[PATCH v2] ASoC: Intel: cirrus-common: Use UID to map correct amp to prefix

[Stefan Binding]

Since the order of the amps in the ACPI determines the device name,
and the ACPI order may change depending on hardware configuration,
use UID to dynamically compute the dai links, allowing dynamic
assignment of the name_prefix.

The UIDs for these amps in ACPI are fixed, and map to a name_prefix,
where:
UID 0x0 -> WL
UID 0x1 -> WR
UID 0x2 -> TL
UID 0x3 -> TR

Signed-off-by: Stefan Binding <sbinding at opensource.cirrus.com>
Signed-off-by: Vitaly Rodionov <vitalyr at opensource.cirrus.com>
---
 sound/soc/intel/boards/sof_cirrus_common.c | 89 +++++++++++-----------
 1 file changed, 46 insertions(+), 43 deletions(-)

diff --git a/sound/soc/intel/boards/sof_cirrus_common.c b/sound/soc/intel/boards/sof_cirrus_common.c
index f4192df962d6..e74c4adbf2a5 100644
--- a/sound/soc/intel/boards/sof_cirrus_common.c
+++ b/sound/soc/intel/boards/sof_cirrus_common.c
@@ -10,6 +10,9 @@
 #include "../../codecs/cs35l41.h"
 #include "sof_cirrus_common.h"
 
+#define CS35L41_HID "CSC3541"
+#define CS35L41_MAX_AMPS 4
+
 /*
  * Cirrus Logic CS35L41/CS35L53
  */
@@ -35,50 +38,12 @@ static const struct snd_soc_dapm_route cs35l41_dapm_routes[] = {
 	{"TR Spk", NULL, "TR SPK"},
 };
 
-static struct snd_soc_dai_link_component cs35l41_components[] = {
-	{
-		.name = CS35L41_DEV0_NAME,
-		.dai_name = CS35L41_CODEC_DAI,
-	},
-	{
-		.name = CS35L41_DEV1_NAME,
-		.dai_name = CS35L41_CODEC_DAI,
-	},
-	{
-		.name = CS35L41_DEV2_NAME,
-		.dai_name = CS35L41_CODEC_DAI,
-	},
-	{
-		.name = CS35L41_DEV3_NAME,
-		.dai_name = CS35L41_CODEC_DAI,
-	},
-};
+static struct snd_soc_dai_link_component cs35l41_components[CS35L41_MAX_AMPS];
 
 /*
  * Mapping between ACPI instance id and speaker position.
- *
- * Four speakers:
- *         0: Tweeter left, 1: Woofer left
- *         2: Tweeter right, 3: Woofer right
  */
-static struct snd_soc_codec_conf cs35l41_codec_conf[] = {
-	{
-		.dlc = COMP_CODEC_CONF(CS35L41_DEV0_NAME),
-		.name_prefix = "TL",
-	},
-	{
-		.dlc = COMP_CODEC_CONF(CS35L41_DEV1_NAME),
-		.name_prefix = "WL",
-	},
-	{
-		.dlc = COMP_CODEC_CONF(CS35L41_DEV2_NAME),
-		.name_prefix = "TR",
-	},
-	{
-		.dlc = COMP_CODEC_CONF(CS35L41_DEV3_NAME),
-		.name_prefix = "WR",
-	},
-};
+static struct snd_soc_codec_conf cs35l41_codec_conf[CS35L41_MAX_AMPS];
 
 static int cs35l41_init(struct snd_soc_pcm_runtime *rtd)
 {
@@ -117,10 +82,10 @@ static int cs35l41_init(struct snd_soc_pcm_runtime *rtd)
 static const struct {
 	unsigned int rx[2];
 } cs35l41_channel_map[] = {
-	{.rx = {0, 1}}, /* TL */
 	{.rx = {0, 1}}, /* WL */
-	{.rx = {1, 0}}, /* TR */
 	{.rx = {1, 0}}, /* WR */
+	{.rx = {0, 1}}, /* TL */
+	{.rx = {1, 0}}, /* TR */
 };
 
 static int cs35l41_hw_params(struct snd_pcm_substream *substream,
@@ -175,10 +140,48 @@ static const struct snd_soc_ops cs35l41_ops = {
 	.hw_params = cs35l41_hw_params,
 };
 
+static const char * const cs35l41_name_prefixes[] = { "WL", "WR", "TL", "TR" };
+
+/*
+ * Expected UIDs are integers (stored as strings).
+ * UID Mapping is fixed:
+ * UID 0x0 -> WL
+ * UID 0x1 -> WR
+ * UID 0x2 -> TL
+ * UID 0x3 -> TR
+ * Note: If there are less than 4 Amps, UIDs still map to WL/WR/TL/TR. Dynamic code will only create
+ * dai links for UIDs which exist, and ignore non-existant ones.
+ * Return number of codecs found.
+ */
+static int cs35l41_compute_codec_conf(void)
+{
+	const char * const uid_strings[] = { "0", "1", "2", "3" };
+	unsigned int uid, sz = 0;
+	struct acpi_device *adev;
+	struct device *physdev;
+
+	for (uid = 0; uid < CS35L41_MAX_AMPS; uid++) {
+		adev = acpi_dev_get_first_match_dev(CS35L41_HID, uid_strings[uid], -1);
+		if (!adev) {
+			pr_warn("Cannot find match for HID %s UID %u (%s)\n", CS35L41_HID, uid,
+				cs35l41_name_prefixes[uid]);
+			continue;
+		}
+		physdev = get_device(acpi_get_first_physical_node(adev));
+		cs35l41_components[sz].name = dev_name(physdev);
+		cs35l41_components[sz].dai_name = CS35L41_CODEC_DAI;
+		cs35l41_codec_conf[sz].dlc.name = dev_name(physdev);
+		cs35l41_codec_conf[sz].name_prefix = cs35l41_name_prefixes[uid];
+		acpi_dev_put(adev);
+		sz++;
+	}
+	return sz;
+}
+
 void cs35l41_set_dai_link(struct snd_soc_dai_link *link)
 {
+	link->num_codecs = cs35l41_compute_codec_conf();
 	link->codecs = cs35l41_components;
-	link->num_codecs = ARRAY_SIZE(cs35l41_components);
 	link->init = cs35l41_init;
 	link->ops = &cs35l41_ops;
 }
-- 
2.34.1