1 // SPDX-License-Identifier: GPL-2.0 2 // 3 // SH7760 ("camelot") DMABRG audio DMA unit support 4 // 5 // Copyright (C) 2007 Manuel Lauss <mano@roarinelk.homelinux.net> 6 // 7 // The SH7760 DMABRG provides 4 dma channels (2x rec, 2x play), which 8 // trigger an interrupt when one half of the programmed transfer size 9 // has been xmitted. 10 // 11 // FIXME: little-endian only for now 12 13 #include <linux/module.h> 14 #include <linux/gfp.h> 15 #include <linux/init.h> 16 #include <linux/platform_device.h> 17 #include <linux/dma-mapping.h> 18 #include <sound/core.h> 19 #include <sound/pcm.h> 20 #include <sound/pcm_params.h> 21 #include <sound/soc.h> 22 #include <asm/dmabrg.h> 23 24 25 /* registers and bits */ 26 #define BRGATXSAR 0x00 27 #define BRGARXDAR 0x04 28 #define BRGATXTCR 0x08 29 #define BRGARXTCR 0x0C 30 #define BRGACR 0x10 31 #define BRGATXTCNT 0x14 32 #define BRGARXTCNT 0x18 33 34 #define ACR_RAR (1 << 18) 35 #define ACR_RDS (1 << 17) 36 #define ACR_RDE (1 << 16) 37 #define ACR_TAR (1 << 2) 38 #define ACR_TDS (1 << 1) 39 #define ACR_TDE (1 << 0) 40 41 /* receiver/transmitter data alignment */ 42 #define ACR_RAM_NONE (0 << 24) 43 #define ACR_RAM_4BYTE (1 << 24) 44 #define ACR_RAM_2WORD (2 << 24) 45 #define ACR_TAM_NONE (0 << 8) 46 #define ACR_TAM_4BYTE (1 << 8) 47 #define ACR_TAM_2WORD (2 << 8) 48 49 50 struct camelot_pcm { 51 unsigned long mmio; /* DMABRG audio channel control reg MMIO */ 52 unsigned int txid; /* ID of first DMABRG IRQ for this unit */ 53 54 struct snd_pcm_substream *tx_ss; 55 unsigned long tx_period_size; 56 unsigned int tx_period; 57 58 struct snd_pcm_substream *rx_ss; 59 unsigned long rx_period_size; 60 unsigned int rx_period; 61 62 } cam_pcm_data[2] = { 63 { 64 .mmio = 0xFE3C0040, 65 .txid = DMABRGIRQ_A0TXF, 66 }, 67 { 68 .mmio = 0xFE3C0060, 69 .txid = DMABRGIRQ_A1TXF, 70 }, 71 }; 72 73 #define BRGREG(x) (*(unsigned long *)(cam->mmio + (x))) 74 75 /* 76 * set a minimum of 16kb per period, to avoid interrupt-"storm" and 77 * resulting skipping. In general, the bigger the minimum size, the 78 * better for overall system performance. (The SH7760 is a puny CPU 79 * with a slow SDRAM interface and poor internal bus bandwidth, 80 * *especially* when the LCDC is active). The minimum for the DMAC 81 * is 8 bytes; 16kbytes are enough to get skip-free playback of a 82 * 44kHz/16bit/stereo MP3 on a lightly loaded system, and maintain 83 * reasonable responsiveness in MPlayer. 84 */ 85 #define DMABRG_PERIOD_MIN 16 * 1024 86 #define DMABRG_PERIOD_MAX 0x03fffffc 87 #define DMABRG_PREALLOC_BUFFER 32 * 1024 88 #define DMABRG_PREALLOC_BUFFER_MAX 32 * 1024 89 90 static const struct snd_pcm_hardware camelot_pcm_hardware = { 91 .info = (SNDRV_PCM_INFO_MMAP | 92 SNDRV_PCM_INFO_INTERLEAVED | 93 SNDRV_PCM_INFO_BLOCK_TRANSFER | 94 SNDRV_PCM_INFO_MMAP_VALID | 95 SNDRV_PCM_INFO_BATCH), 96 .buffer_bytes_max = DMABRG_PERIOD_MAX, 97 .period_bytes_min = DMABRG_PERIOD_MIN, 98 .period_bytes_max = DMABRG_PERIOD_MAX / 2, 99 .periods_min = 2, 100 .periods_max = 2, 101 .fifo_size = 128, 102 }; 103 104 static void camelot_txdma(void *data) 105 { 106 struct camelot_pcm *cam = data; 107 cam->tx_period ^= 1; 108 snd_pcm_period_elapsed(cam->tx_ss); 109 } 110 111 static void camelot_rxdma(void *data) 112 { 113 struct camelot_pcm *cam = data; 114 cam->rx_period ^= 1; 115 snd_pcm_period_elapsed(cam->rx_ss); 116 } 117 118 static int camelot_pcm_open(struct snd_pcm_substream *substream) 119 { 120 struct snd_soc_pcm_runtime *rtd = substream->private_data; 121 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 122 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 123 int ret, dmairq; 124 125 snd_soc_set_runtime_hwparams(substream, &camelot_pcm_hardware); 126 127 /* DMABRG buffer half/full events */ 128 dmairq = (recv) ? cam->txid + 2 : cam->txid; 129 if (recv) { 130 cam->rx_ss = substream; 131 ret = dmabrg_request_irq(dmairq, camelot_rxdma, cam); 132 if (unlikely(ret)) { 133 pr_debug("audio unit %d irqs already taken!\n", 134 rtd->cpu_dai->id); 135 return -EBUSY; 136 } 137 (void)dmabrg_request_irq(dmairq + 1,camelot_rxdma, cam); 138 } else { 139 cam->tx_ss = substream; 140 ret = dmabrg_request_irq(dmairq, camelot_txdma, cam); 141 if (unlikely(ret)) { 142 pr_debug("audio unit %d irqs already taken!\n", 143 rtd->cpu_dai->id); 144 return -EBUSY; 145 } 146 (void)dmabrg_request_irq(dmairq + 1, camelot_txdma, cam); 147 } 148 return 0; 149 } 150 151 static int camelot_pcm_close(struct snd_pcm_substream *substream) 152 { 153 struct snd_soc_pcm_runtime *rtd = substream->private_data; 154 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 155 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 156 int dmairq; 157 158 dmairq = (recv) ? cam->txid + 2 : cam->txid; 159 160 if (recv) 161 cam->rx_ss = NULL; 162 else 163 cam->tx_ss = NULL; 164 165 dmabrg_free_irq(dmairq + 1); 166 dmabrg_free_irq(dmairq); 167 168 return 0; 169 } 170 171 static int camelot_hw_params(struct snd_pcm_substream *substream, 172 struct snd_pcm_hw_params *hw_params) 173 { 174 struct snd_soc_pcm_runtime *rtd = substream->private_data; 175 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 176 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 177 int ret; 178 179 ret = snd_pcm_lib_malloc_pages(substream, 180 params_buffer_bytes(hw_params)); 181 if (ret < 0) 182 return ret; 183 184 if (recv) { 185 cam->rx_period_size = params_period_bytes(hw_params); 186 cam->rx_period = 0; 187 } else { 188 cam->tx_period_size = params_period_bytes(hw_params); 189 cam->tx_period = 0; 190 } 191 return 0; 192 } 193 194 static int camelot_hw_free(struct snd_pcm_substream *substream) 195 { 196 return snd_pcm_lib_free_pages(substream); 197 } 198 199 static int camelot_prepare(struct snd_pcm_substream *substream) 200 { 201 struct snd_pcm_runtime *runtime = substream->runtime; 202 struct snd_soc_pcm_runtime *rtd = substream->private_data; 203 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 204 205 pr_debug("PCM data: addr 0x%08ulx len %d\n", 206 (u32)runtime->dma_addr, runtime->dma_bytes); 207 208 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { 209 BRGREG(BRGATXSAR) = (unsigned long)runtime->dma_area; 210 BRGREG(BRGATXTCR) = runtime->dma_bytes; 211 } else { 212 BRGREG(BRGARXDAR) = (unsigned long)runtime->dma_area; 213 BRGREG(BRGARXTCR) = runtime->dma_bytes; 214 } 215 216 return 0; 217 } 218 219 static inline void dmabrg_play_dma_start(struct camelot_pcm *cam) 220 { 221 unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); 222 /* start DMABRG engine: XFER start, auto-addr-reload */ 223 BRGREG(BRGACR) = acr | ACR_TDE | ACR_TAR | ACR_TAM_2WORD; 224 } 225 226 static inline void dmabrg_play_dma_stop(struct camelot_pcm *cam) 227 { 228 unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); 229 /* forcibly terminate data transmission */ 230 BRGREG(BRGACR) = acr | ACR_TDS; 231 } 232 