ASoC: ep93xx i2s audio driver

Add ep93xx i2s audio driver

Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

8 files changed, 865 insertions, 0 deletions

diff --git a/sound/soc/Kconfig b/sound/soc/Kconfig
index 5e68ac88083..d35f848db6b 100644
--- a/sound/soc/Kconfig
+++ b/sound/soc/Kconfig
@@ -28,6 +28,7 @@ source "sound/soc/atmel/Kconfig"
 source "sound/soc/au1x/Kconfig"
 source "sound/soc/blackfin/Kconfig"
 source "sound/soc/davinci/Kconfig"
+source "sound/soc/ep93xx/Kconfig"
 source "sound/soc/fsl/Kconfig"
 source "sound/soc/imx/Kconfig"
 source "sound/soc/nuc900/Kconfig"
diff --git a/sound/soc/Makefile b/sound/soc/Makefile
index 05d5d340968..97661b747b9 100644
--- a/sound/soc/Makefile
+++ b/sound/soc/Makefile
@@ -6,6 +6,7 @@ obj-$(CONFIG_SND_SOC)	+= atmel/
 obj-$(CONFIG_SND_SOC)   += au1x/
 obj-$(CONFIG_SND_SOC)   += blackfin/
 obj-$(CONFIG_SND_SOC)   += davinci/
+obj-$(CONFIG_SND_SOC)   += ep93xx/
 obj-$(CONFIG_SND_SOC)   += fsl/
 obj-$(CONFIG_SND_SOC)   += imx/
 obj-$(CONFIG_SND_SOC)   += nuc900/
diff --git a/sound/soc/ep93xx/Kconfig b/sound/soc/ep93xx/Kconfig
new file mode 100644
index 00000000000..ba66ac8e141
--- /dev/null
+++ b/sound/soc/ep93xx/Kconfig
@@ -0,0 +1,9 @@
+config SND_EP93XX_SOC
+        tristate "SoC Audio support for the Cirrus Logic EP93xx series"
+        depends on ARCH_EP93XX && SND_SOC
+        help
+          Say Y or M if you want to add support for codecs attached to
+          the EP93xx I2S interface.
+
+config SND_EP93XX_SOC_I2S
+        tristate
diff --git a/sound/soc/ep93xx/Makefile b/sound/soc/ep93xx/Makefile
new file mode 100644
index 00000000000..0239da36cea
--- /dev/null
+++ b/sound/soc/ep93xx/Makefile
@@ -0,0 +1,8 @@
+# EP93xx Platform Support
+snd-soc-ep93xx-objs                             := ep93xx-pcm.o
+snd-soc-ep93xx-i2s-objs                         := ep93xx-i2s.o
+
+obj-$(CONFIG_SND_EP93XX_SOC)                    += snd-soc-ep93xx.o
+obj-$(CONFIG_SND_EP93XX_SOC_I2S)                += snd-soc-ep93xx-i2s.o
+
+# EP93XX Machine Support
diff --git a/sound/soc/ep93xx/ep93xx-i2s.c b/sound/soc/ep93xx/ep93xx-i2s.c
new file mode 100644
index 00000000000..00b94663218
--- /dev/null
+++ b/sound/soc/ep93xx/ep93xx-i2s.c
@@ -0,0 +1,487 @@
+/*
+ * linux/sound/soc/ep93xx-i2s.c
+ * EP93xx I2S driver
+ *
+ * Copyright (C) 2010 Ryan Mallon <ryan@bluewatersys.com>
+ *
+ * Based on the original driver by:
+ *   Copyright (C) 2007 Chase Douglas <chasedouglas@gmail>
+ *   Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/initval.h>
+#include <sound/soc.h>
+
+#include <mach/hardware.h>
+#include <mach/ep93xx-regs.h>
+#include <mach/dma.h>
+
+#include "ep93xx-pcm.h"
+#include "ep93xx-i2s.h"
+
+#define EP93XX_I2S_TXCLKCFG             0x00
+#define EP93XX_I2S_RXCLKCFG             0x04
+#define EP93XX_I2S_GLCTRL               0x0C
+
+#define EP93XX_I2S_TXLINCTRLDATA        0x28
+#define EP93XX_I2S_TXCTRL               0x2C
+#define EP93XX_I2S_TXWRDLEN             0x30
+#define EP93XX_I2S_TX0EN                0x34
+
+#define EP93XX_I2S_RXLINCTRLDATA        0x58
+#define EP93XX_I2S_RXCTRL               0x5C
+#define EP93XX_I2S_RXWRDLEN             0x60
+#define EP93XX_I2S_RX0EN                0x64
+
+#define EP93XX_I2S_WRDLEN_16            (0 << 0)
+#define EP93XX_I2S_WRDLEN_24            (1 << 0)
+#define EP93XX_I2S_WRDLEN_32            (2 << 0)
+
+#define EP93XX_I2S_LINCTRLDATA_R_JUST   (1 << 2) /* Right justify */
+
+#define EP93XX_I2S_CLKCFG_LRS           (1 << 0) /* lrclk polarity */
+#define EP93XX_I2S_CLKCFG_CKP           (1 << 1) /* Bit clock polarity */
+#define EP93XX_I2S_CLKCFG_REL           (1 << 2) /* First bit transition */
+#define EP93XX_I2S_CLKCFG_MASTER        (1 << 3) /* Master mode */
