1 files changed, 353 insertions, 0 deletions
diff --git a/sound/soc/sh/dma-sh7760.c b/sound/soc/sh/dma-sh7760.c
new file mode 100644
index 0000000..9faa126
--- /dev/null
+++ b/sound/soc/sh/dma-sh7760.c
@@ -0,0 +1,353 @@
+/*
+ * 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/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_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>");