diff mbox

[2/2] ASoC: sunxi: add support for the on-chip codec on early Allwinner SoCs

Message ID 1442064384-23379-3-git-send-email-maxime.ripard@free-electrons.com (mailing list archive)
State New, archived
Headers show

Commit Message

Maxime Ripard Sept. 12, 2015, 1:26 p.m. UTC
From: Emilio López <emilio@elopez.com.ar>

The sun4i, sun5i and sun7i SoC families have a built-in codec, capable
of both audio capture and playback.

While this is called a codec by Allwinner, it really is an in-SoC
combination of a codec and a DAI, with its own DAC/ADC and amplifiers
in a single memory-mapped controller.

The capture part has been left out for now, and will be added eventually.

Signed-off-by: Emilio López <emilio@elopez.com.ar>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 sound/soc/Kconfig             |   1 +
 sound/soc/Makefile            |   1 +
 sound/soc/sunxi/Kconfig       |  11 +
 sound/soc/sunxi/Makefile      |   2 +
 sound/soc/sunxi/sun4i-codec.c | 720 ++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 735 insertions(+)
 create mode 100644 sound/soc/sunxi/Kconfig
 create mode 100644 sound/soc/sunxi/Makefile
 create mode 100644 sound/soc/sunxi/sun4i-codec.c

Comments

Mark Brown Sept. 16, 2015, 7:16 p.m. UTC | #1
On Sat, Sep 12, 2015 at 03:26:24PM +0200, Maxime Ripard wrote:

This looks pretty good, there's a few minor things below but I'll apply
anyway - please send followup patches fixing these.

> +	if (clk_set_rate(scodec->clk_module, clk_freq))
> +		return -EINVAL;

Better to pass back the error code here rather than silently discard it
(it might have more information).

> +static struct snd_soc_dai_driver sun4i_codec_dai = {
> +	.name	= "Codec",
> +	.ops	= &sun4i_codec_dai_ops,
> +	.playback = {
> +		.stream_name	= "Codec Playback",
> +		.channels_min	= 1,
> +		.channels_max	= 2,
> +		.rate_min	= 8000,
> +		.rate_max	= 192000,
> +		.rates		= SNDRV_PCM_RATE_8000_48000 |
> +				  SNDRV_PCM_RATE_96000 |
> +				  SNDRV_PCM_RATE_192000 |
> +				  SNDRV_PCM_RATE_KNOT,

No need to specify both explicit rates and _KNOT, _KNOT covers
everything.

> +		.formats	= SNDRV_PCM_FMTBIT_S16_LE |
> +				  SNDRV_PCM_FMTBIT_S32_LE,
> +		.sig_bits	= 24,

So presumably also S24_LE (ie, 24 bits packed into a 32 bit word)?

> +	/* Enable the bus clock */
> +	if (clk_prepare_enable(scodec->clk_apb)) {
> +		dev_err(&pdev->dev, "Failed to enable the APB clock\n");
> +		return -EINVAL;
> +	}

Ideally we'd have runtime power management to disable the clocks when
idle.
Maxime Ripard Sept. 17, 2015, 1:31 p.m. UTC | #2
Hi Mark,

On Wed, Sep 16, 2015 at 08:16:12PM +0100, Mark Brown wrote:
> On Sat, Sep 12, 2015 at 03:26:24PM +0200, Maxime Ripard wrote:
> 
> This looks pretty good, there's a few minor things below but I'll apply
> anyway - please send followup patches fixing these.

Sure, I will. Thanks!

> 
> > +	if (clk_set_rate(scodec->clk_module, clk_freq))
> > +		return -EINVAL;
> 
> Better to pass back the error code here rather than silently discard it
> (it might have more information).

Yep.

> 
> > +static struct snd_soc_dai_driver sun4i_codec_dai = {
> > +	.name	= "Codec",
> > +	.ops	= &sun4i_codec_dai_ops,
> > +	.playback = {
> > +		.stream_name	= "Codec Playback",
> > +		.channels_min	= 1,
> > +		.channels_max	= 2,
> > +		.rate_min	= 8000,
> > +		.rate_max	= 192000,
> > +		.rates		= SNDRV_PCM_RATE_8000_48000 |
> > +				  SNDRV_PCM_RATE_96000 |
> > +				  SNDRV_PCM_RATE_192000 |
> > +				  SNDRV_PCM_RATE_KNOT,
> 
> No need to specify both explicit rates and _KNOT, _KNOT covers
> everything.

Ack.

