[ALSA] ASoC AT91RM92000 audio DMA

This patch adds ASoC audio DMA support to the Atmel AT91RM9200 CPU.
Features:-
 o Playback/Capture supported.
 o 16 Bit data size.

Signed-off-by: Frank Mandarino <fmandarino@endrelia.com>
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>

2 files changed, 503 insertions, 0 deletions

diff --git a/sound/soc/at91/at91rm9200-pcm.c b/sound/soc/at91/at91rm9200-pcm.c
new file mode 100644
index 000000000000..237bc5f07579
--- /dev/null
+++ b/sound/soc/at91/at91rm9200-pcm.c
@@ -0,0 +1,428 @@
+/*
+ * at91rm9200-pcm.c -- ALSA PCM interface for the Atmel AT91RM9200 chip.
+ *
+ * Author:      Frank Mandarino <fmandarino@endrelia.com>
+ *              Endrelia Technologies Inc.
+ * Created:     Mar 3, 2006
+ *
+ * Based on pxa2xx-pcm.c by:
+ *
+ * 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/arch/at91rm9200.h>
+#include <asm/arch/at91rm9200_ssc.h>
+#include <asm/arch/at91rm9200_pdc.h>
+#include <asm/arch/hardware.h>
+
+#include "at91rm9200-pcm.h"
+
+#if 0
+#define DBG(x...)       printk(KERN_INFO "at91rm9200-pcm: " x)
+#else
+#define DBG(x...)
+#endif
+
+static const snd_pcm_hardware_t at91rm9200_pcm_hardware = {
+        .info                   = SNDRV_PCM_INFO_MMAP |
+                                  SNDRV_PCM_INFO_MMAP_VALID |
+                                  SNDRV_PCM_INFO_INTERLEAVED |
+                                  SNDRV_PCM_INFO_PAUSE,
+        .formats                = SNDRV_PCM_FMTBIT_S16_LE,
+        .period_bytes_min       = 32,
+        .period_bytes_max       = 8192,
+        .periods_min            = 2,
+        .periods_max            = 1024,
+        .buffer_bytes_max       = 32 * 1024,
+};
+
+struct at91rm9200_runtime_data {
+        at91rm9200_pcm_dma_params_t *params;
+        dma_addr_t dma_buffer;                  /* physical address of dma buffer */
+        dma_addr_t dma_buffer_end;              /* first address beyond DMA buffer */
+        size_t period_size;
+        dma_addr_t period_ptr;                  /* physical address of next period */
+        u32 pdc_xpr_save;                       /* PDC register save */
+        u32 pdc_xcr_save;
+        u32 pdc_xnpr_save;
+        u32 pdc_xncr_save;
+};
+
+static void at91rm9200_pcm_dma_irq(u32 ssc_sr,
+        struct snd_pcm_substream *substream)
+{
+        struct at91rm9200_runtime_data *prtd = substream->runtime->private_data;
+        at91rm9200_pcm_dma_params_t *params = prtd->params;
+        static int count = 0;
+
+        count++;
+
+        if (ssc_sr & params->mask->ssc_endbuf) {
+
+                printk(KERN_WARNING
+                        "at91rm9200-pcm: buffer %s on %s (SSC_SR=%#x, count=%d)\n",
+                        substream->stream == SNDRV_PCM_STREAM_PLAYBACK
+                                ? "underrun" : "overrun",
+                        params->name, ssc_sr, count);
+
+                /* re-start the PDC */
+                at91_ssc_write(params->pdc->ptcr, params->mask->pdc_disable);
+
+                prtd->period_ptr += prtd->period_size;
+                if (prtd->period_ptr >= prtd->dma_buffer_end) {
+                        prtd->period_ptr = prtd->dma_buffer;
+                }
+
+                at91_ssc_write(params->pdc->xpr, prtd->period_ptr);
+                at91_ssc_write(params->pdc->xcr,
+                                prtd->period_size / params->pdc_xfer_size);
+
+                at91_ssc_write(params->pdc->ptcr, params->mask->pdc_enable);
+        }
+
+        if (ssc_sr & params->mask->ssc_endx) {
+
+                /* Load the PDC next pointer and counter registers */
+                prtd->period_ptr += prtd->period_size;
+                if (prtd->period_ptr >= prtd->dma_buffer_end) {
+                        prtd->period_ptr = prtd->dma_buffer;
+                }
+                at91_ssc_write(params->pdc->xnpr, prtd->period_ptr);
+                at91_ssc_write(params->pdc->xncr,
+                                prtd->period_size / params->pdc_xfer_size);
+        }
+
+        snd_pcm_period_elapsed(substream);
+}
+
+static int at91rm9200_pcm_hw_params(struct snd_pcm_substream *substream,
