ASoC: SOF: Intel: hda: Add support for DSPless mode

Via the SOF_DBG_DSPLESS_MODE sof_debug flag the SOF stack can be asked to
not use the DSP for audio.

The use of DSPless mode is governed by the sdev->dspless_mode_selected
flag which is only going to be set if the user sets sof_debug=0x8000 and
the platform advertises that the DSPless mode is supported on them.
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@intel.com>
Link: https://lore.kernel.org/r/20230404092115.27949-6-peter.ujfalusi@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/sof/intel/hda-dai-ops.c

@@ -319,13 +319,44 @@ static const struct hda_dai_widget_dma_ops hda_ipc3_dma_ops = {
 	.post_trigger = hda_ipc3_post_trigger,
 };
 
+static struct hdac_ext_stream *
+hda_dspless_get_hext_stream(struct snd_sof_dev *sdev, struct snd_soc_dai *cpu_dai,
+			    struct snd_pcm_substream *substream)
+{
+	struct hdac_stream *hstream = substream->runtime->private_data;
+
+	return stream_to_hdac_ext_stream(hstream);
+}
+
+static void hda_dspless_setup_hext_stream(struct snd_sof_dev *sdev,
+					  struct hdac_ext_stream *hext_stream,
+					  unsigned int format_val)
+{
+	/*
+	 * Save the format_val which was adjusted by the maxbps of the codec.
+	 * This information is not available on the FE side since there we are
+	 * using dummy_codec.
+	 */
+	hext_stream->hstream.format_val = format_val;
+}
+
+static const struct hda_dai_widget_dma_ops hda_dspless_dma_ops = {
+	.get_hext_stream = hda_dspless_get_hext_stream,
+	.setup_hext_stream = hda_dspless_setup_hext_stream,
+};
+
 #endif
 
 const struct hda_dai_widget_dma_ops *
 hda_select_dai_widget_ops(struct snd_sof_dev *sdev, struct snd_sof_widget *swidget)
 {
 #if IS_ENABLED(CONFIG_SND_SOC_SOF_HDA_AUDIO_CODEC)
-	struct snd_sof_dai *sdai = swidget->private;
+	struct snd_sof_dai *sdai;
+
+	if (sdev->dspless_mode_selected)
+		return &hda_dspless_dma_ops;
+
+	sdai = swidget->private;
 
 	switch (sdev->pdata->ipc_type) {
 	case SOF_IPC:

sound/soc/sof/intel/hda-dai.c

@@ -31,11 +31,18 @@ int hda_dai_config(struct snd_soc_dapm_widget *w, unsigned int flags,
 		   struct snd_sof_dai_config_data *data)
 {
 	struct snd_sof_widget *swidget = w->dobj.private;
-	struct snd_soc_component *component = swidget->scomp;
-	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(component);
-	const struct sof_ipc_tplg_ops *tplg_ops = sof_ipc_get_ops(sdev, tplg);
+	const struct sof_ipc_tplg_ops *tplg_ops;
+	struct snd_soc_component *component;
+	struct snd_sof_dev *sdev;
 	int ret;
 
+	if (!swidget)
+		return 0;
+
+	component = swidget->scomp;
+	sdev = snd_soc_component_get_drvdata(component);
+	tplg_ops = sof_ipc_get_ops(sdev, tplg);
+
 	if (tplg_ops && tplg_ops->dai_config) {
 		ret = tplg_ops->dai_config(sdev, swidget, flags, data);
 		if (ret < 0) {
@@ -56,13 +63,21 @@ hda_dai_get_ops(struct snd_pcm_substream *substream, struct snd_soc_dai *cpu_dai
 	struct snd_soc_dapm_widget *w = snd_soc_dai_get_widget(cpu_dai, substream->stream);
 	struct snd_sof_dev *sdev = snd_soc_component_get_drvdata(cpu_dai->component);
 	struct snd_sof_widget *swidget = w->dobj.private;
-	struct snd_sof_dai *sdai = swidget->private;
+	struct snd_sof_dai *sdai;
+
+	/*
+	 * The swidget parameter of hda_select_dai_widget_ops() is ignored in
+	 * case of DSPless mode
+	 */
+	if (sdev->dspless_mode_selected)
+		return hda_select_dai_widget_ops(sdev, NULL);
+
+	sdai = swidget->private;
 