+#define EP93XX_I2S_CLKCFG_NBCG          (1 << 4) /* Not bit clock gating */
+
+struct ep93xx_i2s_info {
+        struct clk                      *mclk;
+        struct clk                      *sclk;
+        struct clk                      *lrclk;
+        struct ep93xx_pcm_dma_params    *dma_params;
+        struct resource                 *mem;
+        void __iomem                    *regs;
+};
+
+struct ep93xx_pcm_dma_params ep93xx_i2s_dma_params[] = {
+        [SNDRV_PCM_STREAM_PLAYBACK] = {
+                .name           = "i2s-pcm-out",
+                .dma_port       = EP93XX_DMA_M2P_PORT_I2S1,
+        },
+        [SNDRV_PCM_STREAM_CAPTURE] = {
+                .name           = "i2s-pcm-in",
+                .dma_port       = EP93XX_DMA_M2P_PORT_I2S1,
+        },
+};
+
+static inline void ep93xx_i2s_write_reg(struct ep93xx_i2s_info *info,
+                                        unsigned reg, unsigned val)
+{
+        __raw_writel(val, info->regs + reg);
+}
+
+static inline unsigned ep93xx_i2s_read_reg(struct ep93xx_i2s_info *info,
+                                           unsigned reg)
+{
+        return __raw_readl(info->regs + reg);
+}
+
+static void ep93xx_i2s_enable(struct ep93xx_i2s_info *info, int stream)
+{
+        unsigned base_reg;
+        int i;
+
+        if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
+            (ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
+                /* Enable clocks */
+                clk_enable(info->mclk);
+                clk_enable(info->sclk);
+                clk_enable(info->lrclk);
+
+                /* Enable i2s */
+                ep93xx_i2s_write_reg(info, EP93XX_I2S_GLCTRL, 1);
+        }
+
+        /* Enable fifos */
+        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+                base_reg = EP93XX_I2S_TX0EN;
+        else
+                base_reg = EP93XX_I2S_RX0EN;
+        for (i = 0; i < 3; i++)
+                ep93xx_i2s_write_reg(info, base_reg + (i * 4), 1);
+}
+
+static void ep93xx_i2s_disable(struct ep93xx_i2s_info *info, int stream)
+{
+        unsigned base_reg;
+        int i;
+
+        /* Disable fifos */
+        if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+                base_reg = EP93XX_I2S_TX0EN;
+        else
+                base_reg = EP93XX_I2S_RX0EN;
+        for (i = 0; i < 3; i++)
+                ep93xx_i2s_write_reg(info, base_reg + (i * 4), 0);
+
+        if ((ep93xx_i2s_read_reg(info, EP93XX_I2S_TX0EN) & 0x1) == 0 &&
+            (ep93xx_i2s_read_reg(info, EP93XX_I2S_RX0EN) & 0x1) == 0) {
+                /* Disable i2s */
+                ep93xx_i2s_write_reg(info, EP93XX_I2S_GLCTRL, 0);
+
+                /* Disable clocks */
+                clk_disable(info->lrclk);
+                clk_disable(info->sclk);
+                clk_disable(info->mclk);
+        }
+}
+
+static int ep93xx_i2s_startup(struct snd_pcm_substream *substream,
+                              struct snd_soc_dai *dai)
+{
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;
+        struct ep93xx_i2s_info *info = rtd->dai->cpu_dai->private_data;
+
+        snd_soc_dai_set_dma_data(cpu_dai, substream,
+                                 &info->dma_params[substream->stream]);
+        return 0;
+}
+
+static void ep93xx_i2s_shutdown(struct snd_pcm_substream *substream,
+                                struct snd_soc_dai *dai)
+{
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct ep93xx_i2s_info *info = rtd->dai->cpu_dai->private_data;
+
+        ep93xx_i2s_disable(info, substream->stream);
+}
+
+static int ep93xx_i2s_set_dai_fmt(struct snd_soc_dai *cpu_dai,
+                                  unsigned int fmt)
+{
