1 /* 2 * SH7760 ("camelot") DMABRG audio DMA unit support 3 * 4 * Copyright (C) 2007 Manuel Lauss <mano@roarinelk.homelinux.net> 5 * licensed under the terms outlined in the file COPYING at the root 6 * of the linux kernel sources. 7 * 8 * The SH7760 DMABRG provides 4 dma channels (2x rec, 2x play), which 9 * trigger an interrupt when one half of the programmed transfer size 10 * has been xmitted. 11 * 12 * FIXME: little-endian only for now 13 */ 14 15 #include <linux/module.h> 16 #include <linux/gfp.h> 17 #include <linux/init.h> 18 #include <linux/platform_device.h> 19 #include <linux/dma-mapping.h> 20 #include <sound/core.h> 21 #include <sound/pcm.h> 22 #include <sound/pcm_params.h> 23 #include <sound/soc.h> 24 #include <asm/dmabrg.h> 25 26 27 /* registers and bits */ 28 #define BRGATXSAR 0x00 29 #define BRGARXDAR 0x04 30 #define BRGATXTCR 0x08 31 #define BRGARXTCR 0x0C 32 #define BRGACR 0x10 33 #define BRGATXTCNT 0x14 34 #define BRGARXTCNT 0x18 35 36 #define ACR_RAR (1 << 18) 37 #define ACR_RDS (1 << 17) 38 #define ACR_RDE (1 << 16) 39 #define ACR_TAR (1 << 2) 40 #define ACR_TDS (1 << 1) 41 #define ACR_TDE (1 << 0) 42 43 /* receiver/transmitter data alignment */ 44 #define ACR_RAM_NONE (0 << 24) 45 #define ACR_RAM_4BYTE (1 << 24) 46 #define ACR_RAM_2WORD (2 << 24) 47 #define ACR_TAM_NONE (0 << 8) 48 #define ACR_TAM_4BYTE (1 << 8) 49 #define ACR_TAM_2WORD (2 << 8) 50 51 52 struct camelot_pcm { 53 unsigned long mmio; /* DMABRG audio channel control reg MMIO */ 54 unsigned int txid; /* ID of first DMABRG IRQ for this unit */ 55 56 struct snd_pcm_substream *tx_ss; 57 unsigned long tx_period_size; 58 unsigned int tx_period; 59 60 struct snd_pcm_substream *rx_ss; 61 unsigned long rx_period_size; 62 unsigned int rx_period; 63 64 } cam_pcm_data[2] = { 65 { 66 .mmio = 0xFE3C0040, 67 .txid = DMABRGIRQ_A0TXF, 68 }, 69 { 70 .mmio = 0xFE3C0060, 71 .txid = DMABRGIRQ_A1TXF, 72 }, 73 }; 74 75 #define BRGREG(x) (*(unsigned long *)(cam->mmio + (x))) 76 77 /* 78 * set a minimum of 16kb per period, to avoid interrupt-"storm" and 79 * resulting skipping. In general, the bigger the minimum size, the 80 * better for overall system performance. (The SH7760 is a puny CPU 81 * with a slow SDRAM interface and poor internal bus bandwidth, 82 * *especially* when the LCDC is active). The minimum for the DMAC 83 * is 8 bytes; 16kbytes are enough to get skip-free playback of a 84 * 44kHz/16bit/stereo MP3 on a lightly loaded system, and maintain 85 * reasonable responsiveness in MPlayer. 86 */ 87 #define DMABRG_PERIOD_MIN 16 * 1024 88 #define DMABRG_PERIOD_MAX 0x03fffffc 89 #define DMABRG_PREALLOC_BUFFER 32 * 1024 90 #define DMABRG_PREALLOC_BUFFER_MAX 32 * 1024 91 92 static const struct snd_pcm_hardware camelot_pcm_hardware = { 93 .info = (SNDRV_PCM_INFO_MMAP | 94 SNDRV_PCM_INFO_INTERLEAVED | 95 SNDRV_PCM_INFO_BLOCK_TRANSFER | 96 SNDRV_PCM_INFO_MMAP_VALID | 97 SNDRV_PCM_INFO_BATCH), 98 .buffer_bytes_max = DMABRG_PERIOD_MAX, 99 .period_bytes_min = DMABRG_PERIOD_MIN, 100 .period_bytes_max = DMABRG_PERIOD_MAX / 2, 101 .periods_min = 2, 102 .periods_max = 2, 103 .fifo_size = 128, 104 }; 105 106 static void camelot_txdma(void *data) 107 { 108 struct camelot_pcm *cam = data; 109 cam->tx_period ^= 1; 110 snd_pcm_period_elapsed(cam->tx_ss); 111 } 112 113 static void camelot_rxdma(void *data) 114 { 115 struct camelot_pcm *cam = data; 116 cam->rx_period ^= 1; 117 snd_pcm_period_elapsed(cam->rx_ss); 118 } 119 120 