From 7f29222b1731e8182ba94a331531dec18865a1e4 Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Sun, 27 Jul 2014 09:31:47 +0100
Subject: [PATCH 48/53] asoc: add mt7620 support

Signed-off-by: John Crispin <blogic@openwrt.org>
---
 sound/soc/Kconfig                |    1 +
 sound/soc/Makefile               |    1 +
 sound/soc/ralink/Kconfig         |   15 ++
 sound/soc/ralink/Makefile        |   11 +
 sound/soc/ralink/mt7620-i2s.c    |  436 ++++++++++++++++++++++++++++++++++++++
 sound/soc/ralink/mt7620-wm8960.c |  233 ++++++++++++++++++++
 7 files changed, 699 insertions(+)
 create mode 100644 sound/soc/ralink/Kconfig
 create mode 100644 sound/soc/ralink/Makefile
 create mode 100644 sound/soc/ralink/mt7620-i2s.c
 create mode 100644 sound/soc/ralink/mt7620-wm8960.c

--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -107,6 +107,7 @@ source "sound/soc/mxs/Kconfig"
 source "sound/soc/pxa/Kconfig"
 source "sound/soc/qcom/Kconfig"
 source "sound/soc/rockchip/Kconfig"
+source "sound/soc/ralink/Kconfig"
 source "sound/soc/samsung/Kconfig"
 source "sound/soc/sh/Kconfig"
 source "sound/soc/sof/Kconfig"
--- a/sound/soc/Makefile
+++ b/sound/soc/Makefile
@@ -60,6 +60,7 @@ obj-$(CONFIG_SND_SOC)	+= kirkwood/
 obj-$(CONFIG_SND_SOC)	+= pxa/
 obj-$(CONFIG_SND_SOC)	+= qcom/
 obj-$(CONFIG_SND_SOC)	+= rockchip/
+obj-$(CONFIG_SND_SOC)	+= ralink/
 obj-$(CONFIG_SND_SOC)	+= samsung/
 obj-$(CONFIG_SND_SOC)	+= sh/
 obj-$(CONFIG_SND_SOC)	+= sof/
--- /dev/null
+++ b/sound/soc/ralink/Kconfig
@@ -0,0 +1,8 @@
+config SND_RALINK_SOC_I2S
+	depends on RALINK && SND_SOC && !SOC_RT288X
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+	select REGMAP_MMIO
+	tristate "SoC Audio (I2S protocol) for Ralink SoC"
+	help
+	  Say Y if you want to use I2S protocol and I2S codec on Ralink/MediaTek
+	  based boards.
--- /dev/null
+++ b/sound/soc/ralink/Makefile
@@ -0,0 +1,6 @@
+#
+# Ralink/MediaTek Platform Support
+#
+snd-soc-ralink-i2s-objs := ralink-i2s.o
+
+obj-$(CONFIG_SND_RALINK_SOC_I2S) += snd-soc-ralink-i2s.o
--- /dev/null
+++ b/sound/soc/ralink/ralink-i2s.c
@@ -0,0 +1,921 @@
+/*
+ *  Copyright (C) 2010, Lars-Peter Clausen <lars@metafoo.de>
+ *  Copyright (C) 2016 Michael Lee <igvtee@gmail.com>
+ *
+ *  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.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+#include <linux/debugfs.h>
+#include <linux/of_device.h>
+#include <sound/pcm_params.h>
+#include <sound/dmaengine_pcm.h>
+
+#include <asm/mach-ralink/ralink_regs.h>
+
+#define DRV_NAME "ralink-i2s"
+
+#define I2S_REG_CFG0		0x00
+#define I2S_REG_INT_STATUS	0x04
+#define I2S_REG_INT_EN		0x08
+#define I2S_REG_FF_STATUS	0x0c
+#define I2S_REG_WREG		0x10
+#define I2S_REG_RREG		0x14
+#define I2S_REG_CFG1		0x18
+#define I2S_REG_DIVCMP		0x20
+#define I2S_REG_DIVINT		0x24
+
+/* I2S_REG_CFG0 */
+#define I2S_REG_CFG0_EN		BIT(31)
+#define I2S_REG_CFG0_DMA_EN	BIT(30)
+#define I2S_REG_CFG0_BYTE_SWAP	BIT(28)
+#define I2S_REG_CFG0_TX_EN	BIT(24)
+#define I2S_REG_CFG0_RX_EN	BIT(20)
+#define I2S_REG_CFG0_SLAVE	BIT(16)
+#define I2S_REG_CFG0_RX_THRES	12
+#define I2S_REG_CFG0_TX_THRES	4
