[ALSA] ASoC pxa2xx DMA support

This patch adds pxa2xx ASoC DMA audio support. It's based on
sound/arm/pxa-pcm.c by Nicolas Pitre with the following differences.
o Modified driver structure to use ASoC core PCM callbacks and data
structures.
o Registration with ASoC core.
From: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Liam Girdwood <liam.girdwood@wolfsonmicro.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 363 insertions, 0 deletions

diff --git a/sound/soc/pxa/pxa2xx-pcm.c b/sound/soc/pxa/pxa2xx-pcm.c
new file mode 100644
index 000000000000..ff32f892287e
--- /dev/null
+++ b/sound/soc/pxa/pxa2xx-pcm.c
@@ -0,0 +1,363 @@
+/*
+ * linux/sound/arm/pxa2xx-pcm.c -- ALSA PCM interface for the Intel PXA2xx chip
+ *
+ * Author:      Nicolas Pitre
+ * Created:     Nov 30, 2004
+ * Copyright:   (C) 2004 MontaVista Software, Inc.
+ *
+ * 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/platform_device.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+
+#include <sound/driver.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+
+#include <asm/dma.h>
+#include <asm/hardware.h>
+#include <asm/arch/pxa-regs.h>
+#include <asm/arch/audio.h>
+
+#include "pxa2xx-pcm.h"
+
+static const struct snd_pcm_hardware pxa2xx_pcm_hardware = {
+        .info                   = SNDRV_PCM_INFO_MMAP |
+                                  SNDRV_PCM_INFO_MMAP_VALID |
+                                  SNDRV_PCM_INFO_INTERLEAVED |
+                                  SNDRV_PCM_INFO_PAUSE |
+                                  SNDRV_PCM_INFO_RESUME,
+        .formats                = SNDRV_PCM_FMTBIT_S16_LE |
+                                        SNDRV_PCM_FMTBIT_S24_LE |
+                                        SNDRV_PCM_FMTBIT_S32_LE,
+        .period_bytes_min       = 32,
+        .period_bytes_max       = 8192 - 32,
+        .periods_min            = 1,
+        .periods_max            = PAGE_SIZE/sizeof(pxa_dma_desc),
+        .buffer_bytes_max       = 128 * 1024,
+        .fifo_size              = 32,
+};
+
+struct pxa2xx_runtime_data {
+        int dma_ch;
+        struct pxa2xx_pcm_dma_params *params;
+        pxa_dma_desc *dma_desc_array;
+        dma_addr_t dma_desc_array_phys;
+};
+
+static void pxa2xx_pcm_dma_irq(int dma_ch, void *dev_id)
+{
+        struct snd_pcm_substream *substream = dev_id;
+        struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
+        int dcsr;
+
+        dcsr = DCSR(dma_ch);
+        DCSR(dma_ch) = dcsr & ~DCSR_STOPIRQEN;
+
+        if (dcsr & DCSR_ENDINTR) {
+                snd_pcm_period_elapsed(substream);
+        } else {
+                printk( KERN_ERR "%s: DMA error on channel %d (DCSR=%#x)\n",
+                        prtd->params->name, dma_ch, dcsr );
+        }
+}
+
+static int pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
+        struct snd_pcm_hw_params *params)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct pxa2xx_runtime_data *prtd = runtime->private_data;
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct pxa2xx_pcm_dma_params *dma = rtd->cpu_dai->dma_data;
+        size_t totsize = params_buffer_bytes(params);
+        size_t period = params_period_bytes(params);
+        pxa_dma_desc *dma_desc;
+        dma_addr_t dma_buff_phys, next_desc_phys;
+        int ret;
+
+        /* this may get called several times by oss emulation
+         * with different params */
+        if (prtd->params == NULL) {
+                prtd->params = dma;
+                ret = pxa_request_dma(prtd->params->name, DMA_PRIO_LOW,
+                              pxa2xx_pcm_dma_irq, substream);
+                if (ret < 0)
+                        return ret;
+                prtd->dma_ch = ret;
+        } else if (prtd->params != dma) {
+                pxa_free_dma(prtd->dma_ch);
+                prtd->params = dma;
+                ret = pxa_request_dma(prtd->params->name, DMA_PRIO_LOW,
+                              pxa2xx_pcm_dma_irq, substream);
