ASoC: codecs: add wm8524 codec driver

WM8524 is a 24-bit 192KHz stereo digital/analog converter (DAC) with
integral charge pump and a simple hardware control interface.
Product information can be found at:
https://www.cirrus.com/products/wm8524/Signed-off-by: NMihai Serban <mihai.serban@nxp.com>
Signed-off-by: NShengjiu Wang <shengjiu.wang@nxp.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/wm8524.txt

+WM8524 audio CODEC
+
+This device does not use I2C or SPI but a simple Hardware Control Interface.
+
+Required properties:
+
+  - compatible : "wlf,wm8524"
+
+  - wlf,mute-gpios: a GPIO spec for the MUTE pin.
+
+Example:
+
+codec: wm8524@0 {
+	compatible = "wlf,wm8524";
+	wlf,mute-gpios = <&gpio1 8 GPIO_ACTIVE_LOW>;
+};

sound/soc/codecs/Kconfig

@@ -173,6 +173,7 @@ config SND_SOC_ALL_CODECS
 	select SND_SOC_WM8400 if MFD_WM8400
 	select SND_SOC_WM8510 if SND_SOC_I2C_AND_SPI
 	select SND_SOC_WM8523 if I2C
+	select SND_SOC_WM8524 if GPIOLIB
 	select SND_SOC_WM8580 if I2C
 	select SND_SOC_WM8711 if SND_SOC_I2C_AND_SPI
 	select SND_SOC_WM8727
@@ -967,6 +968,10 @@ config SND_SOC_WM8523
 	tristate "Wolfson Microelectronics WM8523 DAC"
 	depends on I2C
 
+config SND_SOC_WM8524
+	tristate "Wolfson Microelectronics WM8524 DAC"
+	depends on GPIOLIB
+
 config SND_SOC_WM8580
 	tristate "Wolfson Microelectronics WM8580 and WM8581 CODECs"
 	depends on I2C

sound/soc/codecs/Makefile

@@ -182,6 +182,7 @@ snd-soc-wm8350-objs := wm8350.o
 snd-soc-wm8400-objs := wm8400.o
 snd-soc-wm8510-objs := wm8510.o
 snd-soc-wm8523-objs := wm8523.o
+snd-soc-wm8524-objs := wm8524.o
 snd-soc-wm8580-objs := wm8580.o
 snd-soc-wm8711-objs := wm8711.o
 snd-soc-wm8727-objs := wm8727.o
@@ -414,6 +415,7 @@ obj-$(CONFIG_SND_SOC_WM8350)	+= snd-soc-wm8350.o
 obj-$(CONFIG_SND_SOC_WM8400)	+= snd-soc-wm8400.o
 obj-$(CONFIG_SND_SOC_WM8510)	+= snd-soc-wm8510.o
 obj-$(CONFIG_SND_SOC_WM8523)	+= snd-soc-wm8523.o
+obj-$(CONFIG_SND_SOC_WM8524)	+= snd-soc-wm8524.o
 obj-$(CONFIG_SND_SOC_WM8580)	+= snd-soc-wm8580.o
 obj-$(CONFIG_SND_SOC_WM8711)	+= snd-soc-wm8711.o
 obj-$(CONFIG_SND_SOC_WM8727)	+= snd-soc-wm8727.o

