ASoC: meson: add axg spdif input

Add support for the spdif input decoder of the axg SoC family

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

3 files changed, 531 insertions, 1 deletions

diff --git a/sound/soc/meson/Kconfig b/sound/soc/meson/Kconfig
index 8b8426ed2363..8779fe23671d 100644
--- a/sound/soc/meson/Kconfig
+++ b/sound/soc/meson/Kconfig
@@ -54,6 +54,7 @@ config SND_MESON_AXG_SOUND_CARD
 	imply SND_MESON_AXG_TDMIN
 	imply SND_MESON_AXG_TDMOUT
 	imply SND_MESON_AXG_SPDIFOUT
+	imply SND_MESON_AXG_SPDIFIN
 	imply SND_MESON_AXG_PDM
 	help
 	  Select Y or M to add support for the AXG SoC sound card
@@ -67,6 +68,13 @@ config SND_MESON_AXG_SPDIFOUT
 	  Select Y or M to add support for SPDIF output serializer embedded
 	  in the Amlogic AXG SoC family
 
+config SND_MESON_AXG_SPDIFIN
+	tristate "Amlogic AXG SPDIF Input Support"
+	imply SND_SOC_SPDIF
+	help
+	  Select Y or M to add support for SPDIF input embedded
+	  in the Amlogic AXG SoC family
+
 config SND_MESON_AXG_PDM
 	tristate "Amlogic AXG PDM Input Support"
 	imply SND_SOC_DMIC
@@ -74,5 +82,4 @@ config SND_MESON_AXG_PDM
 	help
 	  Select Y or M to add support for PDM input embedded
 	  in the Amlogic AXG SoC family
-
 endmenu
diff --git a/sound/soc/meson/Makefile b/sound/soc/meson/Makefile
index 4cd25104029d..b45dfb9e2f88 100644
--- a/sound/soc/meson/Makefile
+++ b/sound/soc/meson/Makefile
@@ -8,6 +8,7 @@ snd-soc-meson-axg-tdm-interface-objs := axg-tdm-interface.o
 snd-soc-meson-axg-tdmin-objs := axg-tdmin.o
 snd-soc-meson-axg-tdmout-objs := axg-tdmout.o
 snd-soc-meson-axg-sound-card-objs := axg-card.o
+snd-soc-meson-axg-spdifin-objs := axg-spdifin.o
 snd-soc-meson-axg-spdifout-objs := axg-spdifout.o
 snd-soc-meson-axg-pdm-objs := axg-pdm.o
 
@@ -19,5 +20,6 @@ obj-$(CONFIG_SND_MESON_AXG_TDM_INTERFACE) += snd-soc-meson-axg-tdm-interface.o
 obj-$(CONFIG_SND_MESON_AXG_TDMIN) += snd-soc-meson-axg-tdmin.o
 obj-$(CONFIG_SND_MESON_AXG_TDMOUT) += snd-soc-meson-axg-tdmout.o
 obj-$(CONFIG_SND_MESON_AXG_SOUND_CARD) += snd-soc-meson-axg-sound-card.o
+obj-$(CONFIG_SND_MESON_AXG_SPDIFIN) += snd-soc-meson-axg-spdifin.o
 obj-$(CONFIG_SND_MESON_AXG_SPDIFOUT) += snd-soc-meson-axg-spdifout.o
 obj-$(CONFIG_SND_MESON_AXG_PDM) += snd-soc-meson-axg-pdm.o
diff --git a/sound/soc/meson/axg-spdifin.c b/sound/soc/meson/axg-spdifin.c
new file mode 100644
index 000000000000..09f385a2bbba
--- /dev/null
+++ b/sound/soc/meson/axg-spdifin.c
@@ -0,0 +1,521 @@
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+//
+// Copyright (c) 2018 BayLibre, SAS.
