Quelle  aio-dma.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0
//
// Socionext UniPhier AIO DMA driver.
//
// Copyright (c) 2016-2018 Socionext Inc.

#include <linux/dma-mapping.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/soc.h>

#include "aio.h"

static const struct snd_pcm_hardware uniphier_aiodma_hw = {
 .info = SNDRV_PCM_INFO_MMAP |
  SNDRV_PCM_INFO_MMAP_VALID |
  SNDRV_PCM_INFO_INTERLEAVED,
 .period_bytes_min = 256,
 .period_bytes_max = 4096,
 .periods_min      = 4,
 .periods_max      = 1024,
 .buffer_bytes_max = 128 * 1024,
};

static void aiodma_pcm_irq(struct uniphier_aio_sub *sub)
{
 struct snd_pcm_runtime *runtime = sub->substream->runtime;
 int bytes = runtime->period_size *
  runtime->channels * samples_to_bytes(runtime, 1);
 int ret;

 spin_lock(&sub->lock);
 ret = aiodma_rb_set_threshold(sub, runtime->dma_bytes,
          sub->threshold + bytes);
 if (!ret)
  sub->threshold += bytes;

 aiodma_rb_sync(sub, runtime->dma_addr, runtime->dma_bytes, bytes);
 aiodma_rb_clear_irq(sub);
 spin_unlock(&sub->lock);

 snd_pcm_period_elapsed(sub->substream);
}

static void aiodma_compr_irq(struct uniphier_aio_sub *sub)
{
 struct snd_compr_runtime *runtime = sub->cstream->runtime;
 int bytes = runtime->fragment_size;
 int ret;

 spin_lock(&sub->lock);
 ret = aiodma_rb_set_threshold(sub, sub->compr_bytes,
          sub->threshold + bytes);
 if (!ret)
  sub->threshold += bytes;

 aiodma_rb_sync(sub, sub->compr_addr, sub->compr_bytes, bytes);
 aiodma_rb_clear_irq(sub);
 spin_unlock(&sub->lock);

 snd_compr_fragment_elapsed(sub->cstream);
}

static irqreturn_t aiodma_irq(int irq, void *p)
{
 struct platform_device *pdev = p;
 struct uniphier_aio_chip *chip = platform_get_drvdata(pdev);
 irqreturn_t ret = IRQ_NONE;
 int i, j;

 for (i = 0; i < chip->num_aios; i++) {
  struct uniphier_aio *aio = &chip->aios[i];

  for (j = 0; j < ARRAY_SIZE(aio->sub); j++) {
   struct uniphier_aio_sub *sub = &aio->sub[j];

   /* Skip channel that does not trigger */
   if (!sub->running || !aiodma_rb_is_irq(sub))
    continue;

   if (sub->substream)
    aiodma_pcm_irq(sub);
   if (sub->cstream)
    aiodma_compr_irq(sub);

   ret = IRQ_HANDLED;
  }
 }

 return ret;
}

static int uniphier_aiodma_open(struct snd_soc_component *component,
    struct snd_pcm_substream *substream)
{
 struct snd_pcm_runtime *runtime = substream->runtime;

 snd_soc_set_runtime_hwparams(substream, &uniphier_aiodma_hw);

 return snd_pcm_hw_constraint_step(runtime, 0,
  SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 256);
}

static int uniphier_aiodma_prepare(struct snd_soc_component *component,
       struct snd_pcm_substream *substream)
{
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 struct uniphier_aio *aio = uniphier_priv(snd_soc_rtd_to_cpu(rtd, 0));
 struct uniphier_aio_sub *sub = &aio->sub[substream->stream];
 int bytes = runtime->period_size *
  runtime->channels * samples_to_bytes(runtime, 1);
 unsigned long flags;
 int ret;

 ret = aiodma_ch_set_param(sub);
 if (ret)
  return ret;

 spin_lock_irqsave(&sub->lock, flags);
 ret = aiodma_rb_set_buffer(sub, runtime->dma_addr,
       runtime->dma_addr + runtime->dma_bytes,
       bytes);
 spin_unlock_irqrestore(&sub->lock, flags);
 if (ret)
  return ret;

 return 0;
}

static int uniphier_aiodma_trigger(struct snd_soc_component *component,
       struct snd_pcm_substream *substream, int cmd)
{
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 struct uniphier_aio *aio = uniphier_priv(snd_soc_rtd_to_cpu(rtd, 0));
 struct uniphier_aio_sub *sub = &aio->sub[substream->stream];
 struct device *dev = &aio->chip->pdev->dev;
 int bytes = runtime->period_size *
  runtime->channels * samples_to_bytes(runtime, 1);
 unsigned long flags;

