ASoC: SOF: Add PCM operations support

Add support for exposing PCMs to userspace. PCMs are defined by topology
and the operations in this patch map to SOF IPC calls.

The .get_module_upon_open field is set to allow for module load/unload
tests. There is no risk of the sof-pci/acpi-dev module being removed
while the platform components are in use. This may need to be
revisited when DT platforms are supported.
Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/pcm.c

+// SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
+//
+// This file is provided under a dual BSD/GPLv2 license.  When using or
+// redistributing this file, you may do so under either license.
+//
+// Copyright(c) 2018 Intel Corporation. All rights reserved.
+//
+// Author: Liam Girdwood <liam.r.girdwood@linux.intel.com>
+//
+// PCM Layer, interface between ALSA and IPC.
+//
+
+#include <linux/pm_runtime.h>
+#include <sound/pcm_params.h>
+#include <sound/sof.h>
+#include "sof-priv.h"
+#include "ops.h"
+
+#define DRV_NAME	"sof-audio-component"
+
+/* Create DMA buffer page table for DSP */
+static int create_page_table(struct snd_pcm_substream *substream,
+			     unsigned char *dma_area, size_t size)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	struct snd_dma_buffer *dmab = snd_pcm_get_dma_buf(substream);
+	int stream = substream->stream;
+
+	spcm = snd_sof_find_spcm_dai(sdev, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	return snd_sof_create_page_table(sdev, dmab,
+		spcm->stream[stream].page_table.area, size);
+}
+
+static int sof_pcm_dsp_params(struct snd_sof_pcm *spcm, struct snd_pcm_substream *substream,
+			      const struct sof_ipc_pcm_params_reply *reply)
+{
+	struct snd_sof_dev *sdev = spcm->sdev;
+	/* validate offset */
+	int ret = snd_sof_ipc_pcm_params(sdev, substream, reply);
+
+	if (ret < 0)
+		dev_err(sdev->dev, "error: got wrong reply for PCM %d\n",
+			spcm->pcm.pcm_id);
+
+	return ret;
+}
+
+/* this may get called several times by oss emulation */
+static int sof_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 snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	struct sof_ipc_pcm_params pcm;
+	struct sof_ipc_pcm_params_reply ipc_params_reply;
+	int ret;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(sdev, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	dev_dbg(sdev->dev, "pcm: hw params stream %d dir %d\n",
+		spcm->pcm.pcm_id, substream->stream);
+
+	memset(&pcm, 0, sizeof(pcm));
+
+	/* allocate audio buffer pages */
+	ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: could not allocate %d bytes for PCM %d\n",
+			params_buffer_bytes(params), spcm->pcm.pcm_id);
+		return ret;
+	}
+	if (ret) {
+		/*
+		 * ret == 1 means the buffer is changed
+		 * create compressed page table for audio firmware
+		 * ret == 0 means the buffer is not changed
+		 * so no need to regenerate the page table
+		 */
+		ret = create_page_table(substream, runtime->dma_area,
+					runtime->dma_bytes);
+		if (ret < 0)
+			return ret;
+	}
+
+	/* number of pages should be rounded up */
+	pcm.params.buffer.pages = PFN_UP(runtime->dma_bytes);
+
+	/* set IPC PCM parameters */
+	pcm.hdr.size = sizeof(pcm);
+	pcm.hdr.cmd = SOF_IPC_GLB_STREAM_MSG | SOF_IPC_STREAM_PCM_PARAMS;
+	pcm.comp_id = spcm->stream[substream->stream].comp_id;
+	pcm.params.hdr.size = sizeof(pcm.params);
+	pcm.params.buffer.phy_addr =
