1// SPDX-License-Identifier: GPL-2.0 2// 3// Serial Sound Interface (I2S) support for SH7760/SH7780 4// 5// Copyright (c) 2007 Manuel Lauss <mano@roarinelk.homelinux.net> 6// 7// dont forget to set IPSEL/OMSEL register bits (in your board code) to 8// enable SSI output pins! 9 10/* 11 * LIMITATIONS: 12 * The SSI unit has only one physical data line, so full duplex is 13 * impossible. This can be remedied on the SH7760 by using the 14 * other SSI unit for recording; however the SH7780 has only 1 SSI 15 * unit, and its pins are shared with the AC97 unit, among others. 16 * 17 * FEATURES: 18 * The SSI features "compressed mode": in this mode it continuously 19 * streams PCM data over the I2S lines and uses LRCK as a handshake 20 * signal. Can be used to send compressed data (AC3/DTS) to a DSP. 21 * The number of bits sent over the wire in a frame can be adjusted 22 * and can be independent from the actual sample bit depth. This is 23 * useful to support TDM mode codecs like the AD1939 which have a 24 * fixed TDM slot size, regardless of sample resolution. 25 */ 26 27#include <linux/init.h> 28#include <linux/module.h> 29#include <linux/platform_device.h> 30#include <sound/core.h> 31#include <sound/pcm.h> 32#include <sound/initval.h> 33#include <sound/soc.h> 34#include <asm/io.h> 35 36#define SSICR 0x00 37#define SSISR 0x04 38 39#define CR_DMAEN (1 << 28) 40#define CR_CHNL_SHIFT 22 41#define CR_CHNL_MASK (3 << CR_CHNL_SHIFT) 42#define CR_DWL_SHIFT 19 43#define CR_DWL_MASK (7 << CR_DWL_SHIFT) 44#define CR_SWL_SHIFT 16 45#define CR_SWL_MASK (7 << CR_SWL_SHIFT) 46#define CR_SCK_MASTER (1 << 15) /* bitclock master bit */ 47#define CR_SWS_MASTER (1 << 14) /* wordselect master bit */ 48#define CR_SCKP (1 << 13) /* I2Sclock polarity */ 49#define CR_SWSP (1 << 12) /* LRCK polarity */ 50#define CR_SPDP (1 << 11) 51#define CR_SDTA (1 << 10) /* i2s alignment (msb/lsb) */ 52#define CR_PDTA (1 << 9) /* fifo data alignment */ 53#define CR_DEL (1 << 8) /* delay data by 1 i2sclk */ 54#define CR_BREN (1 << 7) /* clock gating in burst mode */ 55#define CR_CKDIV_SHIFT 4 56#define CR_CKDIV_MASK (7 << CR_CKDIV_SHIFT) /* bitclock divider */ 57#define CR_MUTE (1 << 3) /* SSI mute */ 58#define CR_CPEN (1 << 2) /* compressed mode */ 59#define CR_TRMD (1 << 1) /* transmit/receive select */ 60#define CR_EN (1 << 0) /* enable SSI */ 61 62#define SSIREG(reg) (*(unsigned long *)(ssi->mmio + (reg))) 63 64struct ssi_priv { 65 unsigned long mmio; 66 unsigned long sysclk; 67 int inuse; 68} ssi_cpu_data[] = { 69#if defined(CONFIG_CPU_SUBTYPE_SH7760) 70 { 71 .mmio = 0xFE680000, 72 }, 73 { 74 .mmio = 0xFE690000, 75 }, 76#elif defined(CONFIG_CPU_SUBTYPE_SH7780) 77 { 78 .mmio = 0xFFE70000, 79 }, 80#else 81#error "Unsupported SuperH SoC" 82#endif 83}; 84 85/* 86 * track usage of the SSI; it is simplex-only so prevent attempts of 87 * concurrent playback + capture. FIXME: any locking required? 