+        struct ep93xx_i2s_info *info = cpu_dai->private_data;
+        unsigned int clk_cfg, lin_ctrl;
+
+        clk_cfg  = ep93xx_i2s_read_reg(info, EP93XX_I2S_RXCLKCFG);
+        lin_ctrl = ep93xx_i2s_read_reg(info, EP93XX_I2S_RXLINCTRLDATA);
+
+        switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+        case SND_SOC_DAIFMT_I2S:
+                clk_cfg |= EP93XX_I2S_CLKCFG_REL;
+                lin_ctrl &= ~EP93XX_I2S_LINCTRLDATA_R_JUST;
+                break;
+
+        case SND_SOC_DAIFMT_LEFT_J:
+                clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
+                lin_ctrl &= ~EP93XX_I2S_LINCTRLDATA_R_JUST;
+                break;
+
+        case SND_SOC_DAIFMT_RIGHT_J:
+                clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
+                lin_ctrl |= EP93XX_I2S_LINCTRLDATA_R_JUST;
+                break;
+
+        default:
+                return -EINVAL;
+        }
+
+        switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+        case SND_SOC_DAIFMT_CBS_CFS:
+                /* CPU is master */
+                clk_cfg |= EP93XX_I2S_CLKCFG_MASTER;
+                break;
+
+        case SND_SOC_DAIFMT_CBM_CFM:
+                /* Codec is master */
+                clk_cfg &= ~EP93XX_I2S_CLKCFG_MASTER;
+                break;
+
+        default:
+                return -EINVAL;
+        }
+
+        switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+        case SND_SOC_DAIFMT_NB_NF:
+                /* Negative bit clock, lrclk low on left word */
+                clk_cfg &= ~(EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_REL);
+                break;
+
+        case SND_SOC_DAIFMT_NB_IF:
+                /* Negative bit clock, lrclk low on right word */
+                clk_cfg &= ~EP93XX_I2S_CLKCFG_CKP;
+                clk_cfg |= EP93XX_I2S_CLKCFG_REL;
+                break;
+
+        case SND_SOC_DAIFMT_IB_NF:
+                /* Positive bit clock, lrclk low on left word */
+                clk_cfg |= EP93XX_I2S_CLKCFG_CKP;
+                clk_cfg &= ~EP93XX_I2S_CLKCFG_REL;
+                break;
+
+        case SND_SOC_DAIFMT_IB_IF:
+                /* Positive bit clock, lrclk low on right word */
+                clk_cfg |= EP93XX_I2S_CLKCFG_CKP | EP93XX_I2S_CLKCFG_REL;
+                break;
+        }
+
+        /* Write new register values */
+        ep93xx_i2s_write_reg(info, EP93XX_I2S_RXCLKCFG, clk_cfg);
+        ep93xx_i2s_write_reg(info, EP93XX_I2S_TXCLKCFG, clk_cfg);
+        ep93xx_i2s_write_reg(info, EP93XX_I2S_RXLINCTRLDATA, lin_ctrl);
+        ep93xx_i2s_write_reg(info, EP93XX_I2S_TXLINCTRLDATA, lin_ctrl);
+        return 0;
+}
+
+static int ep93xx_i2s_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 snd_soc_dai *cpu_dai = rtd->dai->cpu_dai;
+        struct ep93xx_i2s_info *info = cpu_dai->private_data;
+        unsigned word_len, div, sdiv, lrdiv;
+        int found = 0, err;
+
+        switch (params_format(params)) {
+        case SNDRV_PCM_FORMAT_S16_LE:
+                word_len = EP93XX_I2S_WRDLEN_16;
+                break;
+
+        case SNDRV_PCM_FORMAT_S24_LE:
+                word_len = EP93XX_I2S_WRDLEN_24;
+                break;
+
+        case SNDRV_PCM_FORMAT_S32_LE:
+                word_len = EP93XX_I2S_WRDLEN_32;
+                break;
+
+        default:
+                return -EINVAL;
+        }
+
+        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+                ep93xx_i2s_write_reg(info, EP93XX_I2S_TXWRDLEN, word_len);
+        else
+                ep93xx_i2s_write_reg(info, EP93XX_I2S_RXWRDLEN, word_len);
+
+        /*
+         * Calculate the sdiv (bit clock) and lrdiv (left/right clock) values.