+                if (ret < 0)
+                        return ret;
+                prtd->dma_ch = ret;
+        }
+
+        snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+        runtime->dma_bytes = totsize;
+
+        dma_desc = prtd->dma_desc_array;
+        next_desc_phys = prtd->dma_desc_array_phys;
+        dma_buff_phys = runtime->dma_addr;
+        do {
+                next_desc_phys += sizeof(pxa_dma_desc);
+                dma_desc->ddadr = next_desc_phys;
+                if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+                        dma_desc->dsadr = dma_buff_phys;
+                        dma_desc->dtadr = prtd->params->dev_addr;
+                } else {
+                        dma_desc->dsadr = prtd->params->dev_addr;
+                        dma_desc->dtadr = dma_buff_phys;
+                }
+                if (period > totsize)
+                        period = totsize;
+                dma_desc->dcmd = prtd->params->dcmd | period | DCMD_ENDIRQEN;
+                dma_desc++;
+                dma_buff_phys += period;
+        } while (totsize -= period);
+        dma_desc[-1].ddadr = prtd->dma_desc_array_phys;
+
+        return 0;
+}
+
+static int pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+        struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
+
+        if (prtd && prtd->params)
+                *prtd->params->drcmr = 0;
+
+        if (prtd->dma_ch) {
+                snd_pcm_set_runtime_buffer(substream, NULL);
+                pxa_free_dma(prtd->dma_ch);
+                prtd->dma_ch = 0;
+        }
+
+        return 0;
+}
+
+static int pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
+{
+        struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
+
+        DCSR(prtd->dma_ch) &= ~DCSR_RUN;
+        DCSR(prtd->dma_ch) = 0;
+        DCMD(prtd->dma_ch) = 0;
+        *prtd->params->drcmr = prtd->dma_ch | DRCMR_MAPVLD;
+
+        return 0;
+}
+
+static int pxa2xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+        struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
+        int ret = 0;
+
+        switch (cmd) {
+        case SNDRV_PCM_TRIGGER_START:
+                DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
+                DCSR(prtd->dma_ch) = DCSR_RUN;
+                break;
+
+        case SNDRV_PCM_TRIGGER_STOP:
+        case SNDRV_PCM_TRIGGER_SUSPEND:
+        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+                DCSR(prtd->dma_ch) &= ~DCSR_RUN;
+                break;
+
+        case SNDRV_PCM_TRIGGER_RESUME:
+                DCSR(prtd->dma_ch) |= DCSR_RUN;
+                break;
+        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+                DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
+                DCSR(prtd->dma_ch) |= DCSR_RUN;
+                break;
+
+        default:
+                ret = -EINVAL;
+        }
+
+        return ret;
+}
+
+static snd_pcm_uframes_t
+pxa2xx_pcm_pointer(struct snd_pcm_substream *substream)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct pxa2xx_runtime_data *prtd = runtime->private_data;
+
+        dma_addr_t ptr = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
+                         DSADR(prtd->dma_ch) : DTADR(prtd->dma_ch);
+        snd_pcm_uframes_t x = bytes_to_frames(runtime, ptr - runtime->dma_addr);
+
+        if (x == runtime->buffer_size)
+                x = 0;
+        return x;
+}
+
+static int pxa2xx_pcm_open(struct snd_pcm_substream *substream)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct pxa2xx_runtime_data *prtd;
+        int ret;
+
+        snd_soc_set_runtime_hwparams(substream, &pxa2xx_pcm_hardware);
+
+        /*
+         * For mysterious reasons (and despite what the manual says)
+         * playback samples are lost if the DMA count is not a multiple
+         * of the DMA burst size.  Let's add a rule to enforce that.