> > +		.formats	= SNDRV_PCM_FMTBIT_S16_LE |
> > +				  SNDRV_PCM_FMTBIT_S32_LE,
> > +		.sig_bits	= 24,
> 
> So presumably also S24_LE (ie, 24 bits packed into a 32 bit word)?

Hmm, probably yes, I'll test that.

> > +	/* Enable the bus clock */
> > +	if (clk_prepare_enable(scodec->clk_apb)) {
> > +		dev_err(&pdev->dev, "Failed to enable the APB clock\n");
> > +		return -EINVAL;
> > +	}
> 
> Ideally we'd have runtime power management to disable the clocks when
> idle.

We don't really have any kind of power management support currently,
but adding runtime pm everywhere is definitely on the todo list. It
might not happen before a while though.

Thanks!
Maxime
Mark Brown Sept. 17, 2015, 5:37 p.m. UTC | #3
On Thu, Sep 17, 2015 at 11:10:41PM +0800, Chen-Yu Tsai wrote:
> On Thu, Sep 17, 2015 at 9:31 PM, Maxime Ripard

> >> > +           .formats        = SNDRV_PCM_FMTBIT_S16_LE |
> >> > +                             SNDRV_PCM_FMTBIT_S32_LE,
> >> > +           .sig_bits       = 24,

> >> So presumably also S24_LE (ie, 24 bits packed into a 32 bit word)?

> > Hmm, probably yes, I'll test that.

> IIRC when Emilio first wrote the driver, we tried 24 bit and no sound
> came out. Turns out it's an alignment issue. The codec's FIFO register
> is 32 bits wide, and takes the higher 24 bits as input when set to 24
> bit mode. The internal FIFO is only 24 bits wide. A20 user manual P174
> describes how the bits are copied.

> So for 24 bit audio, you would actually send it 32 bit audio samples,
> and let it truncate or drop the least significant 8 bits. This is why
> we have SNDRV_PCM_FMTBIT_S32_LE with .sig_bits = 24.

> I don't know if this is just a workaround, but a few other drivers do
> this as well, for example twl3040 and omap-mcpdm.

