alternative sound module in linux-4.4, add support Capture, for Allwinner A10,A13,R8,A20 Audio Codec

sun4i-codec.c

/*
 * Copyright 2014 Emilio López <emilio@elopez.com.ar>
 * Copyright 2014 Jon Smirl <jonsmirl@gmail.com>
 * Copyright 2015 Maxime Ripard <maxime.ripard@free-electrons.com>
 *
 * Based on the Allwinner SDK driver, released under the GPL.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/clk.h>
#include <linux/regmap.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/tlv.h>
#include <sound/initval.h>
#include <sound/dmaengine_pcm.h>

/* Audio Codec DAC register offsets and bit fields */
#define SUN4I_DAC_DPC			(0x00) /* Digital Part Control */
#define SUN4I_DAC_DPC_EN_DA			(31)
#define SUN4I_DAC_DPC_MODQU			(25)
#define SUN4I_DAC_DPC_DWA			(24)
#define SUN4I_DAC_DPC_HPF_EN			(18)
#define SUN4I_DAC_DPC_DVOL			(12)
#define SUN4I_DAC_FIFOC			(0x04) /* FIFO Control */
#define SUN4I_DAC_FIFOC_DAC_FS			(29)
#define SUN4I_DAC_FIFOC_FIR_VERSION		(28)
#define SUN4I_DAC_FIFOC_SEND_LASAT		(26)
#define SUN4I_DAC_FIFOC_FIFO_MODE		(24)
#define SUN4I_DAC_FIFOC_DAC_DRQ_CLR_CNT		(21)
#define SUN4I_DAC_FIFOC_TX_TRIG_LEVEL		(8)
#define SUN4I_DAC_FIFOC_ADDA_LOOP_EN		(7)
#define SUN4I_DAC_FIFOC_DAC_MONO_EN		(6)
#define SUN4I_DAC_FIFOC_TX_SAMPLE_BITS		(5)
#define SUN4I_DAC_FIFOC_DAC_DRQ_EN		(4)
#define SUN4I_DAC_FIFOC_DAC_IRQ_EN		(3)
#define SUN4I_DAC_FIFOC_FIFO_UNDERRUN_IRQ_EN	(2)
#define SUN4I_DAC_FIFOC_FIFO_OVERRUN_IRQ_EN	(1)
#define SUN4I_DAC_FIFOC_FIFO_FLUSH		(0)
#define SUN4I_DAC_FIFOS			(0x08) /* FIFO Status */
#define SUN4I_DAC_FIFOS_TX_EMPTY		(23)
#define SUN4I_DAC_FIFOS_TXE_CNT			(8)
#define SUN4I_DAC_FIFOS_TXE_INT			(3)
#define SUN4I_DAC_FIFOS_TXU_INT			(2)
#define SUN4I_DAC_FIFOS_TXO_INT			(1)
#define SUN4I_DAC_TXDATA		(0x0c) /* TX Data */
#define SUN4I_DAC_TXDATA_TX_DATA		(0)
#define SUN4I_DAC_ACTL			(0x10) /* Analog Control */
#define SUN4I_DAC_ACTL_DACAREN			(31)
#define SUN4I_DAC_ACTL_DACALEN			(30)
#define SUN4I_DAC_ACTL_MIXEN			(29)
#define SUN4I_DAC_ACTL_LNG			(26)
#define SUN4I_DAC_ACTL_FMG			(23)
#define SUN4I_DAC_ACTL_MICG			(20)
#define SUN4I_DAC_ACTL_LLNS			(19)
#define SUN4I_DAC_ACTL_RLNS			(18)
#define SUN4I_DAC_ACTL_LFMS			(17)
#define SUN4I_DAC_ACTL_RFMS			(16)
#define SUN4I_DAC_ACTL_LDACLMIXS		(15)
#define SUN4I_DAC_ACTL_RDACRMIXS		(14)
#define SUN4I_DAC_ACTL_LDACRMIXS		(13)
#define SUN4I_DAC_ACTL_MIC1LS			(12)
#define SUN4I_DAC_ACTL_MIC1RS			(11)
#define SUN4I_DAC_ACTL_MIC2LS			(10)
#define SUN4I_DAC_ACTL_MIC2RS			(9)
#define SUN4I_DAC_ACTL_DACPAS			(8)
#define SUN4I_DAC_ACTL_MIXPAS			(7)
#define SUN4I_DAC_ACTL_PAMUTE			(6)
#define SUN4I_DAC_ACTL_PAVOL			(0)

#define SUN4I_DAC_TUNE			(0x14) /* Undocumented */
#define SUN4I_DAC_DEBUG			(0x18) /* Undocumented */