88 */ 89static int ssi_startup(struct snd_pcm_substream *substream, 90 struct snd_soc_dai *dai) 91{ 92 struct ssi_priv *ssi = &ssi_cpu_data[dai->id]; 93 if (ssi->inuse) { 94 pr_debug("ssi: already in use!\n"); 95 return -EBUSY; 96 } else 97 ssi->inuse = 1; 98 return 0; 99} 100 101static void ssi_shutdown(struct snd_pcm_substream *substream, 102 struct snd_soc_dai *dai) 103{ 104 struct ssi_priv *ssi = &ssi_cpu_data[dai->id]; 105 106 ssi->inuse = 0; 107} 108 109static int ssi_trigger(struct snd_pcm_substream *substream, int cmd, 110 struct snd_soc_dai *dai) 111{ 112 struct ssi_priv *ssi = &ssi_cpu_data[dai->id]; 113 114 switch (cmd) { 115 case SNDRV_PCM_TRIGGER_START: 116 SSIREG(SSICR) |= CR_DMAEN | CR_EN; 117 break; 118 case SNDRV_PCM_TRIGGER_STOP: 119 SSIREG(SSICR) &= ~(CR_DMAEN | CR_EN); 120 break; 121 default: 122 return -EINVAL; 123 } 124 125 return 0; 126} 127 128static int ssi_hw_params(struct snd_pcm_substream *substream, 129 struct snd_pcm_hw_params *params, 130 struct snd_soc_dai *dai) 131{ 132 struct ssi_priv *ssi = &ssi_cpu_data[dai->id]; 133 unsigned long ssicr = SSIREG(SSICR); 134 unsigned int bits, channels, swl, recv, i; 135 136 channels = params_channels(params); 137 bits = params->msbits; 138 recv = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ? 0 : 1; 139 140 pr_debug("ssi_hw_params() enter\nssicr was %08lx\n", ssicr); 141 pr_debug("bits: %u channels: %u\n", bits, channels); 142 143 ssicr &= ~(CR_TRMD | CR_CHNL_MASK | CR_DWL_MASK | CR_PDTA | 144 CR_SWL_MASK); 145 146 /* direction (send/receive) */ 147 if (!recv) 148 ssicr |= CR_TRMD; /* transmit */ 149 150 /* channels */ 151 if ((channels < 2) || (channels > 8) || (channels & 1)) { 152 pr_debug("ssi: invalid number of channels\n"); 153 return -EINVAL; 154 } 155 ssicr |= ((channels >> 1) - 1) << CR_CHNL_SHIFT; 156 157 /* DATA WORD LENGTH (DWL): databits in audio sample */ 158 i = 0; 159 switch (bits) { 160 case 32: ++i; 161 case 24: ++i; 162 case 22: ++i; 163 case 20: ++i; 164 case 18: ++i; 165 case 16: ++i; 166 ssicr |= i << CR_DWL_SHIFT; 167 case 8: break; 168 default: 169 pr_debug("ssi: invalid sample width\n"); 170 return -EINVAL; 171 } 172 173 /* 174 * SYSTEM WORD LENGTH: size in bits of half a frame over the I2S 175 * wires. This is usually bits_per_sample x channels/2; i.e. in 176 * Stereo mode the SWL equals DWL. SWL can be bigger than the 177 * product of (channels_per_slot x samplebits), e.g. for codecs 178 * like the AD1939 which only accept 32bit wide TDM slots. For 179 * "standard" I2S operation we set SWL = chans / 2 * DWL here. 180 * Waiting for ASoC to get TDM support ;-) 181 */ 182 if ((bits > 16) && (bits <= 24)) { 183 bits = 