soc/fsl/mpc5200_dma.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 //
0003 // Freescale MPC5200 PSC DMA
0004 // ALSA SoC Platform driver
0005 //
0006 // Copyright (C) 2008 Secret Lab Technologies Ltd.
0007 // Copyright (C) 2009 Jon Smirl, Digispeaker
0008
0009 #include <linux/module.h>
0010 #include <linux/of_device.h>
0011 #include <linux/dma-mapping.h>
0012 #include <linux/slab.h>
0013 #include <linux/of_address.h>
0014 #include <linux/of_irq.h>
0015 #include <linux/of_platform.h>
0016
0017 #include <sound/soc.h>
0018
0019 #include <linux/fsl/bestcomm/bestcomm.h>
0020 #include <linux/fsl/bestcomm/gen_bd.h>
0021 #include <asm/mpc52xx_psc.h>
0022
0023 #include "mpc5200_dma.h"
0024
0025 #define DRV_NAME "mpc5200_dma"
0026
0027 /*
0028  * Interrupt handlers
0029  */
0030 static irqreturn_t psc_dma_status_irq(int irq, void *_psc_dma)
0031 {
0032     struct psc_dma *psc_dma = _psc_dma;
0033     struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
0034     u16 isr;
0035
0036     isr = in_be16(&regs->mpc52xx_psc_isr);
0037
0038     /* Playback underrun error */
0039     if (psc_dma->playback.active && (isr & MPC52xx_PSC_IMR_TXEMP))
0040         psc_dma->stats.underrun_count++;
0041
0042     /* Capture overrun error */
0043     if (psc_dma->capture.active && (isr & MPC52xx_PSC_IMR_ORERR))
0044         psc_dma->stats.overrun_count++;
0045
0046     out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
0047
0048     return IRQ_HANDLED;
0049 }
0050
0051 /**
0052  * psc_dma_bcom_enqueue_next_buffer - Enqueue another audio buffer
0053  * @s: pointer to stream private data structure
0054  *
0055  * Enqueues another audio period buffer into the bestcomm queue.
0056  *
0057  * Note: The routine must only be called when there is space available in
0058  * the queue.  Otherwise the enqueue will fail and the audio ring buffer
0059  * will get out of sync
0060  */
0061 static void psc_dma_bcom_enqueue_next_buffer(struct psc_dma_stream *s)
0062 {
0063     struct bcom_bd *bd;
0064
0065     /* Prepare and enqueue the next buffer descriptor */
0066     bd = bcom_prepare_next_buffer(s->bcom_task);
0067     bd->status = s->period_bytes;
0068     bd->data[0] = s->runtime->dma_addr + (s->period_next * s->period_bytes);
0069     bcom_submit_next_buffer(s->bcom_task, NULL);
0070
0071     /* Update for next period */
0072     s->period_next = (s->period_next + 1) % s->runtime->periods;
0073 }
0074
0075 /* Bestcomm DMA irq handler */
0076 static irqreturn_t psc_dma_bcom_irq(int irq, void *_psc_dma_stream)
0077 {
0078     struct psc_dma_stream *s = _psc_dma_stream;
0079
0080     spin_lock(&s->psc_dma->lock);
0081     /* For each finished period, dequeue the completed period buffer
0082      * and enqueue a new one in it's place. */
0083     while (bcom_buffer_done(s->bcom_task)) {
0084         bcom_retrieve_buffer(s->bcom_task, NULL, NULL);
0085
0086         s->period_current = (s->period_current+1) % s->runtime->periods;
0087         s->period_count++;
0088
0089         psc_dma_bcom_enqueue_next_buffer(s);
0090     }
0091     spin_unlock(&s->psc_dma->lock);
0092
0093     /* If the stream is active, then also inform the PCM middle layer
0094      * of the period finished event. */
0095     if (s->active)
0096         snd_pcm_period_elapsed(s->stream);
0097
0098     return IRQ_HANDLED;
0099 }
0100
0101 /**
0102  * psc_dma_trigger: start and stop the DMA transfer.
0103  *
0104  * This function is called by ALSA to start, stop, pause, and resume the DMA
0105  * transfer of data.