+#define I2S_REG_CFG0_THRES_MASK	(0xf << I2S_REG_CFG0_RX_THRES) | \
+	(4 << I2S_REG_CFG0_TX_THRES)
+#define I2S_REG_CFG0_DFT_THRES	(4 << I2S_REG_CFG0_RX_THRES) | \
+	(4 << I2S_REG_CFG0_TX_THRES)
+/* RT305x */
+#define I2S_REG_CFG0_CLK_DIS	BIT(8)
+#define I2S_REG_CFG0_TXCH_SWAP	BIT(3)
+#define I2S_REG_CFG0_TXCH1_OFF	BIT(2)
+#define I2S_REG_CFG0_TXCH0_OFF	BIT(1)
+#define I2S_REG_CFG0_SLAVE_EN	BIT(0)
+/* RT3883 */
+#define I2S_REG_CFG0_RXCH_SWAP	BIT(11)
+#define I2S_REG_CFG0_RXCH1_OFF	BIT(10)
+#define I2S_REG_CFG0_RXCH0_OFF	BIT(9)
+#define I2S_REG_CFG0_WS_INV	BIT(0)
+/* MT7628 */
+#define I2S_REG_CFG0_FMT_LE	BIT(29)
+#define I2S_REG_CFG0_SYS_BE	BIT(28)
+#define I2S_REG_CFG0_NORM_24	BIT(18)
+#define I2S_REG_CFG0_DATA_24	BIT(17)
+
+/* I2S_REG_INT_STATUS */
+#define I2S_REG_INT_RX_FAULT	BIT(7)
+#define I2S_REG_INT_RX_OVRUN	BIT(6)
+#define I2S_REG_INT_RX_UNRUN	BIT(5)
+#define I2S_REG_INT_RX_THRES	BIT(4)
+#define I2S_REG_INT_TX_FAULT	BIT(3)
+#define I2S_REG_INT_TX_OVRUN	BIT(2)
+#define I2S_REG_INT_TX_UNRUN	BIT(1)
+#define I2S_REG_INT_TX_THRES	BIT(0)
+#define I2S_REG_INT_TX_MASK	0xf
+#define I2S_REG_INT_RX_MASK	0xf0
+
+/* I2S_REG_INT_STATUS */
+#define I2S_RX_AVCNT(x)		((x >> 4) & 0xf)
+#define I2S_TX_AVCNT(x)		(x & 0xf)
+/* MT7628 */
+#define MT7628_I2S_RX_AVCNT(x)	((x >> 8) & 0x1f)
+#define MT7628_I2S_TX_AVCNT(x)	(x & 0x1f)
+
+/* I2S_REG_CFG1 */
+#define I2S_REG_CFG1_LBK	BIT(31)
+#define I2S_REG_CFG1_EXTLBK	BIT(30)
+/* RT3883 */
+#define I2S_REG_CFG1_LEFT_J	BIT(0)
+#define I2S_REG_CFG1_RIGHT_J	BIT(1)
+#define I2S_REG_CFG1_FMT_MASK	0x3
+
+/* I2S_REG_DIVCMP */
+#define I2S_REG_DIVCMP_CLKEN	BIT(31)
+#define I2S_REG_DIVCMP_DIVCOMP_MASK	0x1ff
+
+/* I2S_REG_DIVINT */
+#define I2S_REG_DIVINT_MASK	0x3ff
+
+/* BCLK dividers */
+#define RALINK_I2S_DIVCMP	0
+#define RALINK_I2S_DIVINT	1
+
+/* FIFO */
+#define RALINK_I2S_FIFO_SIZE	32
+
+/* feature flags */
+#define RALINK_FLAGS_TXONLY	BIT(0)
+#define RALINK_FLAGS_LEFT_J	BIT(1)
+#define RALINK_FLAGS_RIGHT_J	BIT(2)
+#define RALINK_FLAGS_ENDIAN	BIT(3)
+#define RALINK_FLAGS_24BIT	BIT(4)
+
+#define RALINK_I2S_INT_EN	0
+
+struct ralink_i2s_stats {
+	u32 dmafault;
+	u32 overrun;
+	u32 underrun;
+	u32 belowthres;
+};
+
+struct ralink_i2s {
+	struct device *dev;
+	void __iomem *regs;
+	struct clk *clk;
+	struct regmap *regmap;
+	u32 flags;
+	unsigned int fmt;
+	u16 txdma_req;
+	u16 rxdma_req;
+
+	struct snd_dmaengine_dai_dma_data playback_dma_data;
+	struct snd_dmaengine_dai_dma_data capture_dma_data;
+
+	struct dentry *dbg_dir;
+	struct ralink_i2s_stats txstats;
+	struct ralink_i2s_stats rxstats;
+};
+
+static void ralink_i2s_dump_regs(struct ralink_i2s *i2s)
+{
+	u32 buf[10];
+	int ret;
+
+	ret = regmap_bulk_read(i2s->regmap, I2S_REG_CFG0,
+			buf, ARRAY_SIZE(buf));
+
+	dev_dbg(i2s->dev, "CFG0: %08x, INTSTAT: %08x, INTEN: %08x, " \
+			"FFSTAT: %08x, WREG: %08x, RREG: %08x, " \
+			"CFG1: %08x, DIVCMP: %08x, DIVINT: %08x\n",
+			buf[0], buf[1], buf[2], buf[3], buf[4],
+			buf[5], buf[6], buf[8], buf[9]);
+}
+
+static int ralink_i2s_set_sysclk(struct snd_soc_dai *dai,
+			int clk_id, unsigned int freq, int dir)
+{
+	return 0;
+}
+
