDRV_PCM_HW_PARAM_CHANNELS);
+       const struct snd_interval *r =
+               hw_param_interval_c(params, SNDRV_PCM_HW_PARAM_RATE);
+       struct snd_interval t = {
+               .min = UINT_MAX, .max = 0, .integer = 1
+       };
+       unsigned int i, mode;
+
+       for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
+               mode = get_multiplier_mode_with_index(i);
+               if (!snd_interval_test(r, amdtp_rate_table[i]))
+                       continue;
+
+               t.min = min(t.min, pcm_channels[mode]);
+               t.max = max(t.max, pcm_channels[mode]);
+       }
+
+       return snd_interval_refine(c, &t);
+}
+
+static void limit_channels_and_rates(struct snd_pcm_hardware *hw,
+                                    const unsigned int *pcm_channels)
+{
+       unsigned int mode;
+       unsigned int rate, channels;
+       int i;
+
+       hw->channels_min = UINT_MAX;
+       hw->channels_max = 0;
+       hw->rate_min = UINT_MAX;
+       hw->rate_max = 0;
+
+       for (i = 0; i < ARRAY_SIZE(amdtp_rate_table); i++) {
+               mode = get_multiplier_mode_with_index(i);
+
+               channels = pcm_channels[mode];
+               if (pcm_channels[mode] == 0)
+                       continue;
+               hw->channels_min = min(hw->channels_min, channels);
+               hw->channels_max = max(hw->channels_max, channels);
+
+               rate = amdtp_rate_table[i];
+               hw->rates |= snd_pcm_rate_to_rate_bit(rate);
+               hw->rate_min = min(hw->rate_min, rate);
+               hw->rate_max = max(hw->rate_max, rate);
+       }
+}
+
+static void limit_period_and_buffer(struct snd_pcm_hardware *hw)
+{
+       hw->periods_min = 2;            /* SNDRV_PCM_INFO_BATCH */
+       hw->periods_max = UINT_MAX;
+
+       hw->period_bytes_min = 4 * hw->channels_max;    /* bytes for a frame */
+
+       /* Just to prevent from allocating much pages. */
+       hw->period_bytes_max = hw->period_bytes_min * 2048;
+       hw->buffer_bytes_max = hw->period_bytes_max * hw->periods_min;
+}
+
+static int pcm_init_hw_params(struct snd_ff *ff,
+                             struct snd_pcm_substream *substream)
+{
+       struct snd_pcm_runtime *runtime = substream->runtime;
+       struct amdtp_stream *s;
+       const unsigned int *pcm_channels;
+       int err;
+
+       runtime->hw.info = SNDRV_PCM_INFO_BATCH |
+                          SNDRV_PCM_INFO_BLOCK_TRANSFER |
+                          SNDRV_PCM_INFO_INTERLEAVED |
+                          SNDRV_PCM_INFO_JOINT_DUPLEX |
+                          SNDRV_PCM_INFO_MMAP |
+                          SNDRV_PCM_INFO_MMAP_VALID;
+
+       if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
+               runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
+               s = &ff->tx_stream;
+               pcm_channels = ff->spec->pcm_capture_channels;
+       } else {
+               runtime->hw.formats = SNDRV_PCM_FMTBIT_S32;
+               s = &ff->rx_stream;
+               pcm_channels = ff->spec->pcm_playback_channels;
+       }
+
+       /* limit rates */
+       limit_channels_and_rates(&runtime->hw, pcm_channels);
+       limit_period_and_buffer(&runtime->hw);
+
+       err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_CHANNELS,
+                                 hw_rule_channels, (void *)pcm_channels,
+                                 SNDRV_PCM_HW_PARAM_RATE, -1);
+       if (err < 0)
+               return err;
+
+       err = snd_pcm_hw_rule_add(runtime, 0, SNDRV_PCM_HW_PARAM_RATE,
+                                 hw_rule_rate, (void *)pcm_channels,
+                                 SNDRV_PCM_HW_PARAM_CHANNELS, -1);
+       if (err < 0)
+               return err;
+
+       return amdtp_ff_add_pcm_hw_constraints(s, runtime);
+}
+
+static int pcm_open(struct snd_pcm_substream *substream)
+{
+       struct snd_ff *ff = substream->private_data;
+       unsigned int rate;
+       enum snd_ff_clock_src src;
+       int i, err;
+
+       err = pcm_init_hw_params(ff, substream);
+       if (err < 0)
+               return err;
+
+       err = ff->spec->protocol->get_clock(ff, &rate, &src);
+       if (err < 0)
+               return err;
+
+       if (src != SND_FF_CLOCK_SRC_INTERNAL) {
+               for (i = 0; i < CIP_SFC_COUNT; ++i) {
+                       if (amdtp_rate_table[i] == rate)
+                               break;
+               }
+               /*
+                * The unit is configured at sampling frequency which packet
+                * streaming engine can't support.
