[PATCH v4 5/6] ASoC: sophgo: add CV1800B internal DAC codec driver

Anton D. Stavinskii
2026-01-20T19:06:27Z

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 <stavinsky@gmail.com>
---
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 12d1a57ea308..e4786f087589 100644
--- a/sound/soc/sophgo/Kconfig
+++ b/sound/soc/sophgo/Kconfig
@@ -28,10 +28,19 @@ 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 <stavinsky@gmail.com>");
+MODULE_LICENSE("GPL");

--
2.43.0