+         * If the lrclk is pulse length is larger than the word size, then the
+         * bit clock will be gated for the unused bits.
+         */
+        div = (clk_get_rate(info->mclk) / params_rate(params)) *
+                params_channels(params);
+        for (sdiv = 2; sdiv <= 4; sdiv += 2)
+                for (lrdiv = 32; lrdiv <= 128; lrdiv <<= 1)
+                        if (sdiv * lrdiv == div) {
+                                found = 1;
+                                goto out;
+                        }
+out:
+        if (!found)
+                return -EINVAL;
+
+        err = clk_set_rate(info->sclk, clk_get_rate(info->mclk) / sdiv);
+        if (err)
+                return err;
+
+        err = clk_set_rate(info->lrclk, clk_get_rate(info->sclk) / lrdiv);
+        if (err)
+                return err;
+
+        ep93xx_i2s_enable(info, substream->stream);
+        return 0;
+}
+
+static int ep93xx_i2s_set_sysclk(struct snd_soc_dai *cpu_dai, int clk_id,
+                                 unsigned int freq, int dir)
+{
+        struct ep93xx_i2s_info *info = cpu_dai->private_data;
+
+        if (dir == SND_SOC_CLOCK_IN || clk_id != 0)
+                return -EINVAL;
+
+        return clk_set_rate(info->mclk, freq);
+}
+
+#ifdef CONFIG_PM
+static int ep93xx_i2s_suspend(struct snd_soc_dai *dai)
+{
+        struct ep93xx_i2s_info *info = dai->private_data;
+
+        if (!dai->active)
+                return;
+
+        ep93xx_i2s_disable(info, SNDRV_PCM_STREAM_PLAYBACK);
+        ep93xx_i2s_disable(info, SNDRV_PCM_STREAM_CAPTURE);
+}
+
+static int ep93xx_i2s_resume(struct snd_soc_dai *dai)
+{
+        struct ep93xx_i2s_info *info = dai->private_data;
+
+        if (!dai->active)
+                return;
+
+        ep93xx_i2s_enable(info, SNDRV_PCM_STREAM_PLAYBACK);
+        ep93xx_i2s_enable(info, SNDRV_PCM_STREAM_CAPTURE);
+}
+#else
+#define ep93xx_i2s_suspend      NULL
+#define ep93xx_i2s_resume       NULL
+#endif
+
+static struct snd_soc_dai_ops ep93xx_i2s_dai_ops = {
+        .startup        = ep93xx_i2s_startup,
+        .shutdown       = ep93xx_i2s_shutdown,
+        .hw_params      = ep93xx_i2s_hw_params,
+        .set_sysclk     = ep93xx_i2s_set_sysclk,
+        .set_fmt        = ep93xx_i2s_set_dai_fmt,
+};
+
+#define EP93XX_I2S_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | \
+                            SNDRV_PCM_FMTBIT_S24_LE | \
+                            SNDRV_PCM_FMTBIT_S32_LE)
+
+struct snd_soc_dai ep93xx_i2s_dai = {
+        .name           = "ep93xx-i2s",
+        .id             = 0,
+        .symmetric_rates= 1,
+        .suspend        = ep93xx_i2s_suspend,
+        .resume         = ep93xx_i2s_resume,
+        .playback       = {
+                .channels_min   = 2,
+                .channels_max   = 2,
+                .rates          = SNDRV_PCM_RATE_8000_48000,
+                .formats        = EP93XX_I2S_FORMATS,
+        },
+        .capture        = {
+                 .channels_min  = 2,
+                 .channels_max  = 2,
+                 .rates         = SNDRV_PCM_RATE_8000_48000,
+                 .formats       = EP93XX_I2S_FORMATS,
+        },
+        .ops            = &ep93xx_i2s_dai_ops,
+};
+EXPORT_SYMBOL_GPL(ep93xx_i2s_dai);
+
+static int ep93xx_i2s_probe(struct platform_device *pdev)
+{
+        struct ep93xx_i2s_info *info;
+        struct resource *res;
+        int err;
+
+        info = kzalloc(sizeof(struct ep93xx_i2s_info), GFP_KERNEL);
+        if (!info) {
+                err = -ENOMEM;
+                goto fail;
+        }
+
+        ep93xx_i2s_dai.dev = &pdev->dev;
+        ep93xx_i2s_dai.private_data = info;