+// Author: Jerome Brunet <jbrunet@baylibre.com>
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/regmap.h>
+#include <sound/soc.h>
+#include <sound/soc-dai.h>
+#include <sound/pcm_params.h>
+
+#define SPDIFIN_CTRL0			0x00
+#define  SPDIFIN_CTRL0_EN		BIT(31)
+#define  SPDIFIN_CTRL0_RST_OUT		BIT(29)
+#define  SPDIFIN_CTRL0_RST_IN		BIT(28)
+#define  SPDIFIN_CTRL0_WIDTH_SEL	BIT(24)
+#define  SPDIFIN_CTRL0_STATUS_CH_SHIFT	11
+#define  SPDIFIN_CTRL0_STATUS_SEL	GENMASK(10, 8)
+#define  SPDIFIN_CTRL0_SRC_SEL		GENMASK(5, 4)
+#define  SPDIFIN_CTRL0_CHK_VALID	BIT(3)
+#define SPDIFIN_CTRL1			0x04
+#define  SPDIFIN_CTRL1_BASE_TIMER	GENMASK(19, 0)
+#define  SPDIFIN_CTRL1_IRQ_MASK		GENMASK(27, 20)
+#define SPDIFIN_CTRL2			0x08
+#define  SPDIFIN_THRES_PER_REG		3
+#define  SPDIFIN_THRES_WIDTH		10
+#define SPDIFIN_CTRL3			0x0c
+#define SPDIFIN_CTRL4			0x10
+#define  SPDIFIN_TIMER_PER_REG		4
+#define  SPDIFIN_TIMER_WIDTH		8
+#define SPDIFIN_CTRL5			0x14
+#define SPDIFIN_CTRL6			0x18
+#define SPDIFIN_STAT0			0x1c
+#define  SPDIFIN_STAT0_MODE		GENMASK(30, 28)
+#define  SPDIFIN_STAT0_MAXW		GENMASK(17, 8)
+#define  SPDIFIN_STAT0_IRQ		GENMASK(7, 0)
+#define  SPDIFIN_IRQ_MODE_CHANGED	BIT(2)
+#define SPDIFIN_STAT1			0x20
+#define SPDIFIN_STAT2			0x24
+#define SPDIFIN_MUTE_VAL		0x28
+
+#define SPDIFIN_MODE_NUM		7
+
+struct axg_spdifin_cfg {
+	const unsigned int *mode_rates;
+	unsigned int ref_rate;
+};
+
+struct axg_spdifin {
+	const struct axg_spdifin_cfg *conf;
+	struct regmap *map;
+	struct clk *refclk;
+	struct clk *pclk;
+};
+
+/*
+ * TODO:
+ * It would have been nice to check the actual rate against the sample rate
+ * requested in hw_params(). Unfortunately, I was not able to make the mode
+ * detection and IRQ work reliably:
+ *
+ * 1. IRQs are generated on mode change only, so there is no notification
+ *    on transition between no signal and mode 0 (32kHz).
+ * 2. Mode detection very often has glitches, and may detects the
+ *    lowest or the highest mode before zeroing in on the actual mode.
+ *
+ * This makes calling snd_pcm_stop() difficult to get right. Even notifying
+ * the kcontrol would be very unreliable at this point.
+ * Let's keep things simple until the magic spell that makes this work is
+ * found.
+ */
+
+static unsigned int axg_spdifin_get_rate(struct axg_spdifin *priv)
+{
+	unsigned int stat, mode, rate = 0;
+
+	regmap_read(priv->map, SPDIFIN_STAT0, &stat);
+	mode = FIELD_GET(SPDIFIN_STAT0_MODE, stat);
+
+	/*
+	 * If max width is zero, we are not capturing anything.
+	 * Also Sometimes, when the capture is on but there is no data,
+	 * mode is SPDIFIN_MODE_NUM, but not always ...
