// SPDX-License-Identifier: GPL-2.0+ // // Copyright (C) 2013, Analog Devices Inc. // Author: Lars-Peter Clausen <lars@metafoo.de> #include <linux/module.h> #include <linux/init.h> #include <linux/dmaengine.h> #include <linux/slab.h> #include <sound/pcm.h> #include <sound/pcm_params.h> #include <sound/soc.h> #include <linux/dma-mapping.h> #include <linux/of.h> #include <sound/dmaengine_pcm.h> static unsigned int prealloc_buffer_size_kbytes = 512; module_param(prealloc_buffer_size_kbytes, uint, 0444); MODULE_PARM_DESC(prealloc_buffer_size_kbytes, "Preallocate DMA buffer size (KB)."); /* * The platforms dmaengine driver does not support reporting the amount of * bytes that are still left to transfer. */ #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(31) static struct device *dmaengine_dma_dev(struct dmaengine_pcm *pcm, struct snd_pcm_substream *substream) { if (!pcm->chan[substream->stream]) return NULL; return pcm->chan[substream->stream]->device->dev; } /** * snd_dmaengine_pcm_prepare_slave_config() - Generic prepare_slave_config callback * @substream: PCM substream * @params: hw_params * @slave_config: DMA slave config to prepare * * This function can be used as a generic prepare_slave_config callback for * platforms which make use of the snd_dmaengine_dai_dma_data struct for their * DAI DMA data. Internally the function will first call * snd_hwparams_to_dma_slave_config to fill in the slave config based on the * hw_params, followed by snd_dmaengine_set_config_from_dai_data to fill in the * remaining fields based on the DAI DMA data. */ int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) { struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); struct snd_dmaengine_dai_dma_data *dma_data; int ret; if (rtd->num_cpus > 1) { dev_err(rtd->dev, "%s doesn't support Multi CPU yet\n", __func__); return -EINVAL; } dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); if (ret) return ret; snd_dmaengine_pcm_set_config_from_dai_data(substream, dma_data, slave_config); return 0; } EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_prepare_slave_config); static int dmaengine_pcm_hw_params(struct snd_soc_component *component, struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params) { struct dmaengine_pcm *pcm = soc_component_to_pcm(component); struct dma_chan *chan = snd_dmaengine_pcm_get_chan(substream); struct dma_slave_config slave_config; int ret; if (!pcm->config->prepare_slave_config) return 0; memset(&slave_config, 0, sizeof(slave_config)); ret = pcm->config->prepare_slave_config(substream, params, &slave_config); if (ret) return ret; return dmaengine_slave_config(chan, &slave_config); } static int dmaengine_pcm_set_runtime_hwparams(struct snd_soc_component *component, struct snd_pcm_substream *substream) { struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream); struct dmaengine_pcm *pcm = soc_component_to_pcm(component); struct device *dma_dev = dmaengine_dma_dev(pcm, substream); struct dma_chan *chan = pcm->chan[substream->stream]; struct snd_dmaengine_dai_dma_data *dma_data; struct snd_pcm_hardware hw; if (rtd->num_cpus > 1) { dev_err(rtd->dev, "%s doesn't support Multi CPU yet\n", __func__); return -EINVAL; } if (pcm->config->pcm_hardware) return snd_soc_set_runtime_hwparams(substream, pcm->config->pcm_hardware); dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); memset(&hw, 0, sizeof(hw)); hw.info = SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_INTERLEAVED; hw.periods_min = 2; hw.periods_max = UINT_MAX; hw.period_bytes_min = dma_data->maxburst * DMA_SLAVE_BUSWIDTH_8_BYTES; if (!hw.period_bytes_min) hw.period_bytes_min = 256; hw.period_bytes_max = dma_get_max_seg_size(dma_dev); hw.buffer_bytes_max = SIZE_MAX; hw.fifo_size = dma_data->fifo_size; if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) hw.info |= SNDRV_PCM_INFO_BATCH; /** * FIXME: Remove the return value check to align with the code * before adding snd_dmaengine_pcm_refine_runtime_hwparams * function. */ snd_dmaengine_pcm_refine_runtime_hwparams(substream, dma_data, &hw, chan); return snd_soc_set_runtime_hwparams(substream, &hw); } static int dmaengine_pcm_open(struct snd_soc_component *component, struct snd_pcm_substream *substream) { struct dmaengine_pcm *pcm = soc_component_to_pcm(component); struct dma_chan *chan = pcm->chan[substream->stream]; int ret; ret = dmaengine_pcm_set_runtime_hwparams(component, substream); if (ret) return ret; return snd_dmaengine_pcm_open(substream, chan); } static int dmaengine_pcm_close(struct snd_soc_component *component, struct snd_pcm_substream *substream) { return snd_dmaengine_pcm_close(substream); } static int dmaengine_pcm_trigger(struct snd_soc_component *component, struct snd_pcm_substream *substream, int cmd) { return snd_dmaengine_pcm_trigger(substream, cmd); } static struct dma_chan *dmaengine_pcm_compat_request_channel( struct snd_soc_component *component, struct snd_soc_pcm_runtime *rtd, struct snd_pcm_substream *substream) { struct dmaengine_pcm *pcm = soc_component_to_pcm(component); struct snd_dmaengine_dai_dma_data *dma_data; if (rtd->num_cpus > 1) { dev_err(rtd->dev, "%s doesn't support Multi CPU yet\n", __func__); return NULL; } dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream); if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) && pcm->chan[0]) return pcm->chan[0]; if (pcm->config->compat_request_channel) return pcm->config->compat_request_channel(rtd, substream); return snd_dmaengine_pcm_request_channel(pcm->config->compat_filter_fn, dma_data->filter_data); } static bool dmaengine_pcm_can_report_residue(struct device *dev, struct dma_chan *chan) { struct dma_slave_caps dma_caps; int ret; ret = dma_get_slave_caps(chan, &dma_caps); if (ret != 0) { dev_warn(dev, "Failed to get DMA channel capabilities, falling back to period counting: %d\n", ret); return false; } if (dma_caps.residue_granularity == DMA_RESIDUE_GRANULARITY_DESCRIPTOR) return false; return true; } static int dmaengine_pcm_new(struct snd_soc_component *component, struct snd_soc_pcm_runtime *rtd) { struct dmaengine_pcm *pcm = soc_component_to_pcm(component); const struct snd_dmaengine_pcm_config *config = pcm->config; struct device *dev = component->dev; size_t prealloc_buffer_size; size_t max_buffer_size; unsigned int i; if (config->prealloc_buffer_size) prealloc_buffer_size = config->prealloc_buffer_size; else prealloc_buffer_size = prealloc_buffer_size_kbytes * 1024; if (config->pcm_hardware && config->pcm_hardware->buffer_bytes_max) max_buffer_size = config->pcm_hardware->buffer_bytes_max; else max_buffer_size = SIZE_MAX; for_each_pcm_streams(i) { struct snd_pcm_substream *substream = rtd->pcm->streams[i].substream; if (!substream) continue; if (!pcm->chan[i] && config->chan_names[i]) pcm->chan[i] = dma_request_slave_channel(dev, config->chan_names[i]); if (!pcm->chan[i] && (pcm->flags & SND_DMAENGINE_PCM_FLAG_COMPAT)) { pcm->chan[i] = dmaengine_pcm_compat_request_channel( component, rtd, substream); } if (!pcm->chan[i]) { dev_err(component->dev, "Missing dma channel for stream: %d\n", i); return -EINVAL; } snd_pcm_set_managed_buffer(substream, SNDRV_DMA_TYPE_DEV_IRAM, dmaengine_dma_dev(pcm, substream), prealloc_buffer_size, max_buffer_size); if (!dmaengine_pcm_can_report_residue(dev, pcm->chan[i])) pcm->flags |= SND_DMAENGINE_PCM_FLAG_NO_RESIDUE; if (rtd->pcm->streams[i].pcm->name[0] == '\0') { strscpy_pad(rtd->pcm->streams[i].pcm->name, rtd->pcm->streams[i].pcm->id, sizeof(rtd->pcm->streams[i].pcm->name)); } } return 0; } static snd_pcm_uframes_t dmaengine_pcm_pointer( struct snd_soc_component *component, struct snd_pcm_substream *substream) { struct dmaengine_pcm *pcm = soc_component_to_pcm(component); if (pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_RESIDUE) return snd_dmaengine_pcm_pointer_no_residue(substream); else return snd_dmaengine_pcm_pointer(substream); } static int dmaengine_copy_user(struct snd_soc_component *component, struct snd_pcm_substream *substream, int channel, unsigned long hwoff, void __user *buf, unsigned long bytes) { struct snd_pcm_runtime *runtime = substream->runtime; struct dmaengine_pcm *pcm = soc_component_to_pcm(component); int (*process)(struct snd_pcm_substream *substream, int channel, unsigned long hwoff, void *buf, unsigned long bytes) = pcm->config->process; bool is_playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK; void *dma_ptr = runtime->dma_area + hwoff + channel * (runtime->dma_bytes / runtime->channels); if (is_playback) if (copy_from_user(dma_ptr, buf, bytes)) return -EFAULT; if (process) { int ret = process(substream, channel, hwoff, (__force void *)buf, bytes); if (ret < 0) return ret; } if (!is_playback) if (copy_to_user(buf, dma_ptr, bytes)) return -EFAULT; return 0; } static const struct snd_soc_component_driver