[ALSA] SH7760 ASoC support

ALSA ASoC support for SH7760
This patch adds ALSA ASoC drivers for the Audio interfaces
of the SH7760 SoC:
Add driver for the SH7760 DMA engine (dmabrg)
Add AC97 driver for HAC unit(s) found on SH7760/SH7780
Add I2S driver for SSI unit(s) found on SH7760/SH7780
Add a generic SH7760-AC97 machine driver.
Hook it all up with the build system.

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 354 insertions, 0 deletions

diff --git a/sound/soc/sh/dma-sh7760.c b/sound/soc/sh/dma-sh7760.c
new file mode 100644
index 000000000000..cdee374b843e
--- /dev/null
+++ b/sound/soc/sh/dma-sh7760.c
@@ -0,0 +1,354 @@
+/*
+ * SH7760 ("camelot") DMABRG audio DMA unit support
+ *
+ * Copyright (C) 2007 Manuel Lauss <mano@roarinelk.homelinux.net>
+ *  licensed under the terms outlined in the file COPYING at the root
+ *  of the linux kernel sources.
+ *
+ * The SH7760 DMABRG provides 4 dma channels (2x rec, 2x play), which
+ * trigger an interrupt when one half of the programmed transfer size
+ * has been xmitted.
+ *
+ * FIXME: little-endian only for now
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.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/dmabrg.h>
+
+
+/* registers and bits */
+#define BRGATXSAR       0x00
+#define BRGARXDAR       0x04
+#define BRGATXTCR       0x08
+#define BRGARXTCR       0x0C
+#define BRGACR          0x10
+#define BRGATXTCNT      0x14
+#define BRGARXTCNT      0x18
+
+#define ACR_RAR         (1 << 18)
+#define ACR_RDS         (1 << 17)
+#define ACR_RDE         (1 << 16)
+#define ACR_TAR         (1 << 2)
+#define ACR_TDS         (1 << 1)
+#define ACR_TDE         (1 << 0)
+
+/* receiver/transmitter data alignment */
+#define ACR_RAM_NONE    (0 << 24)
+#define ACR_RAM_4BYTE   (1 << 24)
+#define ACR_RAM_2WORD   (2 << 24)
+#define ACR_TAM_NONE    (0 << 8)
+#define ACR_TAM_4BYTE   (1 << 8)
+#define ACR_TAM_2WORD   (2 << 8)
+
+
+struct camelot_pcm {
+        unsigned long mmio;  /* DMABRG audio channel control reg MMIO */
+        unsigned int txid;    /* ID of first DMABRG IRQ for this unit */
+
+        struct snd_pcm_substream *tx_ss;
+        unsigned long tx_period_size;
+        unsigned int  tx_period;
+
+        struct snd_pcm_substream *rx_ss;
+        unsigned long rx_period_size;
+        unsigned int  rx_period;
+
+} cam_pcm_data[2] = {
+        {
+                .mmio   =       0xFE3C0040,
+                .txid   =       DMABRGIRQ_A0TXF,
+        },
+        {
+                .mmio   =       0xFE3C0060,
+                .txid   =       DMABRGIRQ_A1TXF,
+        },
+};
+
+#define BRGREG(x)       (*(unsigned long *)(cam->mmio + (x)))
+
+/*
+ * set a minimum of 16kb per period, to avoid interrupt-"storm" and
+ * resulting skipping. In general, the bigger the minimum size, the
+ * better for overall system performance. (The SH7760 is a puny CPU
+ * with a slow SDRAM interface and poor internal bus bandwidth,
+ * *especially* when the LCDC is active).  The minimum for the DMAC
+ * is 8 bytes; 16kbytes are enough to get skip-free playback of a
+ * 44kHz/16bit/stereo MP3 on a lightly loaded system, and maintain
+ * reasonable responsiveness in MPlayer.
