--- /dev/null
+/*
+ * 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/gfp.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
+
+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 |
+ SNDRV_PCM_INFO_BATCH),
+ .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->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->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->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->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->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->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->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->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 int camelot_pcm_new(struct snd_soc_pcm_runtime *rtd)
+{
+ struct snd_pcm *pcm = rtd->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;
+}
+
+static struct snd_soc_platform_driver sh7760_soc_platform = {
+ .ops = &camelot_pcm_ops,
+ .pcm_new = camelot_pcm_new,
+};
+
+static int sh7760_soc_platform_probe(struct platform_device *pdev)
+{
+ return snd_soc_register_platform(&pdev->dev, &sh7760_soc_platform);
+}
+
+static int sh7760_soc_platform_remove(struct platform_device *pdev)
+{
+ snd_soc_unregister_platform(&pdev->dev);
+ return 0;
+}
+
+static struct platform_driver sh7760_pcm_driver = {
+ .driver = {
+ .name = "sh7760-pcm-audio",
+ },
+
+ .probe = sh7760_soc_platform_probe,
+ .remove = sh7760_soc_platform_remove,
+};
+
+module_platform_driver(sh7760_pcm_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SH7760 Audio DMA (DMABRG) driver");
+MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>");
Code Review / kvmfornfv.git / blobdiff