/* Audio Codec ADC register offsets and bit fields */
#define SUN4I_ADC_FIFOC			(0x1c) /* FIFO Control */
#define SUN4I_ADC_FIFOC_ADFS			(29)
#define SUN4I_ADC_FIFOC_EN_AD			(28)
#define SUN4I_ADC_FIFOC_RX_FIFO_MODE		(24)
#define SUN4I_ADC_FIFOC_RX_FIFO_TRG_LEVEL	(8)
#define SUN4I_ADC_FIFOC_ADC_MONO_EN		(7)
#define SUN4I_ADC_FIFOC_RX_SAMPLE_BITS		(6)
#define SUN4I_ADC_FIFOC_ADC_DRQ_EN		(4)
#define SUN4I_ADC_FIFOC_ADC_IRQ_EN		(3)
#define SUN4I_ADC_FIFOC_ADC_OVERRUN_IRQ_EN	(1)
#define SUN4I_ADC_FIFOC_ADC_FIFO_FLUSH		(0)
#define SUN4I_ADC_FIFOS			(0x20) /* FIFO Status */
#define SUN4I_ADC_FIFOS_RXA			(23)
#define SUN4I_ADC_FIFOS_RXA_CNT			(8)
#define SUN4I_ADC_FIFOS_RXA_INT			(3)
#define SUN4I_ADC_FIFOS_RXO_INT			(1)
#define SUN4I_ADC_RXDATA		(0x24) /* RX Data */
#define SUN4I_ADC_RXDATA_RX_DATA		(0)
#define SUN4I_ADC_ACTL			(0x28) /* Analog Control */
#define SUN4I_ADC_ACTL_ADCREN			(31)
#define SUN4I_ADC_ACTL_ADCLEN			(30)
#define SUN4I_ADC_ACTL_PREG1EN			(29)
#define SUN4I_ADC_ACTL_PREG2EN			(28)
#define SUN4I_ADC_ACTL_VMICEN			(27)
#define SUN4I_ADC_ACTL_PREG1			(25) /* A10-13 R8 */
#define SUN4I_ADC_ACTL_PREG2			(23) /* A10-13 R8 */
#define SUN4I_ADC_ACTL_ADCG			(20)
#define SUN4I_ADC_ACTL_ADCIS			(17)
#define SUN4I_ADC_ACTL_LNRDF			(16)
#define SUN4I_ADC_ACTL_LNPREG			(13)
#define SUN4I_ADC_ACTL_MIC1NEN			(12) /* A10-13 R8 */
#define SUN4I_ADC_ACTL_LHPOUTN			(11) /* A20 */
#define SUN4I_ADC_ACTL_RHPOUTN			(10) /* A20 */
#define SUN4I_ADC_ACTL_DITHER			(8)
#define SUN4I_ADC_ACTL_DITHER_CLK_SELECT	(6) /* A20 */
#define SUN4I_ADC_ACTL_PA_EN			(4)
#define SUN4I_ADC_ACTL_DDE			(3)
#define SUN4I_ADC_ACTL_COMPTEN			(2)
#define SUN4I_ADC_ACTL_PTDBS			(0)

#define SUN4I_ADC_DEBUG			(0x2c) /* Undocumented */

/* counter registers */
#define SUN4I_DAC_CNT			(0x30) /* TX FIFO Counter */
#define SUN4I_DAC_CNT_TX_CNT			(0)
#define SUN4I_ADC_CNT			(0x34) /* RX FIFO Counter */
#define SUN4I_ADC_CNT_RX_CNT			(0)

/* A20 registers */
#define SUN4I_SYS_VERI			(0x38) /* System Calibration Verify */
#define SUN4I_SYS_VERI_BIASCALIVERIFY		(23)
#define SUN4I_SYS_VERI_BIASVERIFY		(17)
#define SUN4I_SYS_VERI_BIASCALI			(11)
#define SUN4I_SYS_VERI_DA16CALIVERIFY		(10)
#define SUN4I_SYS_VERI_DA16VERIFY		(5)
#define SUN4I_SYS_VERI_DA16CALI			(0)
#define SUN4I_MIC_PHONE_CAL		(0x3c) /* MIC Gain & Phone out Ctrl */
#define SUN4I_MIC_PHONE_CAL_PREG1		(29)
#define SUN4I_MIC_PHONE_CAL_PREG2		(26)
#define SUN4I_MIC_PHONE_CAL_PHONEOUTG		(5)
#define SUN4I_MIC_PHONE_CAL_PHONEOUTEN		(4)
#define SUN4I_MIC_PHONE_CAL_PHONEOUTS3		(3)
#define SUN4I_MIC_PHONE_CAL_PHONEOUTS2		(2)
#define SUN4I_MIC_PHONE_CAL_PHONEOUTS1		(1)
#define SUN4I_MIC_PHONE_CAL_PHONEOUTS0		(0)

/* supported rates and formats */
#define SUN4I_DAC_PCM_RATES	(SNDRV_PCM_RATE_8000_48000 | \
				 SNDRV_PCM_RATE_96000 | \
				 SNDRV_PCM_RATE_192000 | \
				 SNDRV_PCM_RATE_KNOT)
#define SUN4I_ADC_PCM_RATES	(SNDRV_PCM_RATE_8000_48000 | \
				 SNDRV_PCM_RATE_KNOT)

