sound/soc/soc-generic-dmaengine-pcm.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 //
0003 //  Copyright (C) 2013, Analog Devices Inc.
0004 //  Author: Lars-Peter Clausen <lars@metafoo.de>
0005
0006 #include <linux/module.h>
0007 #include <linux/init.h>
0008 #include <linux/dmaengine.h>
0009 #include <linux/slab.h>
0010 #include <sound/pcm.h>
0011 #include <sound/pcm_params.h>
0012 #include <sound/soc.h>
0013 #include <linux/dma-mapping.h>
0014 #include <linux/of.h>
0015
0016 #include <sound/dmaengine_pcm.h>
0017
0018 static unsigned int prealloc_buffer_size_kbytes = 512;
0019 module_param(prealloc_buffer_size_kbytes, uint, 0444);
0020 MODULE_PARM_DESC(prealloc_buffer_size_kbytes, "Preallocate DMA buffer size (KB).");
0021
0022 /*
0023  * The platforms dmaengine driver does not support reporting the amount of
0024  * bytes that are still left to transfer.
0025  */
0026 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31)
0027
0028 static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm,
0029     struct snd_pcm_substream *substream)
0030 {
0031     if (!pcm->chan[substream->stream])
0032         return NULL;
0033
0034     return pcm->chan[substream->stream]->device->dev;
0035 }
0036
0037 /**
0038  * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback
0039  * @substream: PCM substream
0040  * @params: hw_params
0041  * @slave_config: DMA slave config to prepare
0042  *
0043  * This function can be used as a generic prepare_slave_config callback for
0044  * platforms which make use of the snd_dmaengine_dai_dma_data struct for their
0045  * DAI DMA data. Internally the function will first call
0046  * snd_hwparams_to_dma_slave_config to fill in the slave config based on the
0047  * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the
0048  * remaining fields based on the DAI DMA data.
0049  */
0050 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
0051     struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
0052 {
0053     struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
0054     struct snd_dmaengine_dai_dma_data *dma_data;
0055     int ret;
0056
0057     if (rtd->num_cpus > 1) {
0058         dev_err(rtd->dev,
0059             "%s doesn't support Multi CPU yet\n", __func__);
0060         return -EINVAL;
0061     }
0062
0063     dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
0064
0065     ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
0066     if (ret)
0067         return ret;
0068
0069     snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data,
0070         slave_config);
0071
0072     return 0;
0073 }
0074 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config);
0075
0076 static int dmaengine_pcm_hw_params(struct snd_soc_component *component,
0077                    struct snd_pcm_substream *substream,
0078                    struct snd_pcm_hw_params *params)
0079 {
0080     struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
0081     struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream);
0082     struct dma_slave_config slave_config;
0083     int ret;
0084
0085     if (!pcm->config->prepare_slave_config)
0086         return 0;
0087
0088     memset(&slave_config, 0, sizeof(slave_config));
0089
0090     ret = pcm->config->prepare_slave_config(substream, params, &slave_config);
0091     if (ret)
0092         return ret;
0093
0094     return dmaengine_slave_config(chan, &slave_config);
0095 }
0096
0097 static int
0098 dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component,
0099                    struct snd_pcm_substream *substream)
0100 {
0101     struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
0102     struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
0103     struct device *dma_dev = dmaengine_dma_dev(pcm, substream);
0104     struct dma_chan *chan = pcm->chan[substream->stream];
0105     struct snd_dmaengine_dai_dma_data *dma_data;
0106     struct snd_pcm_hardware hw;
0107
0108     if (rtd->num_cpus > 1) {
0109         dev_err(rtd->dev,
0110             "%s doesn't support Multi CPU yet\n", __func__);
0111         return -EINVAL;
0112     }
0113
0114     if (pcm->config->pcm_hardware)
0115         return snd_soc_set_runtime_hwparams(substream,
0116                 pcm->config->pcm_hardware);
0117
0118     dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
0119
0120     memset(&hw, 0, sizeof(hw));
0121     hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID |
0122             SNDRV_PCM_INFO_INTERLEAVED;
0123     hw.periods_min = 2;
0124     hw.periods_max = UINT_MAX;
0125     hw.period_bytes_min = dma_data->maxburst * DMA_SLAVE_BUSWIDTH_8_BYTES;
0126     if (!hw.period_bytes_min)
0127         hw.period_bytes_min = 256;
0128     hw.period_bytes_max = dma_get_max_seg_size(dma_dev);
0129     hw.buffer_bytes_max = SIZE_MAX;
0130     hw.fifo_size = dma_data->fifo_size;
0131
0132     if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
0133         hw.info |= SNDRV_PCM_INFO_BATCH;
0134
0135     /**
0136      * FIXME: Remove the return value check to align with the code
0137      * before adding snd_dmaengine_pcm_refine_runtime_hwparams
0138      * function.