+static int ralink_i2s_set_sys_bclk(struct snd_soc_dai *dai, int width, int rate)
+{
+	struct ralink_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	unsigned long clk = clk_get_rate(i2s->clk);
+	int div;
+	uint32_t data;
+
+	/* disable clock at slave mode */
+	if ((i2s->fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
+			SND_SOC_DAIFMT_CBM_CFM) {
+		regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+				I2S_REG_CFG0_CLK_DIS,
+				I2S_REG_CFG0_CLK_DIS);
+		return 0;
+	}
+
+	/* FREQOUT = FREQIN / (I2S_CLK_DIV + 1) */
+	div = (clk / rate ) - 1;
+
+	data = rt_sysc_r32(0x30);
+	data &= (0xff << 8);
+	data |= (0x1 << 15) | (div << 8);
+	rt_sysc_w32(data, 0x30);
+
+	/* enable clock */
+	regmap_update_bits(i2s->regmap, I2S_REG_CFG0, I2S_REG_CFG0_CLK_DIS, 0);
+
+	dev_dbg(i2s->dev, "clk: %lu, rate: %u, div: %d\n",
+			clk, rate, div);
+
+	return 0;
+}
+
+static int ralink_i2s_set_bclk(struct snd_soc_dai *dai, int width, int rate)
+{
+	struct ralink_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	unsigned long clk = clk_get_rate(i2s->clk);
+	int divint, divcomp;
+
+	/* disable clock at slave mode */
+	if ((i2s->fmt & SND_SOC_DAIFMT_MASTER_MASK) ==
+			SND_SOC_DAIFMT_CBM_CFM) {
+		regmap_update_bits(i2s->regmap, I2S_REG_DIVCMP,
+				I2S_REG_DIVCMP_CLKEN, 0);
+		return 0;
+	}
+
+	/* FREQOUT = FREQIN * (1/2) * (1/(DIVINT + DIVCOMP/512)) */
+	clk = clk / (2 * 2 * width);
+	divint = clk / rate;
+	divcomp = ((clk % rate) * 512) / rate;
+
+	if ((divint > I2S_REG_DIVINT_MASK) ||
+			(divcomp > I2S_REG_DIVCMP_DIVCOMP_MASK))
+		return -EINVAL;
+
+	regmap_update_bits(i2s->regmap, I2S_REG_DIVINT,
+			I2S_REG_DIVINT_MASK, divint);
+	regmap_update_bits(i2s->regmap, I2S_REG_DIVCMP,
+			I2S_REG_DIVCMP_DIVCOMP_MASK, divcomp);
+
+	/* enable clock */
+	regmap_update_bits(i2s->regmap, I2S_REG_DIVCMP, I2S_REG_DIVCMP_CLKEN,
+			I2S_REG_DIVCMP_CLKEN);
+
+	dev_dbg(i2s->dev, "clk: %lu, rate: %u, int: %d, comp: %d\n",
+			clk_get_rate(i2s->clk), rate, divint, divcomp);
+
+	return 0;
+}
+
+static int ralink_i2s_set_fmt(struct snd_soc_dai *dai, unsigned int fmt)
+{
+	struct ralink_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	unsigned int cfg0 = 0, cfg1 = 0;
+
+	/* set master/slave audio interface */
+	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBM_CFM:
+		if (i2s->flags & RALINK_FLAGS_TXONLY)
+			cfg0 |= I2S_REG_CFG0_SLAVE_EN;
+		else
+			cfg0 |= I2S_REG_CFG0_SLAVE;
+		break;
+	case SND_SOC_DAIFMT_CBS_CFS:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	/* interface format */
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_I2S:
+		break;
+	case SND_SOC_DAIFMT_RIGHT_J:
+		if (i2s->flags & RALINK_FLAGS_RIGHT_J) {
+			cfg1 |= I2S_REG_CFG1_RIGHT_J;
+			break;
+		}
+		return -EINVAL;
+	case SND_SOC_DAIFMT_LEFT_J:
+		if (i2s->flags & RALINK_FLAGS_LEFT_J) {
+			cfg1 |= I2S_REG_CFG1_LEFT_J;
+			break;
+		}
+		return -EINVAL;
+	default:
+		return -EINVAL;
+	}
+
+	/* clock inversion */
+	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_NB_NF:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (i2s->flags & RALINK_FLAGS_TXONLY) {
+		regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+				I2S_REG_CFG0_SLAVE_EN, cfg0);
