ASoC: meson: aiu: add i2s and spdif support

Add support for the i2s and spdif audio outputs (AIU) found in the
amlogic Gx SoC family

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20200213155159.3235792-5-jbrunet@baylibre.com
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/meson/Kconfig

@@ -2,6 +2,13 @@
 menu "ASoC support for Amlogic platforms"
 	depends on ARCH_MESON || COMPILE_TEST
 
+config SND_MESON_AIU
+	tristate "Amlogic AIU"
+	select SND_PCM_IEC958
+	help
+	  Select Y or M to add support for the Audio output subsystem found
+	  in the Amlogic GX SoC family
+
 config SND_MESON_AXG_FIFO
 	tristate
 	select REGMAP_MMIO

sound/soc/meson/Makefile

@@ -1,5 +1,11 @@
 # SPDX-License-Identifier: (GPL-2.0 OR MIT)
 
+snd-soc-meson-aiu-objs := aiu.o
+snd-soc-meson-aiu-objs += aiu-encoder-i2s.o
+snd-soc-meson-aiu-objs += aiu-encoder-spdif.o
+snd-soc-meson-aiu-objs += aiu-fifo.o
+snd-soc-meson-aiu-objs += aiu-fifo-i2s.o
+snd-soc-meson-aiu-objs += aiu-fifo-spdif.o
 snd-soc-meson-axg-fifo-objs := axg-fifo.o
 snd-soc-meson-axg-frddr-objs := axg-frddr.o
 snd-soc-meson-axg-toddr-objs := axg-toddr.o
@@ -14,6 +20,7 @@ snd-soc-meson-axg-pdm-objs := axg-pdm.o
 snd-soc-meson-codec-glue-objs := meson-codec-glue.o
 snd-soc-meson-g12a-tohdmitx-objs := g12a-tohdmitx.o
 
+obj-$(CONFIG_SND_MESON_AIU) += snd-soc-meson-aiu.o
 obj-$(CONFIG_SND_MESON_AXG_FIFO) += snd-soc-meson-axg-fifo.o
 obj-$(CONFIG_SND_MESON_AXG_FRDDR) += snd-soc-meson-axg-frddr.o
 obj-$(CONFIG_SND_MESON_AXG_TODDR) += snd-soc-meson-axg-toddr.o

