[PATCH v2 6/7] ASoC: sophgo: add CV1800B internal DAC codec driver

Codec DAI endpoint for TXDAC. The codec does only a few things
- set up decimation
- enable codec and I2S output
- ensures the driver doesn't have dac overwrite enabled. (unmute the
  output)

Signed-off-by: Anton D. Stavinskii <[email protected]>
---
 sound/soc/sophgo/Kconfig             |  11 +-
 sound/soc/sophgo/Makefile            |   1 +
 sound/soc/sophgo/cv1800b-sound-dac.c | 204 +++++++++++++++++++++++++++++++++++
 3 files changed, 215 insertions(+), 1 deletion(-)

diff --git a/sound/soc/sophgo/Kconfig b/sound/soc/sophgo/Kconfig
index 813ab30d6da3..e7c617b44db6 100644
--- a/sound/soc/sophgo/Kconfig
+++ b/sound/soc/sophgo/Kconfig
@@ -23,10 +23,19 @@ config SND_SOC_CV1800B_ADC_CODEC
 	help
 	  This driver provides an ASoC codec DAI for capture and basic
 	  control of the RXADC registers.
-
 	  Say Y or M to build support for the Sophgo CV1800B
 	  internal analog ADC codec block (RXADC).
 	  The module will be called cv1800b-sound-adc
 
+config SND_SOC_CV1800B_DAC_CODEC
+	tristate "Sophgo CV1800B/SG2002 internal DAC codec"
+	depends on SND_SOC
+	help
+	  This driver provides an ASoC codec DAI for playback and basic
+	  control of the TXDAC registers.
+
+	  Say Y or M to build support for the Sophgo CV1800B
+	  internal analog DAC codec block (TXDAC).
+	  The module will be called cv1800b-sound-dac
 
