ASoC: Intel: sof_pcm512x: make HDMI optional for all platforms

Make HDMI optional for APL and later platforms. If no HDMI codec
is found on the HDA bus, the graphics side driver is missing or
correct codec driver is not part of kernel build, codec_mask
reflects this and HDMI is disabled. The DSP topology will still
have the links for HDMI, so connect these to dummy codec to avoid
failures in topology loading.

This change also fixes a kernel oops that was triggered if
sof_pcm512x was used with SOF configured to use hdac-hdmi (can be
done via "use_common_hdmi=0" or by selecting
CONFIG_SND_SOC_SOF_HDA_COMMON_HDMI_CODEC=n). This is not a supported
configuration.
Signed-off-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200312194859.4051-4-pierre-louis.bossart@linux.intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/boards/sof_pcm512x.c

@@ -27,6 +27,8 @@
 #define SOF_PCM512X_SSP_CODEC(quirk)		((quirk) & GENMASK(3, 0))
 #define SOF_PCM512X_SSP_CODEC_MASK			(GENMASK(3, 0))
 
+#define IDISP_CODEC_MASK	0x4
+
 /* Default: SSP5 */
 static unsigned long sof_pcm512x_quirk = SOF_PCM512X_SSP_CODEC(5);
 
@@ -40,6 +42,7 @@ struct sof_hdmi_pcm {
 
 struct sof_card_private {
 	struct list_head hdmi_pcm_list;
+	bool idisp_codec;
 };
 
 static int sof_pcm512x_quirk_cb(const struct dmi_system_id *id)
@@ -136,6 +139,9 @@ static int sof_card_late_probe(struct snd_soc_card *card)
 	if (list_empty(&ctx->hdmi_pcm_list))
 		return -EINVAL;
 
+	if (!ctx->idisp_codec)
+		return 0;
+
 	pcm = list_first_entry(&ctx->hdmi_pcm_list, struct sof_hdmi_pcm, head);
 
 	return hda_dsp_hdmi_build_controls(card, pcm->codec_dai->component);
@@ -214,7 +220,8 @@ SND_SOC_DAILINK_DEF(dmic_component,
 static struct snd_soc_dai_link *sof_card_dai_links_create(struct device *dev,
 							  int ssp_codec,
 							  int dmic_be_num,
-							  int hdmi_num)
+							  int hdmi_num,
+							  bool idisp_codec)
 {
 	struct snd_soc_dai_link_component *idisp_components;
 	struct snd_soc_dai_link_component *cpus;
@@ -316,11 +323,19 @@ static struct snd_soc_dai_link *sof_card_dai_links_create(struct device *dev,
 		if (!links[id].cpus->dai_name)
 			goto devm_err;
 
+		/*
+		 * topology cannot be loaded if codec is missing, so
+		 * use the dummy codec if needed
+		 */
+		if (idisp_codec) {
 			idisp_components[i - 1].name = "ehdaudio0D2";
-		idisp_components[i - 1].dai_name = devm_kasprintf(dev,
-								  GFP_KERNEL,
-								  "intel-hdmi-hifi%d",
-								  i);
+			idisp_components[i - 1].dai_name =
+				devm_kasprintf(dev, GFP_KERNEL,
+					       "intel-hdmi-hifi%d", i);
+		} else {
+			idisp_components[i - 1].name = "snd-soc-dummy";
+			idisp_components[i - 1].dai_name = "snd-soc-dummy-dai";
+		}
 		if (!idisp_components[i - 1].dai_name)
 			goto devm_err;
 
@@ -341,8 +356,8 @@ static struct snd_soc_dai_link *sof_card_dai_links_create(struct device *dev,
 
 static int sof_audio_probe(struct platform_device *pdev)
 {
+	struct snd_soc_acpi_mach *mach = pdev->dev.platform_data;
 	struct snd_soc_dai_link *dai_links;
-	struct snd_soc_acpi_mach *mach;
 	struct sof_card_private *ctx;
 	int dmic_be_num, hdmi_num;
 	int ret, ssp_codec;
@@ -360,6 +375,11 @@ static int sof_audio_probe(struct platform_device *pdev)
 	} else {
 		dmic_be_num = 2;
 #if IS_ENABLED(CONFIG_SND_HDA_CODEC_HDMI)
+		if (mach->mach_params.common_hdmi_codec_drv &&
+		    (mach->mach_params.codec_mask & IDISP_CODEC_MASK))
+			ctx->idisp_codec = true;
+
+		/* links are always present in topology */
 		hdmi_num = 3;
 #endif
 	}
@@ -374,7 +394,8 @@ static int sof_audio_probe(struct platform_device *pdev)
 	sof_audio_card_pcm512x.num_links = 1 + dmic_be_num + hdmi_num;
 
 	dai_links = sof_card_dai_links_create(&pdev->dev, ssp_codec,
-					      dmic_be_num, hdmi_num);
+					      dmic_be_num, hdmi_num,
+					      ctx->idisp_codec);
 	if (!dai_links)
 		return -ENOMEM;
 
@@ -383,7 +404,6 @@ static int sof_audio_probe(struct platform_device *pdev)
 	INIT_LIST_HEAD(&ctx->hdmi_pcm_list);
 
 	sof_audio_card_pcm512x.dev = &pdev->dev;
-	mach = (&pdev->dev)->platform_data;
 
 	/* set platform name for each dailink */
 	ret = snd_soc_fixup_dai_links_platform_name(&sof_audio_card_pcm512x,