Quelle  imx-pcm-fiq.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0+
// imx-pcm-fiq.c  --  ALSA Soc Audio Layer
//
// Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
//
// This code is based on code copyrighted by Freescale,
// Liam Girdwood, Javier Martin and probably others.

#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

#include <sound/core.h>
#include <sound/dmaengine_pcm.h>
#include <sound/initval.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#include <asm/fiq.h>

#include <linux/platform_data/asoc-imx-ssi.h>

#include "imx-ssi.h"
#include "imx-pcm.h"

struct imx_pcm_runtime_data {
 unsigned int period;
 int periods;
 unsigned long offset;
 struct hrtimer hrt;
 int poll_time_ns;
 struct snd_pcm_substream *substream;
 atomic_t playing;
 atomic_t capturing;
};

static enum hrtimer_restart snd_hrtimer_callback(struct hrtimer *hrt)
{
 struct imx_pcm_runtime_data *iprtd =
  container_of(hrt, struct imx_pcm_runtime_data, hrt);
 struct snd_pcm_substream *substream = iprtd->substream;
 struct pt_regs regs;

 if (!atomic_read(&iprtd->playing) && !atomic_read(&iprtd->capturing))
  return HRTIMER_NORESTART;

 get_fiq_regs(®s);

 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  iprtd->offset = regs.ARM_r8 & 0xffff;
 else
  iprtd->offset = regs.ARM_r9 & 0xffff;

 snd_pcm_period_elapsed(substream);

 hrtimer_forward_now(hrt, ns_to_ktime(iprtd->poll_time_ns));

 return HRTIMER_RESTART;
}

static struct fiq_handler fh = {
 .name  = DRV_NAME,
};

static int snd_imx_pcm_hw_params(struct snd_soc_component *component,
     struct snd_pcm_substream *substream,
     struct snd_pcm_hw_params *params)
{
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct imx_pcm_runtime_data *iprtd = runtime->private_data;

 iprtd->periods = params_periods(params);
 iprtd->period = params_period_bytes(params);
 iprtd->offset = 0;
 iprtd->poll_time_ns = 1000000000 / params_rate(params) *
    params_period_size(params);

 return 0;
}

static int snd_imx_pcm_prepare(struct snd_soc_component *component,
          struct snd_pcm_substream *substream)
{
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct imx_pcm_runtime_data *iprtd = runtime->private_data;
 struct pt_regs regs;

 get_fiq_regs(®s);
 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  regs.ARM_r8 = (iprtd->period * iprtd->periods - 1) << 16;
 else
  regs.ARM_r9 = (iprtd->period * iprtd->periods - 1) << 16;

 set_fiq_regs(®s);

 return 0;
}

static int imx_pcm_fiq;

static int snd_imx_pcm_trigger(struct snd_soc_component *component,
          struct snd_pcm_substream *substream, int cmd)
{
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct imx_pcm_runtime_data *iprtd = runtime->private_data;

 switch (cmd) {
 case SNDRV_PCM_TRIGGER_START:
 case SNDRV_PCM_TRIGGER_RESUME:
 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
   atomic_set(&iprtd->playing, 1);
  else
   atomic_set(&iprtd->capturing, 1);
  hrtimer_start(&iprtd->hrt, ns_to_ktime(iprtd->poll_time_ns),
        HRTIMER_MODE_REL);
  enable_fiq(imx_pcm_fiq);
  break;

 case SNDRV_PCM_TRIGGER_STOP:
 case SNDRV_PCM_TRIGGER_SUSPEND:
 case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
   atomic_set(&iprtd->playing, 0);
  else
   atomic_set(&iprtd->capturing, 0);
  if (!atomic_read(&iprtd->playing) &&
    !atomic_read(&iprtd->capturing))
   disable_fiq(imx_pcm_fiq);
  break;

 default:
  return -EINVAL;
 }

 return 0;
}

static snd_pcm_uframes_t
snd_imx_pcm_pointer(struct snd_soc_component *component,
      struct snd_pcm_substream *substream)
{
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct imx_pcm_runtime_data *iprtd = runtime->private_data;

 return bytes_to_frames(substream->runtime, iprtd->offset);
}

static const struct snd_pcm_hardware snd_imx_hardware = {
 .info = SNDRV_PCM_INFO_INTERLEAVED |
  SNDRV_PCM_INFO_BLOCK_TRANSFER |
  SNDRV_PCM_INFO_MMAP |
  SNDRV_PCM_INFO_MMAP_VALID |
  SNDRV_PCM_INFO_PAUSE |
  SNDRV_PCM_INFO_RESUME,
 .formats = SNDRV_PCM_FMTBIT_S16_LE,
 .buffer_bytes_max = IMX_SSI_DMABUF_SIZE,
 .period_bytes_min = 128,
 .period_bytes_max = 16 * 1024,
 .periods_min = 4,
 .periods_max = 255,
 .fifo_size = 0,
};