+        info->dma_params = ep93xx_i2s_dma_params;
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                err = -ENODEV;
+                goto fail;
+        }
+
+        info->mem = request_mem_region(res->start, resource_size(res),
+                                       pdev->name);
+        if (!info->mem) {
+                err = -EBUSY;
+                goto fail;
+        }
+
+        info->regs = ioremap(info->mem->start, resource_size(info->mem));
+        if (!info->regs) {
+                err = -ENXIO;
+                goto fail_release_mem;
+        }
+
+        info->mclk = clk_get(&pdev->dev, "mclk");
+        if (IS_ERR(info->mclk)) {
+                err = PTR_ERR(info->mclk);
+                goto fail_unmap_mem;
+        }
+
+        info->sclk = clk_get(&pdev->dev, "sclk");
+        if (IS_ERR(info->sclk)) {
+                err = PTR_ERR(info->sclk);
+                goto fail_put_mclk;
+        }
+
+        info->lrclk = clk_get(&pdev->dev, "lrclk");
+        if (IS_ERR(info->lrclk)) {
+                err = PTR_ERR(info->lrclk);
+                goto fail_put_sclk;
+        }
+
+        err = snd_soc_register_dai(&ep93xx_i2s_dai);
+        if (err)
+                goto fail_put_lrclk;
+
+        return 0;
+
+fail_put_lrclk:
+        clk_put(info->lrclk);
+fail_put_sclk:
+        clk_put(info->sclk);
+fail_put_mclk:
+        clk_put(info->mclk);
+fail_unmap_mem:
+        iounmap(info->regs);
+fail_release_mem:
+        release_mem_region(info->mem->start, resource_size(info->mem));
+        kfree(info);
+fail:
+        return err;
+}
+
+static int __devexit ep93xx_i2s_remove(struct platform_device *pdev)
+{
+        struct ep93xx_i2s_info *info = ep93xx_i2s_dai.private_data;
+
+        snd_soc_unregister_dai(&ep93xx_i2s_dai);
+        clk_put(info->lrclk);
+        clk_put(info->sclk);
+        clk_put(info->mclk);
+        iounmap(info->regs);
+        release_mem_region(info->mem->start, resource_size(info->mem));
+        kfree(info);
+        return 0;
+}
+
+static struct platform_driver ep93xx_i2s_driver = {
+        .probe  = ep93xx_i2s_probe,
+        .remove = __devexit_p(ep93xx_i2s_remove),
+        .driver = {
+                .name   = "ep93xx-i2s",
+                .owner  = THIS_MODULE,
+        },
+};
+
+static int __init ep93xx_i2s_init(void)
+{
+        return platform_driver_register(&ep93xx_i2s_driver);
+}
+
+static void __exit ep93xx_i2s_exit(void)
+{
+        platform_driver_unregister(&ep93xx_i2s_driver);
+}
+
+module_init(ep93xx_i2s_init);
+module_exit(ep93xx_i2s_exit);
+
+MODULE_ALIAS("platform:ep93xx-i2s");
+MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com>");
+MODULE_DESCRIPTION("EP93XX I2S driver");
+MODULE_LICENSE("GPL");
diff --git a/sound/soc/ep93xx/ep93xx-i2s.h b/sound/soc/ep93xx/ep93xx-i2s.h
new file mode 100644
index 00000000000..3bd4ebfaa1d
--- /dev/null
+++ b/sound/soc/ep93xx/ep93xx-i2s.h
@@ -0,0 +1,18 @@
+/*
+ * linux/sound/soc/ep93xx-i2s.h
+ * EP93xx I2S driver
+ *
+ * Copyright (C) 2010 Ryan Mallon <ryan@bluewatersys.com>
+ *  
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#ifndef _EP93XX_SND_SOC_I2S_H
+#define _EP93XX_SND_SOC_I2S_H
+
+extern struct snd_soc_dai ep93xx_i2s_dai;
+
+#endif /* _EP93XX_SND_SOC_I2S_H */
diff --git a/sound/soc/ep93xx/ep93xx-pcm.c b/sound/soc/ep93xx/ep93xx-pcm.c
new file mode 100644
index 00000000000..4ba93840079
--- /dev/null
+++ b/sound/soc/ep93xx/ep93xx-pcm.c
@@ -0,0 +1,319 @@
+/*
+ * linux/sound/arm/ep93xx-pcm.c - EP93xx ALSA PCM interface
+ *
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ * Copyright (C) 2006 Applied Data Systems
+ *
+ * Rewritten for the SoC audio subsystem (Based on PXA2xx code):