0106  */
0107 static int psc_dma_trigger(struct snd_soc_component *component,
0108                struct snd_pcm_substream *substream, int cmd)
0109 {
0110     struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
0111     struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
0112     struct snd_pcm_runtime *runtime = substream->runtime;
0113     struct psc_dma_stream *s = to_psc_dma_stream(substream, psc_dma);
0114     struct mpc52xx_psc __iomem *regs = psc_dma->psc_regs;
0115     u16 imr;
0116     unsigned long flags;
0117     int i;
0118
0119     switch (cmd) {
0120     case SNDRV_PCM_TRIGGER_START:
0121         dev_dbg(psc_dma->dev, "START: stream=%i fbits=%u ps=%u #p=%u\n",
0122             substream->pstr->stream, runtime->frame_bits,
0123             (int)runtime->period_size, runtime->periods);
0124         s->period_bytes = frames_to_bytes(runtime,
0125                           runtime->period_size);
0126         s->period_next = 0;
0127         s->period_current = 0;
0128         s->active = 1;
0129         s->period_count = 0;
0130         s->runtime = runtime;
0131
0132         /* Fill up the bestcomm bd queue and enable DMA.
0133          * This will begin filling the PSC's fifo.
0134          */
0135         spin_lock_irqsave(&psc_dma->lock, flags);
0136
0137         if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
0138             bcom_gen_bd_rx_reset(s->bcom_task);
0139         else
0140             bcom_gen_bd_tx_reset(s->bcom_task);
0141
0142         for (i = 0; i < runtime->periods; i++)
0143             if (!bcom_queue_full(s->bcom_task))
0144                 psc_dma_bcom_enqueue_next_buffer(s);
0145
0146         bcom_enable(s->bcom_task);
0147         spin_unlock_irqrestore(&psc_dma->lock, flags);
0148
0149         out_8(&regs->command, MPC52xx_PSC_RST_ERR_STAT);
0150
0151         break;
0152
0153     case SNDRV_PCM_TRIGGER_STOP:
0154         dev_dbg(psc_dma->dev, "STOP: stream=%i periods_count=%i\n",
0155             substream->pstr->stream, s->period_count);
0156         s->active = 0;
0157
0158         spin_lock_irqsave(&psc_dma->lock, flags);
0159         bcom_disable(s->bcom_task);
0160         if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
0161             bcom_gen_bd_rx_reset(s->bcom_task);
0162         else
0163             bcom_gen_bd_tx_reset(s->bcom_task);
0164         spin_unlock_irqrestore(&psc_dma->lock, flags);
0165
0166         break;
0167
0168     default:
0169         dev_dbg(psc_dma->dev, "unhandled trigger: stream=%i cmd=%i\n",
0170             substream->pstr->stream, cmd);
0171         return -EINVAL;
0172     }
0173
0174     /* Update interrupt enable settings */
0175     imr = 0;
0176     if (psc_dma->playback.active)
0177         imr |= MPC52xx_PSC_IMR_TXEMP;
0178     if (psc_dma->capture.active)
0179         imr |= MPC52xx_PSC_IMR_ORERR;
0180     out_be16(&regs->isr_imr.imr, psc_dma->imr | imr);
0181
0182     return 0;
0183 }
0184
0185
0186 /* ---------------------------------------------------------------------
0187  * The PSC DMA 'ASoC platform' driver
0188  *
0189  * Can be referenced by an 'ASoC machine' driver
0190  * This driver only deals with the audio bus; it doesn't have any
0191  * interaction with the attached codec
0192  */
0193
0194 static const struct snd_pcm_hardware psc_dma_hardware = {
0195     .info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
0196         SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
0197         SNDRV_PCM_INFO_BATCH,
0198     .formats = SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_S16_BE |
0199         SNDRV_PCM_FMTBIT_S24_BE | SNDRV_PCM_FMTBIT_S32_BE,
0200     .period_bytes_max   = 1024 * 1024,
0201     .period_bytes_min   = 32,
0202     .periods_min        = 2,
0203     .periods_max        = 256,
0204     .buffer_bytes_max   = 2 * 1024 * 1024,
0205     .fifo_size      = 512,
0206 };
0207
0208 static int psc_dma_open(struct snd_soc_component *component,
0209             struct snd_pcm_substream *substream)
0210 {
0211     struct snd_pcm_runtime *runtime = substream->runtime;
0212     struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
0213     struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
0214     struct psc_dma_stream *s;
0215     int rc;
0216
0217     dev_dbg(psc_dma->dev, "psc_dma_open(substream=%p)\n", substream);