+ */
+#define DMABRG_PERIOD_MIN               16 * 1024
+#define DMABRG_PERIOD_MAX               0x03fffffc
+#define DMABRG_PREALLOC_BUFFER          32 * 1024
+#define DMABRG_PREALLOC_BUFFER_MAX      32 * 1024
+
+/* support everything the SSI supports */
+#define DMABRG_RATES    \
+        SNDRV_PCM_RATE_8000_192000
+
+#define DMABRG_FMTS     \
+        (SNDRV_PCM_FMTBIT_S8      | SNDRV_PCM_FMTBIT_U8      |  \
+         SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_U16_LE  |  \
+         SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_U20_3LE |  \
+         SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_U24_3LE |  \
+         SNDRV_PCM_FMTBIT_S32_LE  | SNDRV_PCM_FMTBIT_U32_LE)
+
+static struct snd_pcm_hardware camelot_pcm_hardware = {
+        .info = (SNDRV_PCM_INFO_MMAP |
+                SNDRV_PCM_INFO_INTERLEAVED |
+                SNDRV_PCM_INFO_BLOCK_TRANSFER |
+                SNDRV_PCM_INFO_MMAP_VALID),
+        .formats =      DMABRG_FMTS,
+        .rates =        DMABRG_RATES,
+        .rate_min =             8000,
+        .rate_max =             192000,
+        .channels_min =         2,
+        .channels_max =         8,              /* max of the SSI */
+        .buffer_bytes_max =     DMABRG_PERIOD_MAX,
+        .period_bytes_min =     DMABRG_PERIOD_MIN,
+        .period_bytes_max =     DMABRG_PERIOD_MAX / 2,
+        .periods_min =          2,
+        .periods_max =          2,
+        .fifo_size =            128,
+};
+
+static void camelot_txdma(void *data)
+{
+        struct camelot_pcm *cam = data;
+        cam->tx_period ^= 1;
+        snd_pcm_period_elapsed(cam->tx_ss);
+}
+
+static void camelot_rxdma(void *data)
+{
+        struct camelot_pcm *cam = data;
+        cam->rx_period ^= 1;
+        snd_pcm_period_elapsed(cam->rx_ss);
+}
+
+static int camelot_pcm_open(struct snd_pcm_substream *substream)
+{
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
+        int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
+        int ret, dmairq;
+
+        snd_soc_set_runtime_hwparams(substream, &camelot_pcm_hardware);
+
+        /* DMABRG buffer half/full events */
+        dmairq = (recv) ? cam->txid + 2 : cam->txid;
+        if (recv) {
+                cam->rx_ss = substream;
+                ret = dmabrg_request_irq(dmairq, camelot_rxdma, cam);
+                if (unlikely(ret)) {
+                        pr_debug("audio unit %d irqs already taken!\n",
+                             rtd->dai->cpu_dai->id);
+                        return -EBUSY;
+                }
+                (void)dmabrg_request_irq(dmairq + 1,camelot_rxdma, cam);
+        } else {
+                cam->tx_ss = substream;
+                ret = dmabrg_request_irq(dmairq, camelot_txdma, cam);
+                if (unlikely(ret)) {
+                        pr_debug("audio unit %d irqs already taken!\n",
+                             rtd->dai->cpu_dai->id);
+                        return -EBUSY;
+                }
+                (void)dmabrg_request_irq(dmairq + 1, camelot_txdma, cam);
+        }
+        return 0;
+}
+
+static int camelot_pcm_close(struct snd_pcm_substream *substream)
+{
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
+        int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
+        int dmairq;
+
+        dmairq = (recv) ? cam->txid + 2 : cam->txid;
+
+        if (recv)
+                cam->rx_ss = NULL;
+        else
+                cam->tx_ss = NULL;
+
+        dmabrg_free_irq(dmairq + 1);
+        dmabrg_free_irq(dmairq);
+
+        return 0;
+}
+
+static int camelot_hw_params(struct snd_pcm_substream *substream,
+                             struct snd_pcm_hw_params *hw_params)
+{
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
+        int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
+        int ret;
+
+        ret = snd_pcm_lib_malloc_pages(substream,
+                                       params_buffer_bytes(hw_params));
+        if (ret < 0)
+                return ret;
+
+        if (recv) {
+                cam->rx_period_size = params_period_bytes(hw_params);
+                cam->rx_period = 0;
+        } else {
+                cam->tx_period_size = params_period_bytes(hw_params);
+                cam->tx_period = 0;
+        }
+        return 0;
+}
+
+static int camelot_hw_free(struct snd_pcm_substream *substream)
+{
+        return snd_pcm_lib_free_pages(substream);
+}
+
+static int camelot_prepare(struct snd_pcm_substream *substream)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