0139      */
0140     snd_dmaengine_pcm_refine_runtime_hwparams(substream,
0141                           dma_data,
0142                           &hw,
0143                           chan);
0144
0145     return snd_soc_set_runtime_hwparams(substream, &hw);
0146 }
0147
0148 static int dmaengine_pcm_open(struct snd_soc_component *component,
0149                   struct snd_pcm_substream *substream)
0150 {
0151     struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
0152     struct dma_chan *chan = pcm->chan[substream->stream];
0153     int ret;
0154
0155     ret = dmaengine_pcm_set_runtime_hwparams(component, substream);
0156     if (ret)
0157         return ret;
0158
0159     return snd_dmaengine_pcm_open(substream, chan);
0160 }
0161
0162 static int dmaengine_pcm_close(struct snd_soc_component *component,
0163                    struct snd_pcm_substream *substream)
0164 {
0165     return snd_dmaengine_pcm_close(substream);
0166 }
0167
0168 static int dmaengine_pcm_trigger(struct snd_soc_component *component,
0169                  struct snd_pcm_substream *substream, int cmd)
0170 {
0171     return snd_dmaengine_pcm_trigger(substream, cmd);
0172 }
0173
0174 static struct dma_chan *dmaengine_pcm_compat_request_channel(
0175     struct snd_soc_component *component,
0176     struct snd_soc_pcm_runtime *rtd,
0177     struct snd_pcm_substream *substream)
0178 {
0179     struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
0180     struct snd_dmaengine_dai_dma_data *dma_data;
0181
0182     if (rtd->num_cpus > 1) {
0183         dev_err(rtd->dev,
0184             "%s doesn't support Multi CPU yet\n", __func__);
0185         return NULL;
0186     }
0187
0188     dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
0189
0190     if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0])
0191         return pcm->chan[0];
0192
0193     if (pcm->config->compat_request_channel)
0194         return pcm->config->compat_request_channel(rtd, substream);
0195
0196     return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn,
0197                          dma_data->filter_data);
0198 }
0199
0200 static bool dmaengine_pcm_can_report_residue(struct device *dev,
0201     struct dma_chan *chan)
0202 {
0203     struct dma_slave_caps dma_caps;
0204     int ret;
0205
0206     ret = dma_get_slave_caps(chan, &dma_caps);
0207     if (ret != 0) {
0208         dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n",
0209              ret);
0210         return false;
0211     }
0212
0213     if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR)
0214         return false;
0215
0216     return true;
0217 }
0218
0219 static int dmaengine_pcm_new(struct snd_soc_component *component,
0220                  struct snd_soc_pcm_runtime *rtd)
0221 {
0222     struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
0223     const struct snd_dmaengine_pcm_config *config = pcm->config;
0224     struct device *dev = component->dev;
0225     size_t prealloc_buffer_size;
0226     size_t max_buffer_size;
0227     unsigned int i;
0228
0229     if (config->prealloc_buffer_size)
0230         prealloc_buffer_size = config->prealloc_buffer_size;
0231     else
0232         prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024;
0233
0234     if (config->pcm_hardware && config->pcm_hardware->buffer_bytes_max)
0235         max_buffer_size = config->pcm_hardware->buffer_bytes_max;
0236     else
0237         max_buffer_size = SIZE_MAX;
0238
0239     for_each_pcm_streams(i) {
0240         struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream;
0241         if (!substream)
0242             continue;
0243
0244         if (!pcm->chan[i] && config->chan_names[i])
0245             pcm->chan[i] = dma_request_slave_channel(dev,
0246                 config->chan_names[i]);
0247
0248         if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) {
0249             pcm->chan[i] = dmaengine_pcm_compat_request_channel(
0250                 component, rtd, substream);
0251         }
0252
0253         if (!pcm->chan[i]) {
0254             dev_err(component->dev,
0255                 "Missing dma channel for stream: %d\n", i);