sound/soc/codecs/wm8524.c

+/*
+ * wm8524.c  --  WM8524 ALSA SoC Audio driver
+ *
+ * Copyright 2009 Wolfson Microelectronics plc
+ * Copyright 2017 NXP
+ *
+ * Based on WM8523 ALSA SoC Audio driver written by Mark Brown
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/gpio/consumer.h>
+#include <linux/of_device.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/initval.h>
+
+#define WM8524_NUM_RATES 7
+
+/* codec private data */
+struct wm8524_priv {
+	struct gpio_desc *mute;
+	unsigned int sysclk;
+	unsigned int rate_constraint_list[WM8524_NUM_RATES];
+	struct snd_pcm_hw_constraint_list rate_constraint;
+};
+
+
+static const struct snd_soc_dapm_widget wm8524_dapm_widgets[] = {
+SND_SOC_DAPM_DAC("DAC", "Playback", SND_SOC_NOPM, 0, 0),
+SND_SOC_DAPM_OUTPUT("LINEVOUTL"),
+SND_SOC_DAPM_OUTPUT("LINEVOUTR"),
+};
+
+static const struct snd_soc_dapm_route wm8524_dapm_routes[] = {
+	{ "LINEVOUTL", NULL, "DAC" },
+	{ "LINEVOUTR", NULL, "DAC" },
+};
+
+static const struct {
+	int value;
+	int ratio;
+} lrclk_ratios[WM8524_NUM_RATES] = {
+	{ 1, 128 },
+	{ 2, 192 },
+	{ 3, 256 },
+	{ 4, 384 },
+	{ 5, 512 },
+	{ 6, 768 },
+	{ 7, 1152 },
+};
+
+static int wm8524_startup(struct snd_pcm_substream *substream,
+			  struct snd_soc_dai *dai)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct wm8524_priv *wm8524 = snd_soc_codec_get_drvdata(codec);
+
+	/* The set of sample rates that can be supported depends on the
+	 * MCLK supplied to the CODEC - enforce this.
+	 */
+	if (!wm8524->sysclk) {
+		dev_err(codec->dev,
+			"No MCLK configured, call set_sysclk() on init\n");
+		return -EINVAL;
+	}
+
+	snd_pcm_hw_constraint_list(substream->runtime, 0,
+				   SNDRV_PCM_HW_PARAM_RATE,
+				   &wm8524->rate_constraint);
+
+	gpiod_set_value_cansleep(wm8524->mute, 1);
+
+	return 0;
+}
+
+static void wm8524_shutdown(struct snd_pcm_substream *substream,
+			  struct snd_soc_dai *dai)
+{
+	struct snd_soc_codec *codec = dai->codec;
+	struct wm8524_priv *wm8524 = snd_soc_codec_get_drvdata(codec);
+
+	gpiod_set_value_cansleep(wm8524->mute, 0);
+}
+
+static int wm8524_set_dai_sysclk(struct snd_soc_dai *codec_dai,
+		int clk_id, unsigned int freq, int dir)
+{
+	struct snd_soc_codec *codec = codec_dai->codec;
+	struct wm8524_priv *wm8524 = snd_soc_codec_get_drvdata(codec);
+	unsigned int val;
+	int i, j = 0;
+
+	wm8524->sysclk = freq;
+
+	wm8524->rate_constraint.count = 0;
+	for (i = 0; i < ARRAY_SIZE(lrclk_ratios); i++) {
+		val = freq / lrclk_ratios[i].ratio;
+		/* Check that it's a standard rate since core can't
+		 * cope with others and having the odd rates confuses
+		 * constraint matching.
+		 */
+		switch (val) {
+		case 8000:
+		case 32000:
+		case 44100:
+		case 48000:
+		case 88200:
+		case 96000:
+		case 176400:
+		case 192000:
+			dev_err(codec->dev, "Supported sample rate: %dHz\n",
+				val);
+			wm8524->rate_constraint_list[j++] = val;
+			wm8524->rate_constraint.count++;
+			break;
+		default:
+			dev_dbg(codec->dev, "Skipping sample rate: %dHz\n",
+				val);
+		}
+	}
+
+	/* Need at least one supported rate... */
+	if (wm8524->rate_constraint.count == 0)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int wm8524_set_fmt(struct snd_soc_dai *codec_dai, unsigned int fmt)
+{