#define SUN4I_PCM_FORMATS	(SNDRV_PCM_FMTBIT_S16_LE | \
				 SNDRV_PCM_FMTBIT_S32_LE)

/* Supported SoC families - used for quirks */
enum sun4i_soc_family {
	SUN4IA,	/* A10 SoC - revision A */
	SUN4I,	/* A10 SoC - later revisions */
	SUN5IS,	/* A10s SoCs */
	SUN5I,	/* A13, R8 SoCs */
	SUN7I,	/* A20 SoC */
};

struct sun4i_priv {
	struct device *dev;
	struct regmap *regmap;
	struct clk *clk_apb;
	struct clk *clk_module;
	enum sun4i_soc_family revision;
	struct snd_dmaengine_dai_dma_data playback_dma_data;
	struct snd_dmaengine_dai_dma_data capture_dma_data;
};

/* convenient macros */
#define SUN4I_REGMAP_UPDBIT(map, reg, shift, x) \
			regmap_update_bits(map, reg, 1u << shift, (x) << shift)
#define SUN4I_REGMAP_UPDVAL(map, reg, shift, bits, val) \
			regmap_update_bits(map, reg, \
				(0xffffffff >> (32 - (bits))) << shift, \
							(val) << shift)

static void sun4iac_play_start(struct sun4i_priv *priv)
{
	/* enable DAC DRQ */
	SUN4I_REGMAP_UPDBIT(priv->regmap, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_DAC_DRQ_EN, 1);
	/* flush TX FIFO */
	SUN4I_REGMAP_UPDBIT(priv->regmap, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_FIFO_FLUSH, 0);
}

static void sun4iac_play_stop(struct sun4i_priv *priv)
{
	/* disable DAC DRQ */
	SUN4I_REGMAP_UPDBIT(priv->regmap, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_DAC_DRQ_EN, 0);
}

static void sun4iac_capture_start(struct sun4i_priv *priv)
{
	struct regmap *rgmp = priv->regmap;

	/* enable ADC digital */
	SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_EN_AD, 1);
	/* enable ADC DRQ */
	SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_ADC_DRQ_EN, 1);
	SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_ADC_FIFO_FLUSH, 0);
}

static void sun4iac_capture_stop(struct sun4i_priv *priv)
{
	struct regmap *rgmp = priv->regmap;

	/* disable ADC DRQ */
	SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_ADC_DRQ_EN, 0);
	/* flush RX FIFO */
	SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_ADC_FIFO_FLUSH, 1);
	/* disable ADC digital */
	SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_EN_AD, 0);
	/* disable ADC analog	#  ADCREN + ADCLEN (R+L) */
	SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_ADC_ACTL,
					SUN4I_ADC_ACTL_ADCLEN, 2, 0);
	if (priv->revision == SUN7I)
		SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_DAC_TUNE, 8, 2, 0);
}

static int sun4iac_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct sun4i_priv *priv = snd_soc_card_get_drvdata(rtd->card);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			sun4iac_play_start(priv);
		else
			sun4iac_capture_start(priv);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
			sun4iac_play_stop(priv);
		else
			sun4iac_capture_stop(priv);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int sun4iac_prepare(struct snd_pcm_substream *substream)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct sun4i_priv *priv = snd_soc_card_get_drvdata(rtd->card);
	struct regmap *rgmp = priv->regmap;

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {

		SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_FIFO_FLUSH, 1);
		if (substream->runtime->rate > 32000)
			SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_FIR_VERSION, 0);
		else
			SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_FIR_VERSION, 1);

		/* send last sample when DAC FIFO under run */
		SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_SEND_LASAT, 0);
	}
	else {
		SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_ADC_FIFO_FLUSH, 1);
		/* enable ADC analog	#  ADCREN + ADCLEN (R+L) */
		SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_ADC_ACTL,
					SUN4I_ADC_ACTL_ADCLEN, 2, 0x3);
		if (priv->revision == SUN7I)
			/* boost up record effect */
			SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_DAC_TUNE, 8, 2, 0x3);
	}

	return 0;
}

static int sun4iac_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct sun4i_priv *priv = snd_soc_card_get_drvdata(rtd->card);
	struct regmap *rgmp = priv->regmap;
	int is_mono = (params_channels(params) == 1);
	int is_24bit = (hw_param_interval(params,
					  SNDRV_PCM_HW_PARAM_SAMPLE_BITS)->
								min == 32);
	unsigned int rate = params_rate(params);
	unsigned int hwrate = 0;