0256             return -EINVAL;
0257         }
0258
0259         snd_pcm_set_managed_buffer(substream,
0260                 SNDRV_DMA_TYPE_DEV_IRAM,
0261                 dmaengine_dma_dev(pcm, substream),
0262                 prealloc_buffer_size,
0263                 max_buffer_size);
0264
0265         if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i]))
0266             pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE;
0267
0268         if (rtd->pcm->streams[i].pcm->name[0] == '\0') {
0269             strscpy_pad(rtd->pcm->streams[i].pcm->name,
0270                     rtd->pcm->streams[i].pcm->id,
0271                     sizeof(rtd->pcm->streams[i].pcm->name));
0272         }
0273     }
0274
0275     return 0;
0276 }
0277
0278 static snd_pcm_uframes_t dmaengine_pcm_pointer(
0279     struct snd_soc_component *component,
0280     struct snd_pcm_substream *substream)
0281 {
0282     struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
0283
0284     if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE)
0285         return snd_dmaengine_pcm_pointer_no_residue(substream);
0286     else
0287         return snd_dmaengine_pcm_pointer(substream);
0288 }
0289
0290 static int dmaengine_copy_user(struct snd_soc_component *component,
0291                    struct snd_pcm_substream *substream,
0292                    int channel, unsigned long hwoff,
0293                    void __user *buf, unsigned long bytes)
0294 {
0295     struct snd_pcm_runtime *runtime = substream->runtime;
0296     struct dmaengine_pcm *pcm = soc_component_to_pcm(component);
0297     int (*process)(struct snd_pcm_substream *substream,
0298                int channel, unsigned long hwoff,
0299                void *buf, unsigned long bytes) = pcm->config->process;
0300     bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
0301     void *dma_ptr = runtime->dma_area + hwoff +
0302             channel * (runtime->dma_bytes / runtime->channels);
0303
0304     if (is_playback)
0305         if (copy_from_user(dma_ptr, buf, bytes))
0306             return -EFAULT;
0307
0308     if (process) {
0309         int ret = process(substream, channel, hwoff, (__force void *)buf, bytes);
0310         if (ret < 0)
0311             return ret;
0312     }
0313
0314     if (!is_playback)
0315         if (copy_to_user(buf, dma_ptr, bytes))
0316             return -EFAULT;
0317
0318     return 0;
0319 }
0320
0321 static const struct snd_soc_component_driver dmaengine_pcm_component = {
0322     .name       = SND_DMAENGINE_PCM_DRV_NAME,
0323     .probe_order    = SND_SOC_COMP_ORDER_LATE,
0324     .open       = dmaengine_pcm_open,
0325     .close      = dmaengine_pcm_close,
0326     .hw_params  = dmaengine_pcm_hw_params,
0327     .trigger    = dmaengine_pcm_trigger,
0328     .pointer    = dmaengine_pcm_pointer,
0329     .pcm_construct  = dmaengine_pcm_new,
0330 };
0331
0332 static const struct snd_soc_component_driver dmaengine_pcm_component_process = {
0333     .name       = SND_DMAENGINE_PCM_DRV_NAME,
0334     .probe_order    = SND_SOC_COMP_ORDER_LATE,
0335     .open       = dmaengine_pcm_open,
0336     .close      = dmaengine_pcm_close,
0337     .hw_params  = dmaengine_pcm_hw_params,
0338     .trigger    = dmaengine_pcm_trigger,
0339     .pointer    = dmaengine_pcm_pointer,
0340     .copy_user  = dmaengine_copy_user,
0341     .pcm_construct  = dmaengine_pcm_new,
0342 };
0343
0344 static const char * const dmaengine_pcm_dma_channel_names[] = {
0345     [SNDRV_PCM_STREAM_PLAYBACK] = "tx",
0346     [SNDRV_PCM_STREAM_CAPTURE] = "rx",
0347 };
0348
0349 static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm,
0350     struct device *dev, const struct snd_dmaengine_pcm_config *config)
0351 {
0352     unsigned int i;
0353     const char *name;
0354     struct dma_chan *chan;
0355
0356     if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node &&
0357         !(config->dma_dev && config->dma_dev->of_node)))
0358         return 0;
0359
0360     if (config->dma_dev) {
0361         /*
0362          * If this warning is seen, it probably means that your Linux
0363          * device structure does not match your HW device structure.