+                */
+               if (i >= CIP_SFC_COUNT)
+                       return -EIO;
+
+               substream->runtime->hw.rate_min = rate;
+               substream->runtime->hw.rate_max = rate;
+       } else {
+               if (amdtp_stream_pcm_running(&ff->rx_stream) ||
+                   amdtp_stream_pcm_running(&ff->tx_stream)) {
+                       rate = amdtp_rate_table[ff->rx_stream.sfc];
+                       substream->runtime->hw.rate_min = rate;
+                       substream->runtime->hw.rate_max = rate;
+               }
+       }
+
+       snd_pcm_set_sync(substream);
+
+       return 0;
+}
+
+static int pcm_close(struct snd_pcm_substream *substream)
+{
+       return 0;
+}
+
+static int pcm_capture_hw_params(struct snd_pcm_substream *substream,
+                                struct snd_pcm_hw_params *hw_params)
+{
+       struct snd_ff *ff = substream->private_data;
+       int err;
+
+       err = snd_pcm_lib_alloc_vmalloc_buffer(substream,
+                                              params_buffer_bytes(hw_params));
+       if (err < 0)
+               return err;
+
+       if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
+               mutex_lock(&ff->mutex);
+               ff->substreams_counter++;
+               mutex_unlock(&ff->mutex);
+       }
+
+       return 0;
+}
+
+static int pcm_playback_hw_params(struct snd_pcm_substream *substream,
+                                 struct snd_pcm_hw_params *hw_params)
+{
+       struct snd_ff *ff = substream->private_data;
+       int err;
+
+       err = snd_pcm_lib_alloc_vmalloc_buffer(substream,
+                                              params_buffer_bytes(hw_params));
+       if (err < 0)
+               return err;
+
+       if (substream->runtime->status->state == SNDRV_PCM_STATE_OPEN) {
+               mutex_lock(&ff->mutex);
+               ff->substreams_counter++;
+               mutex_unlock(&ff->mutex);
+       }
+
+       return 0;
+}
+
+static int pcm_capture_hw_free(struct snd_pcm_substream *substream)
+{
+       struct snd_ff *ff = substream->private_data;
+
+       mutex_lock(&ff->mutex);
+
+       if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
+               ff->substreams_counter--;
+
+       snd_ff_stream_stop_duplex(ff);
+
+       mutex_unlock(&ff->mutex);
+
+       return snd_pcm_lib_free_vmalloc_buffer(substream);
+}
+
+static int pcm_playback_hw_free(struct snd_pcm_substream *substream)
+{
+       struct snd_ff *ff = substream->private_data;
+
+       mutex_lock(&ff->mutex);
+
+       if (substream->runtime->status->state != SNDRV_PCM_STATE_OPEN)
+               ff->substreams_counter--;
+
+       snd_ff_stream_stop_duplex(ff);
+
+       mutex_unlock(&ff->mutex);
+
+       return snd_pcm_lib_free_vmalloc_buffer(substream);
+}
+
+static int pcm_capture_prepare(struct snd_pcm_substream *substream)
+{
+       struct snd_ff *ff = substream->private_data;
+       struct snd_pcm_runtime *runtime = substream->runtime;
+       int err;
+
+       mutex_lock(&ff->mutex);
+
+       err = snd_ff_stream_start_duplex(ff, runtime->rate);
+       if (err >= 0)
+               amdtp_stream_pcm_prepare(&ff->tx_stream);
+
+       mutex_unlock(&ff->mutex);
+