+ *   Copyright (c) 2008 Ryan Mallon <ryan@bluewatersys.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include <mach/dma.h>
+#include <mach/hardware.h>
+#include <mach/ep93xx-regs.h>
+
+#include "ep93xx-pcm.h"
+
+static const struct snd_pcm_hardware ep93xx_pcm_hardware = {
+        .info                   = (SNDRV_PCM_INFO_MMAP          |
+                                   SNDRV_PCM_INFO_MMAP_VALID    |
+                                   SNDRV_PCM_INFO_INTERLEAVED   |
+                                   SNDRV_PCM_INFO_BLOCK_TRANSFER),
+                                   
+        .rates                  = SNDRV_PCM_RATE_8000_48000,
+        .rate_min               = SNDRV_PCM_RATE_8000,
+        .rate_max               = SNDRV_PCM_RATE_48000,
+        
+        .formats                = (SNDRV_PCM_FMTBIT_S16_LE |
+                                   SNDRV_PCM_FMTBIT_S24_LE |
+                                   SNDRV_PCM_FMTBIT_S32_LE),
+        
+        .buffer_bytes_max       = 131072,
+        .period_bytes_min       = 32,
+        .period_bytes_max       = 32768,
+        .periods_min            = 1,
+        .periods_max            = 32,
+        .fifo_size              = 32,
+};
+
+struct ep93xx_runtime_data
+{
+        struct ep93xx_dma_m2p_client    cl;
+        struct ep93xx_pcm_dma_params    *params;
+        int                             pointer_bytes;
+        struct tasklet_struct           period_tasklet;
+        int                             periods;
+        struct ep93xx_dma_buffer        buf[32];
+};
+
+static void ep93xx_pcm_period_elapsed(unsigned long data)
+{
+        struct snd_pcm_substream *substream = (struct snd_pcm_substream *)data;
+        snd_pcm_period_elapsed(substream);
+}
+
+static void ep93xx_pcm_buffer_started(void *cookie,
+                                      struct ep93xx_dma_buffer *buf)
+{
+}
+
+static void ep93xx_pcm_buffer_finished(void *cookie, 
+                                       struct ep93xx_dma_buffer *buf, 
+                                       int bytes, int error)
+{
+        struct snd_pcm_substream *substream = cookie;
+        struct ep93xx_runtime_data *rtd = substream->runtime->private_data;
+
+        if (buf == rtd->buf + rtd->periods - 1)
+                rtd->pointer_bytes = 0;
+        else
+                rtd->pointer_bytes += buf->size;
+
+        if (!error) {
+                ep93xx_dma_m2p_submit_recursive(&rtd->cl, buf);
+                tasklet_schedule(&rtd->period_tasklet);
+        } else {
+                snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
+        }
+}
+
+static int ep93xx_pcm_open(struct snd_pcm_substream *substream)
+{
+        struct snd_soc_pcm_runtime *soc_rtd = substream->private_data;
+        struct snd_soc_dai *cpu_dai = soc_rtd->dai->cpu_dai;
+        struct ep93xx_pcm_dma_params *dma_params;
+        struct ep93xx_runtime_data *rtd;    
+        int ret;
+
+        dma_params = snd_soc_dai_get_dma_data(cpu_dai, substream);
+        snd_soc_set_runtime_hwparams(substream, &ep93xx_pcm_hardware);
+
+        rtd = kmalloc(sizeof(*rtd), GFP_KERNEL);
+        if (!rtd) 
+                return -ENOMEM;
+
+        memset(&rtd->period_tasklet, 0, sizeof(rtd->period_tasklet));
+        rtd->period_tasklet.func = ep93xx_pcm_period_elapsed;
+        rtd->period_tasklet.data = (unsigned long)substream;
+
+        rtd->cl.name = dma_params->name;
+        rtd->cl.flags = dma_params->dma_port | EP93XX_DMA_M2P_IGNORE_ERROR |
+                ((substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
+                 EP93XX_DMA_M2P_TX : EP93XX_DMA_M2P_RX);