0364          * It would be best to refactor the Linux device structure to
0365          * correctly match the HW structure.
0366          */
0367         dev_warn(dev, "DMA channels sourced from device %s",
0368              dev_name(config->dma_dev));
0369         dev = config->dma_dev;
0370     }
0371
0372     for_each_pcm_streams(i) {
0373         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
0374             name = "rx-tx";
0375         else
0376             name = dmaengine_pcm_dma_channel_names[i];
0377         if (config->chan_names[i])
0378             name = config->chan_names[i];
0379         chan = dma_request_chan(dev, name);
0380         if (IS_ERR(chan)) {
0381             /*
0382              * Only report probe deferral errors, channels
0383              * might not be present for devices that
0384              * support only TX or only RX.
0385              */
0386             if (PTR_ERR(chan) == -EPROBE_DEFER)
0387                 return -EPROBE_DEFER;
0388             pcm->chan[i] = NULL;
0389         } else {
0390             pcm->chan[i] = chan;
0391         }
0392         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
0393             break;
0394     }
0395
0396     if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
0397         pcm->chan[1] = pcm->chan[0];
0398
0399     return 0;
0400 }
0401
0402 static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm)
0403 {
0404     unsigned int i;
0405
0406     for_each_pcm_streams(i) {
0407         if (!pcm->chan[i])
0408             continue;
0409         dma_release_channel(pcm->chan[i]);
0410         if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX)
0411             break;
0412     }
0413 }
0414
0415 static const struct snd_dmaengine_pcm_config snd_dmaengine_pcm_default_config = {
0416     .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
0417 };
0418
0419 /**
0420  * snd_dmaengine_pcm_register - Register a dmaengine based PCM device
0421  * @dev: The parent device for the PCM device
0422  * @config: Platform specific PCM configuration
0423  * @flags: Platform specific quirks
0424  */
0425 int snd_dmaengine_pcm_register(struct device *dev,
0426     const struct snd_dmaengine_pcm_config *config, unsigned int flags)
0427 {
0428     const struct snd_soc_component_driver *driver;
0429     struct dmaengine_pcm *pcm;
0430     int ret;
0431
0432     pcm = kzalloc(sizeof(*pcm), GFP_KERNEL);
0433     if (!pcm)
0434         return -ENOMEM;
0435
0436 #ifdef CONFIG_DEBUG_FS
0437     pcm->component.debugfs_prefix = "dma";
0438 #endif
0439     if (!config)
0440         config = &snd_dmaengine_pcm_default_config;
0441     pcm->config = config;
0442     pcm->flags = flags;
0443
0444     ret = dmaengine_pcm_request_chan_of(pcm, dev, config);
0445     if (ret)
0446         goto err_free_dma;
0447
0448     if (config->process)
0449         driver = &dmaengine_pcm_component_process;
0450     else
0451         driver = &dmaengine_pcm_component;
0452
0453     ret = snd_soc_component_initialize(&pcm->component, driver, dev);
0454     if (ret)
0455         goto err_free_dma;
0456
0457     ret = snd_soc_add_component(&pcm->component, NULL, 0);
0458     if (ret)
0459         goto err_free_dma;
0460
0461     return 0;
0462
0463 err_free_dma:
0464     dmaengine_pcm_release_chan(pcm);
0465     kfree(pcm);
0466     return ret;
0467 }
0468 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register);
0469
0470 /**
0471  * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device
0472  * @dev: Parent device the PCM was register with
0473  *
0474  * Removes a dmaengine based PCM device previously registered with
0475  * snd_dmaengine_pcm_register.
0476  */
0477 void snd_dmaengine_pcm_unregister(struct device *dev)
0478 {
0479     struct snd_soc_component *component;
0480     struct dmaengine_pcm *pcm;
0481
0482     component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME);
0483     if (!component)
0484         return;
0485
0486     pcm = soc_component_to_pcm(component);
0487
0488     snd_soc_unregister_component_by_driver(dev, component->driver);
0489     dmaengine_pcm_release_chan(pcm);
0490     kfree(pcm);
0491 }
0492 EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister);
0493
0494 MODULE_LICENSE("GPL");