 	/* select and set the DAI widget ops if not set already */
 	if (!sdai->platform_private) {
 		const struct hda_dai_widget_dma_ops *ops =
 			hda_select_dai_widget_ops(sdev, swidget);
-
 		if (!ops)
 			return NULL;
 

sound/soc/sof/intel/hda-pcm.c

@@ -101,18 +101,23 @@ int hda_dsp_pcm_hw_params(struct snd_sof_dev *sdev,
 	struct sof_intel_hda_dev *hda = sdev->pdata->hw_pdata;
 	struct snd_dma_buffer *dmab;
 	int ret;
-	u32 size, rate, bits;
-
-	size = params_buffer_bytes(params);
-	rate = hda_dsp_get_mult_div(sdev, params_rate(params));
-	bits = hda_dsp_get_bits(sdev, params_width(params));
 
 	hstream->substream = substream;
 
 	dmab = substream->runtime->dma_buffer_p;
 
-	hstream->format_val = rate | bits | (params_channels(params) - 1);
-	hstream->bufsize = size;
+	/*
+	 * Use the codec required format val (which is link_bps adjusted) when
+	 * the DSP is not in use
+	 */
+	if (!sdev->dspless_mode_selected) {
+		u32 rate = hda_dsp_get_mult_div(sdev, params_rate(params));
+		u32 bits = hda_dsp_get_bits(sdev, params_width(params));
+
+		hstream->format_val = rate | bits | (params_channels(params) - 1);
+	}
+
+	hstream->bufsize = params_buffer_bytes(params);
 	hstream->period_bytes = params_period_bytes(params);
 	hstream->no_period_wakeup  =
 			(params->info & SNDRV_PCM_INFO_NO_PERIOD_WAKEUP) &&
@@ -249,6 +254,11 @@ int hda_dsp_pcm_open(struct snd_sof_dev *sdev,
 	snd_pcm_hw_constraint_integer(substream->runtime,
 				      SNDRV_PCM_HW_PARAM_PERIODS);
 
+	/* Only S16 and S32 supported by HDA hardware when used without DSP */
+	if (sdev->dspless_mode_selected)
+		snd_pcm_hw_constraint_mask64(substream->runtime, SNDRV_PCM_HW_PARAM_FORMAT,
+					     SNDRV_PCM_FMTBIT_S16 | SNDRV_PCM_FMTBIT_S32);
+
 	/* binding pcm substream to hda stream */
 	substream->runtime->private_data = &dsp_stream->hstream;
 	return 0;

sound/soc/sof/intel/hda-stream.c

@@ -503,11 +503,12 @@ int hda_dsp_stream_hw_params(struct snd_sof_dev *sdev,
 
 	hstream = &hext_stream->hstream;
 	sd_offset = SOF_STREAM_SD_OFFSET(hstream);
+	mask = BIT(hstream->index);
 
-	/* decouple host and link DMA */
-	mask = 0x1 << hstream->index;
-	snd_sof_dsp_update_bits(sdev, HDA_DSP_PP_BAR, SOF_HDA_REG_PP_PPCTL,
-				mask, mask);
+	/* decouple host and link DMA if the DSP is used */
+	if (!sdev->dspless_mode_selected)
+		snd_sof_dsp_update_bits(sdev, HDA_DSP_PP_BAR, SOF_HDA_REG_PP_PPCTL,
+					mask, mask);
 
 	/* clear stream status */
 	snd_sof_dsp_update_bits(sdev, HDA_DSP_HDA_BAR, sd_offset,
@@ -608,11 +609,10 @@ int hda_dsp_stream_hw_params(struct snd_sof_dev *sdev,
 	 *    enable decoupled mode
 	 */
 
-	if (chip->quirks & SOF_INTEL_PROCEN_FMT_QUIRK) {
+	if (!sdev->dspless_mode_selected && (chip->quirks & SOF_INTEL_PROCEN_FMT_QUIRK))
 		/* couple host and link DMA, disable DSP features */
 		snd_sof_dsp_update_bits(sdev, HDA_DSP_PP_BAR, SOF_HDA_REG_PP_PPCTL,
 					mask, 0);
-	}
 
 	/* program stream format */
 	snd_sof_dsp_update_bits(sdev, HDA_DSP_HDA_BAR,
@@ -620,11 +620,10 @@ int hda_dsp_stream_hw_params(struct snd_sof_dev *sdev,
 				SOF_HDA_ADSP_REG_SD_FORMAT,
 				0xffff, hstream->format_val);
 
-	if (chip->quirks & SOF_INTEL_PROCEN_FMT_QUIRK) {
+	if (!sdev->dspless_mode_selected && (chip->quirks & SOF_INTEL_PROCEN_FMT_QUIRK))
 		/* decouple host and link DMA, enable DSP features */
 		snd_sof_dsp_update_bits(sdev, HDA_DSP_PP_BAR, SOF_HDA_REG_PP_PPCTL,
 					mask, mask);
-	}
 