+	} else {
+		regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+				I2S_REG_CFG0_SLAVE, cfg0);
+	}
+	regmap_update_bits(i2s->regmap, I2S_REG_CFG1,
+			I2S_REG_CFG1_FMT_MASK, cfg1);
+	i2s->fmt = fmt;
+
+	return 0;
+}
+
+static int ralink_i2s_startup(struct snd_pcm_substream *substream,
+		struct snd_soc_dai *dai)
+{
+	struct ralink_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+	if (snd_soc_dai_active(dai))
+		return 0;
+
+	/* setup status interrupt */
+#if (RALINK_I2S_INT_EN)
+	regmap_write(i2s->regmap, I2S_REG_INT_EN, 0xff);
+#else
+	regmap_write(i2s->regmap, I2S_REG_INT_EN, 0x0);
+#endif
+
+	/* enable */
+	regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+			I2S_REG_CFG0_EN | I2S_REG_CFG0_DMA_EN |
+			I2S_REG_CFG0_THRES_MASK,
+			I2S_REG_CFG0_EN | I2S_REG_CFG0_DMA_EN |
+			I2S_REG_CFG0_DFT_THRES);
+
+	return 0;
+}
+
+static void ralink_i2s_shutdown(struct snd_pcm_substream *substream,
+		struct snd_soc_dai *dai)
+{
+	struct ralink_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+	/* If both streams are stopped, disable module and clock */
+	if (snd_soc_dai_active(dai))
+		return;
+
+	/*
+	 * datasheet mention when disable all control regs are cleared
+	 * to initial values. need reinit at startup.
+	 */
+	regmap_update_bits(i2s->regmap, I2S_REG_CFG0, I2S_REG_CFG0_EN, 0);
+}
+
+static int ralink_i2s_hw_params(struct snd_pcm_substream *substream,
+		struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
+{
+	struct ralink_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	int width;
+	int ret;
+
+	width = params_width(params);
+	switch (width) {
+	case 16:
+		if (i2s->flags & RALINK_FLAGS_24BIT)
+			regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+					I2S_REG_CFG0_DATA_24, 0);
+		break;
+	case 24:
+		if (i2s->flags & RALINK_FLAGS_24BIT) {
+			regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+					I2S_REG_CFG0_DATA_24,
+					I2S_REG_CFG0_DATA_24);
+			break;
+		}
+		return -EINVAL;
+	default:
+		return -EINVAL;
+	}
+
+	switch (params_channels(params)) {
+	case 2:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (i2s->flags & RALINK_FLAGS_ENDIAN) {
+		/* system endian */
+#ifdef SNDRV_LITTLE_ENDIAN
+		regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+				I2S_REG_CFG0_SYS_BE, 0);
+#else
+		regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+				I2S_REG_CFG0_SYS_BE,
+				I2S_REG_CFG0_SYS_BE);
+#endif
+
+		/* data endian */
+		switch (params_format(params)) {
+		case SNDRV_PCM_FORMAT_S16_LE:
+		case SNDRV_PCM_FORMAT_S24_LE:
+			regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+					I2S_REG_CFG0_FMT_LE,
+					I2S_REG_CFG0_FMT_LE);
+			break;
+		case SNDRV_PCM_FORMAT_S16_BE:
+		case SNDRV_PCM_FORMAT_S24_BE:
+			regmap_update_bits(i2s->regmap, I2S_REG_CFG0,
+					I2S_REG_CFG0_FMT_LE, 0);
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	/* setup bclk rate */
+	if (i2s->flags & RALINK_FLAGS_TXONLY)
+		ret = ralink_i2s_set_sys_bclk(dai, width, params_rate(params));
+	else
+		ret = ralink_i2s_set_bclk(dai, width, params_rate(params));
+
+	return ret;
+}
+