That's very common - it's essentially what S24_LE mode is.
diff mbox

Patch

diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 2ae9619443d1..79c12008c4f0 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -54,6 +54,7 @@  source "sound/soc/samsung/Kconfig"
 source "sound/soc/sh/Kconfig"
 source "sound/soc/sirf/Kconfig"
 source "sound/soc/spear/Kconfig"
+source "sound/soc/sunxi/Kconfig"
 source "sound/soc/tegra/Kconfig"
 source "sound/soc/txx9/Kconfig"
 source "sound/soc/ux500/Kconfig"
diff --git a/sound/soc/Makefile b/sound/soc/Makefile
index e189903fabf4..3bf920252435 100644
--- a/sound/soc/Makefile
+++ b/sound/soc/Makefile
@@ -36,6 +36,7 @@  obj-$(CONFIG_SND_SOC)	+= samsung/
 obj-$(CONFIG_SND_SOC)	+= sh/
 obj-$(CONFIG_SND_SOC)	+= sirf/
 obj-$(CONFIG_SND_SOC)	+= spear/
+obj-$(CONFIG_SND_SOC)	+= sunxi/
 obj-$(CONFIG_SND_SOC)	+= tegra/
 obj-$(CONFIG_SND_SOC)	+= txx9/
 obj-$(CONFIG_SND_SOC)	+= ux500/
diff --git a/sound/soc/sunxi/Kconfig b/sound/soc/sunxi/Kconfig
new file mode 100644
index 000000000000..84c72ec6ad73
--- /dev/null
+++ b/sound/soc/sunxi/Kconfig
@@ -0,0 +1,11 @@ 
+menu "Allwinner SoC Audio support"
+
+config SND_SUN4I_CODEC
+	tristate "Allwinner A10 Codec Support"
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select REGMAP_MMIO
+	help
+	  Select Y or M to add support for the Codec embedded in the Allwinner
+	  A10 and affiliated SoCs.
+
+endmenu
diff --git a/sound/soc/sunxi/Makefile b/sound/soc/sunxi/Makefile
new file mode 100644
index 000000000000..ea8a08c881d6
--- /dev/null
+++ b/sound/soc/sunxi/Makefile
@@ -0,0 +1,2 @@ 
+obj-$(CONFIG_SND_SUN4I_CODEC) += sun4i-codec.o
+
diff --git a/sound/soc/sunxi/sun4i-codec.c b/sound/soc/sunxi/sun4i-codec.c
new file mode 100644
index 000000000000..6e83e62ef039
--- /dev/null
+++ b/sound/soc/sunxi/sun4i-codec.c
@@ -0,0 +1,720 @@ 
+/*
+ * 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>
+
+/* Codec DAC register offsets and bit fields */
+#define SUN4I_CODEC_DAC_DPC			(0x00)
+#define SUN4I_CODEC_DAC_DPC_EN_DA			(31)
+#define SUN4I_CODEC_DAC_DPC_DVOL			(12)
+#define SUN4I_CODEC_DAC_FIFOC			(0x04)
+#define SUN4I_CODEC_DAC_FIFOC_DAC_FS			(29)
+#define SUN4I_CODEC_DAC_FIFOC_FIR_VERSION		(28)
+#define SUN4I_CODEC_DAC_FIFOC_SEND_LASAT		(26)
+#define SUN4I_CODEC_DAC_FIFOC_TX_FIFO_MODE		(24)
+#define SUN4I_CODEC_DAC_FIFOC_DRQ_CLR_CNT		(21)
+#define SUN4I_CODEC_DAC_FIFOC_TX_TRIG_LEVEL		(8)
+#define SUN4I_CODEC_DAC_FIFOC_MONO_EN			(6)
+#define SUN4I_CODEC_DAC_FIFOC_TX_SAMPLE_BITS		(5)
+#define SUN4I_CODEC_DAC_FIFOC_DAC_DRQ_EN		(4)
+#define SUN4I_CODEC_DAC_FIFOC_FIFO_FLUSH		(0)
+#define SUN4I_CODEC_DAC_FIFOS			(0x08)
+#define SUN4I_CODEC_DAC_TXDATA			(0x0c)
+#define SUN4I_CODEC_DAC_ACTL			(0x10)
+#define SUN4I_CODEC_DAC_ACTL_DACAENR			(31)
+#define SUN4I_CODEC_DAC_ACTL_DACAENL			(30)
+#define SUN4I_CODEC_DAC_ACTL_MIXEN			(29)
+#define SUN4I_CODEC_DAC_ACTL_LDACLMIXS			(15)
+#define SUN4I_CODEC_DAC_ACTL_RDACRMIXS			(14)
+#define SUN4I_CODEC_DAC_ACTL_LDACRMIXS			(13)
+#define SUN4I_CODEC_DAC_ACTL_DACPAS			(8)
+#define SUN4I_CODEC_DAC_ACTL_MIXPAS			(7)
+#define SUN4I_CODEC_DAC_ACTL_PA_MUTE			(6)
+#define SUN4I_CODEC_DAC_ACTL_PA_VOL			(0)
+#define SUN4I_CODEC_DAC_TUNE			(0x14)
+#define SUN4I_CODEC_DAC_DEBUG			(0x18)
+
+/* Codec ADC register offsets and bit fields */
+#define SUN4I_CODEC_ADC_FIFOC			(0x1c)
+#define SUN4I_CODEC_ADC_FIFOC_EN_AD			(28)
+#define SUN4I_CODEC_ADC_FIFOC_RX_FIFO_MODE		(24)
+#define SUN4I_CODEC_ADC_FIFOC_RX_TRIG_LEVEL		(8)