+       return err;
+}
+
+static int pcm_playback_prepare(struct snd_pcm_substream *substream)
+{
+       struct snd_ff *ff = substream->private_data;
+       struct snd_pcm_runtime *runtime = substream->runtime;
+       int err;
+
+       mutex_lock(&ff->mutex);
+
+       err = snd_ff_stream_start_duplex(ff, runtime->rate);
+       if (err >= 0)
+               amdtp_stream_pcm_prepare(&ff->rx_stream);
+
+       mutex_unlock(&ff->mutex);
+
+       return err;
+}
+
+static int pcm_capture_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+       struct snd_ff *ff = substream->private_data;
+
+       switch (cmd) {
+       case SNDRV_PCM_TRIGGER_START:
+               amdtp_stream_pcm_trigger(&ff->tx_stream, substream);
+               break;
+       case SNDRV_PCM_TRIGGER_STOP:
+               amdtp_stream_pcm_trigger(&ff->tx_stream, NULL);
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int pcm_playback_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+       struct snd_ff *ff = substream->private_data;
+
+       switch (cmd) {
+       case SNDRV_PCM_TRIGGER_START:
+               amdtp_stream_pcm_trigger(&ff->rx_stream, substream);
+               break;
+       case SNDRV_PCM_TRIGGER_STOP:
+               amdtp_stream_pcm_trigger(&ff->rx_stream, NULL);
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static snd_pcm_uframes_t pcm_capture_pointer(struct snd_pcm_substream *sbstrm)
+{
+       struct snd_ff *ff = sbstrm->private_data;
+
+       return amdtp_stream_pcm_pointer(&ff->tx_stream);
+}
+
+static snd_pcm_uframes_t pcm_playback_pointer(struct snd_pcm_substream *sbstrm)
+{
+       struct snd_ff *ff = sbstrm->private_data;
+
+       return amdtp_stream_pcm_pointer(&ff->rx_stream);
+}
+
+static struct snd_pcm_ops pcm_capture_ops = {
+       .open           = pcm_open,
+       .close          = pcm_close,
+       .ioctl          = snd_pcm_lib_ioctl,
+       .hw_params      = pcm_capture_hw_params,
+       .hw_free        = pcm_capture_hw_free,
+       .prepare        = pcm_capture_prepare,
+       .trigger        = pcm_capture_trigger,
+       .pointer        = pcm_capture_pointer,
+       .page           = snd_pcm_lib_get_vmalloc_page,
+};
+
+static struct snd_pcm_ops pcm_playback_ops = {
+       .open           = pcm_open,
+       .close          = pcm_close,
+       .ioctl          = snd_pcm_lib_ioctl,
+       .hw_params      = pcm_playback_hw_params,
+       .hw_free        = pcm_playback_hw_free,
+       .prepare        = pcm_playback_prepare,
+       .trigger        = pcm_playback_trigger,
+       .pointer        = pcm_playback_pointer,
+       .page           = snd_pcm_lib_get_vmalloc_page,
+       .mmap           = snd_pcm_lib_mmap_vmalloc,
+};
+
+int snd_ff_create_pcm_devices(struct snd_ff *ff)
+{
+       struct snd_pcm *pcm;
+       int err;
+
+       err = snd_pcm_new(ff->card, ff->card->driver, 0, 1, 1, &pcm);
+       if (err < 0)
+               return err;
+
+       pcm->private_data = ff;
+       snprintf(pcm->name, sizeof(pcm->name),
+                "%s PCM", ff->card->shortname);
+       snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_playback_ops);
+       snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &pcm_capture_ops);
+
+       return 0;
+}