+        struct snd_pcm_hw_params *params)
+{
+        snd_pcm_runtime_t *runtime = substream->runtime;
+        struct at91rm9200_runtime_data *prtd = runtime->private_data;
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+
+        /* this may get called several times by oss emulation
+         * with different params */
+
+        snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+        runtime->dma_bytes = params_buffer_bytes(params);
+
+        prtd->params = rtd->cpu_dai->dma_data;
+        prtd->params->dma_intr_handler = at91rm9200_pcm_dma_irq;
+
+        prtd->dma_buffer = runtime->dma_addr;
+        prtd->dma_buffer_end = runtime->dma_addr + runtime->dma_bytes;
+        prtd->period_size = params_period_bytes(params);
+
+        DBG("hw_params: DMA for %s initialized (dma_bytes=%d, period_size=%d)\n",
+                prtd->params->name, runtime->dma_bytes, prtd->period_size);
+        return 0;
+}
+
+static int at91rm9200_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+        struct at91rm9200_runtime_data *prtd = substream->runtime->private_data;
+        at91rm9200_pcm_dma_params_t *params = prtd->params;
+
+        if (params != NULL) {
+                at91_ssc_write(params->pdc->ptcr, params->mask->pdc_disable);
+                prtd->params->dma_intr_handler = NULL;
+        }
+
+        return 0;
+}
+
+static int at91rm9200_pcm_prepare(struct snd_pcm_substream *substream)
+{
+        struct at91rm9200_runtime_data *prtd = substream->runtime->private_data;
+        at91rm9200_pcm_dma_params_t *params = prtd->params;
+
+        at91_ssc_write(params->ssc->idr,
+                        params->mask->ssc_endx | params->mask->ssc_endbuf);
+
+        at91_ssc_write(params->pdc->ptcr, params->mask->pdc_disable);
+        return 0;
+}
+
+static int at91rm9200_pcm_trigger(struct snd_pcm_substream *substream,
+        int cmd)
+{
+        struct at91rm9200_runtime_data *prtd = substream->runtime->private_data;
+        at91rm9200_pcm_dma_params_t *params = prtd->params;
+        int ret = 0;
+
+        switch (cmd) {
+        case SNDRV_PCM_TRIGGER_START:
+                prtd->period_ptr = prtd->dma_buffer;
+
+                at91_ssc_write(params->pdc->xpr, prtd->period_ptr);
+                at91_ssc_write(params->pdc->xcr,
+                                prtd->period_size / params->pdc_xfer_size);
+
+                prtd->period_ptr += prtd->period_size;
+                at91_ssc_write(params->pdc->xnpr, prtd->period_ptr);
+                at91_ssc_write(params->pdc->xncr,
+                                prtd->period_size / params->pdc_xfer_size);
+
+                DBG("trigger: period_ptr=%lx, xpr=%lx, xcr=%ld, xnpr=%lx, xncr=%ld\n",
+                        (unsigned long) prtd->period_ptr,
+                        at91_ssc_read(params->pdc->xpr),
+                        at91_ssc_read(params->pdc->xcr),
+                        at91_ssc_read(params->pdc->xnpr),
+                        at91_ssc_read(params->pdc->xncr));
+
+                at91_ssc_write(params->ssc->ier,
+                        params->mask->ssc_endx | params->mask->ssc_endbuf);
+
+                at91_ssc_write(params->pdc->ptcr, params->mask->pdc_enable);
+
+                DBG("sr=%lx imr=%lx\n", at91_ssc_read(params->ssc->ier - 4),
+                                        at91_ssc_read(params->ssc->ier + 8));
+                break;
+
+        case SNDRV_PCM_TRIGGER_STOP:
+        case SNDRV_PCM_TRIGGER_SUSPEND:
+        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+                at91_ssc_write(params->pdc->ptcr, params->mask->pdc_disable);
+                break;
+
+        case SNDRV_PCM_TRIGGER_RESUME:
+        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+                at91_ssc_write(params->pdc->ptcr, params->mask->pdc_enable);
+                break;
+
+        default:
+                ret = -EINVAL;
+        }
+
+        return ret;
+}
+
+static snd_pcm_uframes_t at91rm9200_pcm_pointer(
+        struct snd_pcm_substream *substream)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct at91rm9200_runtime_data *prtd = runtime->private_data;