+#define SUN4I_CODEC_ADC_FIFOC_MONO_EN			(7)
+#define SUN4I_CODEC_ADC_FIFOC_RX_SAMPLE_BITS		(6)
+#define SUN4I_CODEC_ADC_FIFOC_ADC_DRQ_EN		(4)
+#define SUN4I_CODEC_ADC_FIFOC_FIFO_FLUSH		(0)
+#define SUN4I_CODEC_ADC_FIFOS			(0x20)
+#define SUN4I_CODEC_ADC_RXDATA			(0x24)
+#define SUN4I_CODEC_ADC_ACTL			(0x28)
+#define SUN4I_CODEC_ADC_ACTL_ADC_R_EN			(31)
+#define SUN4I_CODEC_ADC_ACTL_ADC_L_EN			(30)
+#define SUN4I_CODEC_ADC_ACTL_PREG1EN			(29)
+#define SUN4I_CODEC_ADC_ACTL_PREG2EN			(28)
+#define SUN4I_CODEC_ADC_ACTL_VMICEN			(27)
+#define SUN4I_CODEC_ADC_ACTL_VADCG			(20)
+#define SUN4I_CODEC_ADC_ACTL_ADCIS			(17)
+#define SUN4I_CODEC_ADC_ACTL_PA_EN			(4)
+#define SUN4I_CODEC_ADC_ACTL_DDE			(3)
+#define SUN4I_CODEC_ADC_DEBUG			(0x2c)
+
+/* Other various ADC registers */
+#define SUN4I_CODEC_DAC_TXCNT			(0x30)
+#define SUN4I_CODEC_ADC_RXCNT			(0x34)
+#define SUN4I_CODEC_AC_SYS_VERI			(0x38)
+#define SUN4I_CODEC_AC_MIC_PHONE_CAL		(0x3c)
+
+struct sun4i_codec {
+	struct device	*dev;
+	struct regmap	*regmap;
+	struct clk	*clk_apb;
+	struct clk	*clk_module;
+
+	struct snd_dmaengine_dai_dma_data	playback_dma_data;
+};
+
+static void sun4i_codec_start_playback(struct sun4i_codec *scodec)
+{
+	/*
+	 * FIXME: according to the BSP, we might need to drive a PA
+	 *        GPIO high here on some boards
+	 */
+
+	/* Flush TX FIFO */
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   BIT(SUN4I_CODEC_DAC_FIFOC_FIFO_FLUSH),
+			   BIT(SUN4I_CODEC_DAC_FIFOC_FIFO_FLUSH));
+
+	/* Enable DAC DRQ */
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   BIT(SUN4I_CODEC_DAC_FIFOC_DAC_DRQ_EN),
+			   BIT(SUN4I_CODEC_DAC_FIFOC_DAC_DRQ_EN));
+}
+
+static void sun4i_codec_stop_playback(struct sun4i_codec *scodec)
+{
+	/*
+	 * FIXME: according to the BSP, we might need to drive a PA
+	 *        GPIO low here on some boards
+	 */
+
+	/* Disable DAC DRQ */
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   BIT(SUN4I_CODEC_DAC_FIFOC_DAC_DRQ_EN),
+			   0);
+}
+
+static int sun4i_codec_trigger(struct snd_pcm_substream *substream, int cmd,
+			       struct snd_soc_dai *dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct sun4i_codec *scodec = snd_soc_card_get_drvdata(rtd->card);
+
+	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return -ENOTSUPP;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		sun4i_codec_start_playback(scodec);
+		break;
+
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		sun4i_codec_stop_playback(scodec);
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int sun4i_codec_prepare(struct snd_pcm_substream *substream,
+			       struct snd_soc_dai *dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct sun4i_codec *scodec = snd_soc_card_get_drvdata(rtd->card);
+	u32 val;
+
+	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return -ENOTSUPP;
+
+	/* Flush the TX FIFO */
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   BIT(SUN4I_CODEC_DAC_FIFOC_FIFO_FLUSH),
+			   BIT(SUN4I_CODEC_DAC_FIFOC_FIFO_FLUSH));
+
+	/* Set TX FIFO Empty Trigger Level */
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   0x3f << SUN4I_CODEC_DAC_FIFOC_TX_TRIG_LEVEL,
+			   0xf << SUN4I_CODEC_DAC_FIFOC_TX_TRIG_LEVEL);
+
+	if (substream->runtime->rate > 32000)
+		/* Use 64 bits FIR filter */
+		val = 0;
+	else
+		/* Use 32 bits FIR filter */
+		val = BIT(SUN4I_CODEC_DAC_FIFOC_FIR_VERSION);
+
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   BIT(SUN4I_CODEC_DAC_FIFOC_FIR_VERSION),
+			   val);
+
+	/* Send zeros when we have an underrun */