24; /* these are padded by the SSI */ 184 /*ssicr |= CR_PDTA;*/ /* cpu/data endianness ? */ 185 } 186 i = 0; 187 swl = (bits * channels) / 2; 188 switch (swl) { 189 case 256: ++i; 190 case 128: ++i; 191 case 64: ++i; 192 case 48: ++i; 193 case 32: ++i; 194 case 16: ++i; 195 ssicr |= i << CR_SWL_SHIFT; 196 case 8: break; 197 default: 198 pr_debug("ssi: invalid system word length computed\n"); 199 return -EINVAL; 200 } 201 202 SSIREG(SSICR) = ssicr; 203 204 pr_debug("ssi_hw_params() leave\nssicr is now %08lx\n", ssicr); 205 return 0; 206} 207 208static int ssi_set_sysclk(struct snd_soc_dai *cpu_dai, int clk_id, 209 unsigned int freq, int dir) 210{ 211 struct ssi_priv *ssi = &ssi_cpu_data[cpu_dai->id]; 212 213 ssi->sysclk = freq; 214 215 return 0; 216} 217 218/* 219 * This divider is used to generate the SSI_SCK (I2S bitclock) from the 220 * clock at the HAC_BIT_CLK ("oversampling clock") pin. 221 */ 222static int ssi_set_clkdiv(struct snd_soc_dai *dai, int did, int div) 223{ 224 struct ssi_priv *ssi = &ssi_cpu_data[dai->id]; 225 unsigned long ssicr; 226 int i; 227 228 i = 0; 229 ssicr = SSIREG(SSICR) & ~CR_CKDIV_MASK; 230 switch (div) { 231 case 16: ++i; 232 case 8: ++i; 233 case 4: ++i; 234 case 2: ++i; 235 SSIREG(SSICR) = ssicr | (i << CR_CKDIV_SHIFT); 236 case 1: break; 237 default: 238 pr_debug("ssi: invalid sck divider %d\n", div); 239 return -EINVAL; 240 } 241 242 return 0; 243} 244 245static int ssi_set_fmt(struct snd_soc_dai *dai, unsigned int fmt) 246{ 247 struct ssi_priv *ssi = &ssi_cpu_data[dai->id]; 248 unsigned long ssicr = SSIREG(SSICR); 249 250 pr_debug("ssi_set_fmt()\nssicr was 0x%08lx\n", ssicr); 251 252 ssicr &= ~(CR_DEL | CR_PDTA | CR_BREN | CR_SWSP | CR_SCKP | 253 CR_SWS_MASTER | CR_SCK_MASTER); 254 255 switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) { 256 case SND_SOC_DAIFMT_I2S: 257 break; 258 case SND_SOC_DAIFMT_RIGHT_J: 259 ssicr |= CR_DEL | CR_PDTA; 260 break; 261 case SND_SOC_DAIFMT_LEFT_J: 262 ssicr |= CR_DEL; 263 break; 264 default: 265 pr_debug("ssi: unsupported format\n"); 266 return -EINVAL; 267 } 268 269 switch (fmt & SND_SOC_DAIFMT_CLOCK_MASK) { 270 case SND_SOC_DAIFMT_CONT: 271 break; 272 case SND_SOC_DAIFMT_GATED: 273 ssicr |= CR_BREN; 274 break; 275 } 276 277 switch (fmt & SND_SOC_DAIFMT_INV_MASK) { 278 case SND_SOC_DAIFMT_NB_NF: 279 ssicr |= CR_SCKP; /* sample data at low clkedge */ 280 break; 281 case SND_SOC_DAIFMT_NB_IF: 282 ssicr |= CR_SCKP | CR_SWSP; 283 break; 284 case SND_SOC_DAIFMT_IB_NF: 285 break; 286 case SND_SOC_DAIFMT_IB_IF: 287 ssicr |= CR_SWSP; /* word select starts low */ 288 break; 289 default: 290 pr_debug("ssi: invalid inversion\n"); 291 return -EINVAL; 292 } 293 294 switch (fmt & SND_SOC_DAIFMT_CLOCK_PROVIDER_MASK) { 295 case SND_SOC_DAIFMT_BC_FC: 296 break; 297 case