+static int ralink_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
+		struct snd_soc_dai *dai)
+{
+	struct ralink_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+	unsigned int mask, val;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		mask = I2S_REG_CFG0_TX_EN;
+	else
+		mask = I2S_REG_CFG0_RX_EN;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		val = mask;
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		val = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, I2S_REG_CFG0, mask, val);
+
+	return 0;
+}
+
+static void ralink_i2s_init_dma_data(struct ralink_i2s *i2s,
+		struct resource *res)
+{
+	struct snd_dmaengine_dai_dma_data *dma_data;
+
+	/* Playback */
+	dma_data = &i2s->playback_dma_data;
+	dma_data->addr = res->start + I2S_REG_WREG;
+	dma_data->addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	dma_data->maxburst = 1;
+
+	if (i2s->flags & RALINK_FLAGS_TXONLY)
+		return;
+
+	/* Capture */
+	dma_data = &i2s->capture_dma_data;
+	dma_data->addr = res->start + I2S_REG_RREG;
+	dma_data->addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	dma_data->maxburst = 1;
+}
+
+static int ralink_i2s_dai_probe(struct snd_soc_dai *dai)
+{
+	struct ralink_i2s *i2s = snd_soc_dai_get_drvdata(dai);
+
+	snd_soc_dai_init_dma_data(dai, &i2s->playback_dma_data,
+			&i2s->capture_dma_data);
+
+	return 0;
+}
+
+static int ralink_i2s_dai_remove(struct snd_soc_dai *dai)
+{
+	return 0;
+}
+
+static const struct snd_soc_dai_ops ralink_i2s_dai_ops = {
+	.set_sysclk = ralink_i2s_set_sysclk,
+	.set_fmt = ralink_i2s_set_fmt,
+	.startup = ralink_i2s_startup,
+	.shutdown = ralink_i2s_shutdown,
+	.hw_params = ralink_i2s_hw_params,
+	.trigger = ralink_i2s_trigger,
+	.probe = ralink_i2s_dai_probe,
+	.remove = ralink_i2s_dai_remove,
+};
+
+static struct snd_soc_dai_driver ralink_i2s_dai = {
+	.name = DRV_NAME,
+	.ops = &ralink_i2s_dai_ops,
+	.capture = {
+		.stream_name = "I2S Capture",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rate_min = 5512,
+		.rate_max = 192000,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE,
+	},
+	.playback = {
+		.stream_name = "I2S Playback",
+		.channels_min = 2,
+		.channels_max = 2,
+		.rate_min = 5512,
+		.rate_max = 192000,
+		.rates = SNDRV_PCM_RATE_CONTINUOUS,
+		.formats = SNDRV_PCM_FMTBIT_S16_LE,
+	},
+	.symmetric_rate = 1,
+};
+
+static struct snd_pcm_hardware ralink_pcm_hardware = {
+	.info = SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_BLOCK_TRANSFER,
+	.formats = SNDRV_PCM_FMTBIT_S16_LE,
+	.channels_min		= 2,
+	.channels_max		= 2,
+	.period_bytes_min	= PAGE_SIZE,
+	.period_bytes_max	= PAGE_SIZE * 2,
+	.periods_min		= 2,
+	.periods_max		= 128,
+	.buffer_bytes_max	= 128 * 1024,
+	.fifo_size		= RALINK_I2S_FIFO_SIZE,
+};
+
+static const struct snd_dmaengine_pcm_config ralink_dmaengine_pcm_config = {
+	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
+	.pcm_hardware = &ralink_pcm_hardware,
+	.prealloc_buffer_size = 256 * PAGE_SIZE,
+};
+
+static const struct snd_soc_component_driver ralink_i2s_component = {
+	.name = DRV_NAME,
+};
+
+static bool ralink_i2s_readable_reg(struct device *dev, unsigned int reg)