+		spcm->stream[substream->stream].page_table.addr;
+	pcm.params.buffer.size = runtime->dma_bytes;
+	pcm.params.direction = substream->stream;
+	pcm.params.sample_valid_bytes = params_width(params) >> 3;
+	pcm.params.buffer_fmt = SOF_IPC_BUFFER_INTERLEAVED;
+	pcm.params.rate = params_rate(params);
+	pcm.params.channels = params_channels(params);
+	pcm.params.host_period_bytes = params_period_bytes(params);
+
+	/* container size */
+	ret = snd_pcm_format_physical_width(params_format(params));
+	if (ret < 0)
+		return ret;
+	pcm.params.sample_container_bytes = ret >> 3;
+
+	/* format */
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_S16:
+		pcm.params.frame_fmt = SOF_IPC_FRAME_S16_LE;
+		break;
+	case SNDRV_PCM_FORMAT_S24:
+		pcm.params.frame_fmt = SOF_IPC_FRAME_S24_4LE;
+		break;
+	case SNDRV_PCM_FORMAT_S32:
+		pcm.params.frame_fmt = SOF_IPC_FRAME_S32_LE;
+		break;
+	case SNDRV_PCM_FORMAT_FLOAT:
+		pcm.params.frame_fmt = SOF_IPC_FRAME_FLOAT;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* firmware already configured host stream */
+	ret = snd_sof_pcm_platform_hw_params(sdev,
+					     substream,
+					     params,
+					     &pcm.params);
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: platform hw params failed\n");
+		return ret;
+	}
+
+	dev_dbg(sdev->dev, "stream_tag %d", pcm.params.stream_tag);
+
+	/* send IPC to the DSP */
+	ret = sof_ipc_tx_message(sdev->ipc, pcm.hdr.cmd, &pcm, sizeof(pcm),
+				 &ipc_params_reply, sizeof(ipc_params_reply));
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: hw params ipc failed for stream %d\n",
+			pcm.params.stream_tag);
+		return ret;
+	}
+
+	ret = sof_pcm_dsp_params(spcm, substream, &ipc_params_reply);
+	if (ret < 0)
+		return ret;
+
+	/* save pcm hw_params */
+	memcpy(&spcm->params[substream->stream], params, sizeof(*params));
+
+	return ret;
+}
+
+static int sof_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	struct sof_ipc_stream stream;
+	struct sof_ipc_reply reply;
+	int ret;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(sdev, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	dev_dbg(sdev->dev, "pcm: free stream %d dir %d\n", spcm->pcm.pcm_id,
+		substream->stream);
+
+	stream.hdr.size = sizeof(stream);
+	stream.hdr.cmd = SOF_IPC_GLB_STREAM_MSG | SOF_IPC_STREAM_PCM_FREE;
+	stream.comp_id = spcm->stream[substream->stream].comp_id;
+
+	/* send IPC to the DSP */
+	ret = sof_ipc_tx_message(sdev->ipc, stream.hdr.cmd, &stream,
+				 sizeof(stream), &reply, sizeof(reply));
+
+	snd_pcm_lib_free_pages(substream);
+	return ret;
+}
+
+static int sof_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	int ret;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(sdev, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	/*
+	 * check if hw_params needs to be set-up again.
+	 * This is only needed when resuming from system sleep.
+	 */
+	if (!spcm->hw_params_upon_resume[substream->stream])
+		return 0;
+
+	dev_dbg(sdev->dev, "pcm: prepare stream %d dir %d\n", spcm->pcm.pcm_id,
+		substream->stream);
+
+	/* set hw_params */
+	ret = sof_pcm_hw_params(substream, &spcm->params[substream->stream]);
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: set pcm hw_params after resume\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+/*
+ * FE dai link trigger actions are always executed in non-atomic context because
+ * they involve IPC's.