SND_SOC_DAIFMT_BP_FC: 298 ssicr |= CR_SCK_MASTER; 299 break; 300 case SND_SOC_DAIFMT_BC_FP: 301 ssicr |= CR_SWS_MASTER; 302 break; 303 case SND_SOC_DAIFMT_BP_FP: 304 ssicr |= CR_SWS_MASTER | CR_SCK_MASTER; 305 break; 306 default: 307 pr_debug("ssi: invalid master/secondary configuration\n"); 308 return -EINVAL; 309 } 310 311 SSIREG(SSICR) = ssicr; 312 pr_debug("ssi_set_fmt() leave\nssicr is now 0x%08lx\n", ssicr); 313 314 return 0; 315} 316 317/* the SSI depends on an external clocksource (at HAC_BIT_CLK) even in 318 * Master mode, so really this is board specific; the SSI can do any 319 * rate with the right bitclk and divider settings. 320 */ 321#define SSI_RATES \ 322 SNDRV_PCM_RATE_8000_192000 323 324/* the SSI can do 8-32 bit samples, with 8 possible channels */ 325#define SSI_FMTS \ 326 (SNDRV_PCM_FMTBIT_S8 | SNDRV_PCM_FMTBIT_U8 | \ 327 SNDRV_PCM_FMTBIT_S16_LE | SNDRV_PCM_FMTBIT_U16_LE | \ 328 SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_U20_3LE | \ 329 SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_U24_3LE | \ 330 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE) 331 332static const struct snd_soc_dai_ops ssi_dai_ops = { 333 .startup = ssi_startup, 334 .shutdown = ssi_shutdown, 335 .trigger = ssi_trigger, 336 .hw_params = ssi_hw_params, 337 .set_sysclk = ssi_set_sysclk, 338 .set_clkdiv = ssi_set_clkdiv, 339 .set_fmt = ssi_set_fmt, 340}; 341 342static struct snd_soc_dai_driver sh4_ssi_dai[] = { 343{ 344 .name = "ssi-dai.0", 345 .playback = { 346 .rates = SSI_RATES, 347 .formats = SSI_FMTS, 348 .channels_min = 2, 349 .channels_max = 8, 350 }, 351 .capture = { 352 .rates = SSI_RATES, 353 .formats = SSI_FMTS, 354 .channels_min = 2, 355 .channels_max = 8, 356 }, 357 .ops = &ssi_dai_ops, 358}, 359#ifdef CONFIG_CPU_SUBTYPE_SH7760 360{ 361 .name = "ssi-dai.1", 362 .playback = { 363 .rates = SSI_RATES, 364 .formats = SSI_FMTS, 365 .channels_min = 2, 366 .channels_max = 8, 367 }, 368 .capture = { 369 .rates = SSI_RATES, 370 .formats = SSI_FMTS, 371 .channels_min = 2, 372 .channels_max = 8, 373 }, 374 .ops = &ssi_dai_ops, 375}, 376#endif 377}; 378 379static const struct snd_soc_component_driver sh4_ssi_component = { 380 .name = "sh4-ssi", 381 .legacy_dai_naming = 1, 382}; 383 384static int sh4_soc_dai_probe(struct platform_device *pdev) 385{ 386 return devm_snd_soc_register_component(&pdev->dev, &sh4_ssi_component, 387 sh4_ssi_dai, 388 ARRAY_SIZE(sh4_ssi_dai)); 389} 390 391static struct platform_driver sh4_ssi_driver = { 392 .driver = { 393 .name = "sh4-ssi-dai", 394 }, 395 396 .probe = sh4_soc_dai_probe, 397}; 398 399module_platform_driver(sh4_ssi_driver); 400 401MODULE_LICENSE("GPL v2"); 402MODULE_DESCRIPTION("SuperH onchip SSI (I2S) audio driver"); 403MODULE_AUTHOR("Manuel Lauss <mano@roarinelk.homelinux.net>"); 404