1 /* 2 * SuperH Timer Support - CMT 3 * 4 * Copyright (C) 2008 Magnus Damm 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #include <linux/clk.h> 17 #include <linux/clockchips.h> 18 #include <linux/clocksource.h> 19 #include <linux/delay.h> 20 #include <linux/err.h> 21 #include <linux/init.h> 22 #include <linux/interrupt.h> 23 #include <linux/io.h> 24 #include <linux/ioport.h> 25 #include <linux/irq.h> 26 #include <linux/module.h> 27 #include <linux/of.h> 28 #include <linux/platform_device.h> 29 #include <linux/pm_domain.h> 30 #include <linux/pm_runtime.h> 31 #include <linux/sh_timer.h> 32 #include <linux/slab.h> 33 #include <linux/spinlock.h> 34 35 struct sh_cmt_device; 36 37 /* 38 * The CMT comes in 5 different identified flavours, depending not only on the 39 * SoC but also on the particular instance. The following table lists the main 40 * characteristics of those flavours. 41 * 42 * 16B 32B 32B-F 48B 48B-2 43 * ----------------------------------------------------------------------------- 44 * Channels 2 1/4 1 6 2/8 45 * Control Width 16 16 16 16 32 46 * Counter Width 16 32 32 32/48 32/48 47 * Shared Start/Stop Y Y Y Y N 48 * 49 * The 48-bit gen2 version has a per-channel start/stop register located in the 50 * channel registers block. All other versions have a shared start/stop register 51 * located in the global space. 52 * 53 * Channels are indexed from 0 to N-1 in the documentation. The channel index 54 * infers the start/stop bit position in the control register and the channel 55 * registers block address. Some CMT instances have a subset of channels 56 * available, in which case the index in the documentation doesn't match the 57 * "real" index as implemented in hardware. This is for instance the case with 58 * CMT0 on r8a7740, which is a 32-bit variant with a single channel numbered 0 59 * in the documentation but using start/stop bit 5 and having its registers 60 * block at 0x60. 61 * 62 * Similarly CMT0 on r8a73a4, r8a7790 and r8a7791, while implementing 32-bit 63 * channels only, is a 48-bit gen2 CMT with the 48-bit channels unavailable. 64 */ 65 66 enum sh_cmt_model { 67 SH_CMT_16BIT, 68 SH_CMT_32BIT, 69 SH_CMT_32BIT_FAST, 70 SH_CMT_48BIT, 71 SH_CMT_48BIT_GEN2, 72 }; 73 74 struct sh_cmt_info { 75 enum sh_cmt_model model; 76 77 unsigned long width; /* 16 or 32 bit version of hardware block */ 78 unsigned long overflow_bit; 79 unsigned long clear_bits; 80 81 /* callbacks for CMSTR and CMCSR access */ 82 unsigned long (*read_control)(void __iomem *base, unsigned long offs); 83 void (*write_control)(void __iomem *base, unsigned long offs, 84 unsigned long value); 85 86 /* callbacks for CMCNT and CMCOR access */ 87 unsigned long (*read_count)(void __iomem *base, unsigned long offs); 88 void (*write_count)(void __iomem *base, unsigned long offs, 89 unsigned long value); 90 }; 91 92 struct sh_cmt_channel { 93 struct sh_cmt_device *cmt; 94 95 unsigned int index; /* Index in the documentation */ 96 unsigned int hwidx; /* Real hardware index */ 97 98 void __iomem *iostart; 99 void __iomem *ioctrl; 100 101 unsigned int timer_bit; 102 unsigned long flags; 103 unsigned