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   BIT(SUN4I_CODEC_DAC_FIFOC_SEND_LASAT),
+			   0);
+
+	return 0;
+}
+
+static unsigned long sun4i_codec_get_mod_freq(struct snd_pcm_hw_params *params)
+{
+	unsigned int rate = params_rate(params);
+
+	switch (rate) {
+	case 176400:
+	case 88200:
+	case 44100:
+	case 33075:
+	case 22050:
+	case 14700:
+	case 11025:
+	case 7350:
+		return 22579200;
+
+	case 192000:
+	case 96000:
+	case 48000:
+	case 32000:
+	case 24000:
+	case 16000:
+	case 12000:
+	case 8000:
+		return 24576000;
+
+	default:
+		return 0;
+	}
+}
+
+static int sun4i_codec_get_hw_rate(struct snd_pcm_hw_params *params)
+{
+	unsigned int rate = params_rate(params);
+
+	switch (rate) {
+	case 192000:
+	case 176400:
+		return 6;
+
+	case 96000:
+	case 88200:
+		return 7;
+
+	case 48000:
+	case 44100:
+		return 0;
+
+	case 32000:
+	case 33075:
+		return 1;
+
+	case 24000:
+	case 22050:
+		return 2;
+
+	case 16000:
+	case 14700:
+		return 3;
+
+	case 12000:
+	case 11025:
+		return 4;
+
+	case 8000:
+	case 7350:
+		return 5;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static int sun4i_codec_hw_params(struct snd_pcm_substream *substream,
+				 struct snd_pcm_hw_params *params,
+				 struct snd_soc_dai *dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct sun4i_codec *scodec = snd_soc_card_get_drvdata(rtd->card);
+	unsigned long clk_freq;
+	int hwrate;
+	u32 val;
+
+	if (substream->stream != SNDRV_PCM_STREAM_PLAYBACK)
+		return -ENOTSUPP;
+
+	clk_freq = sun4i_codec_get_mod_freq(params);
+	if (!clk_freq)
+		return -EINVAL;
+
+	if (clk_set_rate(scodec->clk_module, clk_freq))
+		return -EINVAL;
+
+	hwrate = sun4i_codec_get_hw_rate(params);
+	if (hwrate < 0)
+		return hwrate;
+
+	/* Set DAC sample rate */
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   7 << SUN4I_CODEC_DAC_FIFOC_DAC_FS,
+			   hwrate << SUN4I_CODEC_DAC_FIFOC_DAC_FS);
+
+	/* Set the number of channels we want to use */
+	if (params_channels(params) == 1)
+		val = BIT(SUN4I_CODEC_DAC_FIFOC_MONO_EN);
+	else
+		val = 0;
+
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   BIT(SUN4I_CODEC_DAC_FIFOC_MONO_EN),
+			   val);
+
+	/* Set the number of sample bits to either 16 or 24 bits */
+	if (hw_param_interval(params, SNDRV_PCM_HW_PARAM_SAMPLE_BITS)->min == 32) {
+		regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+				   BIT(SUN4I_CODEC_DAC_FIFOC_TX_SAMPLE_BITS),
+				   BIT(SUN4I_CODEC_DAC_FIFOC_TX_SAMPLE_BITS));
+
+		/* Set TX FIFO mode to padding the LSBs with 0 */
+		regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+				   BIT(SUN4I_CODEC_DAC_FIFOC_TX_FIFO_MODE),
+				   0);
+
+		scodec->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	} else {
+		regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+				   BIT(SUN4I_CODEC_DAC_FIFOC_TX_SAMPLE_BITS),
+				   0);
+
+		/* Set TX FIFO mode to repeat the MSB */
+		regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+				   BIT(SUN4I_CODEC_DAC_FIFOC_TX_FIFO_MODE),
+				   BIT(SUN4I_CODEC_DAC_FIFOC_TX_FIFO_MODE));
+
+		scodec->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	}
+
+	return 0;
+}
+
+static int sun4i_codec_startup(struct snd_pcm_substream *substream,
+			       struct snd_soc_dai *dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct sun4i_codec *scodec = snd_soc_card_get_drvdata(rtd->card);
+
+	/*
+	 * Stop issuing DRQ when we have room for less than 16 samples
+	 * in our TX FIFO
+	 */