	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK &&
	    rate > 48000)
		return -ENOTSUPP;

	switch (rate) {
	case 176400:
	case 88200:
	case 44100:
	case 29400:
	case 22050:
	case 14700:
	case 11025:
	case 7350:
		clk_set_rate(priv->clk_module, 22579200);
		break;
	case 192000:
	case 96000:
	case 48000:
	case 32000:
	case 24000:
	case 16000:
	case 12000:
	case 8000:
		clk_set_rate(priv->clk_module, 24576000);
		break;
	default:
		return -ENOTSUPP;
	}

	switch (rate) {
	case 192000:
	case 176400:
		hwrate = 6;
		break;
	case 96000:
	case 88200:
		hwrate = 7;
		break;
	case 32000:
	case 29400:
		hwrate = 1;
		break;
	case 24000:
	case 22050:
		hwrate = 2;
		break;
	case 16000:
	case 14700:
		hwrate = 3;
		break;
	case 12000:
	case 11025:
		hwrate = 4;
		break;
	case 8000:
	case 7350:
		hwrate = 5;
		break;
	default:	/* 48000 or 44100 */
		break;
	}

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_DAC_FS, 3, hwrate);
		SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_DAC_MONO_EN, is_mono);
		SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_TX_SAMPLE_BITS, is_24bit);
		SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_DAC_FIFOC,
					SUN4I_DAC_FIFOC_FIFO_MODE, !is_24bit);
		if (is_24bit)
			priv->playback_dma_data.addr_width =
					DMA_SLAVE_BUSWIDTH_4_BYTES;
		else
			priv->playback_dma_data.addr_width =
					DMA_SLAVE_BUSWIDTH_2_BYTES;
	}
	else {	/* capture */
		SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_ADFS, 3, hwrate);
		SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_ADC_MONO_EN, is_mono);
		SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_RX_SAMPLE_BITS, is_24bit);
		SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_FIFOC,
					SUN4I_ADC_FIFOC_RX_FIFO_MODE, !is_24bit);
		if (is_24bit)
			priv->capture_dma_data.addr_width =
					DMA_SLAVE_BUSWIDTH_4_BYTES;
		else
			priv->capture_dma_data.addr_width =
					DMA_SLAVE_BUSWIDTH_2_BYTES;
	}

	return 0;
}


/* initialize */

static int sun4iac_late_probe(struct snd_soc_card *card)
{
	struct snd_soc_dai *cpu_dai = card->rtd[0].cpu_dai;
	struct sun4i_priv *priv = snd_soc_card_get_drvdata(card);
	struct regmap *rgmp = priv->regmap;

	snd_soc_dai_init_dma_data(cpu_dai, &priv->playback_dma_data,
					&priv->capture_dma_data);

	/* DAC enable */
	SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_DAC_DPC, SUN4I_DAC_DPC_EN_DA, 1);

	if (priv->revision > SUN4IA)
		/* set Digital Volume 0dB */
		SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_DAC_DPC,
						SUN4I_DAC_DPC_DVOL, 6, 2);

	/* internal DAC Analog enable	#  DACAREN + DACALEN (R+L) */
	SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_DACALEN, 2, 0x3);
	/* set DAC to Mixer mux		#  LDACLMIXS + RDACRMIXS (Stereo) */
	SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_LDACRMIXS, 3, 0x6);
	/* set Mic1 to Mixer L+R	#  MIC1LS + MIC1RS */
	SUN4I_REGMAP_UPDVAL(rgmp, SUN4I_DAC_ACTL, SUN4I_DAC_ACTL_MIC1RS,
								2, 0x3);
	/* DAC to PowerAmp switch on */
	SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_DAC_ACTL, SUN4I_DAC_ACTL_DACPAS, 1);
	/* PowerAmp enable */
	SUN4I_REGMAP_UPDBIT(rgmp, SUN4I_ADC_ACTL, SUN4I_ADC_ACTL_PA_EN, 1);