233 static inline void dmabrg_rec_dma_start(struct camelot_pcm *cam) 234 { 235 unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); 236 /* start DMABRG engine: recv start, auto-reload */ 237 BRGREG(BRGACR) = acr | ACR_RDE | ACR_RAR | ACR_RAM_2WORD; 238 } 239 240 static inline void dmabrg_rec_dma_stop(struct camelot_pcm *cam) 241 { 242 unsigned long acr = BRGREG(BRGACR) & ~(ACR_TDS | ACR_RDS); 243 /* forcibly terminate data receiver */ 244 BRGREG(BRGACR) = acr | ACR_RDS; 245 } 246 247 static int camelot_trigger(struct snd_pcm_substream *substream, int cmd) 248 { 249 struct snd_soc_pcm_runtime *rtd = substream->private_data; 250 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 251 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 252 253 switch (cmd) { 254 case SNDRV_PCM_TRIGGER_START: 255 if (recv) 256 dmabrg_rec_dma_start(cam); 257 else 258 dmabrg_play_dma_start(cam); 259 break; 260 case SNDRV_PCM_TRIGGER_STOP: 261 if (recv) 262 dmabrg_rec_dma_stop(cam); 263 else 264 dmabrg_play_dma_stop(cam); 265 break; 266 default: 267 return -EINVAL; 268 } 269 270 return 0; 271 } 272 273 static snd_pcm_uframes_t camelot_pos(struct snd_pcm_substream *substream) 274 { 275 struct snd_pcm_runtime *runtime = substream->runtime; 276 struct snd_soc_pcm_runtime *rtd = substream->private_data; 277 struct camelot_pcm *cam = &cam_pcm_data[rtd->cpu_dai->id]; 278 int recv = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? 0:1; 279 unsigned long pos; 280 281 /* cannot use the DMABRG pointer register: under load, by the 282 * time ALSA comes around to read the register, it is already 283 * far ahead (or worse, already done with the fragment) of the 284 * position at the time the IRQ was triggered, which results in 285 * fast-playback sound in my test application (ScummVM) 286 */ 287 if (recv) 288 pos = cam->rx_period ? cam->rx_period_size : 0; 289 else 290 pos = cam->tx_period ? cam->tx_period_size : 0; 291 292 return bytes_to_frames(runtime, pos); 293 } 294 295 static const struct snd_pcm_ops camelot_pcm_ops = { 296 .open = camelot_pcm_open, 297 .close = camelot_pcm_close, 298 .ioctl = snd_pcm_lib_ioctl, 299 .hw_params = camelot_hw_params, 300 .hw_free = camelot_hw_free, 301 .prepare = camelot_prepare, 302 .trigger = camelot_trigger, 303 .pointer = camelot_pos, 304 }; 305 306 static int camelot_pcm_new(struct snd_soc_pcm_runtime *rtd) 307 { 308 struct snd_pcm *pcm = rtd->pcm; 309 310 /* dont use SNDRV_DMA_TYPE_DEV, since it will oops the SH kernel 311 * in MMAP mode (i.e. aplay -M) 312 */ 313 snd_pcm_lib_preallocate_pages_for_all(pcm, 314 SNDRV_DMA_TYPE_CONTINUOUS, 315 snd_dma_continuous_data(GFP_KERNEL), 316 DMABRG_PREALLOC_BUFFER, DMABRG_PREALLOC_BUFFER_MAX); 317 318 return 0; 319 } 320 321 static const struct snd_soc_component_driver sh7760_soc_component = { 322 .ops = &camelot_pcm_ops, 323 .pcm_new = camelot_pcm_new, 324 }; 325 326 static int sh7760_soc_platform_probe(struct platform_device *pdev) 327 { 328 return devm_snd_soc_register_component(&pdev->dev, &sh7760_soc_component, 329 NULL, 0); 330 } 331 332 static struct platform_driver sh7760_pcm_driver = { 333 .driver = { 334 .name = "sh7760-pcm-audio", 335 }, 336 337 .probe = sh7760_soc_platform_probe, 338 }; 339 340 module_platform_driver(sh7760_pcm_driver); 341 342 MODULE_LICENSE("GPL v2"); 343 MODULE_DESCRIPTION("SH7760 Audio DMA (DMABRG) driver"); 344 MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>"); 345