+	regmap_update_bits(scodec->regmap, SUN4I_CODEC_DAC_FIFOC,
+			   3 << SUN4I_CODEC_DAC_FIFOC_DRQ_CLR_CNT,
+			   3 << SUN4I_CODEC_DAC_FIFOC_DRQ_CLR_CNT);
+
+	return clk_prepare_enable(scodec->clk_module);
+}
+
+static void sun4i_codec_shutdown(struct snd_pcm_substream *substream,
+				 struct snd_soc_dai *dai)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct sun4i_codec *scodec = snd_soc_card_get_drvdata(rtd->card);
+
+	clk_disable_unprepare(scodec->clk_module);
+}
+
+static const struct snd_soc_dai_ops sun4i_codec_dai_ops = {
+	.startup	= sun4i_codec_startup,
+	.shutdown	= sun4i_codec_shutdown,
+	.trigger	= sun4i_codec_trigger,
+	.hw_params	= sun4i_codec_hw_params,
+	.prepare	= sun4i_codec_prepare,
+};
+
+static struct snd_soc_dai_driver sun4i_codec_dai = {
+	.name	= "Codec",
+	.ops	= &sun4i_codec_dai_ops,
+	.playback = {
+		.stream_name	= "Codec Playback",
+		.channels_min	= 1,
+		.channels_max	= 2,
+		.rate_min	= 8000,
+		.rate_max	= 192000,
+		.rates		= SNDRV_PCM_RATE_8000_48000 |
+				  SNDRV_PCM_RATE_96000 |
+				  SNDRV_PCM_RATE_192000 |
+				  SNDRV_PCM_RATE_KNOT,
+		.formats	= SNDRV_PCM_FMTBIT_S16_LE |
+				  SNDRV_PCM_FMTBIT_S32_LE,
+		.sig_bits	= 24,
+	},
+};
+
+/*** Codec ***/
+static const struct snd_kcontrol_new sun4i_codec_pa_mute =
+	SOC_DAPM_SINGLE("Switch", SUN4I_CODEC_DAC_ACTL,
+			SUN4I_CODEC_DAC_ACTL_PA_MUTE, 1, 0);
+
+static DECLARE_TLV_DB_SCALE(sun4i_codec_pa_volume_scale, -6300, 100, 1);
+
+static const struct snd_kcontrol_new sun4i_codec_widgets[] = {
+	SOC_SINGLE_TLV("PA Volume", SUN4I_CODEC_DAC_ACTL,
+		       SUN4I_CODEC_DAC_ACTL_PA_VOL, 0x3F, 0,
+		       sun4i_codec_pa_volume_scale),
+};
+
+static const struct snd_kcontrol_new sun4i_codec_left_mixer_controls[] = {
+	SOC_DAPM_SINGLE("Left DAC Playback Switch", SUN4I_CODEC_DAC_ACTL,
+			SUN4I_CODEC_DAC_ACTL_LDACLMIXS, 1, 0),
+};
+
+static const struct snd_kcontrol_new sun4i_codec_right_mixer_controls[] = {
+	SOC_DAPM_SINGLE("Right DAC Playback Switch", SUN4I_CODEC_DAC_ACTL,
+			SUN4I_CODEC_DAC_ACTL_RDACRMIXS, 1, 0),
+	SOC_DAPM_SINGLE("Left DAC Playback Switch", SUN4I_CODEC_DAC_ACTL,
+			SUN4I_CODEC_DAC_ACTL_LDACRMIXS, 1, 0),
+};
+
+static const struct snd_kcontrol_new sun4i_codec_pa_mixer_controls[] = {
+	SOC_DAPM_SINGLE("DAC Playback Switch", SUN4I_CODEC_DAC_ACTL,
+			SUN4I_CODEC_DAC_ACTL_DACPAS, 1, 0),
+	SOC_DAPM_SINGLE("Mixer Playback Switch", SUN4I_CODEC_DAC_ACTL,
+			SUN4I_CODEC_DAC_ACTL_MIXPAS, 1, 0),
+};
+
+static const struct snd_soc_dapm_widget sun4i_codec_dapm_widgets[] = {
+	/* Digital parts of the DACs */
+	SND_SOC_DAPM_SUPPLY("DAC", SUN4I_CODEC_DAC_DPC,
+			    SUN4I_CODEC_DAC_DPC_EN_DA, 0,
+			    NULL, 0),
+
+	/* Analog parts of the DACs */
+	SND_SOC_DAPM_DAC("Left DAC", "Codec Playback", SUN4I_CODEC_DAC_ACTL,
+			 SUN4I_CODEC_DAC_ACTL_DACAENL, 0),
+	SND_SOC_DAPM_DAC("Right DAC", "Codec Playback", SUN4I_CODEC_DAC_ACTL,
+			 SUN4I_CODEC_DAC_ACTL_DACAENR, 0),
+
+	/* Mixers */
+	SND_SOC_DAPM_MIXER("Left Mixer", SND_SOC_NOPM, 0, 0,
+			   sun4i_codec_left_mixer_controls,
+			   ARRAY_SIZE(sun4i_codec_left_mixer_controls)),
+	SND_SOC_DAPM_MIXER("Right Mixer", SND_SOC_NOPM, 0, 0,
+			   sun4i_codec_right_mixer_controls,
+			   ARRAY_SIZE(sun4i_codec_right_mixer_controls)),
+
+	/* Global Mixer Enable */
+	SND_SOC_DAPM_SUPPLY("Mixer Enable", SUN4I_CODEC_DAC_ACTL,
+			    SUN4I_CODEC_DAC_ACTL_MIXEN, 0, NULL, 0),
+
+	/* Pre-Amplifier */
+	SND_SOC_DAPM_MIXER("Pre-Amplifier", SUN4I_CODEC_ADC_ACTL,
+			   SUN4I_CODEC_ADC_ACTL_PA_EN, 0,
