![Lars-Peter Clausen](/assets/img/avatar_default.png)
The ASoC core assumes that the PCM component of the ASoC card transparently moves data around and does not impose any restrictions on the memory layout or the transfer speed. It ignores all fields from the snd_pcm_hardware struct for the PCM driver that are related to this. Setting these fields in the PCM driver might suggest otherwise though, so rather not set them. Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Mark Brown <broonie@linaro.org>
360 lines
9.6 KiB
C
360 lines
9.6 KiB
C
/*
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* SH7760 ("camelot") DMABRG audio DMA unit support
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*
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* Copyright (C) 2007 Manuel Lauss <mano@roarinelk.homelinux.net>
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* licensed under the terms outlined in the file COPYING at the root
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* of the linux kernel sources.
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*
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* The SH7760 DMABRG provides 4 dma channels (2x rec, 2x play), which
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* trigger an interrupt when one half of the programmed transfer size
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* has been xmitted.
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*
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* FIXME: little-endian only for now
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*/
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#include <linux/module.h>
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#include <linux/gfp.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/dma-mapping.h>
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#include <sound/core.h>
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#include <sound/pcm.h>
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#include <sound/pcm_params.h>
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#include <sound/soc.h>
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#include <asm/dmabrg.h>
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/* registers and bits */
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#define BRGATXSAR 0x00
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#define BRGARXDAR 0x04
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#define BRGATXTCR 0x08
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#define BRGARXTCR 0x0C
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#define BRGACR 0x10
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#define BRGATXTCNT 0x14
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#define BRGARXTCNT 0x18
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#define ACR_RAR (1 << 18)
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#define ACR_RDS (1 << 17)
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#define ACR_RDE (1 << 16)
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#define ACR_TAR (1 << 2)
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#define ACR_TDS (1 << 1)
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#define ACR_TDE (1 << 0)
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/* receiver/transmitter data alignment */
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#define ACR_RAM_NONE (0 << 24)
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#define ACR_RAM_4BYTE (1 << 24)
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#define ACR_RAM_2WORD (2 << 24)
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#define ACR_TAM_NONE (0 << 8)
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#define ACR_TAM_4BYTE (1 << 8)
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#define ACR_TAM_2WORD (2 << 8)
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struct camelot_pcm {
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unsigned long mmio; /* DMABRG audio channel control reg MMIO */
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unsigned int txid; /* ID of first DMABRG IRQ for this unit */
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struct snd_pcm_substream *tx_ss;
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unsigned long tx_period_size;
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unsigned int tx_period;
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struct snd_pcm_substream *rx_ss;
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unsigned long rx_period_size;
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unsigned int rx_period;
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} cam_pcm_data[2] = {
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{
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.mmio = 0xFE3C0040,
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.txid = DMABRGIRQ_A0TXF,
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},
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{
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.mmio = 0xFE3C0060,
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.txid = DMABRGIRQ_A1TXF,
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},
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};
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#define BRGREG(x) (*(unsigned long *)(cam->mmio + (x)))
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/*
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* set a minimum of 16kb per period, to avoid interrupt-"storm" and
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* resulting skipping. In general, the bigger the minimum size, the
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* better for overall system performance. (The SH7760 is a puny CPU
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* with a slow SDRAM interface and poor internal bus bandwidth,
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* *especially* when the LCDC is active). The minimum for the DMAC
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* is 8 bytes; 16kbytes are enough to get skip-free playback of a
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* 44kHz/16bit/stereo MP3 on a lightly loaded system, and maintain
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* reasonable responsiveness in MPlayer.
