ASoC: tegra: Add Tegra186 based DSPK driver

The Digital Speaker Controller (DSPK) converts the multi-bit Pulse Code
Modulation (PCM) audio input to oversampled 1-bit Pulse Density Modulation
(PDM) output. From the signal flow perpsective, the DSPK can be viewed as
a PDM transmitter that up-samples the input to the desired sampling rate
by interpolation then converts the oversampled PCM input to the desired
1-bit output via Delta Sigma Modulation (DSM).

This patch registers DSPK component with ASoC framework. The component
driver exposes DAPM widgets, routes and kcontrols for the device. The DAI
driver exposes DSPK interfaces, which can be used to connect different
components in the ASoC layer. Makefile and Kconfig support is added to
allow to build the driver. The DSPK devices can be enabled in the DT via
"nvidia,tegra186-dspk" compatible binding. This driver can be used
on Tegra194 chip as well.

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Link: https://lore.kernel.org/r/1595134890-16470-7-git-send-email-spujar@nvidia.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 442 insertions, 0 deletions

diff --git a/sound/soc/tegra/tegra186_dspk.c b/sound/soc/tegra/tegra186_dspk.c
new file mode 100644
index 000000000000..fe7117171a0e
--- /dev/null
+++ b/sound/soc/tegra/tegra186_dspk.c
@@ -0,0 +1,442 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// tegra186_dspk.c - Tegra186 DSPK driver
+//
+// Copyright (c) 2020 NVIDIA CORPORATION. All rights reserved.
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <sound/core.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include "tegra186_dspk.h"
+#include "tegra_cif.h"
+
+static const struct reg_default tegra186_dspk_reg_defaults[] = {
+	{ TEGRA186_DSPK_RX_INT_MASK, 0x00000007 },
+	{ TEGRA186_DSPK_RX_CIF_CTRL, 0x00007700 },
+	{ TEGRA186_DSPK_CG,	     0x00000001 },
+	{ TEGRA186_DSPK_CORE_CTRL,   0x00000310 },
+	{ TEGRA186_DSPK_CODEC_CTRL,  0x03000000 },
+};
+
+static int tegra186_dspk_get_control(struct snd_kcontrol *kcontrol,
+				     struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *codec = snd_soc_kcontrol_component(kcontrol);
+	struct tegra186_dspk *dspk = snd_soc_component_get_drvdata(codec);
+
+	if (strstr(kcontrol->id.name, "FIFO Threshold"))
+		ucontrol->value.integer.value[0] = dspk->rx_fifo_th;
+	else if (strstr(kcontrol->id.name, "OSR Value"))
+		ucontrol->value.integer.value[0] = dspk->osr_val;
+	else if (strstr(kcontrol->id.name, "LR Polarity Select"))
+		ucontrol->value.integer.value[0] = dspk->lrsel;
+	else if (strstr(kcontrol->id.name, "Channel Select"))
+		ucontrol->value.integer.value[0] = dspk->ch_sel;
+	else if (strstr(kcontrol->id.name, "Mono To Stereo"))
+		ucontrol->value.integer.value[0] = dspk->mono_to_stereo;
+	else if (strstr(kcontrol->id.name, "Stereo To Mono"))
+		ucontrol->value.integer.value[0] = dspk->stereo_to_mono;
+
+	return 0;
+}
+
+static int tegra186_dspk_put_control(struct snd_kcontrol *kcontrol,
+				     struct snd_ctl_elem_value *ucontrol)
+{
+	struct snd_soc_component *codec = snd_soc_kcontrol_component(kcontrol);