+			   sun4i_codec_pa_mixer_controls,
+			   ARRAY_SIZE(sun4i_codec_pa_mixer_controls)),
+	SND_SOC_DAPM_SWITCH("Pre-Amplifier Mute", SND_SOC_NOPM, 0, 0,
+			    &sun4i_codec_pa_mute),
+
+	SND_SOC_DAPM_OUTPUT("HP Right"),
+	SND_SOC_DAPM_OUTPUT("HP Left"),
+};
+
+static const struct snd_soc_dapm_route sun4i_codec_dapm_routes[] = {
+	/* Left DAC Routes */
+	{ "Left DAC", NULL, "DAC" },
+
+	/* Right DAC Routes */
+	{ "Right DAC", NULL, "DAC" },
+
+	/* Right Mixer Routes */
+	{ "Right Mixer", NULL, "Mixer Enable" },
+	{ "Right Mixer", "Left DAC Playback Switch", "Left DAC" },
+	{ "Right Mixer", "Right DAC Playback Switch", "Right DAC" },
+
+	/* Left Mixer Routes */
+	{ "Left Mixer", NULL, "Mixer Enable" },
+	{ "Left Mixer", "Left DAC Playback Switch", "Left DAC" },
+
+	/* Pre-Amplifier Mixer Routes */
+	{ "Pre-Amplifier", "Mixer Playback Switch", "Left Mixer" },
+	{ "Pre-Amplifier", "Mixer Playback Switch", "Right Mixer" },
+	{ "Pre-Amplifier", "DAC Playback Switch", "Left DAC" },
+	{ "Pre-Amplifier", "DAC Playback Switch", "Right DAC" },
+
+	/* PA -> HP path */
+	{ "Pre-Amplifier Mute", "Switch", "Pre-Amplifier" },
+	{ "HP Right", NULL, "Pre-Amplifier Mute" },
+	{ "HP Left", NULL, "Pre-Amplifier Mute" },
+};
+
+static struct snd_soc_codec_driver sun4i_codec_codec = {
+	.controls		= sun4i_codec_widgets,
+	.num_controls		= ARRAY_SIZE(sun4i_codec_widgets),
+	.dapm_widgets		= sun4i_codec_dapm_widgets,
+	.num_dapm_widgets	= ARRAY_SIZE(sun4i_codec_dapm_widgets),
+	.dapm_routes		= sun4i_codec_dapm_routes,
+	.num_dapm_routes	= ARRAY_SIZE(sun4i_codec_dapm_routes),
+};
+
+static const struct snd_soc_component_driver sun4i_codec_component = {
+	.name = "sun4i-codec",
+};
+
+#define SUN4I_CODEC_RATES	SNDRV_PCM_RATE_8000_192000
+#define SUN4I_CODEC_FORMATS	(SNDRV_PCM_FMTBIT_S16_LE | \
+				 SNDRV_PCM_FMTBIT_S32_LE)
+
+static int sun4i_codec_dai_probe(struct snd_soc_dai *dai)
+{
+	struct snd_soc_card *card = snd_soc_dai_get_drvdata(dai);
+	struct sun4i_codec *scodec = snd_soc_card_get_drvdata(card);
+
+	snd_soc_dai_init_dma_data(dai, &scodec->playback_dma_data,
+				  NULL);
+
+	return 0;
+}
+
+static struct snd_soc_dai_driver dummy_cpu_dai = {
+	.name	= "sun4i-codec-cpu-dai",
+	.probe	= sun4i_codec_dai_probe,
+	.playback = {
+		.stream_name	= "Playback",
+		.channels_min	= 1,
+		.channels_max	= 2,
+		.rates		= SUN4I_CODEC_RATES,
+		.formats	= SUN4I_CODEC_FORMATS,
+		.sig_bits	= 24,
+	},
+};
+
+static const struct regmap_config sun4i_codec_regmap_config = {
+	.reg_bits	= 32,
+	.reg_stride	= 4,
+	.val_bits	= 32,
+	.max_register	= SUN4I_CODEC_AC_MIC_PHONE_CAL,
+};
+
+static const struct of_device_id sun4i_codec_of_match[] = {
+	{ .compatible = "allwinner,sun4i-a10-codec" },
+	{ .compatible = "allwinner,sun7i-a20-codec" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sun4i_codec_of_match);
+
+static struct snd_soc_dai_link *sun4i_codec_create_link(struct device *dev,
+							int *num_links)
+{
+	struct snd_soc_dai_link *link = devm_kzalloc(dev, sizeof(*link),
+						     GFP_KERNEL);
+	if (!link)
+		return NULL;
+
+	link->name		= "cdc";
+	link->stream_name	= "CDC PCM";
+	link->codec_dai_name	= "Codec";
+	link->cpu_dai_name	= dev_name(dev);
+	link->codec_name	= dev_name(dev);
+	link->platform_name	= dev_name(dev);
+	link->dai_fmt		= SND_SOC_DAIFMT_I2S;
+
+	*num_links = 1;
+
+	return link;
+};
+
+static struct snd_soc_card *sun4i_codec_create_card(struct device *dev)
+{
+	struct snd_soc_card *card;
+	int ret;
+
+	card = devm_kzalloc(dev, sizeof(*card), GFP_KERNEL);
