imx_gpt.c (15569B)
1 /* 2 * IMX GPT Timer 3 * 4 * Copyright (c) 2008 OK Labs 5 * Copyright (c) 2011 NICTA Pty Ltd 6 * Originally written by Hans Jiang 7 * Updated by Peter Chubb 8 * Updated by Jean-Christophe Dubois <jcd@tribudubois.net> 9 * 10 * This code is licensed under GPL version 2 or later. See 11 * the COPYING file in the top-level directory. 12 * 13 */ 14 15 #include "qemu/osdep.h" 16 #include "hw/irq.h" 17 #include "hw/timer/imx_gpt.h" 18 #include "migration/vmstate.h" 19 #include "qemu/module.h" 20 #include "qemu/log.h" 21 22 #ifndef DEBUG_IMX_GPT 23 #define DEBUG_IMX_GPT 0 24 #endif 25 26 #define DPRINTF(fmt, args...) \ 27 do { \ 28 if (DEBUG_IMX_GPT) { \ 29 fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX_GPT, \ 30 __func__, ##args); \ 31 } \ 32 } while (0) 33 34 static const char *imx_gpt_reg_name(uint32_t reg) 35 { 36 switch (reg) { 37 case 0: 38 return "CR"; 39 case 1: 40 return "PR"; 41 case 2: 42 return "SR"; 43 case 3: 44 return "IR"; 45 case 4: 46 return "OCR1"; 47 case 5: 48 return "OCR2"; 49 case 6: 50 return "OCR3"; 51 case 7: 52 return "ICR1"; 53 case 8: 54 return "ICR2"; 55 case 9: 56 return "CNT"; 57 default: 58 return "[?]"; 59 } 60 } 61 62 static const VMStateDescription vmstate_imx_timer_gpt = { 63 .name = TYPE_IMX_GPT, 64 .version_id = 3, 65 .minimum_version_id = 3, 66 .fields = (VMStateField[]) { 67 VMSTATE_UINT32(cr, IMXGPTState), 68 VMSTATE_UINT32(pr, IMXGPTState), 69 VMSTATE_UINT32(sr, IMXGPTState), 70 VMSTATE_UINT32(ir, IMXGPTState), 71 VMSTATE_UINT32(ocr1, IMXGPTState), 72 VMSTATE_UINT32(ocr2, IMXGPTState), 73 VMSTATE_UINT32(ocr3, IMXGPTState), 74 VMSTATE_UINT32(icr1, IMXGPTState), 75 VMSTATE_UINT32(icr2, IMXGPTState), 76 VMSTATE_UINT32(cnt, IMXGPTState), 77 VMSTATE_UINT32(next_timeout, IMXGPTState), 78 VMSTATE_UINT32(next_int, IMXGPTState), 79 VMSTATE_UINT32(freq, IMXGPTState), 80 VMSTATE_PTIMER(timer, IMXGPTState), 81 VMSTATE_END_OF_LIST() 82 } 83 }; 84 85 static const IMXClk imx25_gpt_clocks[] = { 86 CLK_NONE, /* 000 No clock source */ 87 CLK_IPG, /* 001 ipg_clk, 532MHz*/ 88 CLK_IPG_HIGH, /* 010 ipg_clk_highfreq */ 89 CLK_NONE, /* 011 not defined */ 90 CLK_32k, /* 100 ipg_clk_32k */ 91 CLK_32k, /* 101 ipg_clk_32k */ 92 CLK_32k, /* 110 ipg_clk_32k */ 93 CLK_32k, /* 111 ipg_clk_32k */ 94 }; 95 96 static const IMXClk imx31_gpt_clocks[] = { 97 CLK_NONE, /* 000 No clock source */ 98 CLK_IPG, /* 001 ipg_clk, 532MHz*/ 99 CLK_IPG_HIGH, /* 010 ipg_clk_highfreq */ 100 CLK_NONE, /* 011 not defined */ 101 CLK_32k, /* 100 ipg_clk_32k */ 102 CLK_NONE, /* 101 not defined */ 103 CLK_NONE, /* 110 not defined */ 104 CLK_NONE, /* 111 not defined */ 105 }; 106 107 static const IMXClk imx6_gpt_clocks[] = { 108 CLK_NONE, /* 000 No clock source */ 109 CLK_IPG, /* 001 ipg_clk, 532MHz*/ 110 CLK_IPG_HIGH, /* 010 ipg_clk_highfreq */ 111 CLK_EXT, /* 011 External clock */ 112 CLK_32k, /* 100 ipg_clk_32k */ 113 CLK_HIGH_DIV, /* 101 reference clock / 8 */ 114 CLK_NONE, /* 110 not defined */ 115 CLK_HIGH, /* 111 