0218
0219     if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
0220         s = &psc_dma->capture;
0221     else
0222         s = &psc_dma->playback;
0223
0224     snd_soc_set_runtime_hwparams(substream, &psc_dma_hardware);
0225
0226     rc = snd_pcm_hw_constraint_integer(runtime,
0227         SNDRV_PCM_HW_PARAM_PERIODS);
0228     if (rc < 0) {
0229         dev_err(substream->pcm->card->dev, "invalid buffer size\n");
0230         return rc;
0231     }
0232
0233     s->stream = substream;
0234     return 0;
0235 }
0236
0237 static int psc_dma_close(struct snd_soc_component *component,
0238              struct snd_pcm_substream *substream)
0239 {
0240     struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
0241     struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
0242     struct psc_dma_stream *s;
0243
0244     dev_dbg(psc_dma->dev, "psc_dma_close(substream=%p)\n", substream);
0245
0246     if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
0247         s = &psc_dma->capture;
0248     else
0249         s = &psc_dma->playback;
0250
0251     if (!psc_dma->playback.active &&
0252         !psc_dma->capture.active) {
0253
0254         /* Disable all interrupts and reset the PSC */
0255         out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
0256         out_8(&psc_dma->psc_regs->command, 4 << 4); /* reset error */
0257     }
0258     s->stream = NULL;
0259     return 0;
0260 }
0261
0262 static snd_pcm_uframes_t
0263 psc_dma_pointer(struct snd_soc_component *component,
0264         struct snd_pcm_substream *substream)
0265 {
0266     struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
0267     struct psc_dma *psc_dma = snd_soc_dai_get_drvdata(asoc_rtd_to_cpu(rtd, 0));
0268     struct psc_dma_stream *s;
0269     dma_addr_t count;
0270
0271     if (substream->pstr->stream == SNDRV_PCM_STREAM_CAPTURE)
0272         s = &psc_dma->capture;
0273     else
0274         s = &psc_dma->playback;
0275
0276     count = s->period_current * s->period_bytes;
0277
0278     return bytes_to_frames(substream->runtime, count);
0279 }
0280
0281 static int psc_dma_new(struct snd_soc_component *component,
0282                struct snd_soc_pcm_runtime *rtd)
0283 {
0284     struct snd_card *card = rtd->card->snd_card;
0285     struct snd_soc_dai *dai = asoc_rtd_to_cpu(rtd, 0);
0286     struct snd_pcm *pcm = rtd->pcm;
0287     size_t size = psc_dma_hardware.buffer_bytes_max;
0288     int rc;
0289
0290     dev_dbg(component->dev, "psc_dma_new(card=%p, dai=%p, pcm=%p)\n",
0291         card, dai, pcm);
0292
0293     rc = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
0294     if (rc)
0295         return rc;
0296
0297     return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV, card->dev,
0298                         size);
0299 }
0300
0301 static const struct snd_soc_component_driver mpc5200_audio_dma_component = {
0302     .name       = DRV_NAME,
0303     .open       = psc_dma_open,
0304     .close      = psc_dma_close,
0305     .pointer    = psc_dma_pointer,
0306     .trigger    = psc_dma_trigger,
0307     .pcm_construct  = psc_dma_new,
0308 };
0309
0310 int mpc5200_audio_dma_create(struct platform_device *op)
0311 {
0312     phys_addr_t fifo;
0313     struct psc_dma *psc_dma;
0314     struct resource res;
0315     int size, irq, rc;
0316     const __be32 *prop;
0317     void __iomem *regs;
0318     int ret;
0319
0320     /* Fetch the registers and IRQ of the PSC */
0321     irq = irq_of_parse_and_map(op->dev.of_node, 0);
0322     if (of_address_to_resource(op->dev.of_node, 0, &res)) {
0323         dev_err(&op->dev, "Missing reg property\n");
0324         return -ENODEV;
0325     }
0326     regs = ioremap(res.start, resource_size(&res));
0327     if (!regs) {
0328         dev_err(&op->dev, "Could not map registers\n");
0329         return -ENODEV;
0330     }
0331
0332     /* Allocate and initialize the driver private data */
0333     psc_dma = kzalloc(sizeof *psc_dma, GFP_KERNEL);
0334     if (!psc_dma) {
0335         ret = -ENOMEM;
0336         goto out_unmap;
0337     }
0338
0339     /* Get the PSC ID */
0340     prop = of_get_property(op->dev.of_node, "cell-index", &size);
0341     if (!prop || size < sizeof *prop) {
0342         ret = -ENODEV;
0343         goto out_free;
0344     }
0345
0346     spin_lock_init(&psc_dma->lock);