+	 */
+	if (FIELD_GET(SPDIFIN_STAT0_MAXW, stat) &&
+	    mode < SPDIFIN_MODE_NUM)
+		rate = priv->conf->mode_rates[mode];
+
+	return rate;
+}
+
+static int axg_spdifin_prepare(struct snd_pcm_substream *substream,
+			       struct snd_soc_dai *dai)
+{
+	struct axg_spdifin *priv = snd_soc_dai_get_drvdata(dai);
+
+	/* Apply both reset */
+	regmap_update_bits(priv->map, SPDIFIN_CTRL0,
+			   SPDIFIN_CTRL0_RST_OUT |
+			   SPDIFIN_CTRL0_RST_IN,
+			   0);
+
+	/* Clear out reset before in reset */
+	regmap_update_bits(priv->map, SPDIFIN_CTRL0,
+			   SPDIFIN_CTRL0_RST_OUT, SPDIFIN_CTRL0_RST_OUT);
+	regmap_update_bits(priv->map, SPDIFIN_CTRL0,
+			   SPDIFIN_CTRL0_RST_IN,  SPDIFIN_CTRL0_RST_IN);
+
+	return 0;
+}
+
+static int axg_spdifin_startup(struct snd_pcm_substream *substream,
+			       struct snd_soc_dai *dai)
+{
+	struct axg_spdifin *priv = snd_soc_dai_get_drvdata(dai);
+	int ret;
+
+	ret = clk_prepare_enable(priv->refclk);
+	if (ret) {
+		dev_err(dai->dev,
+			"failed to enable spdifin reference clock\n");
+		return ret;
+	}
+
+	regmap_update_bits(priv->map, SPDIFIN_CTRL0, SPDIFIN_CTRL0_EN,
+			   SPDIFIN_CTRL0_EN);
+
+	return 0;
+}
+
+static void axg_spdifin_shutdown(struct snd_pcm_substream *substream,
+				 struct snd_soc_dai *dai)
+{
+	struct axg_spdifin *priv = snd_soc_dai_get_drvdata(dai);
+
+	regmap_update_bits(priv->map, SPDIFIN_CTRL0, SPDIFIN_CTRL0_EN, 0);
+	clk_disable_unprepare(priv->refclk);
+}
+
+static void axg_spdifin_write_mode_param(struct regmap *map, int mode,
+					 unsigned int val,
+					 unsigned int num_per_reg,
+					 unsigned int base_reg,
+					 unsigned int width)
+{
+	unsigned int offset = mode, rem;
+	unsigned int reg, shift;
+
+	rem = do_div(offset, num_per_reg);
+
+	reg = offset * regmap_get_reg_stride(map) + base_reg;
+	shift = width * (num_per_reg - 1 - rem);
+
+	regmap_update_bits(map, reg, GENMASK(width - 1, 0) << shift,
+			   val << shift);
+}
+
+static void axg_spdifin_write_timer(struct regmap *map, int mode,
+				    unsigned int val)
+{
+	axg_spdifin_write_mode_param(map, mode, val, SPDIFIN_TIMER_PER_REG,
+				     SPDIFIN_CTRL4, SPDIFIN_TIMER_WIDTH);
+}
+
+static void axg_spdifin_write_threshold(struct regmap *map, int mode,
+					unsigned int val)
+{
+	axg_spdifin_write_mode_param(map, mode, val, SPDIFIN_THRES_PER_REG,
+				     SPDIFIN_CTRL2, SPDIFIN_THRES_WIDTH);
+}
+
+static unsigned int axg_spdifin_mode_timer(struct axg_spdifin *priv,
+					   int mode,
+					   unsigned int rate)
+{
+	/*
+	 * Number of period of the reference clock during a period of the
+	 * input signal reference clock
+	 */
+	return rate / (128 * priv->conf->mode_rates[mode]);
+}
+
+static int axg_spdifin_sample_mode_config(struct snd_soc_dai *dai,
+					  struct axg_spdifin *priv)
+{
+	unsigned int rate, t_next;
+	int ret, i = SPDIFIN_MODE_NUM - 1;
+