+	fmt &= (SND_SOC_DAIFMT_FORMAT_MASK | SND_SOC_DAIFMT_INV_MASK |
+		SND_SOC_DAIFMT_MASTER_MASK);
+
+	if (fmt != (SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_NB_NF |
+		    SND_SOC_DAIFMT_CBS_CFS)) {
+		dev_err(codec_dai->dev, "Invalid DAI format\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int wm8524_mute_stream(struct snd_soc_dai *dai, int mute, int stream)
+{
+	struct wm8524_priv *wm8524 = snd_soc_codec_get_drvdata(dai->codec);
+
+	if (wm8524->mute)
+		gpiod_set_value_cansleep(wm8524->mute, mute);
+
+	return 0;
+}
+
+#define WM8524_RATES SNDRV_PCM_RATE_8000_192000
+
+#define WM8524_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_S24_LE)
+
+static const struct snd_soc_dai_ops wm8524_dai_ops = {
+	.startup	= wm8524_startup,
+	.shutdown	= wm8524_shutdown,
+	.set_sysclk	= wm8524_set_dai_sysclk,
+	.set_fmt	= wm8524_set_fmt,
+	.mute_stream	= wm8524_mute_stream,
+};
+
+static struct snd_soc_dai_driver wm8524_dai = {
+	.name = "wm8524-hifi",
+	.playback = {
+		.stream_name = "Playback",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = WM8524_RATES,
+		.formats = WM8524_FORMATS,
+	},
+	.ops = &wm8524_dai_ops,
+};
+
+static int wm8524_probe(struct snd_soc_codec *codec)
+{
+	struct wm8524_priv *wm8524 = snd_soc_codec_get_drvdata(codec);
+
+	wm8524->rate_constraint.list = &wm8524->rate_constraint_list[0];
+	wm8524->rate_constraint.count =
+		ARRAY_SIZE(wm8524->rate_constraint_list);
+
+	return 0;
+}
+
+static const struct snd_soc_codec_driver soc_codec_dev_wm8524 = {
+	.probe =	wm8524_probe,
+
+	.component_driver = {
+		.dapm_widgets		= wm8524_dapm_widgets,
+		.num_dapm_widgets	= ARRAY_SIZE(wm8524_dapm_widgets),
+		.dapm_routes		= wm8524_dapm_routes,
+		.num_dapm_routes	= ARRAY_SIZE(wm8524_dapm_routes),
+	},
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id wm8524_of_match[] = {
+	{ .compatible = "wlf,wm8524" },
+	{ /* sentinel*/ }
+};
+MODULE_DEVICE_TABLE(of, wm8524_of_match);
+#endif
+
+static int wm8524_codec_probe(struct platform_device *pdev)
+{
+	struct wm8524_priv *wm8524;
+	int ret;
+
+	wm8524 = devm_kzalloc(&pdev->dev, sizeof(struct wm8524_priv),
+						  GFP_KERNEL);
+	if (wm8524 == NULL)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, wm8524);
+
+	wm8524->mute = devm_gpiod_get(&pdev->dev, "wlf,mute", GPIOD_OUT_LOW);
+	if (IS_ERR(wm8524->mute)) {
+		ret = PTR_ERR(wm8524->mute);
+		dev_err(&pdev->dev, "Failed to get mute line: %d\n", ret);
+		return ret;
+	}
+
+	ret =  snd_soc_register_codec(&pdev->dev,
+			&soc_codec_dev_wm8524, &wm8524_dai, 1);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "Failed to register codec: %d\n", ret);
+		snd_soc_unregister_platform(&pdev->dev);
+	}
+
+	return ret;
+}
+
+static int wm8524_codec_remove(struct platform_device *pdev)
+{
+	snd_soc_unregister_codec(&pdev->dev);
+	return 0;
+}
+
+static struct platform_driver wm8524_codec_driver = {
+	.probe		= wm8524_codec_probe,
+	.remove		= wm8524_codec_remove,
+	.driver		= {
+		.name	= "wm8524-codec",
+		.of_match_table = wm8524_of_match,
+	},
+};
+module_platform_driver(wm8524_codec_driver);
+
+MODULE_DESCRIPTION("ASoC WM8524 driver");
+MODULE_AUTHOR("Mihai Serban <mihai.serban@nxp.com>");
+MODULE_ALIAS("platform:wm8524-codec");
+MODULE_LICENSE("GPL");