+ */
+static int sof_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	struct sof_ipc_stream stream;
+	struct sof_ipc_reply reply;
+	int ret;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(sdev, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	dev_dbg(sdev->dev, "pcm: trigger stream %d dir %d cmd %d\n",
+		spcm->pcm.pcm_id, substream->stream, cmd);
+
+	stream.hdr.size = sizeof(stream);
+	stream.hdr.cmd = SOF_IPC_GLB_STREAM_MSG;
+	stream.comp_id = spcm->stream[substream->stream].comp_id;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_PAUSE;
+		break;
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_RELEASE;
+		break;
+	case SNDRV_PCM_TRIGGER_RESUME:
+		/* set up hw_params */
+		ret = sof_pcm_prepare(substream);
+		if (ret < 0) {
+			dev_err(sdev->dev,
+				"error: failed to set up hw_params upon resume\n");
+			return ret;
+		}
+
+		/* fallthrough */
+	case SNDRV_PCM_TRIGGER_START:
+		stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_START;
+		break;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_STOP:
+		stream.hdr.cmd |= SOF_IPC_STREAM_TRIG_STOP;
+		break;
+	default:
+		dev_err(sdev->dev, "error: unhandled trigger cmd %d\n", cmd);
+		return -EINVAL;
+	}
+
+	snd_sof_pcm_platform_trigger(sdev, substream, cmd);
+
+	/* send IPC to the DSP */
+	ret = sof_ipc_tx_message(sdev->ipc, stream.hdr.cmd, &stream,
+				 sizeof(stream), &reply, sizeof(reply));
+
+	if (ret < 0 || cmd != SNDRV_PCM_TRIGGER_SUSPEND)
+		return ret;
+
+	/*
+	 * The hw_free op is usually called when the pcm stream is closed.
+	 * Since the stream is not closed during suspend, the DSP needs to be
+	 * notified explicitly to free pcm to prevent errors upon resume.
+	 */
+	stream.hdr.size = sizeof(stream);
+	stream.hdr.cmd = SOF_IPC_GLB_STREAM_MSG | SOF_IPC_STREAM_PCM_FREE;
+	stream.comp_id = spcm->stream[substream->stream].comp_id;
+
+	/* send IPC to the DSP */
+	return sof_ipc_tx_message(sdev->ipc, stream.hdr.cmd, &stream,
+				  sizeof(stream), &reply, sizeof(reply));
+}
+
+static snd_pcm_uframes_t sof_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	snd_pcm_uframes_t host, dai;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	/* use dsp ops pointer callback directly if set */
+	if (sof_ops(sdev)->pcm_pointer)
+		return sof_ops(sdev)->pcm_pointer(sdev, substream);
+
+	spcm = snd_sof_find_spcm_dai(sdev, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	/* read position from DSP */
+	host = bytes_to_frames(substream->runtime,
+			       spcm->stream[substream->stream].posn.host_posn);
+	dai = bytes_to_frames(substream->runtime,
+			      spcm->stream[substream->stream].posn.dai_posn);
+
+	dev_dbg(sdev->dev, "PCM: stream %d dir %d DMA position %lu DAI position %lu\n",
+		spcm->pcm.pcm_id, substream->stream, host, dai);
+
+	return host;
+}
+
+static int sof_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	struct snd_soc_tplg_stream_caps *caps;
+	int ret;
+	int err;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(sdev, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	dev_dbg(sdev->dev, "pcm: open stream %d dir %d\n", spcm->pcm.pcm_id,
+		substream->stream);
+
+	/* clear hw_params_upon_resume flag */
+	spcm->hw_params_upon_resume[substream->stream] = 0;
+
+	caps = &spcm->pcm.caps[substream->stream];
+
+	ret = pm_runtime_get_sync(sdev->dev);