reference clock */ 116 }; 117 118 static const IMXClk imx7_gpt_clocks[] = { 119 CLK_NONE, /* 000 No clock source */ 120 CLK_IPG, /* 001 ipg_clk, 532MHz*/ 121 CLK_IPG_HIGH, /* 010 ipg_clk_highfreq */ 122 CLK_EXT, /* 011 External clock */ 123 CLK_32k, /* 100 ipg_clk_32k */ 124 CLK_HIGH, /* 101 reference clock */ 125 CLK_NONE, /* 110 not defined */ 126 CLK_NONE, /* 111 not defined */ 127 }; 128 129 /* Must be called from within ptimer_transaction_begin/commit block */ 130 static void imx_gpt_set_freq(IMXGPTState *s) 131 { 132 uint32_t clksrc = extract32(s->cr, GPT_CR_CLKSRC_SHIFT, 3); 133 134 s->freq = imx_ccm_get_clock_frequency(s->ccm, 135 s->clocks[clksrc]) / (1 + s->pr); 136 137 DPRINTF("Setting clksrc %d to frequency %d\n", clksrc, s->freq); 138 139 if (s->freq) { 140 ptimer_set_freq(s->timer, s->freq); 141 } 142 } 143 144 static void imx_gpt_update_int(IMXGPTState *s) 145 { 146 if ((s->sr & s->ir) && (s->cr & GPT_CR_EN)) { 147 qemu_irq_raise(s->irq); 148 } else { 149 qemu_irq_lower(s->irq); 150 } 151 } 152 153 static uint32_t imx_gpt_update_count(IMXGPTState *s) 154 { 155 s->cnt = s->next_timeout - (uint32_t)ptimer_get_count(s->timer); 156 157 return s->cnt; 158 } 159 160 static inline uint32_t imx_gpt_find_limit(uint32_t count, uint32_t reg, 161 uint32_t timeout) 162 { 163 if ((count < reg) && (timeout > reg)) { 164 timeout = reg; 165 } 166 167 return timeout; 168 } 169 170 /* Must be called from within ptimer_transaction_begin/commit block */ 171 static void imx_gpt_compute_next_timeout(IMXGPTState *s, bool event) 172 { 173 uint32_t timeout = GPT_TIMER_MAX; 174 uint32_t count; 175 long long limit; 176 177 if (!(s->cr & GPT_CR_EN)) { 178 /* if not enabled just return */ 179 return; 180 } 181 182 /* update the count */ 183 count = imx_gpt_update_count(s); 184 185 if (event) { 186 /* 187 * This is an event (the ptimer reached 0 and stopped), and the 188 * timer counter is now equal to s->next_timeout. 189 */ 190 if (!(s->cr & GPT_CR_FRR) && (count == s->ocr1)) { 191 /* We are in restart mode and we crossed the compare channel 1 192 * value. We need to reset the counter to 0. 193 */ 194 count = s->cnt = s->next_timeout = 0; 195 } else if (count == GPT_TIMER_MAX) { 196 /* We reached GPT_TIMER_MAX so we need to rollover */ 197 count = s->cnt = s->next_timeout = 0; 198 } 199 } 200 201 /* now, find the next timeout related to count */ 202 203 if (s->ir & GPT_IR_OF1IE) { 204 timeout = imx_gpt_find_limit(count, s->ocr1, timeout); 205 } 206 if (s->ir & GPT_IR_OF2IE) { 207 timeout = imx_gpt_find_limit(count, s->ocr2, timeout); 208 } 209 if (s->ir & GPT_IR_OF3IE) { 210 timeout = imx_gpt_find_limit(count, s->ocr3, timeout); 211 } 212 213 /* find the next set of interrupts to raise for next timer event */ 214 215 s->next_int = 0; 216 if ((s->ir & GPT_IR_OF1IE) && (timeout == s->ocr1)) { 217 s->next_int |= GPT_SR_OF1; 218 } 219 if ((s->ir & GPT_IR_OF2IE) && (timeout == s->ocr2)) { 220 s->next_int |= GPT_SR_OF2; 221 } 222 if ((s->ir & GPT_IR_OF3IE) && (timeout == s->ocr3)) { 223 s->next_int |= GPT_SR_OF3; 224 } 225 if ((s->ir & GPT_IR_ROVIE) && (timeout == GPT_TIMER_MAX)) { 226 s->next_int |= GPT_SR_ROV; 227 } 228 229 /* the new range to count down from */ 230 limit = timeout - imx_gpt_update_count(s); 231 232 if (limit < 0) { 233 /* 234 * if we reach here, then QEMU is running too slow and we pass the 235 * timeout limit while computing it. Let's deliver the interrupt 236 * and compute a new limit. 237 */ 238 s->sr |= s->next_int; 239 240 imx_gpt_compute_next_timeout(s, event); 241 242 imx_gpt_update_int(s); 243 } else { 244 /* New timeout value */ 245 s->next_timeout = timeout; 246 247 /* reset the limit to the computed range */ 248 ptimer_set_limit(s->timer, limit, 1); 249 } 250 } 251 252 static uint64_t imx_gpt_read(void *opaque, hwaddr offset, unsigned size) 253 { 254 IMXGPTState *s = IMX_GPT(opaque); 255 uint32_t reg_value = 0; 256 257 switch (offset >> 2) { 258 case 0: /* Control Register */ 259 reg_value = s->cr; 260 break; 261 262 case 1: /* prescaler */ 263 reg_value = s->pr; 264 break; 265 266 case 2: /* Status Register */ 267 reg_value = s->sr; 268 break; 269 270 case 3: /* Interrupt Register */ 271 reg_value = s->ir; 272 break; 273 274 case 4: /* Output Compare Register 1 */ 275 reg_value = s->ocr1; 276 break; 277 278 case 5: /* Output Compare Register 2 */ 279 reg_value = s->ocr2; 280 break; 281 282 case 6: /* Output Compare Register 3 */ 283 reg_value = s->ocr3; 284 break; 285 286 case 7: /* input Capture Register 1 */ 287 qemu_log_mask(LOG_UNIMP, "[%s]%s: icr1 feature is not implemented\n", 288 TYPE_IMX_GPT, __func__); 289 reg_value = s->icr1; 290 break; 291 292 case 8: /* input Capture Register 2 */ 293 qemu_log_mask(LOG_UNIMP, "[%s]%s: icr2 feature is not implemented\n", 294 TYPE_IMX_GPT, __func__); 295 reg_value = s->icr2; 296 break; 297 298 case 9: /* cnt */ 299 imx_gpt_update_count(s); 300 reg_value = s->cnt; 301 break; 302 303 default: 304 qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%" 305 HWADDR_PRIx "\n", TYPE_IMX_GPT, __func__, offset); 306 break; 307 } 308 309 DPRINTF("(%s) = 0x%08x\n", imx_gpt_reg_name(offset >> 2), reg_value); 310 311 return reg_value; 312 } 313 314 315 static void imx_gpt_reset_common(IMXGPTState *s, bool is_soft_reset) 316 { 317 ptimer_transaction_begin(s->timer); 318 /* stop timer */ 319 ptimer_stop(s->timer); 320 321 /* Soft reset and hard reset differ only in their handling of the CR 322 * register -- soft reset preserves the values of some bits there. 323 */ 324 if (is_soft_reset) { 325 /* Clear all CR bits except those that are preserved by soft reset. */ 326 s->cr &= GPT_CR_EN | GPT_CR_ENMOD | GPT_CR_STOPEN | GPT_CR_DOZEN | 327 GPT_CR_WAITEN | GPT_CR_DBGEN | 328 (GPT_CR_CLKSRC_MASK << GPT_CR_CLKSRC_SHIFT); 329 } else { 330 s->cr = 0; 331 } 332 s->sr = 0; 333 s->pr = 0; 334 s->ir = 0; 335 s->cnt = 0; 336 s->ocr1 = GPT_TIMER_MAX; 337 s->ocr2 = GPT_TIMER_MAX; 338 s->ocr3 = GPT_TIMER_MAX; 339 s->icr1 = 0; 