1 /* 2 * atmel-pcm-dma.c -- ALSA PCM DMA support for the Atmel SoC. 3 * 4 * Copyright (C) 2012 Atmel 5 * 6 * Author: Bo Shen <voice.shen@atmel.com> 7 * 8 * Based on atmel-pcm by: 9 * Sedji Gaouaou <sedji.gaouaou@atmel.com> 10 * Copyright 2008 Atmel 11 * 12 * This program is free software; you can redistribute it and/or modify 13 * it under the terms of the GNU General Public License as published by 14 * the Free Software Foundation; either version 2 of the License, or 15 * (at your option) any later version. 16 * 17 * This program is distributed in the hope that it will be useful, 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20 * GNU General Public License for more details. 21 * 22 * You should have received a copy of the GNU General Public License 23 * along with this program; if not, write to the Free Software 24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 25 */ 26 27 #include <linux/module.h> 28 #include <linux/init.h> 29 #include <linux/platform_device.h> 30 #include <linux/slab.h> 31 #include <linux/dma-mapping.h> 32 #include <linux/dmaengine.h> 33 #include <linux/atmel-ssc.h> 34 #include <linux/platform_data/dma-atmel.h> 35 36 #include <sound/core.h> 37 #include <sound/pcm.h> 38 #include <sound/pcm_params.h> 39 #include <sound/soc.h> 40 #include <sound/dmaengine_pcm.h> 41 42 #include "atmel-pcm.h" 43 44 /*--------------------------------------------------------------------------*\ 45 * Hardware definition 46 \*--------------------------------------------------------------------------*/ 47 static const struct snd_pcm_hardware atmel_pcm_dma_hardware = { 48 .info = SNDRV_PCM_INFO_MMAP | 49 SNDRV_PCM_INFO_MMAP_VALID | 50 SNDRV_PCM_INFO_INTERLEAVED | 51 SNDRV_PCM_INFO_RESUME | 52 SNDRV_PCM_INFO_PAUSE, 53 .formats = SNDRV_PCM_FMTBIT_S16_LE, 54 .period_bytes_min = 256, /* lighting DMA overhead */ 55 .period_bytes_max = 2 * 0xffff, /* if 2 bytes format */ 56 .periods_min = 8, 57 .periods_max = 1024, /* no limit */ 58 .buffer_bytes_max = ATMEL_SSC_DMABUF_SIZE, 59 }; 60 61 /** 62 * atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC 63 * 64 * We use DMAENGINE to send/receive data to/from SSC so this ISR is only to 65 * check if any overrun occured. 66 */ 67 static void atmel_pcm_dma_irq(u32 ssc_sr, 68 struct snd_pcm_substream *substream) 69 { 70 struct atmel_pcm_dma_params *prtd; 71 72 prtd = snd_dmaengine_pcm_get_data(substream); 73 74 if (ssc_sr & prtd->mask->ssc_error) { 75 if (snd_pcm_running(substream)) 76 pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n", 77 substream->stream == SNDRV_PCM_STREAM_PLAYBACK 78 ? "underrun" : "overrun", prtd->name, 79 ssc_sr); 80 81 /* stop RX and capture: will be enabled again at restart */ 82 ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable); 83 snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN); 84 85 /* now drain RHR and read status to remove xrun condition */ 86 ssc_readx(prtd->ssc->regs, SSC_RHR); 87 ssc_readx(prtd->ssc->regs, SSC_SR); 88 } 89 } 90 91 /*--------------------------------------------------------------------------*\ 92 * DMAENGINE operations 93 \*--------------------------------------------------------------------------*/ 94 static bool filter(struct dma_chan *chan, void *slave) 95 { 96 struct at_dma_slave *sl = slave; 97 98 if (sl->dma_dev == chan->device->dev) { 99 chan->private = sl; 100 return true; 101 } else { 102 return false; 103 } 104 } 105 106 static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream, 107 struct snd_pcm_hw_params *params) 108 { 109 struct atmel_pcm_dma_params *prtd; 110 struct ssc_device *ssc; 111 struct