+{
+	return true;
+}
+
+static bool ralink_i2s_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case I2S_REG_INT_STATUS:
+	case I2S_REG_FF_STATUS:
+		return true;
+	}
+	return false;
+}
+
+static bool ralink_i2s_writeable_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case I2S_REG_FF_STATUS:
+	case I2S_REG_RREG:
+		return false;
+	}
+	return true;
+}
+
+static const struct regmap_config ralink_i2s_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.writeable_reg = ralink_i2s_writeable_reg,
+	.readable_reg = ralink_i2s_readable_reg,
+	.volatile_reg = ralink_i2s_volatile_reg,
+	.max_register = I2S_REG_DIVINT,
+};
+
+#if (RALINK_I2S_INT_EN)
+static irqreturn_t ralink_i2s_irq(int irq, void *devid)
+{
+	struct ralink_i2s *i2s = devid;
+	u32 status;
+
+	regmap_read(i2s->regmap, I2S_REG_INT_STATUS, &status);
+	if (unlikely(!status))
+		return IRQ_NONE;
+
+	/* tx stats */
+	if (status & I2S_REG_INT_TX_MASK) {
+		if (status & I2S_REG_INT_TX_THRES)
+			i2s->txstats.belowthres++;
+		if (status & I2S_REG_INT_TX_UNRUN)
+			i2s->txstats.underrun++;
+		if (status & I2S_REG_INT_TX_OVRUN)
+			i2s->txstats.overrun++;
+		if (status & I2S_REG_INT_TX_FAULT)
+			i2s->txstats.dmafault++;
+	}
+
+	/* rx stats */
+	if (status & I2S_REG_INT_RX_MASK) {
+		if (status & I2S_REG_INT_RX_THRES)
+			i2s->rxstats.belowthres++;
+		if (status & I2S_REG_INT_RX_UNRUN)
+			i2s->rxstats.underrun++;
+		if (status & I2S_REG_INT_RX_OVRUN)
+			i2s->rxstats.overrun++;
+		if (status & I2S_REG_INT_RX_FAULT)
+			i2s->rxstats.dmafault++;
+	}
+
+	/* clean status bits */
+	regmap_write(i2s->regmap, I2S_REG_INT_STATUS, status);
+
+	return IRQ_HANDLED;
+}
+#endif
+
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+static int ralink_i2s_stats_show(struct seq_file *s, void *unused)
+{
+	struct ralink_i2s *i2s = s->private;
+
+	seq_printf(s, "tx stats\n");
+	seq_printf(s, "\tbelow threshold\t%u\n", i2s->txstats.belowthres);
+	seq_printf(s, "\tunder run\t%u\n", i2s->txstats.underrun);
+	seq_printf(s, "\tover run\t%u\n", i2s->txstats.overrun);
+	seq_printf(s, "\tdma fault\t%u\n", i2s->txstats.dmafault);
+
+	seq_printf(s, "rx stats\n");
+	seq_printf(s, "\tbelow threshold\t%u\n", i2s->rxstats.belowthres);
+	seq_printf(s, "\tunder run\t%u\n", i2s->rxstats.underrun);
+	seq_printf(s, "\tover run\t%u\n", i2s->rxstats.overrun);
+	seq_printf(s, "\tdma fault\t%u\n", i2s->rxstats.dmafault);
+
+	ralink_i2s_dump_regs(i2s);
+
+	return 0;
+}
+
+static inline int ralink_i2s_debugfs_create(struct ralink_i2s *i2s)
+{
+	i2s->dbg_dir = debugfs_create_dir(dev_name(i2s->dev), NULL);
+	if (!i2s->dbg_dir)
+		return -ENOMEM;
+
+	debugfs_create_devm_seqfile(i2s->dev, "stats", i2s->dbg_dir,
+				    &ralink_i2s_stats_show);
+
+	return 0;
+}
+
+static inline void ralink_i2s_debugfs_remove(struct ralink_i2s *i2s)
+{
+	debugfs_remove(i2s->dbg_dir);
+}
+#else
+static inline int ralink_i2s_debugfs_create(struct ralink_i2s *i2s)
+{
+	return 0;
+}
+
+static inline void ralink_i2s_debugfs_remove(struct ralink_i2s *i2s)
+{
+}
+#endif
+
+/*
+ * TODO: these refclk setup functions should use
+ * clock framework instead. hardcode it now.