 spin_lock_irqsave(&sub->lock, flags);
 switch (cmd) {
 case SNDRV_PCM_TRIGGER_START:
  aiodma_rb_sync(sub, runtime->dma_addr, runtime->dma_bytes,
          bytes);
  aiodma_ch_set_enable(sub, 1);
  sub->running = 1;

  break;
 case SNDRV_PCM_TRIGGER_STOP:
  sub->running = 0;
  aiodma_ch_set_enable(sub, 0);

  break;
 default:
  dev_warn(dev, "Unknown trigger(%d) ignored\n", cmd);
  break;
 }
 spin_unlock_irqrestore(&sub->lock, flags);

 return 0;
}

static snd_pcm_uframes_t uniphier_aiodma_pointer(
     struct snd_soc_component *component,
     struct snd_pcm_substream *substream)
{
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
 struct uniphier_aio *aio = uniphier_priv(snd_soc_rtd_to_cpu(rtd, 0));
 struct uniphier_aio_sub *sub = &aio->sub[substream->stream];
 int bytes = runtime->period_size *
  runtime->channels * samples_to_bytes(runtime, 1);
 unsigned long flags;
 snd_pcm_uframes_t pos;

 spin_lock_irqsave(&sub->lock, flags);
 aiodma_rb_sync(sub, runtime->dma_addr, runtime->dma_bytes, bytes);

 if (sub->swm->dir == PORT_DIR_OUTPUT)
  pos = bytes_to_frames(runtime, sub->rd_offs);
 else
  pos = bytes_to_frames(runtime, sub->wr_offs);
 spin_unlock_irqrestore(&sub->lock, flags);

 return pos;
}

static int uniphier_aiodma_mmap(struct snd_soc_component *component,
    struct snd_pcm_substream *substream,
    struct vm_area_struct *vma)
{
 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);

 return remap_pfn_range(vma, vma->vm_start,
          substream->runtime->dma_addr >> PAGE_SHIFT,
          vma->vm_end - vma->vm_start, vma->vm_page_prot);
}

static int uniphier_aiodma_new(struct snd_soc_component *component,
          struct snd_soc_pcm_runtime *rtd)
{
 struct device *dev = rtd->card->snd_card->dev;
 struct snd_pcm *pcm = rtd->pcm;
 int ret;

 ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(33));
 if (ret)
  return ret;

 snd_pcm_set_managed_buffer_all(pcm,
  SNDRV_DMA_TYPE_DEV, dev,
  uniphier_aiodma_hw.buffer_bytes_max,
  uniphier_aiodma_hw.buffer_bytes_max);
 return 0;
}

static const struct snd_soc_component_driver uniphier_soc_platform = {
 .open  = uniphier_aiodma_open,
 .prepare = uniphier_aiodma_prepare,
 .trigger = uniphier_aiodma_trigger,
 .pointer = uniphier_aiodma_pointer,
 .mmap  = uniphier_aiodma_mmap,
 .pcm_construct = uniphier_aiodma_new,
 .compress_ops = &uniphier_aio_compress_ops,
};

static const struct regmap_config aiodma_regmap_config = {
 .reg_bits      = 32,
 .reg_stride    = 4,
 .val_bits      = 32,
 .max_register  = 0x7fffc,
 .cache_type    = REGCACHE_NONE,
};

/**
 * uniphier_aiodma_soc_register_platform - register the AIO DMA
 * @pdev: the platform device
 *
 * Register and setup the DMA of AIO to transfer the sound data to device.
 * This function need to call once at driver startup and need NOT to call
 * unregister function.
 *
 * Return: Zero if successful, otherwise a negative value on error.
 */
int uniphier_aiodma_soc_register_platform(struct platform_device *pdev)
{
 struct uniphier_aio_chip *chip = platform_get_drvdata(pdev);
 struct device *dev = &pdev->dev;
 void __iomem *preg;
 int irq, ret;

 preg = devm_platform_ioremap_resource(pdev, 0);
 if (IS_ERR(preg))
  return PTR_ERR(preg);

 chip->regmap = devm_regmap_init_mmio(dev, preg,
          &aiodma_regmap_config);
 if (IS_ERR(chip->regmap))
  return PTR_ERR(chip->regmap);

 irq = platform_get_irq(pdev, 0);
 if (irq < 0)
  return irq;

 ret = devm_request_irq(dev, irq, aiodma_irq,
          IRQF_SHARED, dev_name(dev), pdev);
 if (ret)
  return ret;

 return devm_snd_soc_register_component(dev, &uniphier_soc_platform,
            NULL, 0);
}
EXPORT_SYMBOL_GPL(uniphier_aiodma_soc_register_platform);