sound/soc/meson/aiu-encoder-i2s.c

@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Copyright (c) 2020 BayLibre, SAS.
+// Author: Jerome Brunet <jbrunet@baylibre.com>
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/soc-dai.h>
+
+#include "aiu.h"
+
+#define AIU_I2S_SOURCE_DESC_MODE_8CH	BIT(0)
+#define AIU_I2S_SOURCE_DESC_MODE_24BIT	BIT(5)
+#define AIU_I2S_SOURCE_DESC_MODE_32BIT	BIT(9)
+#define AIU_I2S_SOURCE_DESC_MODE_SPLIT	BIT(11)
+#define AIU_RST_SOFT_I2S_FAST		BIT(0)
+
+#define AIU_I2S_DAC_CFG_MSB_FIRST	BIT(2)
+#define AIU_I2S_MISC_HOLD_EN		BIT(2)
+#define AIU_CLK_CTRL_I2S_DIV_EN		BIT(0)
+#define AIU_CLK_CTRL_I2S_DIV		GENMASK(3, 2)
+#define AIU_CLK_CTRL_AOCLK_INVERT	BIT(6)
+#define AIU_CLK_CTRL_LRCLK_INVERT	BIT(7)
+#define AIU_CLK_CTRL_LRCLK_SKEW		GENMASK(9, 8)
+#define AIU_CLK_CTRL_MORE_HDMI_AMCLK	BIT(6)
+#define AIU_CLK_CTRL_MORE_I2S_DIV	GENMASK(5, 0)
+#define AIU_CODEC_DAC_LRCLK_CTRL_DIV	GENMASK(11, 0)
+
+struct aiu_encoder_i2s {
+	struct clk *aoclk;
+	struct clk *mclk;
+	struct clk *mixer;
+	struct clk *pclk;
+};
+
+static void aiu_encoder_i2s_divider_enable(struct snd_soc_component *component,
+					   bool enable)
+{
+	snd_soc_component_update_bits(component, AIU_CLK_CTRL,
+				      AIU_CLK_CTRL_I2S_DIV_EN,
+				      enable ? AIU_CLK_CTRL_I2S_DIV_EN : 0);
+}
+
+static void aiu_encoder_i2s_hold(struct snd_soc_component *component,
+				 bool enable)
+{
+	snd_soc_component_update_bits(component, AIU_I2S_MISC,
+				      AIU_I2S_MISC_HOLD_EN,
+				      enable ? AIU_I2S_MISC_HOLD_EN : 0);
+}
+
+static int aiu_encoder_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
+				   struct snd_soc_dai *dai)
+{
+	struct snd_soc_component *component = dai->component;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		aiu_encoder_i2s_hold(component, false);
+		return 0;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		aiu_encoder_i2s_hold(component, true);
+		return 0;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int aiu_encoder_i2s_setup_desc(struct snd_soc_component *component,
+				      struct snd_pcm_hw_params *params)
+{
+	/* Always operate in split (classic interleaved) mode */
+	unsigned int desc = AIU_I2S_SOURCE_DESC_MODE_SPLIT;
+	unsigned int val;
+
+	/* Reset required to update the pipeline */
+	snd_soc_component_write(component, AIU_RST_SOFT, AIU_RST_SOFT_I2S_FAST);
+	snd_soc_component_read(component, AIU_I2S_SYNC, &val);
+
+	switch (params_physical_width(params)) {
+	case 16: /* Nothing to do */
+		break;
+
+	case 32:
+		desc |= (AIU_I2S_SOURCE_DESC_MODE_24BIT |
+			 AIU_I2S_SOURCE_DESC_MODE_32BIT);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	switch (params_channels(params)) {
+	case 2: /* Nothing to do */
+		break;
+	case 8:
+		desc |= AIU_I2S_SOURCE_DESC_MODE_8CH;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	snd_soc_component_update_bits(component, AIU_I2S_SOURCE_DESC,
+				      AIU_I2S_SOURCE_DESC_MODE_8CH |
+				      AIU_I2S_SOURCE_DESC_MODE_24BIT |
+				      AIU_I2S_SOURCE_DESC_MODE_32BIT |
+				      AIU_I2S_SOURCE_DESC_MODE_SPLIT,
+				      desc);
+
+	return 0;
+}
+
+static int aiu_encoder_i2s_set_clocks(struct snd_soc_component *component,
+				      struct snd_pcm_hw_params *params)
+{
+	struct aiu *aiu = snd_soc_component_get_drvdata(component);
+	unsigned int srate = params_rate(params);
+	unsigned int fs, bs;
+
+	/* Get the oversampling factor */
+	fs = DIV_ROUND_CLOSEST(clk_get_rate(aiu->i2s.clks[MCLK].clk), srate);
+
+	if (fs % 64)
+		return -EINVAL;
+
+	/* Send data MSB first */
+	snd_soc_component_update_bits(component, AIU_I2S_DAC_CFG,
+				      AIU_I2S_DAC_CFG_MSB_FIRST,
+				      AIU_I2S_DAC_CFG_MSB_FIRST);
+
+	/* Set bclk to lrlck ratio */
+	snd_soc_component_update_bits(component, AIU_CODEC_DAC_LRCLK_CTRL,
+				      AIU_CODEC_DAC_LRCLK_CTRL_DIV,
+				      FIELD_PREP(AIU_CODEC_DAC_LRCLK_CTRL_DIV,
+						 64 - 1));
+
+	/* Use CLK_MORE for mclk to bclk divider */
+	snd_soc_component_update_bits(component, AIU_CLK_CTRL,
+				      AIU_CLK_CTRL_I2S_DIV, 0);
+
+	/*
+	 * NOTE: this HW is odd.
+	 * In most configuration, the i2s divider is 'mclk / blck'.
+	 * However, in 16 bits - 8ch mode, this factor needs to be
+	 * increased by 50% to get the correct output rate.
+	 * No idea why !
+	 */
+	bs = fs / 64;
+	if (params_width(params) == 16 && params_channels(params) == 8) {
+		if (bs % 2) {
+			dev_err(component->dev,