 	/* program last valid index */
 	snd_sof_dsp_update_bits(sdev, HDA_DSP_HDA_BAR,
@@ -677,20 +676,23 @@ int hda_dsp_stream_hw_free(struct snd_sof_dev *sdev,
 	struct hdac_ext_stream *hext_stream = container_of(hstream,
 							 struct hdac_ext_stream,
 							 hstream);
-	struct hdac_bus *bus = sof_to_bus(sdev);
-	u32 mask = 0x1 << hstream->index;
 	int ret;
 
 	ret = hda_dsp_stream_reset(sdev, hstream);
 	if (ret < 0)
 		return ret;
 
-	spin_lock_irq(&bus->reg_lock);
-	/* couple host and link DMA if link DMA channel is idle */
-	if (!hext_stream->link_locked)
-		snd_sof_dsp_update_bits(sdev, HDA_DSP_PP_BAR,
-					SOF_HDA_REG_PP_PPCTL, mask, 0);
-	spin_unlock_irq(&bus->reg_lock);
+	if (!sdev->dspless_mode_selected) {
+		struct hdac_bus *bus = sof_to_bus(sdev);
+		u32 mask = BIT(hstream->index);
+
+		spin_lock_irq(&bus->reg_lock);
+		/* couple host and link DMA if link DMA channel is idle */
+		if (!hext_stream->link_locked)
+			snd_sof_dsp_update_bits(sdev, HDA_DSP_PP_BAR,
+						SOF_HDA_REG_PP_PPCTL, mask, 0);
+		spin_unlock_irq(&bus->reg_lock);
+	}
 
 	hda_dsp_stream_spib_config(sdev, hext_stream, HDA_DSP_SPIB_DISABLE, 0);
 

sound/soc/sof/intel/hda.c

@@ -47,32 +47,34 @@
 static u32 hda_get_interface_mask(struct snd_sof_dev *sdev)
 {
 	const struct sof_intel_dsp_desc *chip;
-	u32 interface_mask = 0;
+	u32 interface_mask[2] = { 0 };
 
 	chip = get_chip_info(sdev->pdata);
 	switch (chip->hw_ip_version) {
 	case SOF_INTEL_TANGIER:
 	case SOF_INTEL_BAYTRAIL:
 	case SOF_INTEL_BROADWELL:
-		interface_mask = BIT(SOF_DAI_INTEL_SSP);
+		interface_mask[0] =  BIT(SOF_DAI_INTEL_SSP);
 		break;
 	case SOF_INTEL_CAVS_1_5:
 	case SOF_INTEL_CAVS_1_5_PLUS:
-		interface_mask = BIT(SOF_DAI_INTEL_SSP) | BIT(SOF_DAI_INTEL_DMIC) |
-				 BIT(SOF_DAI_INTEL_HDA);
+		interface_mask[0] = BIT(SOF_DAI_INTEL_SSP) | BIT(SOF_DAI_INTEL_DMIC) |
+				    BIT(SOF_DAI_INTEL_HDA);
+		interface_mask[1] = BIT(SOF_DAI_INTEL_HDA);
 		break;
 	case SOF_INTEL_CAVS_1_8:
 	case SOF_INTEL_CAVS_2_0:
 	case SOF_INTEL_CAVS_2_5:
 	case SOF_INTEL_ACE_1_0:
-		interface_mask = BIT(SOF_DAI_INTEL_SSP) | BIT(SOF_DAI_INTEL_DMIC) |
-				 BIT(SOF_DAI_INTEL_HDA) | BIT(SOF_DAI_INTEL_ALH);
+		interface_mask[0] = BIT(SOF_DAI_INTEL_SSP) | BIT(SOF_DAI_INTEL_DMIC) |
+				    BIT(SOF_DAI_INTEL_HDA) | BIT(SOF_DAI_INTEL_ALH);
+		interface_mask[1] = BIT(SOF_DAI_INTEL_HDA);
 		break;
 	default:
 		break;
 	}
 
-	return interface_mask;
+	return interface_mask[sdev->dspless_mode_selected];
 }
 
 #if IS_ENABLED(CONFIG_SND_SOC_SOF_INTEL_SOUNDWIRE)
@@ -1058,6 +1060,9 @@ int hda_dsp_probe(struct snd_sof_dev *sdev)
 	hdev->no_ipc_position = sof_ops(sdev)->pcm_pointer ? 1 : 0;
 #endif
 
+	if (sdev->dspless_mode_selected)
+		hdev->no_ipc_position = 1;
+
 	/* set up HDA base */
 	bus = sof_to_bus(sdev);
 	ret = hda_init(sdev);