+ */
+static void rt3350_refclk_setup(void)
+{
+	uint32_t data;
+
+	/* set refclk output 12Mhz clock */
+	data = rt_sysc_r32(0x2c);
+	data |= (0x1 << 8);
+	rt_sysc_w32(data, 0x2c);
+}
+
+static void rt3883_refclk_setup(void)
+{
+	uint32_t data;
+
+	/* set refclk output 12Mhz clock */
+	data = rt_sysc_r32(0x2c);
+	data &= ~(0x3 << 13);
+	data |= (0x1 << 13);
+	rt_sysc_w32(data, 0x2c);
+}
+
+static void rt3552_refclk_setup(void)
+{
+	uint32_t data;
+
+	/* set refclk output 12Mhz clock */
+	data = rt_sysc_r32(0x2c);
+	data &= ~(0xf << 8);
+	data |= (0x3 << 8);
+	rt_sysc_w32(data, 0x2c);
+}
+
+static void mt7620_refclk_setup(void)
+{
+	uint32_t data;
+
+	/* set refclk output 12Mhz clock */
+	data = rt_sysc_r32(0x2c);
+	data &= ~(0x7 << 9);
+	data |= 0x1 << 9;
+	rt_sysc_w32(data, 0x2c);
+}
+
+static void mt7621_refclk_setup(void)
+{
+	uint32_t data;
+
+	/* set refclk output 12Mhz clock */
+	data = rt_sysc_r32(0x2c);
+	data &= ~(0x1f << 18);
+	data |= (0x19 << 18);
+	data &= ~(0x1f << 12);
+	data |= (0x1 << 12);
+	data &= ~(0x7 << 9);
+	data |= (0x5 << 9);
+	rt_sysc_w32(data, 0x2c);
+}
+
+static void mt7628_refclk_setup(void)
+{
+	uint32_t data;
+
+	/* set i2s and refclk digital pad */
+	data = rt_sysc_r32(0x3c);
+	data |= 0x1f;
+	rt_sysc_w32(data, 0x3c);
+
+	/* Adjust REFCLK0's driving strength */
+	data = rt_sysc_r32(0x1354);
+	data &= ~(0x1 << 5);
+	rt_sysc_w32(data, 0x1354);
+	data = rt_sysc_r32(0x1364);
+	data |= ~(0x1 << 5);
+	rt_sysc_w32(data, 0x1364);
+
+	/* set refclk output 12Mhz clock */
+	data = rt_sysc_r32(0x2c);
+	data &= ~(0x7 << 9);
+	data |= 0x1 << 9;
+	rt_sysc_w32(data, 0x2c);
+}
+
+struct rt_i2s_data {
+	u32 flags;
+	void (*refclk_setup)(void);
+};
+
+struct rt_i2s_data rt3050_i2s_data = { .flags = RALINK_FLAGS_TXONLY };
+struct rt_i2s_data rt3350_i2s_data = { .flags = RALINK_FLAGS_TXONLY,
+	.refclk_setup = rt3350_refclk_setup };
+struct rt_i2s_data rt3883_i2s_data = {
+	.flags = (RALINK_FLAGS_LEFT_J | RALINK_FLAGS_RIGHT_J),
+	.refclk_setup = rt3883_refclk_setup };
+struct rt_i2s_data rt3352_i2s_data = { .refclk_setup = rt3552_refclk_setup};
+struct rt_i2s_data mt7620_i2s_data = { .refclk_setup = mt7620_refclk_setup};
+struct rt_i2s_data mt7621_i2s_data = { .refclk_setup = mt7621_refclk_setup};
+struct rt_i2s_data mt7628_i2s_data = {
+	.flags = (RALINK_FLAGS_ENDIAN | RALINK_FLAGS_24BIT |
+			RALINK_FLAGS_LEFT_J),
+	.refclk_setup = mt7628_refclk_setup};
+
+static const struct of_device_id ralink_i2s_match_table[] = {
+	{ .compatible = "ralink,rt3050-i2s",
+		.data = (void *)&rt3050_i2s_data },
+	{ .compatible = "ralink,rt3350-i2s",
+		.data = (void *)&rt3350_i2s_data },
+	{ .compatible = "ralink,rt3883-i2s",
+		.data = (void *)&rt3883_i2s_data },
+	{ .compatible = "ralink,rt3352-i2s",
+		.data = (void *)&rt3352_i2s_data },
+	{ .compatible = "mediatek,mt7620-i2s",
+		.data = (void *)&mt7620_i2s_data },
+	{ .compatible = "mediatek,mt7621-i2s",
+		.data = (void *)&mt7621_i2s_data },
+	{ .compatible = "mediatek,mt7628-i2s",
+		.data = (void *)&mt7628_i2s_data },
+	{},
+};
+MODULE_DEVICE_TABLE(of, ralink_i2s_match_table);
+
+static int ralink_i2s_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match;
+	struct device_node *np = pdev->dev.of_node;
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct ralink_i2s *i2s;
+	int irq, ret;
+	u32 dma_req;
+	struct rt_i2s_data *data;
+
+	i2s = devm_kzalloc(dev, sizeof(*i2s), GFP_KERNEL);
+	if (!i2s)
