ASoC: intel/skl/hda - add no-HDMI cases to generic HDA driver

Extend the generic HDA driver to support systems where iDisp/HDMI
audio codecs are disabled for some reason. Switch codecs to
SoC dummy in the affected DAI links. This allows to reuse
existing topologies for this case.
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=206085
BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1163677
BugLink: https://github.com/thesofproject/linux/issues/1658
Link: https://lore.kernel.org/r/20200220171028.22023-2-kai.vehmanen@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/boards/skl_hda_dsp_common.h

@@ -49,6 +49,10 @@ static inline int skl_hda_hdmi_build_controls(struct snd_soc_card *card)
 	struct snd_soc_component *component;
 	struct skl_hda_hdmi_pcm *pcm;
 
+	/* HDMI disabled, do not create controls */
+	if (list_empty(&ctx->hdmi_pcm_list))
+		return 0;
+
 	pcm = list_first_entry(&ctx->hdmi_pcm_list, struct skl_hda_hdmi_pcm,
 			       head);
 	component = pcm->codec_dai->component;

sound/soc/intel/boards/skl_hda_dsp_generic.c

@@ -61,6 +61,9 @@ static const struct snd_soc_dapm_route skl_hda_map[] = {
 	{ "Alt Analog CPU Capture", NULL, "Alt Analog Codec Capture" },
 };
 
+SND_SOC_DAILINK_DEF(dummy_codec,
+	DAILINK_COMP_ARRAY(COMP_CODEC("snd-soc-dummy", "snd-soc-dummy-dai")));
+
 static int skl_hda_card_late_probe(struct snd_soc_card *card)
 {
 	return skl_hda_hdmi_jack_init(card);
@@ -114,13 +117,19 @@ static int skl_hda_fill_card_info(struct snd_soc_acpi_mach_params *mach_params)
 {
 	struct snd_soc_card *card = &hda_soc_card;
 	struct snd_soc_dai_link *dai_link;
-	u32 codec_count, codec_mask;
+	u32 codec_count, codec_mask, idisp_mask;
 	int i, num_links, num_route;
 
 	codec_mask = mach_params->codec_mask;
 	codec_count = hweight_long(codec_mask);
+	idisp_mask = codec_mask & IDISP_CODEC_MASK;
+
+	if (!codec_count || codec_count > 2 ||
+	    (codec_count == 2 && !idisp_mask))
+		return -EINVAL;
 
-	if (codec_count == 1 && codec_mask & IDISP_CODEC_MASK) {
+	if (codec_mask == idisp_mask) {
+		/* topology with iDisp as the only HDA codec */
 		num_links = IDISP_DAI_COUNT + DMIC_DAI_COUNT;
 		num_route = IDISP_ROUTE_COUNT;
 
@@ -135,13 +144,19 @@ static int skl_hda_fill_card_info(struct snd_soc_acpi_mach_params *mach_params)
 				skl_hda_be_dai_links[IDISP_DAI_COUNT +
 					HDAC_DAI_COUNT + i];
 		}
-	} else if (codec_count == 2 && codec_mask & IDISP_CODEC_MASK) {
+	} else {
+		/* topology with external and iDisp HDA codecs */
 		num_links = ARRAY_SIZE(skl_hda_be_dai_links);
 		num_route = ARRAY_SIZE(skl_hda_map);
 		card->dapm_widgets = skl_hda_widgets;
 		card->num_dapm_widgets = ARRAY_SIZE(skl_hda_widgets);
-	} else {
-		return -EINVAL;
+		if (!idisp_mask) {
+			for (i = 0; i < IDISP_DAI_COUNT; i++) {
+				skl_hda_be_dai_links[i].codecs = dummy_codec;
+				skl_hda_be_dai_links[i].num_codecs =
+					ARRAY_SIZE(dummy_codec);
+			}
+		}
 	}
 
 	card->num_links = num_links;