+        rtd->cl.cookie = substream;
+        rtd->cl.buffer_started = ep93xx_pcm_buffer_started;
+        rtd->cl.buffer_finished = ep93xx_pcm_buffer_finished;
+        ret = ep93xx_dma_m2p_client_register(&rtd->cl);
+        if (ret < 0) {
+                kfree(rtd);
+                return ret;
+        }
+        
+        substream->runtime->private_data = rtd;
+        return 0;
+}
+
+static int ep93xx_pcm_close(struct snd_pcm_substream *substream)
+{
+        struct ep93xx_runtime_data *rtd = substream->runtime->private_data;
+
+        ep93xx_dma_m2p_client_unregister(&rtd->cl);
+        kfree(rtd);
+        return 0;
+}
+
+static int ep93xx_pcm_hw_params(struct snd_pcm_substream *substream,
+                                struct snd_pcm_hw_params *params)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct ep93xx_runtime_data *rtd = runtime->private_data;
+        size_t totsize = params_buffer_bytes(params);
+        size_t period = params_period_bytes(params);
+        int i;
+
+        snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+        runtime->dma_bytes = totsize;
+
+        rtd->periods = (totsize + period - 1) / period;
+        for (i = 0; i < rtd->periods; i++) {
+                rtd->buf[i].bus_addr = runtime->dma_addr + (i * period);
+                rtd->buf[i].size = period;
+                if ((i + 1) * period > totsize)
+                        rtd->buf[i].size = totsize - (i * period);
+        }
+
+        return 0;
+}
+
+static int ep93xx_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+        snd_pcm_set_runtime_buffer(substream, NULL);
+        return 0;
+}
+
+static int ep93xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+        struct ep93xx_runtime_data *rtd = substream->runtime->private_data;
+        int ret;
+        int i;
+
+        ret = 0;
+        switch (cmd) {
+        case SNDRV_PCM_TRIGGER_START:
+        case SNDRV_PCM_TRIGGER_RESUME:
+        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+                rtd->pointer_bytes = 0;
+                for (i = 0; i < rtd->periods; i++)
+                        ep93xx_dma_m2p_submit(&rtd->cl, rtd->buf + i);
+                break;
+
+        case SNDRV_PCM_TRIGGER_STOP:
+        case SNDRV_PCM_TRIGGER_SUSPEND:
+        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+                ep93xx_dma_m2p_flush(&rtd->cl);
+                break;
+
+        default:
+                ret = -EINVAL;
+                break;
+        }
+
+        return ret;
+}
+
+static snd_pcm_uframes_t ep93xx_pcm_pointer(struct snd_pcm_substream *substream)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct ep93xx_runtime_data *rtd = substream->runtime->private_data;
+
+        /* FIXME: implement this with sub-period granularity */
+        return bytes_to_frames(runtime, rtd->pointer_bytes);
+}
+
+static int ep93xx_pcm_mmap(struct snd_pcm_substream *substream,
+                           struct vm_area_struct *vma)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+
+        return dma_mmap_writecombine(substream->pcm->card->dev, vma,
+                                     runtime->dma_area,
+                                     runtime->dma_addr,
+                                     runtime->dma_bytes);
+}
+
+static struct snd_pcm_ops ep93xx_pcm_ops = {
+        .open           = ep93xx_pcm_open,
+        .close          = ep93xx_pcm_close,
+        .ioctl          = snd_pcm_lib_ioctl,
+        .hw_params      = ep93xx_pcm_hw_params,
+        .hw_free        = ep93xx_pcm_hw_free,
+        .trigger        = ep93xx_pcm_trigger,
+        .pointer        = ep93xx_pcm_pointer,