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*/
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#define DMABRG_PERIOD_MIN 16 * 1024
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#define DMABRG_PERIOD_MAX 0x03fffffc
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#define DMABRG_PREALLOC_BUFFER 32 * 1024
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#define DMABRG_PREALLOC_BUFFER_MAX 32 * 1024
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static struct snd_pcm_hardware camelot_pcm_hardware = {
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.info = (SNDRV_PCM_INFO_MMAP |
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SNDRV_PCM_INFO_INTERLEAVED |
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SNDRV_PCM_INFO_BLOCK_TRANSFER |
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SNDRV_PCM_INFO_MMAP_VALID |
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SNDRV_PCM_INFO_BATCH),
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.buffer_bytes_max = DMABRG_PERIOD_MAX,
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.period_bytes_min = DMABRG_PERIOD_MIN,
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.period_bytes_max = DMABRG_PERIOD_MAX / 2,
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.periods_min = 2,
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.periods_max = 2,
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.fifo_size = 128,
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};
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static void camelot_txdma(void *data)
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{
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struct camelot_pcm *cam = data;
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cam->tx_period ^= 1;
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snd_pcm_period_elapsed(cam->tx_ss);
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}
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static void camelot_rxdma(void *data)
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{
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struct camelot_pcm *cam = data;
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cam->rx_period ^= 1;
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snd_pcm_period_elapsed(cam->rx_ss);
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}
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static int camelot_pcm_open(struct snd_pcm_substream *substream)
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{
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struct snd_soc_pcm_runtime *rtd = substream->private_data;
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struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
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int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
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int ret, dmairq;
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snd_soc_set_runtime_hwparams(substream, &camelot_pcm_hardware);
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/* DMABRG buffer half/full events */
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dmairq = (recv) ? cam->txid + 2 : cam->txid;
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if (recv) {
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cam->rx_ss = substream;
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ret = dmabrg_request_irq(dmairq, camelot_rxdma, cam);
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if (unlikely(ret)) {
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pr_debug("audio unit %d irqs already taken!\n",
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rtd->cpu_dai->id);
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return -EBUSY;
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}
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(void)dmabrg_request_irq(dmairq + 1,camelot_rxdma, cam);
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} else {
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cam->tx_ss = substream;
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ret = dmabrg_request_irq(dmairq, camelot_txdma, cam);
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if (unlikely(ret)) {
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pr_debug("audio unit %d irqs already taken!\n",
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rtd->cpu_dai->id);
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return -EBUSY;
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}
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(void)dmabrg_request_irq(dmairq + 1, camelot_txdma, cam);
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}
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return 0;
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}
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static int camelot_pcm_close(struct snd_pcm_substream *substream)
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{
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struct snd_soc_pcm_runtime *rtd = substream->private_data;
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struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
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int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
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int dmairq;
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dmairq = (recv) ? cam->txid + 2 : cam->txid;
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if (recv)
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cam->rx_ss = NULL;
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else
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cam->tx_ss = NULL;
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dmabrg_free_irq(dmairq + 1);
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dmabrg_free_irq(dmairq);
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return 0;
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}
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static int camelot_hw_params(struct snd_pcm_substream *substream,
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struct snd_pcm_hw_params *hw_params)
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{
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struct snd_soc_pcm_runtime *rtd = substream->private_data;
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struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
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int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
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int ret;
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ret = snd_pcm_lib_malloc_pages(substream,
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params_buffer_bytes(hw_params));
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if (ret < 0)
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return ret;
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if (recv) {
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cam->rx_period_size = params_period_bytes(hw_params);
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cam->rx_period = 0;
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} else {
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cam->tx_period_size = params_period_bytes(hw_params);
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cam->tx_period = 0;
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}
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return 0;
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}
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static int camelot_hw_free(struct snd_pcm_substream *substream)
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{
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return snd_pcm_lib_free_pages(substream);
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}
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static int camelot_prepare(struct snd_pcm_substream *substream)
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{
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struct snd_pcm_runtime *runtime = substream->runtime;
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struct snd_soc_pcm_runtime *rtd = substream->private_data;
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struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
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pr_debug("PCM data: addr 0x%08ulx len %d\n",
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(u32)runtime->dma_addr, runtime->dma_bytes);
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if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
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BRGREG(BRGATXSAR) = (unsigned long)runtime->dma_area;
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BRGREG(BRGATXTCR) = runtime->dma_bytes;
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} else {
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BRGREG(BRGARXDAR) = (unsigned long)runtime->dma_area;
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BRGREG(BRGARXTCR) = runtime->dma_bytes;
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}
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return 0;
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}
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static inline void dmabrg_play_dma_start(struct camelot_pcm *cam)
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{