+        at91rm9200_pcm_dma_params_t *params = prtd->params;
+        dma_addr_t ptr;
+        snd_pcm_uframes_t x;
+
+        ptr = (dma_addr_t) at91_ssc_read(params->pdc->xpr);
+        x = bytes_to_frames(runtime, ptr - prtd->dma_buffer);
+
+        if (x == runtime->buffer_size)
+                x = 0;
+        return x;
+}
+
+static int at91rm9200_pcm_open(struct snd_pcm_substream *substream)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct at91rm9200_runtime_data *prtd;
+        int ret = 0;
+
+        snd_soc_set_runtime_hwparams(substream, &at91rm9200_pcm_hardware);
+
+        /* ensure that buffer size is a multiple of period size */
+        ret = snd_pcm_hw_constraint_integer(runtime, SNDRV_PCM_HW_PARAM_PERIODS);
+        if (ret < 0)
+                goto out;
+
+        prtd = kzalloc(sizeof(struct at91rm9200_runtime_data), GFP_KERNEL);
+        if (prtd == NULL) {
+                ret = -ENOMEM;
+                goto out;
+        }
+        runtime->private_data = prtd;
+
+ out:
+        return ret;
+}
+
+static int at91rm9200_pcm_close(struct snd_pcm_substream *substream)
+{
+        struct at91rm9200_runtime_data *prtd = substream->runtime->private_data;
+
+        kfree(prtd);
+        return 0;
+}
+
+static int at91rm9200_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 at91rm9200_pcm_ops = {
+        .open           = at91rm9200_pcm_open,
+        .close          = at91rm9200_pcm_close,
+        .ioctl          = snd_pcm_lib_ioctl,
+        .hw_params      = at91rm9200_pcm_hw_params,
+        .hw_free        = at91rm9200_pcm_hw_free,
+        .prepare        = at91rm9200_pcm_prepare,
+        .trigger        = at91rm9200_pcm_trigger,
+        .pointer        = at91rm9200_pcm_pointer,
+        .mmap           = at91rm9200_pcm_mmap,
+};
+
+static int at91rm9200_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 = at91rm9200_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);
+
+        DBG("preallocate_dma_buffer: area=%p, addr=%p, size=%d\n",
+                (void *) buf->area,
+                (void *) buf->addr,
+                size);
+
+        if (!buf->area)
+                return -ENOMEM;
+
+        buf->bytes = size;
+        return 0;
+}
+
+static u64 at91rm9200_pcm_dmamask = 0xffffffff;
+
+static int at91rm9200_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 = &at91rm9200_pcm_dmamask;
+        if (!card->dev->coherent_dma_mask)
+                card->dev->coherent_dma_mask = 0xffffffff;
+
+        if (dai->playback.channels_min) {
+                ret = at91rm9200_pcm_preallocate_dma_buffer(pcm,
+                        SNDRV_PCM_STREAM_PLAYBACK);
+                if (ret)
+                        goto out;
+        }
+
+        if (dai->capture.channels_min) {
+                ret = at91rm9200_pcm_preallocate_dma_buffer(pcm,
+                        SNDRV_PCM_STREAM_CAPTURE);
+                if (ret)
+                        goto out;
+        }
+ out:
+        return ret;
+}
+
+static void at91rm9200_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 int at91rm9200_pcm_suspend(struct platform_device *pdev,
+        struct snd_soc_cpu_dai *dai)
+{
+        struct snd_pcm_runtime *runtime = dai->runtime;
+        struct at91rm9200_runtime_data *prtd;
+        at91rm9200_pcm_dma_params_t *params;
+
+        if (!runtime)
+                return 0;
+
+        prtd = runtime->private_data;
+        params = prtd->params;
+
+        /* disable the PDC and save the PDC registers */
+
+        at91_ssc_write(params->pdc->ptcr, params->mask->pdc_disable);
+
+        prtd->pdc_xpr_save  = at91_ssc_read(params->pdc->xpr);
+        prtd->pdc_xcr_save  = at91_ssc_read(params->pdc->xcr);
+        prtd->pdc_xnpr_save = at91_ssc_read(params->pdc->xnpr);
+        prtd->pdc_xncr_save = at91_ssc_read(params->pdc->xncr);
+
+        return 0;
+}
+
+static int at91rm9200_pcm_resume(struct platform_device *pdev,
+        struct snd_soc_cpu_dai *dai)
+{
+        struct snd_pcm_runtime *runtime = dai->runtime;
+        struct at91rm9200_runtime_data *prtd;
+        at91rm9200_pcm_dma_params_t *params;
+
+        if (!runtime)
+                return 0;