+				"Cannot increase i2s divider by 50%%\n");
+			return -EINVAL;
+		}
+		bs += bs / 2;
+	}
+
+	snd_soc_component_update_bits(component, AIU_CLK_CTRL_MORE,
+				      AIU_CLK_CTRL_MORE_I2S_DIV,
+				      FIELD_PREP(AIU_CLK_CTRL_MORE_I2S_DIV,
+						 bs - 1));
+
+	/* Make sure amclk is used for HDMI i2s as well */
+	snd_soc_component_update_bits(component, AIU_CLK_CTRL_MORE,
+				      AIU_CLK_CTRL_MORE_HDMI_AMCLK,
+				      AIU_CLK_CTRL_MORE_HDMI_AMCLK);
+
+	return 0;
+}
+
+static int aiu_encoder_i2s_hw_params(struct snd_pcm_substream *substream,
+				     struct snd_pcm_hw_params *params,
+				     struct snd_soc_dai *dai)
+{
+	struct snd_soc_component *component = dai->component;
+	int ret;
+
+	/* Disable the clock while changing the settings */
+	aiu_encoder_i2s_divider_enable(component, false);
+
+	ret = aiu_encoder_i2s_setup_desc(component, params);
+	if (ret) {
+		dev_err(dai->dev, "setting i2s desc failed\n");
+		return ret;
+	}
+
+	ret = aiu_encoder_i2s_set_clocks(component, params);
+	if (ret) {
+		dev_err(dai->dev, "setting i2s clocks failed\n");
+		return ret;
+	}
+
+	aiu_encoder_i2s_divider_enable(component, true);
+
+	return 0;
+}
+
+static int aiu_encoder_i2s_hw_free(struct snd_pcm_substream *substream,
+				   struct snd_soc_dai *dai)
+{
+	struct snd_soc_component *component = dai->component;
+
+	aiu_encoder_i2s_divider_enable(component, false);
+
+	return 0;
+}
+
+static int aiu_encoder_i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+	struct snd_soc_component *component = dai->component;
+	unsigned int inv = fmt & SND_SOC_DAIFMT_INV_MASK;
+	unsigned int val = 0;
+	unsigned int skew;
+
+	/* Only CPU Master / Codec Slave supported ATM */
+	if ((fmt & SND_SOC_DAIFMT_MASTER_MASK) != SND_SOC_DAIFMT_CBS_CFS)
+		return -EINVAL;
+
+	if (inv == SND_SOC_DAIFMT_NB_IF ||
+	    inv == SND_SOC_DAIFMT_IB_IF)
+		val |= AIU_CLK_CTRL_LRCLK_INVERT;
+
+	if (inv == SND_SOC_DAIFMT_IB_NF ||
+	    inv == SND_SOC_DAIFMT_IB_IF)
+		val |= AIU_CLK_CTRL_AOCLK_INVERT;
+
+	/* Signal skew */
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		/* Invert sample clock for i2s */
+		val ^= AIU_CLK_CTRL_LRCLK_INVERT;
+		skew = 1;
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		skew = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	val |= FIELD_PREP(AIU_CLK_CTRL_LRCLK_SKEW, skew);
+	snd_soc_component_update_bits(component, AIU_CLK_CTRL,
+				      AIU_CLK_CTRL_LRCLK_INVERT |
+				      AIU_CLK_CTRL_AOCLK_INVERT |
+				      AIU_CLK_CTRL_LRCLK_SKEW,
+				      val);
+
+	return 0;
+}
+
+static int aiu_encoder_i2s_set_sysclk(struct snd_soc_dai *dai, int clk_id,
+				      unsigned int freq, int dir)
+{
+	struct aiu *aiu = snd_soc_component_get_drvdata(dai->component);
+	int ret;
+
+	if (WARN_ON(clk_id != 0))
+		return -EINVAL;
+
+	if (dir == SND_SOC_CLOCK_IN)
+		return 0;
+
+	ret = clk_set_rate(aiu->i2s.clks[MCLK].clk, freq);
+	if (ret)
+		dev_err(dai->dev, "Failed to set sysclk to %uHz", freq);
+
+	return ret;
+}
+
+static const unsigned int hw_channels[] = {2, 8};
+static const struct snd_pcm_hw_constraint_list hw_channel_constraints = {
+	.list = hw_channels,
+	.count = ARRAY_SIZE(hw_channels),
+	.mask = 0,
+};
+
+static int aiu_encoder_i2s_startup(struct snd_pcm_substream *substream,
+				   struct snd_soc_dai *dai)
+{
+	struct aiu *aiu = snd_soc_component_get_drvdata(dai->component);
+	int ret;
+
+	/* Make sure the encoder gets either 2 or 8 channels */
+	ret = snd_pcm_hw_constraint_list(substream->runtime, 0,
+					 SNDRV_PCM_HW_PARAM_CHANNELS,
+					 &hw_channel_constraints);
+	if (ret) {
+		dev_err(dai->dev, "adding channels constraints failed\n");
+		return ret;
+	}
+
+	ret = clk_bulk_prepare_enable(aiu->i2s.clk_num, aiu->i2s.clks);
+	if (ret)
+		dev_err(dai->dev, "failed to enable i2s clocks\n");
+
+	return ret;
+}
+
+static void aiu_encoder_i2s_shutdown(struct snd_pcm_substream *substream,
+				     struct snd_soc_dai *dai)
+{
+	struct aiu *aiu = snd_soc_component_get_drvdata(dai->component);
+
+	clk_bulk_disable_unprepare(aiu->i2s.clk_num, aiu->i2s.clks);
+}
+
+const struct snd_soc_dai_ops aiu_encoder_i2s_dai_ops = {
+	.trigger	= aiu_encoder_i2s_trigger,
+	.hw_params	= aiu_encoder_i2s_hw_params,
+	.hw_free	= aiu_encoder_i2s_hw_free,
+	.set_fmt	= aiu_encoder_i2s_set_fmt,
+	.set_sysclk	= aiu_encoder_i2s_set_sysclk,
+	.startup	= aiu_encoder_i2s_startup,
+	.shutdown	= aiu_encoder_i2s_shutdown,
+};
+