diff options
Diffstat (limited to 'sound/soc/at32/at32-pcm.c')
-rw-r--r-- | sound/soc/at32/at32-pcm.c | 492 |
1 files changed, 492 insertions, 0 deletions
diff --git a/sound/soc/at32/at32-pcm.c b/sound/soc/at32/at32-pcm.c new file mode 100644 index 0000000..c83584f --- /dev/null +++ b/sound/soc/at32/at32-pcm.c @@ -0,0 +1,492 @@ +/* sound/soc/at32/at32-pcm.c + * ASoC PCM interface for Atmel AT32 SoC + * + * Copyright (C) 2008 Long Range Systems + * Geoffrey Wossum <gwossum@acm.org> + * + * 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. + * + * Note that this is basically a port of the sound/soc/at91-pcm.c to + * the AVR32 kernel. Thanks to Frank Mandarino for that code. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/dma-mapping.h> +#include <linux/atmel_pdc.h> + +#include <sound/core.h> +#include <sound/pcm.h> +#include <sound/pcm_params.h> +#include <sound/soc.h> + +#include "at32-pcm.h" + + + +/*--------------------------------------------------------------------------*\ + * Hardware definition +\*--------------------------------------------------------------------------*/ +/* TODO: These values were taken from the AT91 platform driver, check + * them against real values for AT32 + */ +static const struct snd_pcm_hardware at32_pcm_hardware = { + .info = (SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_MMAP_VALID | + SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_BLOCK_TRANSFER | + SNDRV_PCM_INFO_PAUSE), + + .formats = SNDRV_PCM_FMTBIT_S16, + .period_bytes_min = 32, + .period_bytes_max = 8192, /* 512 frames * 16 bytes / frame */ + .periods_min = 2, + .periods_max = 1024, + .buffer_bytes_max = 32 * 1024, +}; + + + +/*--------------------------------------------------------------------------*\ + * Data types +\*--------------------------------------------------------------------------*/ +struct at32_runtime_data { + struct at32_pcm_dma_params *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 */ + int periods; /* period index of period_ptr */ + + /* Save PDC registers (for power management) */ + u32 pdc_xpr_save; + u32 pdc_xcr_save; + u32 pdc_xnpr_save; + u32 pdc_xncr_save; +}; + + + +/*--------------------------------------------------------------------------*\ + * Helper functions +\*--------------------------------------------------------------------------*/ +static int at32_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream) +{ + struct snd_pcm_substream *substream = pcm->streams[stream].substream; + struct snd_dma_buffer *dmabuf = &substream->dma_buffer; + size_t size = at32_pcm_hardware.buffer_bytes_max; + + dmabuf->dev.type = SNDRV_DMA_TYPE_DEV; + dmabuf->dev.dev = pcm->card->dev; + dmabuf->private_data = NULL; + dmabuf->area = dma_alloc_coherent(pcm->card->dev, size, + &dmabuf->addr, GFP_KERNEL); + pr_debug("at32_pcm: preallocate_dma_buffer: " + "area=%p, addr=%p, size=%ld\n", + (void *)dmabuf->area, (void *)dmabuf->addr, size); + + if (!dmabuf->area) + return -ENOMEM; + + dmabuf->bytes = size; + return 0; +} + + + +/*--------------------------------------------------------------------------*\ + * ISR +\*--------------------------------------------------------------------------*/ +static void at32_pcm_dma_irq(u32 ssc_sr, struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *rtd = substream->runtime; + struct at32_runtime_data *prtd = rtd->private_data; + struct at32_pcm_dma_params *params = prtd->params; + static int count; + + count++; + if (ssc_sr & params->mask->ssc_endbuf) { + pr_warning("at32-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 */ + ssc_writex(params->ssc->regs, ATMEL_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; + + + ssc_writex(params->ssc->regs, params->pdc->xpr, + prtd->period_ptr); + ssc_writex(params->ssc->regs, params->pdc->xcr, + prtd->period_size / params->pdc_xfer_size); + ssc_writex(params->ssc->regs, ATMEL_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; + ssc_writex(params->ssc->regs, params->pdc->xnpr, + prtd->period_ptr); + ssc_writex(params->ssc->regs, params->pdc->xncr, + prtd->period_size / params->pdc_xfer_size); + } + + + snd_pcm_period_elapsed(substream); +} + + + +/*--------------------------------------------------------------------------*\ + * PCM operations +\*--------------------------------------------------------------------------*/ +static int at32_pcm_hw_params(struct snd_pcm_substream *substream, + struct snd_pcm_hw_params *params) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + struct at32_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->dai->cpu_dai->dma_data; + prtd->params->dma_intr_handler = at32_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); + + pr_debug("hw_params: DMA for %s initialized " + "(dma_bytes=%ld, period_size=%ld)\n", + prtd->params->name, runtime->dma_bytes, prtd->period_size); + + return 0; +} + + + +static int at32_pcm_hw_free(struct snd_pcm_substream *substream) +{ + struct at32_runtime_data *prtd = substream->runtime->private_data; + struct at32_pcm_dma_params *params = prtd->params; + + if (params != NULL) { + ssc_writex(params->ssc->regs, SSC_PDC_PTCR, + params->mask->pdc_disable); + prtd->params->dma_intr_handler = NULL; + } + + return 0; +} + + + +static int at32_pcm_prepare(struct snd_pcm_substream *substream) +{ + struct at32_runtime_data *prtd = substream->runtime->private_data; + struct at32_pcm_dma_params *params = prtd->params; + + ssc_writex(params->ssc->regs, SSC_IDR, + params->mask->ssc_endx | params->mask->ssc_endbuf); + ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR, + params->mask->pdc_disable); + + return 0; +} + + +static int at32_pcm_trigger(struct snd_pcm_substream *substream, int cmd) +{ + struct snd_pcm_runtime *rtd = substream->runtime; + struct at32_runtime_data *prtd = rtd->private_data; + struct at32_pcm_dma_params *params = prtd->params; + int ret = 0; + + pr_debug("at32_pcm_trigger: buffer_size = %ld, " + "dma_area = %p, dma_bytes = %ld\n", + rtd->buffer_size, rtd->dma_area, rtd->dma_bytes); + + switch (cmd) { + case SNDRV_PCM_TRIGGER_START: + prtd->period_ptr = prtd->dma_buffer; + + ssc_writex(params->ssc->regs, params->pdc->xpr, + prtd->period_ptr); + ssc_writex(params->ssc->regs, params->pdc->xcr, + prtd->period_size / params->pdc_xfer_size); + + prtd->period_ptr += prtd->period_size; + ssc_writex(params->ssc->regs, params->pdc->xnpr, + prtd->period_ptr); + ssc_writex(params->ssc->regs, params->pdc->xncr, + prtd->period_size / params->pdc_xfer_size); + + pr_debug("trigger: period_ptr=%lx, xpr=%x, " + "xcr=%d, xnpr=%x, xncr=%d\n", + (unsigned long)prtd->period_ptr, + ssc_readx(params->ssc->regs, params->pdc->xpr), + ssc_readx(params->ssc->regs, params->pdc->xcr), + ssc_readx(params->ssc->regs, params->pdc->xnpr), + ssc_readx(params->ssc->regs, params->pdc->xncr)); + + ssc_writex(params->ssc->regs, SSC_IER, + params->mask->ssc_endx | params->mask->ssc_endbuf); + ssc_writex(params->ssc->regs, SSC_PDC_PTCR, + params->mask->pdc_enable); + + pr_debug("sr=%x, imr=%x\n", + ssc_readx(params->ssc->regs, SSC_SR), + ssc_readx(params->ssc->regs, SSC_IER)); + break; /* SNDRV_PCM_TRIGGER_START */ + + + + case SNDRV_PCM_TRIGGER_STOP: + case SNDRV_PCM_TRIGGER_SUSPEND: + case SNDRV_PCM_TRIGGER_PAUSE_PUSH: + ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR, + params->mask->pdc_disable); + break; + + + case SNDRV_PCM_TRIGGER_RESUME: + case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: + ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR, + params->mask->pdc_enable); + break; + + default: + ret = -EINVAL; + } + + return ret; +} + + + +static snd_pcm_uframes_t at32_pcm_pointer(struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + struct at32_runtime_data *prtd = runtime->private_data; + struct at32_pcm_dma_params *params = prtd->params; + dma_addr_t ptr; + snd_pcm_uframes_t x; + + ptr = (dma_addr_t) ssc_readx(params->ssc->regs, params->pdc->xpr); + x = bytes_to_frames(runtime, ptr - prtd->dma_buffer); + + if (x == runtime->buffer_size) + x = 0; + + return x; +} + + + +static int at32_pcm_open(struct snd_pcm_substream *substream) +{ + struct snd_pcm_runtime *runtime = substream->runtime; + struct at32_runtime_data *prtd; + int ret = 