0347     mutex_init(&psc_dma->mutex);
0348     psc_dma->id = be32_to_cpu(*prop);
0349     psc_dma->irq = irq;
0350     psc_dma->psc_regs = regs;
0351     psc_dma->fifo_regs = regs + sizeof *psc_dma->psc_regs;
0352     psc_dma->dev = &op->dev;
0353     psc_dma->playback.psc_dma = psc_dma;
0354     psc_dma->capture.psc_dma = psc_dma;
0355     snprintf(psc_dma->name, sizeof(psc_dma->name), "PSC%d", psc_dma->id);
0356
0357     /* Find the address of the fifo data registers and setup the
0358      * DMA tasks */
0359     fifo = res.start + offsetof(struct mpc52xx_psc, buffer.buffer_32);
0360     psc_dma->capture.bcom_task =
0361         bcom_psc_gen_bd_rx_init(psc_dma->id, 10, fifo, 512);
0362     psc_dma->playback.bcom_task =
0363         bcom_psc_gen_bd_tx_init(psc_dma->id, 10, fifo);
0364     if (!psc_dma->capture.bcom_task ||
0365         !psc_dma->playback.bcom_task) {
0366         dev_err(&op->dev, "Could not allocate bestcomm tasks\n");
0367         ret = -ENODEV;
0368         goto out_free;
0369     }
0370
0371     /* Disable all interrupts and reset the PSC */
0372     out_be16(&psc_dma->psc_regs->isr_imr.imr, psc_dma->imr);
0373      /* reset receiver */
0374     out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_RX);
0375      /* reset transmitter */
0376     out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_TX);
0377      /* reset error */
0378     out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_RST_ERR_STAT);
0379      /* reset mode */
0380     out_8(&psc_dma->psc_regs->command, MPC52xx_PSC_SEL_MODE_REG_1);
0381
0382     /* Set up mode register;
0383      * First write: RxRdy (FIFO Alarm) generates rx FIFO irq
0384      * Second write: register Normal mode for non loopback
0385      */
0386     out_8(&psc_dma->psc_regs->mode, 0);
0387     out_8(&psc_dma->psc_regs->mode, 0);
0388
0389     /* Set the TX and RX fifo alarm thresholds */
0390     out_be16(&psc_dma->fifo_regs->rfalarm, 0x100);
0391     out_8(&psc_dma->fifo_regs->rfcntl, 0x4);
0392     out_be16(&psc_dma->fifo_regs->tfalarm, 0x100);
0393     out_8(&psc_dma->fifo_regs->tfcntl, 0x7);
0394
0395     /* Lookup the IRQ numbers */
0396     psc_dma->playback.irq =
0397         bcom_get_task_irq(psc_dma->playback.bcom_task);
0398     psc_dma->capture.irq =
0399         bcom_get_task_irq(psc_dma->capture.bcom_task);
0400
0401     rc = request_irq(psc_dma->irq, &psc_dma_status_irq, IRQF_SHARED,
0402              "psc-dma-status", psc_dma);
0403     rc |= request_irq(psc_dma->capture.irq, &psc_dma_bcom_irq, IRQF_SHARED,
0404               "psc-dma-capture", &psc_dma->capture);
0405     rc |= request_irq(psc_dma->playback.irq, &psc_dma_bcom_irq, IRQF_SHARED,
0406               "psc-dma-playback", &psc_dma->playback);
0407     if (rc) {
0408         ret = -ENODEV;
0409         goto out_irq;
0410     }
0411
0412     /* Save what we've done so it can be found again later */
0413     dev_set_drvdata(&op->dev, psc_dma);
0414
0415     /* Tell the ASoC OF helpers about it */
0416     return devm_snd_soc_register_component(&op->dev,
0417                     &mpc5200_audio_dma_component, NULL, 0);
0418 out_irq:
0419     free_irq(psc_dma->irq, psc_dma);
0420     free_irq(psc_dma->capture.irq, &psc_dma->capture);
0421     free_irq(psc_dma->playback.irq, &psc_dma->playback);
0422 out_free:
0423     kfree(psc_dma);
0424 out_unmap:
0425     iounmap(regs);
0426     return ret;
0427 }
0428 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_create);
0429
0430 int mpc5200_audio_dma_destroy(struct platform_device *op)
0431 {
0432     struct psc_dma *psc_dma = dev_get_drvdata(&op->dev);
0433
0434     dev_dbg(&op->dev, "mpc5200_audio_dma_destroy()\n");
0435
0436     bcom_gen_bd_rx_release(psc_dma->capture.bcom_task);
0437     bcom_gen_bd_tx_release(psc_dma->playback.bcom_task);
0438
0439     /* Release irqs */
0440     free_irq(psc_dma->irq, psc_dma);
0441     free_irq(psc_dma->capture.irq, &psc_dma->capture);
0442     free_irq(psc_dma->playback.irq, &psc_dma->playback);
0443
0444     iounmap(psc_dma->psc_regs);
0445     kfree(psc_dma);
0446     dev_set_drvdata(&op->dev, NULL);
0447
0448     return 0;
0449 }
0450 EXPORT_SYMBOL_GPL(mpc5200_audio_dma_destroy);
0451
0452 MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>");
0453 MODULE_DESCRIPTION("Freescale MPC5200 PSC in DMA mode ASoC Driver");
0454 MODULE_LICENSE("GPL");