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: pcm open failed to resume %d\n",
+			ret);
+		pm_runtime_put_noidle(sdev->dev);
+		return ret;
+	}
+
+	/* set any runtime constraints based on topology */
+	snd_pcm_hw_constraint_step(substream->runtime, 0,
+				   SNDRV_PCM_HW_PARAM_BUFFER_BYTES,
+				   le32_to_cpu(caps->period_size_min));
+	snd_pcm_hw_constraint_step(substream->runtime, 0,
+				   SNDRV_PCM_HW_PARAM_PERIOD_BYTES,
+				   le32_to_cpu(caps->period_size_min));
+
+	/* set runtime config */
+	runtime->hw.info = SNDRV_PCM_INFO_MMAP |
+			  SNDRV_PCM_INFO_MMAP_VALID |
+			  SNDRV_PCM_INFO_INTERLEAVED |
+			  SNDRV_PCM_INFO_PAUSE |
+			  SNDRV_PCM_INFO_NO_PERIOD_WAKEUP;
+	runtime->hw.formats = le64_to_cpu(caps->formats);
+	runtime->hw.period_bytes_min = le32_to_cpu(caps->period_size_min);
+	runtime->hw.period_bytes_max = le32_to_cpu(caps->period_size_max);
+	runtime->hw.periods_min = le32_to_cpu(caps->periods_min);
+	runtime->hw.periods_max = le32_to_cpu(caps->periods_max);
+
+	/*
+	 * caps->buffer_size_min is not used since the
+	 * snd_pcm_hardware structure only defines buffer_bytes_max
+	 */
+	runtime->hw.buffer_bytes_max = le32_to_cpu(caps->buffer_size_max);
+
+	dev_dbg(sdev->dev, "period min %zd max %zd bytes\n",
+		runtime->hw.period_bytes_min,
+		runtime->hw.period_bytes_max);
+	dev_dbg(sdev->dev, "period count %d max %d\n",
+		runtime->hw.periods_min,
+		runtime->hw.periods_max);
+	dev_dbg(sdev->dev, "buffer max %zd bytes\n",
+		runtime->hw.buffer_bytes_max);
+
+	/* set wait time - TODO: come from topology */
+	substream->wait_time = 500;
+
+	spcm->stream[substream->stream].posn.host_posn = 0;
+	spcm->stream[substream->stream].posn.dai_posn = 0;
+	spcm->stream[substream->stream].substream = substream;
+
+	ret = snd_sof_pcm_platform_open(sdev, substream);
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: pcm open failed %d\n",
+			ret);
+
+		pm_runtime_mark_last_busy(sdev->dev);
+
+		err = pm_runtime_put_autosuspend(sdev->dev);
+		if (err < 0)
+			dev_err(sdev->dev, "error: pcm close failed to idle %d\n",
+				err);
+	}
+
+	return ret;
+}
+
+static int sof_pcm_close(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	int err;
+
+	/* nothing to do for BE */
+	if (rtd->dai_link->no_pcm)
+		return 0;
+
+	spcm = snd_sof_find_spcm_dai(sdev, rtd);
+	if (!spcm)
+		return -EINVAL;
+
+	dev_dbg(sdev->dev, "pcm: close stream %d dir %d\n", spcm->pcm.pcm_id,
+		substream->stream);
+
+	err = snd_sof_pcm_platform_close(sdev, substream);
+	if (err < 0) {
+		dev_err(sdev->dev, "error: pcm close failed %d\n",
+			err);
+		/*
+		 * keep going, no point in preventing the close
+		 * from happening
+		 */
+	}
+
+	pm_runtime_mark_last_busy(sdev->dev);
+
+	err = pm_runtime_put_autosuspend(sdev->dev);
+	if (err < 0)
+		dev_err(sdev->dev, "error: pcm close failed to idle %d\n",
+			err);
+
+	return 0;
+}
+
+static struct snd_pcm_ops sof_pcm_ops = {
+	.open		= sof_pcm_open,
+	.close		= sof_pcm_close,
+	.ioctl		= snd_pcm_lib_ioctl,
+	.hw_params	= sof_pcm_hw_params,
+	.prepare	= sof_pcm_prepare,
+	.hw_free	= sof_pcm_hw_free,
+	.trigger	= sof_pcm_trigger,
+	.pointer	= sof_pcm_pointer,
+	.page		= snd_pcm_sgbuf_ops_page,
+};
+
+/*
+ * Pre-allocate playback/capture audio buffer pages.
+ * no need to explicitly release memory preallocated by sof_pcm_new in pcm_free
+ * snd_pcm_lib_preallocate_free_for_all() is called by the core.