+	/* Set spdif input reference clock */
+	ret = clk_set_rate(priv->refclk, priv->conf->ref_rate);
+	if (ret) {
+		dev_err(dai->dev, "reference clock rate set failed\n");
+		return ret;
+	}
+
+	/*
+	 * The rate actually set might be slightly different, get
+	 * the actual rate for the following mode calculation
+	 */
+	rate = clk_get_rate(priv->refclk);
+
+	/* HW will update mode every 1ms */
+	regmap_update_bits(priv->map, SPDIFIN_CTRL1,
+			   SPDIFIN_CTRL1_BASE_TIMER,
+			   FIELD_PREP(SPDIFIN_CTRL1_BASE_TIMER, rate / 1000));
+
+	/* Threshold based on the minimum width between two edges */
+	regmap_update_bits(priv->map, SPDIFIN_CTRL0,
+			   SPDIFIN_CTRL0_WIDTH_SEL, SPDIFIN_CTRL0_WIDTH_SEL);
+
+	/* Calculate the last timer which has no threshold */
+	t_next = axg_spdifin_mode_timer(priv, i, rate);
+	axg_spdifin_write_timer(priv->map, i, t_next);
+
+	do {
+		unsigned int t;
+
+		i -= 1;
+
+		/* Calculate the timer */
+		t = axg_spdifin_mode_timer(priv, i, rate);
+
+		/* Set the timer value */
+		axg_spdifin_write_timer(priv->map, i, t);
+
+		/* Set the threshold value */
+		axg_spdifin_write_threshold(priv->map, i, t + t_next);
+
+		/* Save the current timer for the next threshold calculation */
+		t_next = t;
+
+	} while (i > 0);
+
+	return 0;
+}
+
+static int axg_spdifin_dai_probe(struct snd_soc_dai *dai)
+{
+	struct axg_spdifin *priv = snd_soc_dai_get_drvdata(dai);
+	int ret;
+
+	ret = clk_prepare_enable(priv->pclk);
+	if (ret) {
+		dev_err(dai->dev, "failed to enable pclk\n");
+		return ret;
+	}
+
+	ret = axg_spdifin_sample_mode_config(dai, priv);
+	if (ret) {
+		dev_err(dai->dev, "mode configuration failed\n");
+		clk_disable_unprepare(priv->pclk);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int axg_spdifin_dai_remove(struct snd_soc_dai *dai)
+{
+	struct axg_spdifin *priv = snd_soc_dai_get_drvdata(dai);
+
+	clk_disable_unprepare(priv->pclk);
+	return 0;
+}
+
+static const struct snd_soc_dai_ops axg_spdifin_ops = {
+	.prepare	= axg_spdifin_prepare,
+	.startup	= axg_spdifin_startup,
+	.shutdown	= axg_spdifin_shutdown,
+};
+
+static int axg_spdifin_iec958_info(struct snd_kcontrol *kcontrol,
+				   struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_IEC958;
+	uinfo->count = 1;
+
+	return 0;
+}
+
+static int axg_spdifin_get_status_mask(struct snd_kcontrol *kcontrol,
+				       struct snd_ctl_elem_value *ucontrol)
+{
+	int i;
+
+	for (i = 0; i < 24; i++)
+		ucontrol->value.iec958.status[i] = 0xff;
+
+	return 0;
+}
+
+static int axg_spdifin_get_status(struct snd_kcontrol *kcontrol,
+				  struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *c = snd_kcontrol_chip(kcontrol);
+	struct axg_spdifin *priv = snd_soc_component_get_drvdata(c);
+	int i, j;
+
+	for (i = 0; i < 6; i++) {
+		unsigned int val;
+
+		regmap_update_bits(priv->map, SPDIFIN_CTRL0,
+				   SPDIFIN_CTRL0_STATUS_SEL,