	return 0;
}


/*** Mixer Controls ***/

static DECLARE_TLV_DB_SCALE(pa_volume_scale, -6300, 100, 1);
static DECLARE_TLV_DB_SCALE(digi_volume_scale, -7076, 116, 0);
static DECLARE_TLV_DB_SCALE(adc_gain_scale, -450, 150, 0);
static DECLARE_TLV_DB_SCALE(mico_gain_scale, -450, 150, 0);
static DECLARE_TLV_DB_SCALE(line_gain_scale, -1200, 300, 0);
static const char *mic_preamp_text[] = {"0dB", "35dB", "38dB", "41dB"};
static SOC_ENUM_SINGLE_DECL(mic1_preamp_mixer, SUN4I_MIC_PHONE_CAL,
				SUN4I_MIC_PHONE_CAL_PREG1, mic_preamp_text);
static SOC_ENUM_SINGLE_DECL(mic2_preamp_mixer, SUN4I_MIC_PHONE_CAL,
				SUN4I_MIC_PHONE_CAL_PREG2, mic_preamp_text);
static const char *mic_a20preamp_text[] = {"0dB", "24dB", "27dB", "30dB",
					"33dB", "36dB", "39dB", "42dB"};
static SOC_ENUM_SINGLE_DECL(mic1_a20_preamp_mixer, SUN4I_MIC_PHONE_CAL,
				SUN4I_MIC_PHONE_CAL_PREG1, mic_a20preamp_text);
static SOC_ENUM_SINGLE_DECL(mic2_a20_preamp_mixer, SUN4I_MIC_PHONE_CAL,
				SUN4I_MIC_PHONE_CAL_PREG2, mic_a20preamp_text);
static const char *adcis_text[] = {"Line In", "FM In", "Mic1 Mono", "Mic2 Mono",
			"Mic1,Mic2", "Mic1+2 Mono", "MIX Out", "Line,Mic1"};
static SOC_ENUM_SINGLE_DECL(adcis_mixer, SUN4I_ADC_ACTL,
					SUN4I_ADC_ACTL_ADCIS, adcis_text);
static const char *adcis_a13_text[] = {"Mic1 Mono", "MIX Out"};
static const unsigned int adcis_a13_values[] = {0x2, 0x6};
static SOC_VALUE_ENUM_SINGLE_DECL(adcis_a13_mixer, SUN4I_ADC_ACTL,
					SUN4I_ADC_ACTL_ADCIS, 0x7,
					adcis_a13_text, adcis_a13_values);
static const char *mictomix_text[] = {"Off", "MIX.Rch", "MIX.Lch",
					"MIX.L+R"};
					/*	#  MIC1LS + MIC1RS (L+R) */
static SOC_ENUM_SINGLE_DECL(mic1tomix_mixer, SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_MIC1RS, mictomix_text);
					/*	#  MIC2LS + MIC2RS (L+R) */
static SOC_ENUM_SINGLE_DECL(mic2tomix_mixer, SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_MIC2RS, mictomix_text);
static const char *off_on_text[] = {"Off", "On"};
static const char *off_on_lr_text[] = {"Off", "On", "L,-", "-,R"};
static const unsigned int linetomix_values[] = {0, 0x3, 0x2, 0x1};
					/*	#  LLNS + RLNS (L+R) */
static SOC_VALUE_ENUM_SINGLE_DECL(linetomix_mixer, SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_RLNS, 0x3,
					off_on_lr_text, linetomix_values);
					/*	#  LFMS + RFMS (L+R) */
static SOC_VALUE_ENUM_SINGLE_DECL(fmtomix_mixer, SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_RFMS, 0x3,
					off_on_lr_text, linetomix_values);
static const char *dacmixs_text[] = {"Off", "Stereo", "Mono(L)", "-,L", "-,R",
							"-,LR", "L,-", "L,LR"};
static const unsigned int dacmixs_values[] = {0, 0x6, 0x5, 0x1, 0x2,
							0x3, 0x4, 0x7};
				/*	#  LDACLMIXS + RDACRMIXS + LDACRMIXS */
static SOC_VALUE_ENUM_SINGLE_DECL(dacmixs_mixer, SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_LDACRMIXS, 0x7,
					dacmixs_text, dacmixs_values);
static SOC_ENUM_SINGLE_DECL(mixenable_mixer, SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_MIXEN, off_on_text);
static SOC_ENUM_SINGLE_DECL(vmicen_mixer, SUN4I_ADC_ACTL,
					SUN4I_ADC_ACTL_VMICEN, off_on_text);
static SOC_ENUM_SINGLE_DECL(hpfen_mixer, SUN4I_DAC_DPC,
					SUN4I_DAC_DPC_HPF_EN, off_on_text);

static struct snd_kcontrol_new sun4iac_controls[20] = {
	SOC_SINGLE("Mic1 Switch", SUN4I_ADC_ACTL, SUN4I_ADC_ACTL_PREG1EN, 1, 0),
	SOC_SINGLE_TLV("Mic MIX Gain Volume", SUN4I_DAC_ACTL,
				SUN4I_DAC_ACTL_MICG, 0x7, 0, mico_gain_scale),
	SOC_ENUM("Mic1-MIX", mic1tomix_mixer),
	SOC_SINGLE_TLV("Capture Volume", SUN4I_ADC_ACTL,
				SUN4I_ADC_ACTL_ADCG, 0x7, 0, adc_gain_scale),
	SOC_SINGLE("MIX-PA Switch", SUN4I_DAC_ACTL, SUN4I_DAC_ACTL_MIXPAS,
								1, 0),
	SOC_SINGLE("DAC-PA Playback Switch", SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_DACPAS, 1, 0),
	SOC_ENUM("DAC-MIX Playback Enum", dacmixs_mixer),
	SOC_ENUM("Mic BiasVolt", vmicen_mixer),
	SOC_SINGLE("Master Playback Switch", SUN4I_DAC_ACTL,
					SUN4I_DAC_ACTL_PAMUTE, 1, 0),
	/* 9 fixed items plus below variable items. */
};

