ASoC: Intel: sof_sdw_cs_amp: Connect outputs to a speaker widget

Hookup the CS35L56 DAPM_OUTPUT widgets to a DAPM_SPK widget so
that there is a complete logical path to a speaker.

There is no particular reason to use multiple speaker widgets.
The CS35L56 are designed to work together as a set so they have
all been connected to a single speaker widget.

Instead of a hardcoded list of codec widget names, the code walks
through all the codecs on the dailink and for every cs35l56 it uses
its name prefix to construct the source end of the route. This adds
a small amount of overhead during probe but has the benefit that it
isn't dependent on every system using the same prefixes.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Acked-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20231205135001.2506070-1-rf@opensource.cirrus.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/intel/boards/sof_sdw_cs_amp.c

@@ -9,15 +9,24 @@
 #include <linux/errno.h>
 #include <sound/soc.h>
 #include <sound/soc-acpi.h>
+#include <sound/soc-dai.h>
 #include "sof_sdw_common.h"
 
 #define CODEC_NAME_SIZE	8
 
+static const struct snd_soc_dapm_widget sof_widgets[] = {
+	SND_SOC_DAPM_SPK("Speakers", NULL),
+};
+
 static int cs_spk_init(struct snd_soc_pcm_runtime *rtd)
 {
 	const char *dai_name = rtd->dai_link->codecs->dai_name;
 	struct snd_soc_card *card = rtd->card;
 	char codec_name[CODEC_NAME_SIZE];
+	char widget_name[16];
+	struct snd_soc_dapm_route route = { "Speakers", NULL, widget_name };
+	struct snd_soc_dai *codec_dai;
+	int i, ret;
 
 	snprintf(codec_name, CODEC_NAME_SIZE, "%s", dai_name);
 	card->components = devm_kasprintf(card->dev, GFP_KERNEL,
@@ -26,17 +35,34 @@ static int cs_spk_init(struct snd_soc_pcm_runtime *rtd)
 	if (!card->components)
 		return -ENOMEM;
 
+	ret = snd_soc_dapm_new_controls(&card->dapm, sof_widgets,
+					ARRAY_SIZE(sof_widgets));
+	if (ret) {
+		dev_err(card->dev, "widgets addition failed: %d\n", ret);
+		return ret;
+	}
+
+	for_each_rtd_codec_dais(rtd, i, codec_dai) {
+		if (!strstr(codec_dai->name, "cs35l56"))
+			continue;
+
+		snprintf(widget_name, sizeof(widget_name), "%s SPK",
+			 codec_dai->component->name_prefix);
+		ret = snd_soc_dapm_add_routes(&card->dapm, &route, 1);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
-
 int sof_sdw_cs_amp_init(struct snd_soc_card *card,
 			const struct snd_soc_acpi_link_adr *link,
 			struct snd_soc_dai_link *dai_links,
 			struct sof_sdw_codec_info *info,
 			bool playback)
 {
-	/* Count amp number and do init on playback link only. */
+	/* Do init on playback link only. */
 	if (!playback)
 		return 0;