static int snd_imx_open(struct snd_soc_component *component,
   struct snd_pcm_substream *substream)
{
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct imx_pcm_runtime_data *iprtd;
 int ret;

 iprtd = kzalloc(sizeof(*iprtd), GFP_KERNEL);
 if (iprtd == NULL)
  return -ENOMEM;
 runtime->private_data = iprtd;

 iprtd->substream = substream;

 atomic_set(&iprtd->playing, 0);
 atomic_set(&iprtd->capturing, 0);
 hrtimer_setup(&iprtd->hrt, snd_hrtimer_callback, CLOCK_MONOTONIC, HRTIMER_MODE_REL);

 ret = snd_pcm_hw_constraint_integer(substream->runtime,
   SNDRV_PCM_HW_PARAM_PERIODS);
 if (ret < 0) {
  kfree(iprtd);
  return ret;
 }

 snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);
 return 0;
}

static int snd_imx_close(struct snd_soc_component *component,
    struct snd_pcm_substream *substream)
{
 struct snd_pcm_runtime *runtime = substream->runtime;
 struct imx_pcm_runtime_data *iprtd = runtime->private_data;

 hrtimer_cancel(&iprtd->hrt);

 kfree(iprtd);

 return 0;
}

static int imx_pcm_new(struct snd_soc_pcm_runtime *rtd)
{
 struct snd_card *card = rtd->card->snd_card;
 struct snd_pcm *pcm = rtd->pcm;
 int ret;

 ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
 if (ret)
  return ret;

 return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV_WC,
         pcm->card->dev,
         IMX_SSI_DMABUF_SIZE);
}

static int ssi_irq;

static int snd_imx_pcm_new(struct snd_soc_component *component,
      struct snd_soc_pcm_runtime *rtd)
{
 struct snd_pcm *pcm = rtd->pcm;
 struct snd_pcm_substream *substream;
 int ret;

 ret = imx_pcm_new(rtd);
 if (ret)
  return ret;

 substream = pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream;
 if (substream) {
  struct snd_dma_buffer *buf = &substream->dma_buffer;

  imx_ssi_fiq_tx_buffer = (unsigned long)buf->area;
 }

 substream = pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream;
 if (substream) {
  struct snd_dma_buffer *buf = &substream->dma_buffer;

  imx_ssi_fiq_rx_buffer = (unsigned long)buf->area;
 }

 set_fiq_handler(&imx_ssi_fiq_start,
  &imx_ssi_fiq_end - &imx_ssi_fiq_start);

 return 0;
}

static void snd_imx_pcm_free(struct snd_soc_component *component,
        struct snd_pcm *pcm)
{
 mxc_set_irq_fiq(ssi_irq, 0);
 release_fiq(&fh);
}

static const struct snd_soc_component_driver imx_soc_component_fiq = {
 .open  = snd_imx_open,
 .close  = snd_imx_close,
 .hw_params = snd_imx_pcm_hw_params,
 .prepare = snd_imx_pcm_prepare,
 .trigger = snd_imx_pcm_trigger,
 .pointer = snd_imx_pcm_pointer,
 .pcm_construct = snd_imx_pcm_new,
 .pcm_destruct = snd_imx_pcm_free,
};

int imx_pcm_fiq_init(struct platform_device *pdev,
  struct imx_pcm_fiq_params *params)
{
 int ret;

 ret = claim_fiq(&fh);
 if (ret) {
  dev_err(&pdev->dev, "failed to claim fiq: %d", ret);
  return ret;
 }

 mxc_set_irq_fiq(params->irq, 1);
 ssi_irq = params->irq;

 imx_pcm_fiq = params->irq;

 imx_ssi_fiq_base = (unsigned long)params->base;

 params->dma_params_tx->maxburst = 4;
 params->dma_params_rx->maxburst = 6;

 ret = devm_snd_soc_register_component(&pdev->dev, &imx_soc_component_fiq,
           NULL, 0);
 if (ret)
  goto failed_register;

 return 0;

failed_register:
 mxc_set_irq_fiq(ssi_irq, 0);
 release_fiq(&fh);

 return ret;
}
EXPORT_SYMBOL_GPL(imx_pcm_fiq_init);

void imx_pcm_fiq_exit(struct platform_device *pdev)
{
}
EXPORT_SYMBOL_GPL(imx_pcm_fiq_exit);

MODULE_DESCRIPTION("Freescale i.MX PCM FIQ handler");
MODULE_LICENSE("GPL");