static const struct snd_kcontrol_new sun4iac_add_items[] = {
	SOC_SINGLE_TLV("Master Playback Volume", SUN4I_DAC_ACTL,
			SUN4I_DAC_ACTL_PAVOL, 0x3f, 0, pa_volume_scale),
	SOC_SINGLE("Master Playback Volume", SUN4I_DAC_DPC, SUN4I_DAC_DPC_DVOL,
							0x3f, 0),
	SOC_SINGLE_TLV("PCM Digital Playback Volume", SUN4I_DAC_DPC,
			SUN4I_DAC_DPC_DVOL, 0x3f, 1, digi_volume_scale),
	SOC_ENUM("Mic1 Gain", mic1_preamp_mixer),
	SOC_ENUM("Mic2 Gain", mic2_preamp_mixer),
	SOC_ENUM("Mic1 Gain", mic1_a20_preamp_mixer),
	SOC_ENUM("Mic2 Gain", mic2_a20_preamp_mixer),
	SOC_SINGLE("Mic2 Switch", SUN4I_ADC_ACTL, SUN4I_ADC_ACTL_PREG2EN, 1, 0),
	SOC_ENUM("Mic2-MIX", mic2tomix_mixer),
	SOC_SINGLE_TLV("Line Gain Volume", SUN4I_ADC_ACTL,
				SUN4I_ADC_ACTL_LNPREG, 0x7, 0, line_gain_scale),
	SOC_ENUM("Line-MIX", linetomix_mixer),
	SOC_ENUM("FM-MIX", fmtomix_mixer),
	SOC_ENUM("Capture Select Capture Enum", adcis_mixer),
	SOC_ENUM("Capture Select Capture Enum", adcis_a13_mixer),
	SOC_ENUM("HighPassFilter Capture Enum", hpfen_mixer),
};
/*
   not implemented items:
	FM In Gain, MIC Out, PHONE Out, ...
*/

static const bool sun4iac_item_use[SUN7I + 1][ARRAY_SIZE(sun4iac_add_items)] =
{		 /*   mstvl dv micg  a20   mic2  line  fm adcis hp */
	/* A10rA  */ {0, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0}, /* guess */
	/* A10    */ {1, 0, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 1},
	/* A10s   */ {1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 0, 0},
	/* A13 R8 */ {1, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1},
	/* A20    */ {1, 0, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1}
};

/*  item        A10   A10s  A13   A20
   MIC 1 (L)     o     o     o     o
   MIC 2 (R)     o     o     -     o
   LINE IN L/R   o     o     -     o
   FM IN L/R     o     o     -     o
   MIC1OUT       o     o     -     -
   PHONEOUT      -     -     -     o

   DVOL          o     -     o     o
   HPF_EN        o     -     o     o
*/

static const struct snd_kcontrol_new sun4iac_dapm_item =
	SOC_DAPM_ENUM("MIX Enable Switch", mixenable_mixer);

static const struct snd_soc_dapm_widget sun4iac_widgets[] = {
	/* Output */
	SND_SOC_DAPM_DAC("DAC", "AC_Playback", SND_SOC_NOPM, 0, 0),
	SND_SOC_DAPM_MIXER_NAMED_CTL("MIXER", SND_SOC_NOPM, 0, 0,
					&sun4iac_dapm_item, 1),
	SND_SOC_DAPM_OUTPUT("HPOUT"),

	/* Input */
	SND_SOC_DAPM_INPUT("MICIN"),
	SND_SOC_DAPM_ADC("ADC", "AC_Capture", SND_SOC_NOPM, 0, 0),
};

static const struct snd_soc_dapm_route sun4iac_routes[] = {
	{ "MIXER", "MIX Enable Switch", "DAC" },
	{ "HPOUT", NULL, "MIXER" },
	{ "MIXER", "MIX Enable Switch", "MICIN" },
	{ "ADC", NULL, "MIXER" },
};


/*** Board routing ***/

static const struct snd_soc_dapm_widget sun4iac_board_widgets[] = {
	SND_SOC_DAPM_HP("Headphone", NULL),
	SND_SOC_DAPM_MIC("Microphone", NULL),
};

static const struct snd_soc_dapm_route sun4iac_board_routes[] = {
	{ "Headphone", NULL, "HPOUT" },
	{ "MICIN", NULL, "Microphone" },
};


/*** Codec driver & Codec DAI ***/

static struct snd_soc_codec_driver sun4iac_codec_drv = {
	.controls = sun4iac_controls,
/*	.num_controls =  (below func.)	*/
	.dapm_widgets = sun4iac_widgets,
	.num_dapm_widgets = ARRAY_SIZE(sun4iac_widgets),
	.dapm_routes = sun4iac_routes,
	.num_dapm_routes = ARRAY_SIZE(sun4iac_routes),
};

static struct snd_soc_dai_driver sun4iac_codec_dai = {
	.name = "AudioCodec",
	.playback = {
		.stream_name = "AC_Playback",
		.channels_min = 1,
		.channels_max = 2,
		.rate_min = 7350,
		.rate_max = 192000,
		.rates = SUN4I_DAC_PCM_RATES,
		.formats = SUN4I_PCM_FORMATS,
		.sig_bits = 24,
	},
	.capture = {
		.stream_name = "AC_Capture",
		.channels_min = 1,
		.channels_max = 2,
		.rate_min = 7350,
		.rate_max = 48000,
		.rates = SUN4I_ADC_PCM_RATES,
		.formats = SUN4I_PCM_FORMATS,
		.sig_bits = 24,
	},
};

static void sun4iac_init_kcontrol_items(enum sun4i_soc_family revision)
{
	int i, n = 0;

	for (i = 0; i < ARRAY_SIZE(sun4iac_add_items); i++) {
		if (sun4iac_item_use[revision][i]) {
			sun4iac_controls[9 + n] = sun4iac_add_items[i];
			n++;
		}
	}
	sun4iac_codec_drv.num_controls = 9 + n;
}