static int camelot_pcm_open(struct snd_pcm_substream *substream) 121 { 122 struct snd_soc_pcm_runtime *rtd = substream->private_data; 123 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 124 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 125 int ret, dmairq; 126 127 snd_soc_set_runtime_hwparams(substream, &camelot_pcm_hardware); 128 129 /* DMABRG buffer half/full events */ 130 dmairq = (recv) ? cam->txid + 2 : cam->txid; 131 if (recv) { 132 cam->rx_ss = substream; 133 ret = dmabrg_request_irq(dmairq, camelot_rxdma, cam); 134 if (unlikely(ret)) { 135 pr_debug("audio unit %d irqs already taken!\n", 136 rtd->cpu_dai->id); 137 return -EBUSY; 138 } 139 (void)dmabrg_request_irq(dmairq + 1,camelot_rxdma, cam); 140 } else { 141 cam->tx_ss = substream; 142 ret = dmabrg_request_irq(dmairq, camelot_txdma, cam); 143 if (unlikely(ret)) { 144 pr_debug("audio unit %d irqs already taken!\n", 145 rtd->cpu_dai->id); 146 return -EBUSY; 147 } 148 (void)dmabrg_request_irq(dmairq + 1, camelot_txdma, cam); 149 } 150 return 0; 151 } 152 153 static int camelot_pcm_close(struct snd_pcm_substream *substream) 154 { 155 struct snd_soc_pcm_runtime *rtd = substream->private_data; 156 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 157 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 158 int dmairq; 159 160 dmairq = (recv) ? cam->txid + 2 : cam->txid; 161 162 if (recv) 163 cam->rx_ss = NULL; 164 else 165 cam->tx_ss = NULL; 166 167 dmabrg_free_irq(dmairq + 1); 168 dmabrg_free_irq(dmairq); 169 170 return 0; 171 } 172 173 static int camelot_hw_params(struct snd_pcm_substream *substream, 174 struct snd_pcm_hw_params *hw_params) 175 { 176 struct snd_soc_pcm_runtime *rtd = substream->private_data; 177 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 178 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 179 int ret; 180 181 ret = snd_pcm_lib_malloc_pages(substream, 182 params_buffer_bytes(hw_params)); 183 if (ret < 0) 184 return ret; 185 186 if (recv) { 187 cam->rx_period_size = params_period_bytes(hw_params); 188 cam->rx_period = 0; 189 } else { 190 cam->tx_period_size = params_period_bytes(hw_params); 191 cam->tx_period = 0; 192 } 193 return 0; 194 } 195 196 static int camelot_hw_free(struct snd_pcm_substream *substream) 197 { 198 return snd_pcm_lib_free_pages(substream); 199 } 200 201 static int camelot_prepare(struct snd_pcm_substream *substream) 202 { 203 struct snd_pcm_runtime *runtime = substream->runtime; 204 struct snd_soc_pcm_runtime *rtd = substream->private_data; 205 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 206 207 pr_debug("PCM data: addr 0x%08ulx len %d\n", 208 (u32)runtime->dma_addr, runtime->dma_bytes); 209 210 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 211 BRGREG(BRGATXSAR) = (unsigned long)runtime->dma_area; 212 BRGREG(BRGATXTCR) = runtime->dma_bytes; 213 } else { 214 BRGREG(BRGARXDAR) = (unsigned long)runtime->dma_area; 215 BRGREG(BRGARXTCR) = runtime->dma_bytes; 216 } 217 218 return 0; 219 } 220 221 static inline void dmabrg_play_dma_start(struct camelot_pcm *cam) 222 { 223 unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); 224 /* start DMABRG engine: XFER start, auto-addr-reload */ 225 BRGREG(BRGACR) = acr | ACR_TDE | ACR_TAR | ACR_TAM_2WORD; 226 } 227 228 static inline void dmabrg_play_dma_stop(struct camelot_pcm *cam) 229 { 230 unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); 231 /* forcibly terminate data transmission */ 232 BRGREG(BRGACR) = acr | ACR_TDS; 233 } 234 235 static inline void dmabrg_rec_dma_start(struct camelot_pcm *cam) 236 { 237 unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); 238 /* start DMABRG engine: recv start, auto-reload */ 239 BRGREG(BRGACR) = acr | ACR_RDE | ACR_RAR | ACR_RAM_2WORD; 240 } 241 242 static inline void dmabrg_rec_dma_stop(struct camelot_pcm *cam) 243 { 244 unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); 245 /* forcibly terminate data receiver */ 246 BRGREG(BRGACR) = acr | ACR_RDS; 247 } 248 249 static int camelot_trigger(struct snd_pcm_substream *substream, int cmd) 250 { 251 struct snd_soc_pcm_runtime *rtd = substream->private_data; 252 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 253 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 254 255 switch (cmd) { 256 case SNDRV_PCM_TRIGGER_START: 257 if (recv) 258 dmabrg_rec_dma_start(cam); 259 else 260 dmabrg_play_dma_start(cam); 261 break; 262 case SNDRV_PCM_TRIGGER_STOP: 263 if (recv) 264 dmabrg_rec_dma_stop(cam); 265 else 266 dmabrg_play_dma_stop(cam); 267 break; 268 default: 269 return -EINVAL; 270 } 271 272 return 0; 273 } 274 275 static snd_pcm_uframes_t camelot_pos(struct snd_pcm_substream *substream) 276 { 277 struct snd_pcm_runtime *runtime = substream->runtime; 278 struct snd_soc_pcm_runtime *rtd = substream->private_data; 279 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 280 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 281 unsigned long pos; 282 283 /* cannot use the DMABRG pointer register: under load, by the 284 * time ALSA comes around to read the register, it is already 285 * far ahead (or worse, already done with the fragment) of the 286 * position at the time the IRQ was triggered, which results in 287 * fast-playback sound in my test application (ScummVM) 288 */ 289 if (recv) 290 pos = cam->rx_period ? cam->rx_period_size : 0; 291 else 292 pos = cam->tx_period ? cam->tx_period_size : 0; 293 294 return bytes_to_frames(runtime, pos); 295 } 296 297 static const struct snd_pcm_ops camelot_pcm_ops = { 298 .open = camelot_pcm_open, 299 .close = camelot_pcm_close, 300 .ioctl = snd_pcm_lib_ioctl, 301 .hw_params = camelot_hw_params, 302 .hw_free = camelot_hw_free, 303 .prepare = camelot_prepare, 304 .trigger = camelot_trigger, 305 .pointer = camelot_pos, 306 }; 307 308 static int camelot_pcm_new(struct snd_soc_pcm_runtime *rtd) 309 { 310 struct snd_pcm *pcm = rtd->pcm; 311 312 /* dont use SNDRV_DMA_TYPE_DEV, since it will oops the SH kernel 313 * in MMAP mode (i.e. aplay -M) 314 */ 315 snd_pcm_lib_preallocate_pages_for_all(pcm, 316 SNDRV_DMA_TYPE_CONTINUOUS, 317 snd_dma_continuous_data(GFP_KERNEL), 318 DMABRG_PREALLOC_BUFFER, DMABRG_PREALLOC_BUFFER_MAX); 319 320 return 0; 321 } 322 323 static const struct snd_soc_platform_driver sh7760_soc_platform = { 324 .ops = &camelot_pcm_ops, 325 .pcm_new = camelot_pcm_new, 326 }; 327 328 static int sh7760_soc_platform_probe(struct platform_device *pdev) 329 { 330 return devm_snd_soc_register_platform(&pdev->dev, &sh7760_soc_platform); 331 } 332 333 static struct platform_driver sh7760_pcm_driver = { 334 .driver = { 335 .name = "sh7760-pcm-audio", 336 }, 337 338 .probe = sh7760_soc_platform_probe, 339 }; 340 341 module_platform_driver(sh7760_pcm_driver); 342 343 MODULE_LICENSE("GPL"); 344 MODULE_DESCRIPTION("SH7760 Audio DMA (DMABRG) driver"); 345 MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>"); 346