+		return -ENOMEM;
+
+	i2s->dev = dev;
+
+	match = of_match_device(ralink_i2s_match_table, dev);
+	if (!match)
+		return -EINVAL;
+	data = (struct rt_i2s_data *)match->data;
+	i2s->flags = data->flags;
+	/* setup out 12Mhz refclk to codec as mclk */
+	if (data->refclk_setup)
+		data->refclk_setup();
+
+	if (of_property_read_u32(np, "txdma-req", &dma_req)) {
+		dev_err(dev, "no txdma-req define\n");
+		return -EINVAL;
+	}
+	i2s->txdma_req = (u16)dma_req;
+	if (!(i2s->flags & RALINK_FLAGS_TXONLY)) {
+		if (of_property_read_u32(np, "rxdma-req", &dma_req)) {
+			dev_err(dev, "no rxdma-req define\n");
+			return -EINVAL;
+		}
+		i2s->rxdma_req = (u16)dma_req;
+	}
+
+	i2s->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
+	if (IS_ERR(i2s->regs))
+		return PTR_ERR(i2s->regs);
+
+	i2s->regmap = devm_regmap_init_mmio(dev, i2s->regs,
+			&ralink_i2s_regmap_config);
+	if (IS_ERR(i2s->regmap))
+		return dev_err_probe(dev, PTR_ERR(i2s->regmap), "regmap init failed");
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		dev_err(dev, "failed to get irq\n");
+		return -EINVAL;
+	}
+
+#if (RALINK_I2S_INT_EN)
+	ret = devm_request_irq(dev, irq, ralink_i2s_irq,
+			0, dev_name(dev), i2s);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to request irq");
+#endif
+
+	i2s->clk = devm_clk_get_enabled(dev, NULL);
+	if (IS_ERR(i2s->clk))
+		return dev_err_probe(dev, PTR_ERR(i2s->clk), "no clock defined");
+
+	ralink_i2s_init_dma_data(i2s, res);
+
+	ret = device_reset(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "failed to reset device\n");
+
+	/* enable 24bits support */
+	if (i2s->flags & RALINK_FLAGS_24BIT) {
+		ralink_i2s_dai.capture.formats |= SNDRV_PCM_FMTBIT_S24_LE;
+		ralink_i2s_dai.playback.formats |= SNDRV_PCM_FMTBIT_S24_LE;
+	}
+
+	/* enable big endian support */
+	if (i2s->flags & RALINK_FLAGS_ENDIAN) {
+		ralink_i2s_dai.capture.formats |= SNDRV_PCM_FMTBIT_S16_BE;
+		ralink_i2s_dai.playback.formats |= SNDRV_PCM_FMTBIT_S16_BE;
+		ralink_pcm_hardware.formats |= SNDRV_PCM_FMTBIT_S16_BE;
+		if (i2s->flags & RALINK_FLAGS_24BIT) {
+			ralink_i2s_dai.capture.formats |=
+				SNDRV_PCM_FMTBIT_S24_BE;
+			ralink_i2s_dai.playback.formats |=
+				SNDRV_PCM_FMTBIT_S24_BE;
+			ralink_pcm_hardware.formats |=
+				SNDRV_PCM_FMTBIT_S24_BE;
+		}
+	}
+
+	/* disable capture support */
+	if (i2s->flags & RALINK_FLAGS_TXONLY)
+		memset(&ralink_i2s_dai.capture, sizeof(ralink_i2s_dai.capture),
+				0);
+
+	ret = devm_snd_soc_register_component(dev, &ralink_i2s_component,
+			&ralink_i2s_dai, 1);
+	if (ret)
+		return ret;
+
+	ret = devm_snd_dmaengine_pcm_register(dev,
+			&ralink_dmaengine_pcm_config,
+			SND_DMAENGINE_PCM_FLAG_COMPAT);
+	if (ret)
+		return ret;
+
+	dev_info(i2s->dev, "mclk %luMHz\n", clk_get_rate(i2s->clk) / 1000000);
+
+	platform_set_drvdata(pdev, i2s);
+	return ralink_i2s_debugfs_create(i2s);
+}
+
+static void ralink_i2s_remove(struct platform_device *pdev)
+{
+	struct ralink_i2s *i2s = platform_get_drvdata(pdev);
+
+	ralink_i2s_debugfs_remove(i2s);
+}
+
+static struct platform_driver ralink_i2s_driver = {
+	.probe = ralink_i2s_probe,
+	.remove_new = ralink_i2s_remove,
+	.driver = {
+		.name = DRV_NAME,
+		.of_match_table = ralink_i2s_match_table,
+	},
+};
+module_platform_driver(ralink_i2s_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen, <lars@metafoo.de>");
+MODULE_DESCRIPTION("Ralink/MediaTek I2S driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
