ASoC: loongson: Combined regmap definitions

Previously, the regmap configuration for Loongson I2S controller was
duplicated in both PCI and platform glue drivers. Move the common
regmap configuration into the shared loongson_i2s.c to avoid code
duplication and centralize register access handling.

While moving, adjust the following:
- Mark RX_DATA/TX_DATA/I2S_CTRL as volatile registers. The PCI version
  incorrectly marked CFG/CFG1 as volatile, which prevented proper
  regcache synchronization.
- Change cache type from REGCACHE_FLAT to REGCACHE_MAPLE. The register
  map is sparse and the number of registers is small; MAPLE tree provides
  better scalability and is the recommended cache type for modern
  regmap users.

Also, the following warning for the i2s_plat driver will be eliminated:

loongson-i2s-plat loongson-i2s: using zero-initialized flat cache, this may cause unexpected behavior.

Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Link: https://patch.msgid.link/e32d24479fc382dc3de6aded6351c13b43b6391d.1780304703.git.zhoubinbin@loongson.cn
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: AaronDot

sound/soc/loongson/loongson_i2s.c

@@ -254,6 +254,7 @@ static int i2s_suspend(struct device *dev)
 	struct loongson_i2s *i2s = dev_get_drvdata(dev);
 
 	regcache_cache_only(i2s->regmap, true);
+	regcache_mark_dirty(i2s->regmap);
 
 	return 0;
 }
@@ -263,7 +264,7 @@ static int i2s_resume(struct device *dev)
 	struct loongson_i2s *i2s = dev_get_drvdata(dev);
 
 	regcache_cache_only(i2s->regmap, false);
-	regcache_mark_dirty(i2s->regmap);
+
 	return regcache_sync(i2s->regmap);
 }
 
@@ -272,5 +273,58 @@ const struct dev_pm_ops loongson_i2s_pm = {
 };
 EXPORT_SYMBOL_GPL(loongson_i2s_pm);
 
+static bool loongson_i2s_rd_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case LS_I2S_VER:
+	case LS_I2S_CFG:
+	case LS_I2S_CTRL:
+	case LS_I2S_RX_DATA:
+	case LS_I2S_TX_DATA:
+	case LS_I2S_CFG1:
+		return true;
+	default:
+		return false;
+	};
+}
+
+static bool loongson_i2s_wr_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case LS_I2S_CFG:
+	case LS_I2S_CTRL:
+	case LS_I2S_RX_DATA:
+	case LS_I2S_TX_DATA:
+	case LS_I2S_CFG1:
+		return true;
+	default:
+		return false;
+	};
+}
+
+static bool loongson_i2s_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case LS_I2S_CTRL:
+	case LS_I2S_RX_DATA:
+	case LS_I2S_TX_DATA:
+		return true;
+	default:
+		return false;
+	};
+}
+
+const struct regmap_config loongson_i2s_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = LS_I2S_CFG1,
+	.readable_reg = loongson_i2s_rd_reg,
+	.writeable_reg = loongson_i2s_wr_reg,
+	.volatile_reg = loongson_i2s_volatile_reg,
+	.cache_type = REGCACHE_MAPLE,
+};
+EXPORT_SYMBOL_GPL(loongson_i2s_regmap_config);
+
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Common functions for loongson I2S controller driver");

sound/soc/loongson/loongson_i2s.h

@@ -65,6 +65,7 @@ struct loongson_i2s {
 	u32 sysclk;
 };
 
+extern const struct regmap_config loongson_i2s_regmap_config;
 extern const struct dev_pm_ops loongson_i2s_pm;
 extern struct snd_soc_dai_driver loongson_i2s_dai;
 

sound/soc/loongson/loongson_i2s_pci.c

@@ -18,60 +18,6 @@
 
 #define DRIVER_NAME "loongson-i2s-pci"
 
-static bool loongson_i2s_wr_reg(struct device *dev, unsigned int reg)
-{
-	switch (reg) {
-	case LS_I2S_CFG:
-	case LS_I2S_CTRL:
-	case LS_I2S_RX_DATA:
-	case LS_I2S_TX_DATA:
-	case LS_I2S_CFG1:
-		return true;
-	default:
-		return false;
-	};
-}
-
-static bool loongson_i2s_rd_reg(struct device *dev, unsigned int reg)
-{
-	switch (reg) {
-	case LS_I2S_VER:
-	case LS_I2S_CFG:
-	case LS_I2S_CTRL:
-	case LS_I2S_RX_DATA:
-	case LS_I2S_TX_DATA:
-	case LS_I2S_CFG1:
-		return true;
-	default:
-		return false;
-	};
-}
-
-static bool loongson_i2s_volatile_reg(struct device *dev, unsigned int reg)
-{
-	switch (reg) {
-	case LS_I2S_CFG:
-	case LS_I2S_CTRL:
-	case LS_I2S_RX_DATA:
-	case LS_I2S_TX_DATA:
-	case LS_I2S_CFG1:
-		return true;
-	default:
-		return false;
-	};
-}
-
-static const struct regmap_config loongson_i2s_regmap_config = {
-	.reg_bits = 32,
-	.reg_stride = 4,
-	.val_bits = 32,
-	.max_register = LS_I2S_CFG1,
-	.writeable_reg = loongson_i2s_wr_reg,
-	.readable_reg = loongson_i2s_rd_reg,
-	.volatile_reg = loongson_i2s_volatile_reg,
-	.cache_type = REGCACHE_FLAT,
-};
-
 static int loongson_i2s_pci_probe(struct pci_dev *pdev,
 				  const struct pci_device_id *pid)
 {

sound/soc/loongson/loongson_i2s_plat.c

@@ -85,14 +85,6 @@ static const struct snd_soc_component_driver loongson_i2s_component_driver = {
 	.open	= loongson_pcm_open,
 };
 
-static const struct regmap_config loongson_i2s_regmap_config = {
-	.reg_bits = 32,
-	.reg_stride = 4,
-	.val_bits = 32,
-	.max_register = 0x14,
-	.cache_type = REGCACHE_FLAT,
-};
-
 static int loongson_i2s_apbdma_config(struct platform_device *pdev)
 {
 	int val;