+	struct tegra186_dspk *dspk = snd_soc_component_get_drvdata(codec);
+	int val = ucontrol->value.integer.value[0];
+
+	if (strstr(kcontrol->id.name, "FIFO Threshold"))
+		dspk->rx_fifo_th = val;
+	else if (strstr(kcontrol->id.name, "OSR Value"))
+		dspk->osr_val = val;
+	else if (strstr(kcontrol->id.name, "LR Polarity Select"))
+		dspk->lrsel = val;
+	else if (strstr(kcontrol->id.name, "Channel Select"))
+		dspk->ch_sel = val;
+	else if (strstr(kcontrol->id.name, "Mono To Stereo"))
+		dspk->mono_to_stereo = val;
+	else if (strstr(kcontrol->id.name, "Stereo To Mono"))
+		dspk->stereo_to_mono = val;
+
+	return 0;
+}
+
+static int tegra186_dspk_runtime_suspend(struct device *dev)
+{
+	struct tegra186_dspk *dspk = dev_get_drvdata(dev);
+
+	regcache_cache_only(dspk->regmap, true);
+	regcache_mark_dirty(dspk->regmap);
+
+	clk_disable_unprepare(dspk->clk_dspk);
+
+	return 0;
+}
+
+static int tegra186_dspk_runtime_resume(struct device *dev)
+{
+	struct tegra186_dspk *dspk = dev_get_drvdata(dev);
+	int err;
+
+	err = clk_prepare_enable(dspk->clk_dspk);
+	if (err) {
+		dev_err(dev, "failed to enable DSPK clock, err: %d\n", err);
+		return err;
+	}
+
+	regcache_cache_only(dspk->regmap, false);
+	regcache_sync(dspk->regmap);
+
+	return 0;
+}
+
+static int tegra186_dspk_hw_params(struct snd_pcm_substream *substream,
+				   struct snd_pcm_hw_params *params,
+				   struct snd_soc_dai *dai)
+{
+	struct tegra186_dspk *dspk = snd_soc_dai_get_drvdata(dai);
+	unsigned int channels, srate, dspk_clk;
+	struct device *dev = dai->dev;
+	struct tegra_cif_conf cif_conf;
+	unsigned int max_th;
+	int err;
+
+	memset(&cif_conf, 0, sizeof(struct tegra_cif_conf));
+
+	channels = params_channels(params);
+	cif_conf.audio_ch = channels;
+
+	/* Client channel */
+	switch (dspk->ch_sel) {
+	case DSPK_CH_SELECT_LEFT:
+	case DSPK_CH_SELECT_RIGHT:
+		cif_conf.client_ch = 1;
+		break;
+	case DSPK_CH_SELECT_STEREO:
+		cif_conf.client_ch = 2;
+		break;
+	default:
+		dev_err(dev, "Invalid DSPK client channels\n");
+		return -EINVAL;
+	}
+
+	cif_conf.client_bits = TEGRA_ACIF_BITS_24;
+
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_S16_LE:
+		cif_conf.audio_bits = TEGRA_ACIF_BITS_16;
+		break;
+	case SNDRV_PCM_FORMAT_S32_LE:
+		cif_conf.audio_bits = TEGRA_ACIF_BITS_32;
+		break;
+	default:
+		dev_err(dev, "unsupported format!\n");
+		return -EOPNOTSUPP;
+	}
+
+	srate = params_rate(params);
+
+	/* RX FIFO threshold in terms of frames */
+	max_th = (TEGRA186_DSPK_RX_FIFO_DEPTH / cif_conf.audio_ch) - 1;
+
+	if (dspk->rx_fifo_th > max_th)
+		dspk->rx_fifo_th = max_th;
+
+	cif_conf.threshold = dspk->rx_fifo_th;
+	cif_conf.mono_conv = dspk->mono_to_stereo;
+	cif_conf.stereo_conv = dspk->stereo_to_mono;
+
+	tegra_set_cif(dspk->regmap, TEGRA186_DSPK_RX_CIF_CTRL,
+		      &cif_conf);
+
+	/*
+	 * DSPK clock and PDM codec clock should be synchronous with 4:1 ratio,
+	 * this is because it takes 4 clock cycles to send out one sample to
+	 * codec by sigma delta modulator. Finally the clock rate is a multiple
+	 * of 'Over Sampling Ratio', 'Sample Rate' and 'Interface Clock Ratio'.