/*** Component & CPU DAI */

static struct snd_soc_component_driver sun4iac_component = {
	.name = "sun4i-codec-comp",
};

static struct snd_soc_dai_driver sun4iac_cpu_dai = {
	.name	= "sun4i-cpu-dai",
	.playback = {
		.channels_min = 1,
		.channels_max = 2,
		.rates = SUN4I_DAC_PCM_RATES,
		.formats = SUN4I_PCM_FORMATS,
		.sig_bits = 24,
	},
	.capture = {
		.channels_min = 1,
		.channels_max = 2,
		.rates = SUN4I_ADC_PCM_RATES,
		.formats = SUN4I_PCM_FORMATS,
		.sig_bits = 24,
	},
};


/*** Card and DAI Link ***/

static const struct snd_soc_ops sun4iac_ops = {
					/* calling order */
/*	.startup =			 * 1.	*/
/*	.shutdown =				*/
	.hw_params = sun4iac_hw_params,	/* 2.	*/
/*	.hw_free =				*/
	.prepare = sun4iac_prepare,	/* 3.	*/
	.trigger = sun4iac_trigger,	/* 4.	*/
};

static struct snd_soc_dai_link sun4iac_dai_link = {
	.name = "sun4i-codec",
	.stream_name = "sun4i PCM",
	.codec_dai_name = "AudioCodec",
	.dai_fmt = SND_SOC_DAIFMT_I2S,
	.ops = &sun4iac_ops,
};

static struct snd_soc_card sun4iac_card = {
	.name = "sun4i-codec",
	.owner = THIS_MODULE,
	.late_probe = sun4iac_late_probe,
	.dai_link = &sun4iac_dai_link,
	.num_links = 1,
	.dapm_widgets = sun4iac_board_widgets,
	.num_dapm_widgets = ARRAY_SIZE(sun4iac_board_widgets),
	.dapm_routes = sun4iac_board_routes,
	.num_dapm_routes = ARRAY_SIZE(sun4iac_board_routes),
};

static const struct regmap_config sun4iac_regmap_config = {
	.reg_bits = 32,
	.reg_stride = 4,
	.val_bits = 32,
	.max_register = SUN4I_MIC_PHONE_CAL,
};

static const struct of_device_id sun4i_codec_of_match[] = {
	{ .compatible = "allwinner,sun4i-a10a-codec",.data = (void *)SUN4IA},
	{ .compatible = "allwinner,sun4i-a10-codec", .data = (void *)SUN4I },
	{ .compatible = "allwinner,sun5i-a10s-codec",.data = (void *)SUN5IS},
	{ .compatible = "allwinner,sun5i-a13-codec", .data = (void *)SUN5I },
	{ .compatible = "allwinner,sun7i-a20-codec", .data = (void *)SUN7I },
	{ }
};
MODULE_DEVICE_TABLE(of, sun4i_codec_of_match);

static int sun4i_codec_probe(struct platform_device *pdev)
{
	struct device_node *np = pdev->dev.of_node;
	struct snd_soc_card *card = &sun4iac_card;
	const struct of_device_id *of_id;
	struct device *dev = &pdev->dev;
	struct sun4i_priv *priv;
	struct resource *res;
	void __iomem *base;
	int ret;

	if (!of_device_is_available(np))
		return -ENODEV;

	of_id = of_match_device(sun4i_codec_of_match, dev);
	if (!of_id)
		return -EINVAL;

	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->dev = dev;
	card->dev = dev;
	platform_set_drvdata(pdev, card);
	snd_soc_card_set_drvdata(card, priv);

	priv->revision = (enum sun4i_soc_family)of_id->data;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	base = devm_ioremap_resource(dev, res);
	if (IS_ERR(base))
		return PTR_ERR(base);

	priv->regmap = devm_regmap_init_mmio(dev, base,
						&sun4iac_regmap_config);
	if (IS_ERR(priv->regmap))
		return PTR_ERR(priv->regmap);