+        .mmap           = ep93xx_pcm_mmap,
+};
+
+static int ep93xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
+{
+        struct snd_pcm_substream *substream = pcm->streams[stream].substream;
+        struct snd_dma_buffer *buf = &substream->dma_buffer;
+        size_t size = ep93xx_pcm_hardware.buffer_bytes_max;
+
+        buf->dev.type = SNDRV_DMA_TYPE_DEV;
+        buf->dev.dev = pcm->card->dev;
+        buf->private_data = NULL;
+        buf->area = dma_alloc_writecombine(pcm->card->dev, size,
+                                           &buf->addr, GFP_KERNEL);
+        buf->bytes = size;
+
+        return (buf->area == NULL) ? -ENOMEM : 0;
+}
+
+static void ep93xx_pcm_free_dma_buffers(struct snd_pcm *pcm)
+{
+        struct snd_pcm_substream *substream;
+        struct snd_dma_buffer *buf;
+        int stream;
+
+        for (stream = 0; stream < 2; stream++) {                
+                substream = pcm->streams[stream].substream;
+                if (!substream)
+                        continue;
+                
+                buf = &substream->dma_buffer;
+                if (!buf->area)
+                        continue;
+
+                dma_free_writecombine(pcm->card->dev, buf->bytes, buf->area,
+                                      buf->addr);
+                buf->area = NULL;
+        }
+}
+
+static u64 ep93xx_pcm_dmamask = 0xffffffff;
+
+static int ep93xx_pcm_new(struct snd_card *card, struct snd_soc_dai *dai,
+                          struct snd_pcm *pcm)
+{
+        int ret = 0;
+
+        if (!card->dev->dma_mask)
+                card->dev->dma_mask = &ep93xx_pcm_dmamask;
+        if (!card->dev->coherent_dma_mask)
+                card->dev->coherent_dma_mask = 0xffffffff;
+
+        if (dai->playback.channels_min) {
+                ret = ep93xx_pcm_preallocate_dma_buffer(pcm,
+                                        SNDRV_PCM_STREAM_PLAYBACK);
+                if (ret)
+                        return ret;
+        }
+
+        if (dai->capture.channels_min) {
+                ret = ep93xx_pcm_preallocate_dma_buffer(pcm,
+                                        SNDRV_PCM_STREAM_CAPTURE);
+                if (ret)
+                        return ret;
+        }
+
+        return 0;
+}
+
+struct snd_soc_platform ep93xx_soc_platform = {
+        .name           = "ep93xx-audio",
+        .pcm_ops        = &ep93xx_pcm_ops,
+        .pcm_new        = &ep93xx_pcm_new,
+        .pcm_free       = &ep93xx_pcm_free_dma_buffers,
+};
+EXPORT_SYMBOL_GPL(ep93xx_soc_platform);
+
+static int __init ep93xx_soc_platform_init(void)
+{
+        return snd_soc_register_platform(&ep93xx_soc_platform);
+}
+
+static void __exit ep93xx_soc_platform_exit(void)
+{
+        snd_soc_unregister_platform(&ep93xx_soc_platform);
+}
+
+module_init(ep93xx_soc_platform_init);
+module_exit(ep93xx_soc_platform_exit);
+
+MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com>");
+MODULE_DESCRIPTION("EP93xx ALSA PCM interface");
+MODULE_LICENSE("GPL");
diff --git a/sound/soc/ep93xx/ep93xx-pcm.h b/sound/soc/ep93xx/ep93xx-pcm.h
new file mode 100644
index 00000000000..4ffdd3f62fe
--- /dev/null
+++ b/sound/soc/ep93xx/ep93xx-pcm.h
@@ -0,0 +1,22 @@
+/*
+ * sound/soc/ep93xx/ep93xx-pcm.h - EP93xx ALSA PCM interface
+ *
+ * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
+ * Copyright (C) 2006 Applied Data Systems
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef _EP93XX_SND_SOC_PCM_H
+#define _EP93XX_SND_SOC_PCM_H
+
+struct ep93xx_pcm_dma_params {
+        char    *name;
+        int     dma_port;
+};
+
+extern struct snd_soc_platform ep93xx_soc_platform;
+
+#endif /* _EP93XX_SND_SOC_PCM_H */