+ */
+static int sof_pcm_new(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pcm *spcm;
+	struct snd_pcm *pcm = rtd->pcm;
+	struct snd_soc_tplg_stream_caps *caps;
+	int stream = SNDRV_PCM_STREAM_PLAYBACK;
+
+	/* find SOF PCM for this RTD */
+	spcm = snd_sof_find_spcm_dai(sdev, rtd);
+	if (!spcm) {
+		dev_warn(sdev->dev, "warn: can't find PCM with DAI ID %d\n",
+			 rtd->dai_link->id);
+		return 0;
+	}
+
+	dev_dbg(sdev->dev, "creating new PCM %s\n", spcm->pcm.pcm_name);
+
+	/* do we need to pre-allocate playback audio buffer pages */
+	if (!spcm->pcm.playback)
+		goto capture;
+
+	caps = &spcm->pcm.caps[stream];
+
+	/* pre-allocate playback audio buffer pages */
+	dev_dbg(sdev->dev, "spcm: allocate %s playback DMA buffer size 0x%x max 0x%x\n",
+		caps->name, caps->buffer_size_min, caps->buffer_size_max);
+
+	snd_pcm_lib_preallocate_pages(pcm->streams[stream].substream,
+				      SNDRV_DMA_TYPE_DEV_SG, sdev->dev,
+				      le32_to_cpu(caps->buffer_size_min),
+				      le32_to_cpu(caps->buffer_size_max));
+capture:
+	stream = SNDRV_PCM_STREAM_CAPTURE;
+
+	/* do we need to pre-allocate capture audio buffer pages */
+	if (!spcm->pcm.capture)
+		return 0;
+
+	caps = &spcm->pcm.caps[stream];
+
+	/* pre-allocate capture audio buffer pages */
+	dev_dbg(sdev->dev, "spcm: allocate %s capture DMA buffer size 0x%x max 0x%x\n",
+		caps->name, caps->buffer_size_min, caps->buffer_size_max);
+
+	snd_pcm_lib_preallocate_pages(pcm->streams[stream].substream,
+				      SNDRV_DMA_TYPE_DEV_SG, sdev->dev,
+				      le32_to_cpu(caps->buffer_size_min),
+				      le32_to_cpu(caps->buffer_size_max));
+
+	return 0;
+}
+
+/* fixup the BE DAI link to match any values from topology */
+static int sof_pcm_dai_link_fixup(struct snd_soc_pcm_runtime *rtd,
+				  struct snd_pcm_hw_params *params)
+{
+	struct snd_interval *rate = hw_param_interval(params,
+			SNDRV_PCM_HW_PARAM_RATE);
+	struct snd_interval *channels = hw_param_interval(params,
+						SNDRV_PCM_HW_PARAM_CHANNELS);
+	struct snd_mask *fmt = hw_param_mask(params, SNDRV_PCM_HW_PARAM_FORMAT);
+	struct snd_soc_component *component =
+		snd_soc_rtdcom_lookup(rtd, DRV_NAME);
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_dai *dai =
+		snd_sof_find_dai(sdev, (char *)rtd->dai_link->name);
+
+	/* no topology exists for this BE, try a common configuration */
+	if (!dai) {
+		dev_warn(sdev->dev, "warning: no topology found for BE DAI %s config\n",
+			 rtd->dai_link->name);
+
+		/*  set 48k, stereo, 16bits by default */
+		rate->min = 48000;
+		rate->max = 48000;
+
+		channels->min = 2;
+		channels->max = 2;
+
+		snd_mask_none(fmt);
+		snd_mask_set_format(fmt, SNDRV_PCM_FORMAT_S16_LE);
+
+		return 0;
+	}
+
+	/* read format from topology */
+	snd_mask_none(fmt);
+
+	switch (dai->comp_dai.config.frame_fmt) {
+	case SOF_IPC_FRAME_S16_LE:
+		snd_mask_set_format(fmt, SNDRV_PCM_FORMAT_S16_LE);
+		break;
+	case SOF_IPC_FRAME_S24_4LE:
+		snd_mask_set_format(fmt, SNDRV_PCM_FORMAT_S24_LE);
+		break;
+	case SOF_IPC_FRAME_S32_LE:
+		snd_mask_set_format(fmt, SNDRV_PCM_FORMAT_S32_LE);
+		break;
+	default:
+		dev_err(sdev->dev, "error: No available DAI format!\n");
+		return -EINVAL;
+	}
+
+	/* read rate and channels from topology */
+	switch (dai->dai_config->type) {
+	case SOF_DAI_INTEL_SSP:
+		rate->min = dai->dai_config->ssp.fsync_rate;
+		rate->max = dai->dai_config->ssp.fsync_rate;
+		channels->min = dai->dai_config->ssp.tdm_slots;
+		channels->max = dai->dai_config->ssp.tdm_slots;
+
+		dev_dbg(sdev->dev,
+			"rate_min: %d rate_max: %d\n", rate->min, rate->max);
+		dev_dbg(sdev->dev,
+			"channels_min: %d channels_max: %d\n",
+			channels->min, channels->max);
+
+		break;
+	case SOF_DAI_INTEL_DMIC:
+		/* DMIC only supports 16 or 32 bit formats */
+		if (dai->comp_dai.config.frame_fmt == SOF_IPC_FRAME_S24_4LE) {
+			dev_err(sdev->dev,
+				"error: invalid fmt %d for DAI type %d\n",
+				dai->comp_dai.config.frame_fmt,
+				dai->dai_config->type);
+		}
+		break;
+	case SOF_DAI_INTEL_HDA:
+		/* do nothing for HDA dai_link */
+		break;
+	default:
+		dev_err(sdev->dev, "error: invalid DAI type %d\n",
+			dai->dai_config->type);
+		break;
+	}
+
+	return 0;
+}
+
+static int sof_pcm_probe(struct snd_soc_component *component)
+{
+	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
+	struct snd_sof_pdata *plat_data = sdev->pdata;
+	const char *tplg_filename;
+	int ret;
+
+	/* load the default topology */
+	sdev->component = component;
+
+	tplg_filename = devm_kasprintf(sdev->dev, GFP_KERNEL,
+				       "%s/%s",
+				       plat_data->tplg_filename_prefix,
+				       plat_data->tplg_filename);
+	if (!tplg_filename)
+		return -ENOMEM;
+
+	ret = snd_sof_load_topology(sdev, tplg_filename);
+	if (ret < 0) {
+		dev_err(sdev->dev, "error: failed to load DSP topology %d\n",
+			ret);
+		return ret;
+	}
+
+	/*
+	 * Some platforms in SOF, ex: BYT, may not have their platform PM
+	 * callbacks set. Increment the usage count so as to
+	 * prevent the device from entering runtime suspend.
+	 */
+	if (!sof_ops(sdev)->runtime_suspend || !sof_ops(sdev)->runtime_resume)
+		pm_runtime_get_noresume(sdev->dev);
+
+	return ret;
+}
+
+static void sof_pcm_remove(struct snd_soc_component *component)
+{
+	/* remove topology */
+	snd_soc_tplg_component_remove(component, SND_SOC_TPLG_INDEX_ALL);
+}
+
+void snd_sof_new_platform_drv(struct snd_sof_dev *sdev)
+{
+	struct snd_soc_component_driver *pd = &sdev->plat_drv;
+	struct snd_sof_pdata *plat_data = sdev->pdata;
+	const char *drv_name;
+
+	drv_name = plat_data->machine->drv_name;
+
+	pd->name = "sof-audio-component";
+	pd->probe = sof_pcm_probe;
+	pd->remove = sof_pcm_remove;
+	pd->ops	= &sof_pcm_ops;
+#if IS_ENABLED(CONFIG_SND_SOC_SOF_COMPRESS)
+	pd->compr_ops = &sof_compressed_ops;
+#endif
+	pd->pcm_new = sof_pcm_new;
+	pd->ignore_machine = drv_name;
+	pd->be_hw_params_fixup = sof_pcm_dai_link_fixup;
+	pd->be_pcm_base = SOF_BE_PCM_BASE;
+	pd->use_dai_pcm_id = true;
+	pd->topology_name_prefix = "sof";
+
+	 /* increment module refcount when a pcm is opened */
+	pd->module_get_upon_open = 1;
+}