+         */
+        ret = snd_pcm_hw_constraint_step(runtime, 0,
+                SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
+        if (ret)
+                goto out;
+
+        ret = snd_pcm_hw_constraint_step(runtime, 0,
+                SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
+        if (ret)
+                goto out;
+
+        prtd = kzalloc(sizeof(struct pxa2xx_runtime_data), GFP_KERNEL);
+        if (prtd == NULL) {
+                ret = -ENOMEM;
+                goto out;
+        }
+
+        prtd->dma_desc_array =
+                dma_alloc_writecombine(substream->pcm->card->dev, PAGE_SIZE,
+                                       &prtd->dma_desc_array_phys, GFP_KERNEL);
+        if (!prtd->dma_desc_array) {
+                ret = -ENOMEM;
+                goto err1;
+        }
+
+        runtime->private_data = prtd;
+        return 0;
+
+ err1:
+        kfree(prtd);
+ out:
+        return ret;
+}
+
+static int pxa2xx_pcm_close(struct snd_pcm_substream *substream)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct pxa2xx_runtime_data *prtd = runtime->private_data;
+
+        dma_free_writecombine(substream->pcm->card->dev, PAGE_SIZE,
+                              prtd->dma_desc_array, prtd->dma_desc_array_phys);
+        kfree(prtd);
+        return 0;
+}
+
+static int pxa2xx_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);
+}
+
+struct snd_pcm_ops pxa2xx_pcm_ops = {
+        .open           = pxa2xx_pcm_open,
+        .close          = pxa2xx_pcm_close,
+        .ioctl          = snd_pcm_lib_ioctl,
+        .hw_params      = pxa2xx_pcm_hw_params,
+        .hw_free        = pxa2xx_pcm_hw_free,
+        .prepare        = pxa2xx_pcm_prepare,
+        .trigger        = pxa2xx_pcm_trigger,
+        .pointer        = pxa2xx_pcm_pointer,
+        .mmap           = pxa2xx_pcm_mmap,
+};
+
+static int pxa2xx_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 = pxa2xx_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);
+        if (!buf->area)
+                return -ENOMEM;
+        buf->bytes = size;
+        return 0;
+}
+
+static void pxa2xx_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 pxa2xx_pcm_dmamask = DMA_32BIT_MASK;
+
+int pxa2xx_pcm_new(struct snd_card *card, struct snd_soc_codec_dai *dai,
+        struct snd_pcm *pcm)
+{
+        int ret = 0;
+
+        if (!card->dev->dma_mask)
+                card->dev->dma_mask = &pxa2xx_pcm_dmamask;
+        if (!card->dev->coherent_dma_mask)
+                card->dev->coherent_dma_mask = DMA_32BIT_MASK;
+
+        if (dai->playback.channels_min) {
+                ret = pxa2xx_pcm_preallocate_dma_buffer(pcm,
+                        SNDRV_PCM_STREAM_PLAYBACK);
+                if (ret)
+                        goto out;
+        }
+
+        if (dai->capture.channels_min) {
+                ret = pxa2xx_pcm_preallocate_dma_buffer(pcm,
+                        SNDRV_PCM_STREAM_CAPTURE);
+                if (ret)
+                        goto out;
+        }
+ out:
+        return ret;
+}
+
+struct snd_soc_platform pxa2xx_soc_platform = {
+        .name           = "pxa2xx-audio",
+        .pcm_ops        = &pxa2xx_pcm_ops,
+        .pcm_new        = pxa2xx_pcm_new,
+        .pcm_free       = pxa2xx_pcm_free_dma_buffers,
+};
+
+EXPORT_SYMBOL_GPL(pxa2xx_soc_platform);
+
+MODULE_AUTHOR("Nicolas Pitre");
+MODULE_DESCRIPTION("Intel PXA2xx PCM DMA module");
+MODULE_LICENSE("GPL");