dma_chan *dma_chan; 112 struct dma_slave_config slave_config; 113 int ret; 114 115 prtd = snd_dmaengine_pcm_get_data(substream); 116 ssc = prtd->ssc; 117 118 ret = snd_hwparams_to_dma_slave_config(substream, params, 119 &slave_config); 120 if (ret) { 121 pr_err("atmel-pcm: hwparams to dma slave configure failed\n"); 122 return ret; 123 } 124 125 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 126 slave_config.dst_addr = (dma_addr_t)ssc->phybase + SSC_THR; 127 slave_config.dst_maxburst = 1; 128 } else { 129 slave_config.src_addr = (dma_addr_t)ssc->phybase + SSC_RHR; 130 slave_config.src_maxburst = 1; 131 } 132 133 slave_config.device_fc = false; 134 135 dma_chan = snd_dmaengine_pcm_get_chan(substream); 136 if (dmaengine_slave_config(dma_chan, &slave_config)) { 137 pr_err("atmel-pcm: failed to configure dma channel\n"); 138 ret = -EBUSY; 139 return ret; 140 } 141 142 return 0; 143 } 144 145 static int atmel_pcm_hw_params(struct snd_pcm_substream *substream, 146 struct snd_pcm_hw_params *params) 147 { 148 struct snd_soc_pcm_runtime *rtd = substream->private_data; 149 struct atmel_pcm_dma_params *prtd; 150 struct ssc_device *ssc; 151 struct at_dma_slave *sdata = NULL; 152 int ret; 153 154 snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer); 155 156 prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); 157 ssc = prtd->ssc; 158 if (ssc->pdev) 159 sdata = ssc->pdev->dev.platform_data; 160 161 ret = snd_dmaengine_pcm_open(substream, filter, sdata); 162 if (ret) { 163 pr_err("atmel-pcm: dmaengine pcm open failed\n"); 164 return -EINVAL; 165 } 166 167 snd_dmaengine_pcm_set_data(substream, prtd); 168 169 ret = atmel_pcm_configure_dma(substream, params); 170 if (ret) { 171 pr_err("atmel-pcm: failed to configure dmai\n"); 172 goto err; 173 } 174 175 prtd->dma_intr_handler = atmel_pcm_dma_irq; 176 177 return 0; 178 err: 179 snd_dmaengine_pcm_close(substream); 180 return ret; 181 } 182 183 static int atmel_pcm_dma_prepare(struct snd_pcm_substream *substream) 184 { 185 struct atmel_pcm_dma_params *prtd; 186 187 prtd = snd_dmaengine_pcm_get_data(substream); 188 189 ssc_writex(prtd->ssc->regs, SSC_IER, prtd->mask->ssc_error); 190 ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_enable); 191 192 return 0; 193 } 194 195 static int atmel_pcm_open(struct snd_pcm_substream *substream) 196 { 197 snd_soc_set_runtime_hwparams(substream, &atmel_pcm_dma_hardware); 198 199 return 0; 200 } 201 202 static int atmel_pcm_close(struct snd_pcm_substream *substream) 203 { 204 snd_dmaengine_pcm_close(substream); 205 206 return 0; 207 } 208 209 static struct snd_pcm_ops atmel_pcm_ops = { 210 .open = atmel_pcm_open, 211 .close = atmel_pcm_close, 212 .ioctl = snd_pcm_lib_ioctl, 213 .hw_params = atmel_pcm_hw_params, 214 .prepare = atmel_pcm_dma_prepare, 215 .trigger = snd_dmaengine_pcm_trigger, 216 .pointer = snd_dmaengine_pcm_pointer_no_residue, 217 .mmap = atmel_pcm_mmap, 218 }; 219 220 static struct snd_soc_platform_driver atmel_soc_platform = { 221 .ops = &atmel_pcm_ops, 222 .pcm_new = atmel_pcm_new, 223 .pcm_free = atmel_pcm_free, 224 }; 225 226 int atmel_pcm_dma_platform_register(struct device *dev) 227 { 228 return snd_soc_register_platform(dev, &atmel_soc_platform); 229 } 230 EXPORT_SYMBOL(atmel_pcm_dma_platform_register); 231 232 void atmel_pcm_dma_platform_unregister(struct device *dev) 233 { 234 snd_soc_unregister_platform(dev); 235 } 236 EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister); 237 238 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>"); 239 MODULE_DESCRIPTION("Atmel DMA based PCM module"); 240 MODULE_LICENSE("GPL"); 241