	/* Get the clocks from the DT */
	priv->clk_apb = devm_clk_get(dev, "apb");
	if (IS_ERR(priv->clk_apb)) {
		dev_err(dev, "failed to get apb clock\n");
		return PTR_ERR(priv->clk_apb);
	}
	priv->clk_module = devm_clk_get(dev, "codec");
	if (IS_ERR(priv->clk_module)) {
		dev_err(dev, "failed to get codec clock\n");
		return PTR_ERR(priv->clk_module);
	}

	if (clk_prepare_enable(priv->clk_module)) {
		dev_err(dev, "failed to enable codec clock\n");
		return -EINVAL;
	}
	/* Enable the clock on a basic rate */
	ret = clk_set_rate(priv->clk_module, 24576000);
	if (ret) {
		dev_err(dev, "failed to set codec base clock rate\n");
		goto err_clk_disable;
	}

	/* Enable the bus clock */
	if (clk_prepare_enable(priv->clk_apb)) {
		dev_err(dev, "failed to enable apb clock\n");
		ret = -EINVAL;
		goto err_clk_disable;
	}

	/* DMA configuration for TX FIFO */
	priv->playback_dma_data.addr = res->start + SUN4I_DAC_TXDATA;
	priv->playback_dma_data.maxburst = 4;
	priv->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;

	/* DMA configuration for RX FIFO */
	priv->capture_dma_data.addr = res->start + SUN4I_ADC_RXDATA;
	priv->capture_dma_data.maxburst = 4;
	priv->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;

	sun4iac_init_kcontrol_items(priv->revision);
	ret = snd_soc_register_codec(dev, &sun4iac_codec_drv,
					&sun4iac_codec_dai, 1);
	if (ret) {
		dev_err(dev, "snd_soc_register_codec() failed: %d\n", ret);
		goto err_clk_disable2;
	}

	ret = devm_snd_soc_register_component(dev, &sun4iac_component,
						&sun4iac_cpu_dai, 1);
	if (ret) {
		dev_err(dev, "snd_soc_register_component() failed: %d\n", ret);
		goto err;
	}

	ret = devm_snd_dmaengine_pcm_register(dev, NULL, 0);
	if (ret) {
		dev_err(dev, "snd_dmaengine_pcm_register() failed: %d\n", ret);
		goto err;
	}

	sun4iac_dai_link.cpu_dai_name = dev_name(dev);
	sun4iac_dai_link.codec_name = dev_name(dev);
	sun4iac_dai_link.platform_name = dev_name(dev);

	ret = devm_snd_soc_register_card(dev, card);
	if (ret) {
		dev_err(dev, "snd_soc_register_card() failed: %d\n", ret);
		goto err;
	}

	return 0;

err:
	snd_soc_unregister_codec(dev);
err_clk_disable2:
	clk_disable_unprepare(priv->clk_apb);
err_clk_disable:
	clk_disable_unprepare(priv->clk_module);
	return ret;
}

static int sun4i_codec_remove(struct platform_device *pdev)
{
	struct snd_soc_card *card = platform_get_drvdata(pdev);
	struct sun4i_priv *priv = snd_soc_card_get_drvdata(card);

	snd_soc_unregister_codec(&pdev->dev);
	clk_disable_unprepare(priv->clk_apb);
	clk_disable_unprepare(priv->clk_module);

	return 0;
}

static struct platform_driver sun4i_codec_pdriver = {
	.driver = {
		.name = "sun4i-codec",
		.owner = THIS_MODULE,
		.of_match_table = sun4i_codec_of_match,
	},
	.probe = sun4i_codec_probe,
	.remove = sun4i_codec_remove,
};
module_platform_driver(sun4i_codec_pdriver);

MODULE_DESCRIPTION("Allwinner A10-A20 codec driver");
MODULE_AUTHOR("Emilio López <emilio@elopez.com.ar>");
MODULE_AUTHOR("Jon Smirl <jonsmirl@gmail.com>");
MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
MODULE_LICENSE("GPL");

(2017-03-12) it's valid with linux 4.4.52.

On linux-4.4, sound module for Allwinner SoCs (A10-A20) is supported, but there are some issues.

• No capture support (supported from linux-4.5)
• No good harmonious with alsa and pulseaudio
  • Difficult to understand mixer controls have what function from its name
  • With pulseaudio, cannot mapping to Master Volume
• At first bootup time, no sound out till some mixer operation

For these reason, I remade this sound module.

File path:
linux-4.4.X/sound/soc/sunxi/sun4i-codec.c

Kernel config:
CONFIG_SND_SUN4I_CODEC=m or y
CONFIG_DMA_SUN4I=y

For BananaPi or other boards, add lines to linux-4.4.X/arch/arm/boot/dts/sunXi-(your board).dts

&codec {
    status = "okay";
};

After installed new sound module, you may need to do:

rm /var/lib/alsa/*
rm $HOME/.config/pulse/*

You may need to change a line in /usr/share/alsa/alsa.conf

#pcm.front cards.pcm.front
pcm.front cards.pcm.default

Screen captures of alsamixer on Ubuntu vivid (Allwinner A20)

Diagram of flow

        Mic Line FM
           | | |
ADC <------+-+-+----
           | | |   ^
           v v v   |
DAC --+--> Mixer --+--> PA(PowerAmp) --> HeadPhone
      \----(bypass)----/

You can enjoy excellent sound with bypass Mixer.