0; + + snd_soc_set_runtime_hwparams(substream, &at32_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(*prtd), GFP_KERNEL); + if (prtd == NULL) { + ret = -ENOMEM; + goto out; + } + runtime->private_data = prtd; + + +out: + return ret; +} + + + +static int at32_pcm_close(struct snd_pcm_substream *substream) +{ + struct at32_runtime_data *prtd = substream->runtime->private_data; + + kfree(prtd); + return 0; +} + + +static int at32_pcm_mmap(struct snd_pcm_substream *substream, + struct vm_area_struct *vma) +{ + return remap_pfn_range(vma, vma->vm_start, + substream->dma_buffer.addr >> PAGE_SHIFT, + vma->vm_end - vma->vm_start, vma->vm_page_prot); +} + + + +static struct snd_pcm_ops at32_pcm_ops = { + .open = at32_pcm_open, + .close = at32_pcm_close, + .ioctl = snd_pcm_lib_ioctl, + .hw_params = at32_pcm_hw_params, + .hw_free = at32_pcm_hw_free, + .prepare = at32_pcm_prepare, + .trigger = at32_pcm_trigger, + .pointer = at32_pcm_pointer, + .mmap = at32_pcm_mmap, +}; + + + +/*--------------------------------------------------------------------------*\ + * ASoC platform driver +\*--------------------------------------------------------------------------*/ +static u64 at32_pcm_dmamask = 0xffffffff; + +static int at32_pcm_new(struct snd_card *card, + struct snd_soc_dai *dai, + struct snd_pcm *pcm) +{ + int ret = 0; + + if (!card->dev->dma_mask) + card->dev->dma_mask = &at32_pcm_dmamask; + if (!card->dev->coherent_dma_mask) + card->dev->coherent_dma_mask = 0xffffffff; + + if (dai->playback.channels_min) { + ret = at32_pcm_preallocate_dma_buffer( + pcm, SNDRV_PCM_STREAM_PLAYBACK); + if (ret) + goto out; + } + + if (dai->capture.channels_min) { + pr_debug("at32-pcm: Allocating PCM capture DMA buffer\n"); + ret = at32_pcm_preallocate_dma_buffer( + pcm, SNDRV_PCM_STREAM_CAPTURE); + if (ret) + goto out; + } + + +out: + return ret; +} + + + +static void at32_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 == NULL) + continue; + + buf = &substream->dma_buffer; + if (!buf->area) + continue; + dma_free_coherent(pcm->card->dev, buf->bytes, + buf->area, buf->addr); + buf->area = NULL; + } +} + + + +#ifdef CONFIG_PM +static int at32_pcm_suspend(struct platform_device *pdev, + struct snd_soc_dai *dai) +{ + struct snd_pcm_runtime *runtime = dai->runtime; + struct at32_runtime_data *prtd; + struct at32_pcm_dma_params *params; + + if (runtime == NULL) + return 0; + prtd = runtime->private_data; + params = prtd->params; + + /* Disable the PDC and save the PDC registers */ + ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR, + params->mask->pdc_disable); + + prtd->pdc_xpr_save = ssc_readx(params->ssc->regs, params->pdc->xpr); + prtd->pdc_xcr_save = ssc_readx(params->ssc->regs, params->pdc->xcr); + prtd->pdc_xnpr_save = ssc_readx(params->ssc->regs, params->pdc->xnpr); + prtd->pdc_xncr_save = ssc_readx(params->ssc->regs, params->pdc->xncr); + + return 0; +} + + + +static int at32_pcm_resume(struct platform_device *pdev, + struct snd_soc_dai *dai) +{ + struct snd_pcm_runtime *runtime = dai->runtime; + struct at32_runtime_data *prtd; + struct at32_pcm_dma_params *params; + + if (runtime == NULL) + return 0; + prtd = runtime->private_data; + params = prtd->params; + + /* Restore the PDC registers and enable the PDC */ + ssc_writex(params->ssc->regs, params->pdc->xpr, prtd->pdc_xpr_save); + ssc_writex(params->ssc->regs, params->pdc->xcr, prtd->pdc_xcr_save); + ssc_writex(params->ssc->regs, params->pdc->xnpr, prtd->pdc_xnpr_save); + ssc_writex(params->ssc->regs, params->pdc->xncr, prtd->pdc_xncr_save); + + ssc_writex(params->ssc->regs, ATMEL_PDC_PTCR, params->mask->pdc_enable); + return 0; +} +#else /* CONFIG_PM */ +# define at32_pcm_suspend NULL +# define at32_pcm_resume NULL +#endif /* CONFIG_PM */ + + + +struct snd_soc_platform at32_soc_platform = { + .name = "at32-audio", + .pcm_ops = &at32_pcm_ops, + .pcm_new = at32_pcm_new, + .pcm_free = at32_pcm_free_dma_buffers, + .suspend = at32_pcm_suspend, + .resume = at32_pcm_resume, +}; +EXPORT_SYMBOL_GPL(at32_soc_platform); + + + +MODULE_AUTHOR("Geoffrey Wossum <gwossum@acm.org>"); +MODULE_DESCRIPTION("Atmel AT32 PCM module"); +MODULE_LICENSE("GPL"); |