+
+        pr_debug("PCM data: addr 0x%08ulx len %d\n",
+                 (u32)runtime->dma_addr, runtime->dma_bytes);
+ 
+        if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+                BRGREG(BRGATXSAR) = (unsigned long)runtime->dma_area;
+                BRGREG(BRGATXTCR) = runtime->dma_bytes;
+        } else {
+                BRGREG(BRGARXDAR) = (unsigned long)runtime->dma_area;
+                BRGREG(BRGARXTCR) = runtime->dma_bytes;
+        }
+
+        return 0;
+}
+
+static inline void dmabrg_play_dma_start(struct camelot_pcm *cam)
+{
+        unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
+        /* start DMABRG engine: XFER start, auto-addr-reload */
+        BRGREG(BRGACR) = acr | ACR_TDE | ACR_TAR | ACR_TAM_2WORD;
+}
+
+static inline void dmabrg_play_dma_stop(struct camelot_pcm *cam)
+{
+        unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
+        /* forcibly terminate data transmission */
+        BRGREG(BRGACR) = acr | ACR_TDS;
+}
+
+static inline void dmabrg_rec_dma_start(struct camelot_pcm *cam)
+{
+        unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
+        /* start DMABRG engine: recv start, auto-reload */
+        BRGREG(BRGACR) = acr | ACR_RDE | ACR_RAR | ACR_RAM_2WORD;
+}
+
+static inline void dmabrg_rec_dma_stop(struct camelot_pcm *cam)
+{
+        unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
+        /* forcibly terminate data receiver */
+        BRGREG(BRGACR) = acr | ACR_RDS;
+}
+
+static int camelot_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
+        int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
+
+        switch (cmd) {
+        case SNDRV_PCM_TRIGGER_START:
+                if (recv)
+                        dmabrg_rec_dma_start(cam);
+                else
+                        dmabrg_play_dma_start(cam);
+                break;
+        case SNDRV_PCM_TRIGGER_STOP:
+                if (recv)
+                        dmabrg_rec_dma_stop(cam);
+                else
+                        dmabrg_play_dma_stop(cam);
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static snd_pcm_uframes_t camelot_pos(struct snd_pcm_substream *substream)
+{
+        struct snd_pcm_runtime *runtime = substream->runtime;
+        struct snd_soc_pcm_runtime *rtd = substream->private_data;
+        struct camelot_pcm *cam = &cam_pcm_data[rtd->dai->cpu_dai->id];
+        int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
+        unsigned long pos;
+
+        /* cannot use the DMABRG pointer register: under load, by the
+         * time ALSA comes around to read the register, it is already
+         * far ahead (or worse, already done with the fragment) of the
+         * position at the time the IRQ was triggered, which results in
+         * fast-playback sound in my test application (ScummVM)
+         */
+        if (recv)
+                pos = cam->rx_period ? cam->rx_period_size : 0;
+        else
+                pos = cam->tx_period ? cam->tx_period_size : 0;
+
+        return bytes_to_frames(runtime, pos);
+}
+
+static struct snd_pcm_ops camelot_pcm_ops = {
+        .open           = camelot_pcm_open,
+        .close          = camelot_pcm_close,
+        .ioctl          = snd_pcm_lib_ioctl,
+        .hw_params      = camelot_hw_params,
+        .hw_free        = camelot_hw_free,
+        .prepare        = camelot_prepare,
+        .trigger        = camelot_trigger,
+        .pointer        = camelot_pos,
+};
+
+static void camelot_pcm_free(struct snd_pcm *pcm)
+{
+        snd_pcm_lib_preallocate_free_for_all(pcm);
+}
+
+static int camelot_pcm_new(struct snd_card *card,
+                           struct snd_soc_codec_dai *dai,
+                           struct snd_pcm *pcm)
+{
+        /* dont use SNDRV_DMA_TYPE_DEV, since it will oops the SH kernel
+         * in MMAP mode (i.e. aplay -M)
+         */
+        snd_pcm_lib_preallocate_pages_for_all(pcm,
+                SNDRV_DMA_TYPE_CONTINUOUS,
+                snd_dma_continuous_data(GFP_KERNEL),
+                DMABRG_PREALLOC_BUFFER, DMABRG_PREALLOC_BUFFER_MAX);
+
+        return 0;
+}
+
+struct snd_soc_platform sh7760_soc_platform = {
+        .name           = "sh7760-pcm",
+        .pcm_ops        = &camelot_pcm_ops,
+        .pcm_new        = camelot_pcm_new,
+        .pcm_free       = camelot_pcm_free,
+};
+EXPORT_SYMBOL_GPL(sh7760_soc_platform);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SH7760 Audio DMA (DMABRG) driver");
+MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>");