+				   FIELD_PREP(SPDIFIN_CTRL0_STATUS_SEL, i));
+
+		regmap_read(priv->map, SPDIFIN_STAT1, &val);
+
+		for (j = 0; j < 4; j++) {
+			unsigned int offset = i * 4 + j;
+
+			ucontrol->value.iec958.status[offset] =
+				(val >> (j * 8)) & 0xff;
+		}
+	}
+
+	return 0;
+}
+
+#define AXG_SPDIFIN_IEC958_MASK						\
+	{								\
+		.access = SNDRV_CTL_ELEM_ACCESS_READ,			\
+		.iface = SNDRV_CTL_ELEM_IFACE_PCM,			\
+		.name = SNDRV_CTL_NAME_IEC958("", CAPTURE, MASK),	\
+		.info = axg_spdifin_iec958_info,			\
+		.get = axg_spdifin_get_status_mask,			\
+	}
+
+#define AXG_SPDIFIN_IEC958_STATUS					\
+	{								\
+		.access = (SNDRV_CTL_ELEM_ACCESS_READ |			\
+			   SNDRV_CTL_ELEM_ACCESS_VOLATILE),		\
+		.iface = SNDRV_CTL_ELEM_IFACE_PCM,			\
+		.name =	SNDRV_CTL_NAME_IEC958("", CAPTURE, NONE),	\
+		.info = axg_spdifin_iec958_info,			\
+		.get = axg_spdifin_get_status,				\
+	}
+
+static const char * const spdifin_chsts_src_texts[] = {
+	"A", "B",
+};
+
+static SOC_ENUM_SINGLE_DECL(axg_spdifin_chsts_src_enum, SPDIFIN_CTRL0,
+			    SPDIFIN_CTRL0_STATUS_CH_SHIFT,
+			    spdifin_chsts_src_texts);
+
+static int axg_spdifin_rate_lock_info(struct snd_kcontrol *kcontrol,
+				      struct snd_ctl_elem_info *uinfo)
+{
+	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
+	uinfo->count = 1;
+	uinfo->value.integer.min = 0;
+	uinfo->value.integer.max = 192000;
+
+	return 0;
+}
+
+static int axg_spdifin_rate_lock_get(struct snd_kcontrol *kcontrol,
+				     struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *c = snd_kcontrol_chip(kcontrol);
+	struct axg_spdifin *priv = snd_soc_component_get_drvdata(c);
+
+	ucontrol->value.integer.value[0] = axg_spdifin_get_rate(priv);
+
+	return 0;
+}
+
+#define AXG_SPDIFIN_LOCK_RATE(xname)				\
+	{							\
+		.iface = SNDRV_CTL_ELEM_IFACE_PCM,		\
+		.access = (SNDRV_CTL_ELEM_ACCESS_READ |		\
+			   SNDRV_CTL_ELEM_ACCESS_VOLATILE),	\
+		.get = axg_spdifin_rate_lock_get,		\
+		.info = axg_spdifin_rate_lock_info,		\
+		.name = xname,					\
+	}
+
+static const struct snd_kcontrol_new axg_spdifin_controls[] = {
+	AXG_SPDIFIN_LOCK_RATE("Capture Rate Lock"),
+	SOC_DOUBLE("Capture Switch", SPDIFIN_CTRL0, 7, 6, 1, 1),
+	SOC_ENUM(SNDRV_CTL_NAME_IEC958("", CAPTURE, NONE) "Src",
+		 axg_spdifin_chsts_src_enum),
+	AXG_SPDIFIN_IEC958_MASK,
+	AXG_SPDIFIN_IEC958_STATUS,
+};
+
+static const struct snd_soc_component_driver axg_spdifin_component_drv = {
+	.controls		= axg_spdifin_controls,
+	.num_controls		= ARRAY_SIZE(axg_spdifin_controls),
+};
+
+static const struct regmap_config axg_spdifin_regmap_cfg = {
+	.reg_bits	= 32,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+	.max_register	= SPDIFIN_MUTE_VAL,
+};
+
+static const unsigned int axg_spdifin_mode_rates[SPDIFIN_MODE_NUM] = {
+	32000, 44100, 48000, 88200, 96000, 176400, 192000,
+};
+