+	 */
+	dspk_clk = (DSPK_OSR_FACTOR << dspk->osr_val) * srate * DSPK_CLK_RATIO;
+
+	err = clk_set_rate(dspk->clk_dspk, dspk_clk);
+	if (err) {
+		dev_err(dev, "can't set DSPK clock rate %u, err: %d\n",
+			dspk_clk, err);
+
+		return err;
+	}
+
+	regmap_update_bits(dspk->regmap,
+			   /* Reg */
+			   TEGRA186_DSPK_CORE_CTRL,
+			   /* Mask */
+			   TEGRA186_DSPK_OSR_MASK |
+			   TEGRA186_DSPK_CHANNEL_SELECT_MASK |
+			   TEGRA186_DSPK_CTRL_LRSEL_POLARITY_MASK,
+			   /* Value */
+			   (dspk->osr_val << DSPK_OSR_SHIFT) |
+			   ((dspk->ch_sel + 1) << CH_SEL_SHIFT) |
+			   (dspk->lrsel << LRSEL_POL_SHIFT));
+
+	return 0;
+}
+
+static const struct snd_soc_dai_ops tegra186_dspk_dai_ops = {
+	.hw_params	= tegra186_dspk_hw_params,
+};
+
+static struct snd_soc_dai_driver tegra186_dspk_dais[] = {
+	{
+	    .name = "DSPK-CIF",
+	    .playback = {
+		.stream_name = "CIF-Playback",
+		.channels_min = 1,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_8000_48000,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE |
+			   SNDRV_PCM_FMTBIT_S32_LE,
+	    },
+	},
+	{
+	    .name = "DSPK-DAP",
+	    .playback = {
+		.stream_name = "DAP-Playback",
+		.channels_min = 1,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_8000_48000,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE |
+			   SNDRV_PCM_FMTBIT_S32_LE,
+	    },
+	    .ops = &tegra186_dspk_dai_ops,
+	    .symmetric_rates = 1,
+	},
+};
+
+static const struct snd_soc_dapm_widget tegra186_dspk_widgets[] = {
+	SND_SOC_DAPM_AIF_IN("RX", NULL, 0, TEGRA186_DSPK_ENABLE, 0, 0),
+	SND_SOC_DAPM_SPK("SPK", NULL),
+};
+
+static const struct snd_soc_dapm_route tegra186_dspk_routes[] = {
+	{ "XBAR-Playback",	NULL,	"XBAR-TX" },
+	{ "CIF-Playback",	NULL,	"XBAR-Playback" },
+	{ "RX",			NULL,	"CIF-Playback" },
+	{ "DAP-Playback",	NULL,	"RX" },
+	{ "SPK",		NULL,	"DAP-Playback" },
+};
+
+static const char * const tegra186_dspk_ch_sel_text[] = {
+	"Left", "Right", "Stereo",
+};
+
+static const struct soc_enum tegra186_dspk_ch_sel_enum =
+	SOC_ENUM_SINGLE(SND_SOC_NOPM, 0, ARRAY_SIZE(tegra186_dspk_ch_sel_text),
+			tegra186_dspk_ch_sel_text);
+
+static const char * const tegra186_dspk_osr_text[] = {
+	"OSR_32", "OSR_64", "OSR_128", "OSR_256",
+};
+
+static const struct soc_enum tegra186_dspk_osr_enum =
+	SOC_ENUM_SINGLE(SND_SOC_NOPM, 0, ARRAY_SIZE(tegra186_dspk_osr_text),
+			tegra186_dspk_osr_text);
+
+static const char * const tegra186_dspk_lrsel_text[] = {
+	"Left", "Right",
+};
+
+static const char * const tegra186_dspk_mono_conv_text[] = {
+	"Zero", "Copy",
+};
+
+static const struct soc_enum tegra186_dspk_mono_conv_enum =