+
+        prtd = runtime->private_data;
+        params = prtd->params;
+
+        /* restore the PDC registers and enable the PDC */
+        at91_ssc_write(params->pdc->xpr,  prtd->pdc_xpr_save);
+        at91_ssc_write(params->pdc->xcr,  prtd->pdc_xcr_save);
+        at91_ssc_write(params->pdc->xnpr, prtd->pdc_xnpr_save);
+        at91_ssc_write(params->pdc->xncr, prtd->pdc_xncr_save);
+
+        at91_ssc_write(params->pdc->ptcr, params->mask->pdc_enable);
+        return 0;
+}
+
+struct snd_soc_platform at91rm9200_soc_platform = {
+        .name           = "at91rm9200-audio",
+        .pcm_ops        = &at91rm9200_pcm_ops,
+        .pcm_new        = at91rm9200_pcm_new,
+        .pcm_free       = at91rm9200_pcm_free_dma_buffers,
+        .suspend        = at91rm9200_pcm_suspend,
+        .resume         = at91rm9200_pcm_resume,
+};
+
+EXPORT_SYMBOL_GPL(at91rm9200_soc_platform);
+
+MODULE_AUTHOR("Frank Mandarino <fmandarino@endrelia.com>");
+MODULE_DESCRIPTION("Atmel AT91RM9200 PCM module");
+MODULE_LICENSE("GPL");
diff --git a/sound/soc/at91/at91rm9200-pcm.h b/sound/soc/at91/at91rm9200-pcm.h
new file mode 100644
index 000000000000..65468f173771
--- /dev/null
+++ b/sound/soc/at91/at91rm9200-pcm.h
@@ -0,0 +1,75 @@
+/*
+ * at91rm9200-pcm.h - ALSA PCM interface for the Atmel AT91RM9200 chip
+ *
+ * Author:      Frank Mandarino <fmandarino@endrelia.com>
+ *              Endrelia Technologies Inc.
+ * Created:     Mar 3, 2006
+ *
+ * Based on pxa2xx-pcm.h by:
+ *
+ * Author:      Nicolas Pitre
+ * Created:     Nov 30, 2004
+ * Copyright:   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.
+ */
+
+/*
+ * Registers and status bits that are required by the PCM driver.
+ */
+struct at91rm9200_ssc_regs {
+        void __iomem    *cr;            /* SSC control */
+        void __iomem    *ier;           /* SSC interrupt enable */
+        void __iomem    *idr;           /* SSC interrupt disable */
+};
+
+struct at91rm9200_pdc_regs {
+        void __iomem    *xpr;           /* PDC recv/trans pointer */
+        void __iomem    *xcr;           /* PDC recv/trans counter */
+        void __iomem    *xnpr;          /* PDC next recv/trans pointer */
+        void __iomem    *xncr;          /* PDC next recv/trans counter */
+        void __iomem    *ptcr;          /* PDC transfer control */
+};
+
+struct at91rm9200_ssc_mask {
+        u32     ssc_enable;             /* SSC recv/trans enable */
+        u32     ssc_disable;            /* SSC recv/trans disable */
+        u32     ssc_endx;               /* SSC ENDTX or ENDRX */
+        u32     ssc_endbuf;             /* SSC TXBUFE or RXBUFF */
+        u32     pdc_enable;             /* PDC recv/trans enable */
+        u32     pdc_disable;            /* PDC recv/trans disable */
+};
+
+
+/*
+ * This structure, shared between the PCM driver and the interface,
+ * contains all information required by the PCM driver to perform the
+ * PDC DMA operation.  All fields except dma_intr_handler() are initialized
+ * by the interface.  The dms_intr_handler() pointer is set by the PCM
+ * driver and called by the interface SSC interrupt handler if it is
+ * non-NULL.
+ */
+typedef struct {
+        char *name;                     /* stream identifier */
+        int pdc_xfer_size;              /* PDC counter increment in bytes */
+        struct at91rm9200_ssc_regs *ssc; /* SSC register addresses */
+        struct at91rm9200_pdc_regs *pdc; /* PDC receive/transmit registers */
+        struct at91rm9200_ssc_mask *mask;/* SSC & PDC status bits */
+        snd_pcm_substream_t *substream;
+        void (*dma_intr_handler)(u32, snd_pcm_substream_t *);
+} at91rm9200_pcm_dma_params_t;
+
+extern struct snd_soc_cpu_dai at91rm9200_i2s_dai[3];
+extern struct snd_soc_platform at91rm9200_soc_platform;
+
+
+/*
+ * SSC I/O helpers.
+ * E.g., at91_ssc_write(AT91_SSC(1) + AT91_SSC_CR, AT91_SSC_RXEN);
+ */
+#define AT91_SSC(x) (((x)==0) ? AT91_VA_BASE_SSC0 :\
+         ((x)==1) ? AT91_VA_BASE_SSC1 : ((x)==2) ? AT91_VA_BASE_SSC2 : NULL)
+#define at91_ssc_read(a)        ((unsigned long) __raw_readl(a))
+#define at91_ssc_write(a,v)     __raw_writel((v),(a))