340 s->icr2 = 0; 341 342 s->next_timeout = GPT_TIMER_MAX; 343 s->next_int = 0; 344 345 /* compute new freq */ 346 imx_gpt_set_freq(s); 347 348 /* reset the limit to GPT_TIMER_MAX */ 349 ptimer_set_limit(s->timer, GPT_TIMER_MAX, 1); 350 351 /* if the timer is still enabled, restart it */ 352 if (s->freq && (s->cr & GPT_CR_EN)) { 353 ptimer_run(s->timer, 1); 354 } 355 ptimer_transaction_commit(s->timer); 356 } 357 358 static void imx_gpt_soft_reset(DeviceState *dev) 359 { 360 IMXGPTState *s = IMX_GPT(dev); 361 imx_gpt_reset_common(s, true); 362 } 363 364 static void imx_gpt_reset(DeviceState *dev) 365 { 366 IMXGPTState *s = IMX_GPT(dev); 367 imx_gpt_reset_common(s, false); 368 } 369 370 static void imx_gpt_write(void *opaque, hwaddr offset, uint64_t value, 371 unsigned size) 372 { 373 IMXGPTState *s = IMX_GPT(opaque); 374 uint32_t oldreg; 375 376 DPRINTF("(%s, value = 0x%08x)\n", imx_gpt_reg_name(offset >> 2), 377 (uint32_t)value); 378 379 switch (offset >> 2) { 380 case 0: 381 oldreg = s->cr; 382 s->cr = value & ~0x7c14; 383 if (s->cr & GPT_CR_SWR) { /* force reset */ 384 /* handle the reset */ 385 imx_gpt_soft_reset(DEVICE(s)); 386 } else { 387 /* set our freq, as the source might have changed */ 388 ptimer_transaction_begin(s->timer); 389 imx_gpt_set_freq(s); 390 391 if ((oldreg ^ s->cr) & GPT_CR_EN) { 392 if (s->cr & GPT_CR_EN) { 393 if (s->cr & GPT_CR_ENMOD) { 394 s->next_timeout = GPT_TIMER_MAX; 395 ptimer_set_count(s->timer, GPT_TIMER_MAX); 396 imx_gpt_compute_next_timeout(s, false); 397 } 398 ptimer_run(s->timer, 1); 399 } else { 400 /* stop timer */ 401 ptimer_stop(s->timer); 402 } 403 } 404 ptimer_transaction_commit(s->timer); 405 } 406 break; 407 408 case 1: /* Prescaler */ 409 s->pr = value & 0xfff; 410 ptimer_transaction_begin(s->timer); 411 imx_gpt_set_freq(s); 412 ptimer_transaction_commit(s->timer); 413 break; 414 415 case 2: /* SR */ 416 s->sr &= ~(value & 0x3f); 417 imx_gpt_update_int(s); 418 break; 419 420 case 3: /* IR -- interrupt register */ 421 s->ir = value & 0x3f; 422 imx_gpt_update_int(s); 423 424 ptimer_transaction_begin(s->timer); 425 imx_gpt_compute_next_timeout(s, false); 426 ptimer_transaction_commit(s->timer); 427 428 break; 429 430 case 4: /* OCR1 -- output compare register */ 431 s->ocr1 = value; 432 433 ptimer_transaction_begin(s->timer); 434 /* In non-freerun mode, reset count when this register is written */ 435 if (!(s->cr & GPT_CR_FRR)) { 436 s->next_timeout = GPT_TIMER_MAX; 437 ptimer_set_limit(s->timer, GPT_TIMER_MAX, 1); 438 } 439 440 /* compute the new timeout */ 441 imx_gpt_compute_next_timeout(s, false); 442 ptimer_transaction_commit(s->timer); 443 444 break; 445 446 case 5: /* OCR2 -- output compare register */ 447 s->ocr2 = value; 448 449 /* compute the new timeout */ 450 ptimer_transaction_begin(s->timer); 451 imx_gpt_compute_next_timeout(s, false); 452 ptimer_transaction_commit(s->timer); 453 454 break; 455 456 case 6: /* OCR3 -- output compare register */ 457 s->ocr3 = value; 458 