+	SOC_ENUM_SINGLE(SND_SOC_NOPM, 0,
+			ARRAY_SIZE(tegra186_dspk_mono_conv_text),
+			tegra186_dspk_mono_conv_text);
+
+static const char * const tegra186_dspk_stereo_conv_text[] = {
+	"CH0", "CH1", "AVG",
+};
+
+static const struct soc_enum tegra186_dspk_stereo_conv_enum =
+	SOC_ENUM_SINGLE(SND_SOC_NOPM, 0,
+			ARRAY_SIZE(tegra186_dspk_stereo_conv_text),
+			tegra186_dspk_stereo_conv_text);
+
+static const struct soc_enum tegra186_dspk_lrsel_enum =
+	SOC_ENUM_SINGLE(SND_SOC_NOPM, 0, ARRAY_SIZE(tegra186_dspk_lrsel_text),
+			tegra186_dspk_lrsel_text);
+
+static const struct snd_kcontrol_new tegrat186_dspk_controls[] = {
+	SOC_SINGLE_EXT("FIFO Threshold", SND_SOC_NOPM, 0,
+		       TEGRA186_DSPK_RX_FIFO_DEPTH - 1, 0,
+		       tegra186_dspk_get_control, tegra186_dspk_put_control),
+	SOC_ENUM_EXT("OSR Value", tegra186_dspk_osr_enum,
+		     tegra186_dspk_get_control, tegra186_dspk_put_control),
+	SOC_ENUM_EXT("LR Polarity Select", tegra186_dspk_lrsel_enum,
+		     tegra186_dspk_get_control, tegra186_dspk_put_control),
+	SOC_ENUM_EXT("Channel Select", tegra186_dspk_ch_sel_enum,
+		     tegra186_dspk_get_control, tegra186_dspk_put_control),
+	SOC_ENUM_EXT("Mono To Stereo", tegra186_dspk_mono_conv_enum,
+		     tegra186_dspk_get_control, tegra186_dspk_put_control),
+	SOC_ENUM_EXT("Stereo To Mono", tegra186_dspk_stereo_conv_enum,
+		     tegra186_dspk_get_control, tegra186_dspk_put_control),
+};
+
+static const struct snd_soc_component_driver tegra186_dspk_cmpnt = {
+	.dapm_widgets = tegra186_dspk_widgets,
+	.num_dapm_widgets = ARRAY_SIZE(tegra186_dspk_widgets),
+	.dapm_routes = tegra186_dspk_routes,
+	.num_dapm_routes = ARRAY_SIZE(tegra186_dspk_routes),
+	.controls = tegrat186_dspk_controls,
+	.num_controls = ARRAY_SIZE(tegrat186_dspk_controls),
+};
+
+static bool tegra186_dspk_wr_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case TEGRA186_DSPK_RX_INT_MASK ... TEGRA186_DSPK_RX_CIF_CTRL:
+	case TEGRA186_DSPK_ENABLE ... TEGRA186_DSPK_CG:
+	case TEGRA186_DSPK_CORE_CTRL ... TEGRA186_DSPK_CODEC_CTRL:
+		return true;
+	default:
+		return false;
+	};
+}
+
+static bool tegra186_dspk_rd_reg(struct device *dev, unsigned int reg)
+{
+	if (tegra186_dspk_wr_reg(dev, reg))
+		return true;
+
+	switch (reg) {
+	case TEGRA186_DSPK_RX_STATUS:
+	case TEGRA186_DSPK_RX_INT_STATUS:
+	case TEGRA186_DSPK_STATUS:
+	case TEGRA186_DSPK_INT_STATUS:
+		return true;
+	default:
+		return false;
+	};
+}
+
+static bool tegra186_dspk_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case TEGRA186_DSPK_RX_STATUS:
+	case TEGRA186_DSPK_RX_INT_STATUS:
+	case TEGRA186_DSPK_STATUS:
+	case TEGRA186_DSPK_INT_STATUS:
+		return true;
+	default:
+		return false;
+	};
+}
+
+static const struct regmap_config tegra186_dspk_regmap = {
+	.reg_bits		= 32,
+	.reg_stride		= 4,
+	.val_bits		= 32,
+	.max_register		= TEGRA186_DSPK_CODEC_CTRL,
+	.writeable_reg		= tegra186_dspk_wr_reg,
+	.readable_reg		= tegra186_dspk_rd_reg,
+	.volatile_reg		= tegra186_dspk_volatile_reg,
+	.reg_defaults		= tegra186_dspk_reg_defaults,
+	.num_reg_defaults	= ARRAY_SIZE(tegra186_dspk_reg_defaults),
+	.cache_type		= REGCACHE_FLAT,
+};
+
+static const struct of_device_id tegra186_dspk_of_match[] = {
+	{ .compatible = "nvidia,tegra186-dspk" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, tegra186_dspk_of_match);
+
+static int tegra186_dspk_platform_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct tegra186_dspk *dspk;
+	void __iomem *regs;
+	int err;
+
+	dspk = devm_kzalloc(dev, sizeof(*dspk), GFP_KERNEL);
+	if (!dspk)
+		return -ENOMEM;
+
+	dspk->osr_val = DSPK_OSR_64;
+	dspk->lrsel = DSPK_LRSEL_LEFT;
+	dspk->ch_sel = DSPK_CH_SELECT_STEREO;
+	dspk->mono_to_stereo = 0; /* "Zero" */
+
+	dev_set_drvdata(dev, dspk);
+
+	dspk->clk_dspk = devm_clk_get(dev, "dspk");
+	if (IS_ERR(dspk->clk_dspk)) {
+		dev_err(dev, "can't retrieve DSPK clock\n");
+		return PTR_ERR(dspk->clk_dspk);
+	}
+
+	regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	dspk->regmap = devm_regmap_init_mmio(dev, regs, &tegra186_dspk_regmap);
+	if (IS_ERR(dspk->regmap)) {
+		dev_err(dev, "regmap init failed\n");
+		return PTR_ERR(dspk->regmap);
+	}
+
+	regcache_cache_only(dspk->regmap, true);
+
+	err = devm_snd_soc_register_component(dev, &tegra186_dspk_cmpnt,
+					      tegra186_dspk_dais,
+					      ARRAY_SIZE(tegra186_dspk_dais));
+	if (err) {
+		dev_err(dev, "can't register DSPK component, err: %d\n",
+			err);
+		return err;
+	}
+
+	pm_runtime_enable(dev);
+
+	return 0;
+}
+
+static int tegra186_dspk_platform_remove(struct platform_device *pdev)
+{
+	pm_runtime_disable(&pdev->dev);
+
+	return 0;
+}
+
+static const struct dev_pm_ops tegra186_dspk_pm_ops = {
+	SET_RUNTIME_PM_OPS(tegra186_dspk_runtime_suspend,
+			   tegra186_dspk_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+};
+
+static struct platform_driver tegra186_dspk_driver = {
+	.driver = {
+		.name = "tegra186-dspk",
+		.of_match_table = tegra186_dspk_of_match,
+		.pm = &tegra186_dspk_pm_ops,
+	},
+	.probe = tegra186_dspk_platform_probe,
+	.remove = tegra186_dspk_platform_remove,
+};
+module_platform_driver(tegra186_dspk_driver);
+
+MODULE_AUTHOR("Mohan Kumar <mkumard@nvidia.com>");
+MODULE_AUTHOR("Sameer Pujar <spujar@nvidia.com>");
+MODULE_DESCRIPTION("Tegra186 ASoC DSPK driver");
+MODULE_LICENSE("GPL v2");