dmaengine_pcm_component = { .name = SND_DMAENGINE_PCM_DRV_NAME, .probe_order = SND_SOC_COMP_ORDER_LATE, .open = dmaengine_pcm_open, .close = dmaengine_pcm_close, .hw_params = dmaengine_pcm_hw_params, .trigger = dmaengine_pcm_trigger, .pointer = dmaengine_pcm_pointer, .pcm_construct = dmaengine_pcm_new, }; static const struct snd_soc_component_driver dmaengine_pcm_component_process = { .name = SND_DMAENGINE_PCM_DRV_NAME, .probe_order = SND_SOC_COMP_ORDER_LATE, .open = dmaengine_pcm_open, .close = dmaengine_pcm_close, .hw_params = dmaengine_pcm_hw_params, .trigger = dmaengine_pcm_trigger, .pointer = dmaengine_pcm_pointer, .copy_user = dmaengine_copy_user, .pcm_construct = dmaengine_pcm_new, }; static const char * const dmaengine_pcm_dma_channel_names[] = { [SNDRV_PCM_STREAM_PLAYBACK] = "tx", [SNDRV_PCM_STREAM_CAPTURE] = "rx", }; static int dmaengine_pcm_request_chan_of(struct dmaengine_pcm *pcm, struct device *dev, const struct snd_dmaengine_pcm_config *config) { unsigned int i; const char *name; struct dma_chan *chan; if ((pcm->flags & SND_DMAENGINE_PCM_FLAG_NO_DT) || (!dev->of_node && !(config->dma_dev && config->dma_dev->of_node))) return 0; if (config->dma_dev) { /* * If this warning is seen, it probably means that your Linux * device structure does not match your HW device structure. * It would be best to refactor the Linux device structure to * correctly match the HW structure. */ dev_warn(dev, "DMA channels sourced from device %s", dev_name(config->dma_dev)); dev = config->dma_dev; } for_each_pcm_streams(i) { if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) name = "rx-tx"; else name = dmaengine_pcm_dma_channel_names[i]; if (config->chan_names[i]) name = config->chan_names[i]; chan = dma_request_chan(dev, name); if (IS_ERR(chan)) { /* * Only report probe deferral errors, channels * might not be present for devices that * support only TX or only RX. */ if (PTR_ERR(chan) == -EPROBE_DEFER) return -EPROBE_DEFER; pcm->chan[i] = NULL; } else { pcm->chan[i] = chan; } if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) break; } if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) pcm->chan[1] = pcm->chan[0]; return 0; } static void dmaengine_pcm_release_chan(struct dmaengine_pcm *pcm) { unsigned int i; for_each_pcm_streams(i) { if (!pcm->chan[i]) continue; dma_release_channel(pcm->chan[i]); if (pcm->flags & SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX) break; } } static const struct snd_dmaengine_pcm_config snd_dmaengine_pcm_default_config = { .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config, }; /** * snd_dmaengine_pcm_register - Register a dmaengine based PCM device * @dev: The parent device for the PCM device * @config: Platform specific PCM configuration * @flags: Platform specific quirks */ int snd_dmaengine_pcm_register(struct device *dev, const struct snd_dmaengine_pcm_config *config, unsigned int flags) { const struct snd_soc_component_driver *driver; struct dmaengine_pcm *pcm; int ret; pcm = kzalloc(sizeof(*pcm), GFP_KERNEL); if (!pcm) return -ENOMEM; #ifdef CONFIG_DEBUG_FS pcm->component.debugfs_prefix = "dma"; #endif if (!config) config = &snd_dmaengine_pcm_default_config; pcm->config = config; pcm->flags = flags; ret = dmaengine_pcm_request_chan_of(pcm, dev, config); if (ret) goto err_free_dma; if (config->process) driver = &dmaengine_pcm_component_process; else driver = &dmaengine_pcm_component; ret = snd_soc_component_initialize(&pcm->component, driver, dev); if (ret) goto err_free_dma; ret = snd_soc_add_component(&pcm->component, NULL, 0); if (ret) goto err_free_dma; return 0; err_free_dma: dmaengine_pcm_release_chan(pcm); kfree(pcm); return ret; } EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_register); /** * snd_dmaengine_pcm_unregister - Removes a dmaengine based PCM device * @dev: Parent device the PCM was register with * * Removes a dmaengine based PCM device previously registered with * snd_dmaengine_pcm_register. */ void snd_dmaengine_pcm_unregister(struct device *dev) { struct snd_soc_component *component; struct dmaengine_pcm *pcm; component = snd_soc_lookup_component(dev, SND_DMAENGINE_PCM_DRV_NAME); if (!component) return; pcm = soc_component_to_pcm(component); snd_soc_unregister_component_by_driver(dev, component->driver); dmaengine_pcm_release_chan(pcm); kfree(pcm); } EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_unregister); MODULE_LICENSE("GPL");