 endmenu
diff --git a/sound/soc/sophgo/Makefile b/sound/soc/sophgo/Makefile
index c654d6059cbd..ec8dd31efddd 100644
--- a/sound/soc/sophgo/Makefile
+++ b/sound/soc/sophgo/Makefile
@@ -2,3 +2,4 @@
 # Sophgo Platform Support
 obj-$(CONFIG_SND_SOC_CV1800B_TDM) += cv1800b-tdm.o
 obj-$(CONFIG_SND_SOC_CV1800B_ADC_CODEC) += cv1800b-sound-adc.o
+obj-$(CONFIG_SND_SOC_CV1800B_DAC_CODEC) += cv1800b-sound-dac.o
diff --git a/sound/soc/sophgo/cv1800b-sound-dac.c b/sound/soc/sophgo/cv1800b-sound-dac.c
new file mode 100644
index 000000000000..ccf386174639
--- /dev/null
+++ b/sound/soc/sophgo/cv1800b-sound-dac.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Internal DAC codec for cv1800b based CPUs
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <sound/soc.h>
+#include <linux/io.h>
+
+#define CV1800B_TXDAC_CTRL0   0x00
+#define CV1800B_TXDAC_CTRL1   0x04
+#define CV1800B_TXDAC_STATUS  0x08
+#define CV1800B_TXDAC_AFE0    0x0c
+#define CV1800B_TXDAC_AFE1    0x10
+#define CV1800B_TXDAC_ANA0    0x20
+#define CV1800B_TXDAC_ANA1    0x24
+#define CV1800B_TXDAC_ANA2    0x28
+
+/* cv1800b_TXDAC_CTRL0 */
+#define REG_TXDAC_EN GENMASK(0, 0)
+#define REG_I2S_RX_EN GENMASK(1, 1)
+
+/* cv1800b_TXDAC_CTRL1 */
+#define REG_TXDAC_CIC_OPT GENMASK(1, 0)
+
+/* cv1800b_TXDAC_AFE0 */
+#define REG_TXDAC_INIT_DLY_CNT GENMASK(5, 0)
+
+/* cv1800b_TXDAC_ANA2 */
+#define TXDAC_OW_VAL_L_MASK GENMASK(7, 0)
+#define TXDAC_OW_VAL_R_MASK GENMASK(15, 8)
+#define TXDAC_OW_EN_L_MASK GENMASK(16, 16)
+#define TXDAC_OW_EN_R_MASK GENMASK(17, 17)
+
+struct cv1800b_priv {
+	void __iomem *regs;
+	struct device *dev;
+};
+
+enum decimation_values {
+	DECIMATION_64 = 0,
+	DECIMATION_128,
+	DECIMATION_256,
+	DECIMATION_512,
+};
+
+static void cv1800b_dac_enable(struct cv1800b_priv *priv, bool enable)
+{
+	u32 val;
+
+	val = readl(priv->regs + CV1800B_TXDAC_CTRL0);
+	val = u32_replace_bits(val, enable, REG_TXDAC_EN);
+	val = u32_replace_bits(val, enable, REG_I2S_RX_EN);
+	writel(val, priv->regs + CV1800B_TXDAC_CTRL0);
+}
+
+static void cv1800b_dac_mute(struct cv1800b_priv *priv, bool enable)
+{
+	u32 val;
+
+	val = readl(priv->regs + CV1800B_TXDAC_ANA2);
+	val = u32_replace_bits(val, enable, TXDAC_OW_EN_L_MASK);
+	val = u32_replace_bits(val, enable, TXDAC_OW_EN_R_MASK);
+	writel(val, priv->regs + CV1800B_TXDAC_ANA2);
+}
+
+static int cv1800b_dac_decimation(struct cv1800b_priv *priv, u8 dec)
+{
+	u32 val;
+
+	if (dec > 3)
+		return -EINVAL;
+
+	val = readl(priv->regs + CV1800B_TXDAC_CTRL1);
+	val = u32_replace_bits(val, dec, REG_TXDAC_CIC_OPT);
+	writel(val, priv->regs + CV1800B_TXDAC_CTRL1);
+	return 0;
+}
+
+static int cv1800b_dac_dly(struct cv1800b_priv *priv, u32 dly)
+{
+	u32 val;
+
+	if (dly > 63)
+		return -EINVAL;
+
+	val = readl(priv->regs + CV1800B_TXDAC_AFE0);
+	val = u32_replace_bits(val, dly, REG_TXDAC_INIT_DLY_CNT);
+	writel(val, priv->regs + CV1800B_TXDAC_AFE0);
+	return 0;
+}
+
+static int cv1800b_dac_hw_params(struct snd_pcm_substream *substream,
+				 struct snd_pcm_hw_params *params,
+				 struct snd_soc_dai *dai)
+{
+	struct cv1800b_priv *priv = snd_soc_dai_get_drvdata(dai);
+	int ret;
+	unsigned int rate = params_rate(params);
+
+	if (rate != 48000) {
+		dev_err(priv->dev, "rate %u is not supported\n", rate);
+		return -EINVAL;
+	}
+
+	cv1800b_dac_mute(priv, false);
+	/* minimal decimation for 48kHz is 64*/
+	ret = cv1800b_dac_decimation(priv, DECIMATION_64);
+	if (ret)
+		return ret;
+
+	/* value is taken from vendors driver 48kHz
+	 * tested on sg2000 and sg2002.
+	 */
+	ret = cv1800b_dac_dly(priv, 0x19);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int cv1800b_dac_dai_trigger(struct snd_pcm_substream *substream, int cmd,
+				   struct snd_soc_dai *dai)
+{
+	struct cv1800b_priv *priv = snd_soc_dai_get_drvdata(dai);
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		cv1800b_dac_enable(priv, true);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		cv1800b_dac_enable(priv, false);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops cv1800b_dac_dai_ops = {
+	.hw_params = cv1800b_dac_hw_params,
+	.trigger = cv1800b_dac_dai_trigger,
+};
+
+static struct snd_soc_dai_driver cv1800b_dac_dai = {
+	.name = "dac-hifi",
+	.playback = { .stream_name = "DAC Playback",
+		      .channels_min = 2,
+		      .channels_max = 2,
+		      .rates = SNDRV_PCM_RATE_48000,
+		      .formats = SNDRV_PCM_FMTBIT_S16_LE },
+	.ops = &cv1800b_dac_dai_ops,
+};
+
+static const struct snd_soc_component_driver cv1800b_dac_component = {
+	.name = "cv1800b-dac-codec",
+};
+
+static int cv1800b_dac_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cv1800b_priv *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = dev;
+	priv->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->regs))
+		return PTR_ERR(priv->regs);
+
+	platform_set_drvdata(pdev, priv);
+	return devm_snd_soc_register_component(&pdev->dev,
+					       &cv1800b_dac_component,
+					       &cv1800b_dac_dai, 1);
+}
+
+static const struct of_device_id cv1800b_dac_of_match[] = {
+	{ .compatible = "sophgo,cv1800b-sound-dac" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, cv1800b_dac_of_match);
+
+static struct platform_driver cv1800b_dac_driver = {
+	.probe = cv1800b_dac_probe,
+	.driver = {
+		.name = "cv1800b-dac-codec",
+		.of_match_table = cv1800b_dac_of_match,
+	},
+};
+module_platform_driver(cv1800b_dac_driver);
+
+MODULE_DESCRIPTION("DAC codec for CV1800B");
+MODULE_AUTHOR("Anton D. Stavinskii <[email protected]>");
+MODULE_LICENSE("GPL");

-- 
2.43.0