+static const struct axg_spdifin_cfg axg_cfg = {
+	.mode_rates = axg_spdifin_mode_rates,
+	.ref_rate = 333333333,
+};
+
+static const struct of_device_id axg_spdifin_of_match[] = {
+	{
+		.compatible = "amlogic,axg-spdifin",
+		.data = &axg_cfg,
+	}, {}
+};
+MODULE_DEVICE_TABLE(of, axg_spdifin_of_match);
+
+static struct snd_soc_dai_driver *
+axg_spdifin_get_dai_drv(struct device *dev, struct axg_spdifin *priv)
+{
+	struct snd_soc_dai_driver *drv;
+	int i;
+
+	drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL);
+	if (!drv)
+		return ERR_PTR(-ENOMEM);
+
+	drv->name = "SPDIF Input";
+	drv->ops = &axg_spdifin_ops;
+	drv->probe = axg_spdifin_dai_probe;
+	drv->remove = axg_spdifin_dai_remove;
+	drv->capture.stream_name = "Capture";
+	drv->capture.channels_min = 1;
+	drv->capture.channels_max = 2;
+	drv->capture.formats = SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_LE;
+
+	for (i = 0; i < SPDIFIN_MODE_NUM; i++) {
+		unsigned int rb =
+			snd_pcm_rate_to_rate_bit(priv->conf->mode_rates[i]);
+
+		if (rb == SNDRV_PCM_RATE_KNOT)
+			return ERR_PTR(-EINVAL);
+
+		drv->capture.rates |= rb;
+	}
+
+	return drv;
+}
+
+static int axg_spdifin_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct axg_spdifin *priv;
+	struct snd_soc_dai_driver *dai_drv;
+	struct resource *res;
+	void __iomem *regs;
+	int ret;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, priv);
+
+	priv->conf = of_device_get_match_data(dev);
+	if (!priv->conf) {
+		dev_err(dev, "failed to match device\n");
+		return -ENODEV;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	priv->map = devm_regmap_init_mmio(dev, regs, &axg_spdifin_regmap_cfg);
+	if (IS_ERR(priv->map)) {
+		dev_err(dev, "failed to init regmap: %ld\n",
+			PTR_ERR(priv->map));
+		return PTR_ERR(priv->map);
+	}
+
+	priv->pclk = devm_clk_get(dev, "pclk");
+	if (IS_ERR(priv->pclk)) {
+		ret = PTR_ERR(priv->pclk);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "failed to get pclk: %d\n", ret);
+		return ret;
+	}
+
+	priv->refclk = devm_clk_get(dev, "refclk");
+	if (IS_ERR(priv->refclk)) {
+		ret = PTR_ERR(priv->refclk);
+		if (ret != -EPROBE_DEFER)
+			dev_err(dev, "failed to get mclk: %d\n", ret);
+		return ret;
+	}
+
+	dai_drv = axg_spdifin_get_dai_drv(dev, priv);
+	if (IS_ERR(dai_drv)) {
+		dev_err(dev, "failed to get dai driver: %ld\n",
+			PTR_ERR(dai_drv));
+		return PTR_ERR(dai_drv);
+	}
+
+	return devm_snd_soc_register_component(dev, &axg_spdifin_component_drv,
+					       dai_drv, 1);
+}
+
+static struct platform_driver axg_spdifin_pdrv = {
+	.probe = axg_spdifin_probe,
+	.driver = {
+		.name = "axg-spdifin",
+		.of_match_table = axg_spdifin_of_match,
+	},
+};
+module_platform_driver(axg_spdifin_pdrv);
+
+MODULE_DESCRIPTION("Amlogic AXG SPDIF Input driver");
+MODULE_AUTHOR("Jerome Brunet <jbrunet@baylibre.com>");
+MODULE_LICENSE("GPL v2");