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unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
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/* start DMABRG engine: XFER start, auto-addr-reload */
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BRGREG(BRGACR) = acr | ACR_TDE | ACR_TAR | ACR_TAM_2WORD;
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}
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static inline void dmabrg_play_dma_stop(struct camelot_pcm *cam)
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{
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unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
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/* forcibly terminate data transmission */
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BRGREG(BRGACR) = acr | ACR_TDS;
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}
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static inline void dmabrg_rec_dma_start(struct camelot_pcm *cam)
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{
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unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
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/* start DMABRG engine: recv start, auto-reload */
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BRGREG(BRGACR) = acr | ACR_RDE | ACR_RAR | ACR_RAM_2WORD;
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}
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static inline void dmabrg_rec_dma_stop(struct camelot_pcm *cam)
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{
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unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS);
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/* forcibly terminate data receiver */
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BRGREG(BRGACR) = acr | ACR_RDS;
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}
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static int camelot_trigger(struct snd_pcm_substream *substream, int cmd)
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{
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struct snd_soc_pcm_runtime *rtd = substream->private_data;
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struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
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int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
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switch (cmd) {
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case SNDRV_PCM_TRIGGER_START:
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if (recv)
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dmabrg_rec_dma_start(cam);
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else
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dmabrg_play_dma_start(cam);
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break;
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case SNDRV_PCM_TRIGGER_STOP:
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if (recv)
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dmabrg_rec_dma_stop(cam);
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else
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dmabrg_play_dma_stop(cam);
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break;
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default:
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return -EINVAL;
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}
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return 0;
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}
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static snd_pcm_uframes_t camelot_pos(struct snd_pcm_substream *substream)
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{
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struct snd_pcm_runtime *runtime = substream->runtime;
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struct snd_soc_pcm_runtime *rtd = substream->private_data;
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struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id];
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int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1;
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unsigned long pos;
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/* cannot use the DMABRG pointer register: under load, by the
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* time ALSA comes around to read the register, it is already
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* far ahead (or worse, already done with the fragment) of the
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* position at the time the IRQ was triggered, which results in
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* fast-playback sound in my test application (ScummVM)
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*/
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if (recv)
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pos = cam->rx_period ? cam->rx_period_size : 0;
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else
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pos = cam->tx_period ? cam->tx_period_size : 0;
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return bytes_to_frames(runtime, pos);
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}
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static struct snd_pcm_ops camelot_pcm_ops = {
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.open = camelot_pcm_open,
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.close = camelot_pcm_close,
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.ioctl = snd_pcm_lib_ioctl,
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.hw_params = camelot_hw_params,
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.hw_free = camelot_hw_free,
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.prepare = camelot_prepare,
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.trigger = camelot_trigger,
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.pointer = camelot_pos,
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};
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static void camelot_pcm_free(struct snd_pcm *pcm)
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{
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snd_pcm_lib_preallocate_free_for_all(pcm);
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}
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static int camelot_pcm_new(struct snd_soc_pcm_runtime *rtd)
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{
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struct snd_pcm *pcm = rtd->pcm;
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/* dont use SNDRV_DMA_TYPE_DEV, since it will oops the SH kernel
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* in MMAP mode (i.e. aplay -M)
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*/
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snd_pcm_lib_preallocate_pages_for_all(pcm,
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SNDRV_DMA_TYPE_CONTINUOUS,
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snd_dma_continuous_data(GFP_KERNEL),
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DMABRG_PREALLOC_BUFFER, DMABRG_PREALLOC_BUFFER_MAX);
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return 0;
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}
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static struct snd_soc_platform_driver sh7760_soc_platform = {
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.ops = &camelot_pcm_ops,
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.pcm_new = camelot_pcm_new,
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.pcm_free = camelot_pcm_free,
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};
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static int sh7760_soc_platform_probe(struct platform_device *pdev)
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{
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return snd_soc_register_platform(&pdev->dev, &sh7760_soc_platform);
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}
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static int sh7760_soc_platform_remove(struct platform_device *pdev)
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{
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snd_soc_unregister_platform(&pdev->dev);
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return 0;
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}
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static struct platform_driver sh7760_pcm_driver = {
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.driver = {
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.name = "sh7760-pcm-audio",
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.owner = THIS_MODULE,
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},
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.probe = sh7760_soc_platform_probe,
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.remove = sh7760_soc_platform_remove,
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};
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module_platform_driver(sh7760_pcm_driver);
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("SH7760 Audio DMA (DMABRG) driver");
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MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>");
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