459 /* compute the new timeout */ 460 ptimer_transaction_begin(s->timer); 461 imx_gpt_compute_next_timeout(s, false); 462 ptimer_transaction_commit(s->timer); 463 464 break; 465 466 default: 467 qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%" 468 HWADDR_PRIx "\n", TYPE_IMX_GPT, __func__, offset); 469 break; 470 } 471 } 472 473 static void imx_gpt_timeout(void *opaque) 474 { 475 IMXGPTState *s = IMX_GPT(opaque); 476 477 DPRINTF("\n"); 478 479 s->sr |= s->next_int; 480 s->next_int = 0; 481 482 imx_gpt_compute_next_timeout(s, true); 483 484 imx_gpt_update_int(s); 485 486 if (s->freq && (s->cr & GPT_CR_EN)) { 487 ptimer_run(s->timer, 1); 488 } 489 } 490 491 static const MemoryRegionOps imx_gpt_ops = { 492 .read = imx_gpt_read, 493 .write = imx_gpt_write, 494 .endianness = DEVICE_NATIVE_ENDIAN, 495 }; 496 497 498 static void imx_gpt_realize(DeviceState *dev, Error **errp) 499 { 500 IMXGPTState *s = IMX_GPT(dev); 501 SysBusDevice *sbd = SYS_BUS_DEVICE(dev); 502 503 sysbus_init_irq(sbd, &s->irq); 504 memory_region_init_io(&s->iomem, OBJECT(s), &imx_gpt_ops, s, TYPE_IMX_GPT, 505 0x00001000); 506 sysbus_init_mmio(sbd, &s->iomem); 507 508 s->timer = ptimer_init(imx_gpt_timeout, s, PTIMER_POLICY_LEGACY); 509 } 510 511 static void imx_gpt_class_init(ObjectClass *klass, void *data) 512 { 513 DeviceClass *dc = DEVICE_CLASS(klass); 514 515 dc->realize = imx_gpt_realize; 516 dc->reset = imx_gpt_reset; 517 dc->vmsd = &vmstate_imx_timer_gpt; 518 dc->desc = "i.MX general timer"; 519 } 520 521 static void imx25_gpt_init(Object *obj) 522 { 523 IMXGPTState *s = IMX_GPT(obj); 524 525 s->clocks = imx25_gpt_clocks; 526 } 527 528 static void imx31_gpt_init(Object *obj) 529 { 530 IMXGPTState *s = IMX_GPT(obj); 531 532 s->clocks = imx31_gpt_clocks; 533 } 534 535 static void imx6_gpt_init(Object *obj) 536 { 537 IMXGPTState *s = IMX_GPT(obj); 538 539 s->clocks = imx6_gpt_clocks; 540 } 541 542 static void imx7_gpt_init(Object *obj) 543 { 544 IMXGPTState *s = IMX_GPT(obj); 545 546 s->clocks = imx7_gpt_clocks; 547 } 548 549 static const TypeInfo imx25_gpt_info = { 550 .name = TYPE_IMX25_GPT, 551 .parent = TYPE_SYS_BUS_DEVICE, 552 .instance_size = sizeof(IMXGPTState), 553 .instance_init = imx25_gpt_init, 554 .class_init = imx_gpt_class_init, 555 }; 556 557 static const TypeInfo imx31_gpt_info = { 558 .name = TYPE_IMX31_GPT, 559 .parent = TYPE_IMX25_GPT, 560 .instance_init = imx31_gpt_init, 561 }; 562 563 static const TypeInfo imx6_gpt_info = { 564 .name = TYPE_IMX6_GPT, 565 .parent = TYPE_IMX25_GPT, 566 .instance_init = imx6_gpt_init, 567 }; 568 569 static const TypeInfo imx7_gpt_info = { 570 .name = TYPE_IMX7_GPT, 571 .parent = TYPE_IMX25_GPT, 572 .instance_init = imx7_gpt_init, 573 }; 574 575 static void imx_gpt_register_types(void) 576 { 577 type_register_static(&imx25_gpt_info); 578 type_register_static(&imx31_gpt_info); 579 type_register_static(&imx6_gpt_info); 580 type_register_static(&imx7_gpt_info); 581 } 582 583 type_init(imx_gpt_register_types)