+	if (!card)
+		return NULL;
+
+	card->dai_link = sun4i_codec_create_link(dev, &card->num_links);
+	if (!card->dai_link)
+		return NULL;
+
+	card->dev		= dev;
+	card->name		= "sun4i-codec";
+
+	ret = snd_soc_of_parse_audio_routing(card, "routing");
+	if (ret) {
+		dev_err(dev, "Failed to create our audio routing\n");
+		return NULL;
+	}
+
+	return card;
+};
+
+static int sun4i_codec_probe(struct platform_device *pdev)
+{
+	struct snd_soc_card *card;
+	struct sun4i_codec *scodec;
+	struct resource *res;
+	void __iomem *base;
+	int ret;
+
+	scodec = devm_kzalloc(&pdev->dev, sizeof(*scodec), GFP_KERNEL);
+	if (!scodec)
+		return -ENOMEM;
+
+	scodec->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(base)) {
+		dev_err(&pdev->dev, "Failed to map the registers\n");
+		return PTR_ERR(base);
+	}
+
+	scodec->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+					     &sun4i_codec_regmap_config);
+	if (IS_ERR(scodec->regmap)) {
+		dev_err(&pdev->dev, "Failed to create our regmap\n");
+		return PTR_ERR(scodec->regmap);
+	}
+
+	/* Get the clocks from the DT */
+	scodec->clk_apb = devm_clk_get(&pdev->dev, "apb");
+	if (IS_ERR(scodec->clk_apb)) {
+		dev_err(&pdev->dev, "Failed to get the APB clock\n");
+		return PTR_ERR(scodec->clk_apb);
+	}
+
+	scodec->clk_module = devm_clk_get(&pdev->dev, "codec");
+	if (IS_ERR(scodec->clk_module)) {
+		dev_err(&pdev->dev, "Failed to get the module clock\n");
+		return PTR_ERR(scodec->clk_module);
+	}
+
+	/* Enable the bus clock */
+	if (clk_prepare_enable(scodec->clk_apb)) {
+		dev_err(&pdev->dev, "Failed to enable the APB clock\n");
+		return -EINVAL;
+	}
+
+	/* DMA configuration for TX FIFO */
+	scodec->playback_dma_data.addr = res->start + SUN4I_CODEC_DAC_TXDATA;
+	scodec->playback_dma_data.maxburst = 4;
+	scodec->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+
+	ret = snd_soc_register_codec(&pdev->dev, &sun4i_codec_codec,
+				     &sun4i_codec_dai, 1);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register our codec\n");
+		goto err_clk_disable;
+	}
+
+	ret = devm_snd_soc_register_component(&pdev->dev,
+					      &sun4i_codec_component,
+					      &dummy_cpu_dai, 1);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register our DAI\n");
+		goto err_unregister_codec;
+	}
+
+	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register against DMAEngine\n");
+		goto err_unregister_codec;
+	}
+
+	card = sun4i_codec_create_card(&pdev->dev);
+	if (!card) {
+		dev_err(&pdev->dev, "Failed to create our card\n");
+		goto err_unregister_codec;
+	}
+
+	platform_set_drvdata(pdev, card);
+	snd_soc_card_set_drvdata(card, scodec);
+
+	ret = snd_soc_register_card(card);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to register our card\n");
+		goto err_unregister_codec;
+	}
+
+	return 0;
+
+err_unregister_codec:
+	snd_soc_unregister_codec(&pdev->dev);
+err_clk_disable:
+	clk_disable_unprepare(scodec->clk_apb);
+	return ret;
+}
+
+static int sun4i_codec_remove(struct platform_device *pdev)
+{
+	struct snd_soc_card *card = platform_get_drvdata(pdev);
+	struct sun4i_codec *scodec = snd_soc_card_get_drvdata(card);
+
+	snd_soc_unregister_card(card);
+	snd_soc_unregister_codec(&pdev->dev);
+	clk_disable_unprepare(scodec->clk_apb);
+
+	return 0;
+}
+
+static struct platform_driver sun4i_codec_driver = {
+	.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_driver);
+
+MODULE_DESCRIPTION("Allwinner A10 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");