long match_value; 104 unsigned long next_match_value; 105 unsigned long max_match_value; 106 unsigned long rate; 107 raw_spinlock_t lock; 108 struct clock_event_device ced; 109 struct clocksource cs; 110 unsigned long total_cycles; 111 bool cs_enabled; 112 }; 113 114 struct sh_cmt_device { 115 struct platform_device *pdev; 116 117 const struct sh_cmt_info *info; 118 119 void __iomem *mapbase; 120 struct clk *clk; 121 122 raw_spinlock_t lock; /* Protect the shared start/stop register */ 123 124 struct sh_cmt_channel *channels; 125 unsigned int num_channels; 126 unsigned int hw_channels; 127 128 bool has_clockevent; 129 bool has_clocksource; 130 }; 131 132 #define SH_CMT16_CMCSR_CMF (1 << 7) 133 #define SH_CMT16_CMCSR_CMIE (1 << 6) 134 #define SH_CMT16_CMCSR_CKS8 (0 << 0) 135 #define SH_CMT16_CMCSR_CKS32 (1 << 0) 136 #define SH_CMT16_CMCSR_CKS128 (2 << 0) 137 #define SH_CMT16_CMCSR_CKS512 (3 << 0) 138 #define SH_CMT16_CMCSR_CKS_MASK (3 << 0) 139 140 #define SH_CMT32_CMCSR_CMF (1 << 15) 141 #define SH_CMT32_CMCSR_OVF (1 << 14) 142 #define SH_CMT32_CMCSR_WRFLG (1 << 13) 143 #define SH_CMT32_CMCSR_STTF (1 << 12) 144 #define SH_CMT32_CMCSR_STPF (1 << 11) 145 #define SH_CMT32_CMCSR_SSIE (1 << 10) 146 #define SH_CMT32_CMCSR_CMS (1 << 9) 147 #define SH_CMT32_CMCSR_CMM (1 << 8) 148 #define SH_CMT32_CMCSR_CMTOUT_IE (1 << 7) 149 #define SH_CMT32_CMCSR_CMR_NONE (0 << 4) 150 #define SH_CMT32_CMCSR_CMR_DMA (1 << 4) 151 #define SH_CMT32_CMCSR_CMR_IRQ (2 << 4) 152 #define SH_CMT32_CMCSR_CMR_MASK (3 << 4) 153 #define SH_CMT32_CMCSR_DBGIVD (1 << 3) 154 #define SH_CMT32_CMCSR_CKS_RCLK8 (4 << 0) 155 #define SH_CMT32_CMCSR_CKS_RCLK32 (5 << 0) 156 #define SH_CMT32_CMCSR_CKS_RCLK128 (6 << 0) 157 #define SH_CMT32_CMCSR_CKS_RCLK1 (7 << 0) 158 #define SH_CMT32_CMCSR_CKS_MASK (7 << 0) 159 160 static unsigned long sh_cmt_read16(void __iomem *base, unsigned long offs) 161 { 162 return ioread16(base + (offs << 1)); 163 } 164 165 static unsigned long sh_cmt_read32(void __iomem *base, unsigned long offs) 166 { 167 return ioread32(base + (offs << 2)); 168 } 169 170 static void sh_cmt_write16(void __iomem *base, unsigned long offs, 171 unsigned long value) 172 { 173 iowrite16(value, base + (offs << 1)); 174 } 175 176 static void sh_cmt_write32(void __iomem *base, unsigned long offs, 177 unsigned long value) 178 { 179 iowrite32(value, base + (offs << 2)); 180 } 181 182 static const struct sh_cmt_info sh_cmt_info[] = { 183 [SH_CMT_16BIT] = { 184 .model = SH_CMT_16BIT, 185 .width = 16, 186 .overflow_bit = SH_CMT16_CMCSR_CMF, 187 .clear_bits = ~SH_CMT16_CMCSR_CMF, 188 .read_control = sh_cmt_read16, 189 .write_control = sh_cmt_write16, 190 .read_count = sh_cmt_read16, 191 .write_count = sh_cmt_write16, 192 }, 193 [SH_CMT_32BIT] = { 194 .model = SH_CMT_32BIT, 195 .width = 32, 196 .overflow_bit = SH_CMT32_CMCSR_CMF, 197 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 198 .read_control = sh_cmt_read16, 199 .write_control = sh_cmt_write16, 200 .read_count = sh_cmt_read32, 201 .write_count = sh_cmt_write32, 202 }, 203 [SH_CMT_32BIT_FAST] = { 204 .model = SH_CMT_32BIT_FAST, 205 .width = 32, 206 .overflow_bit = SH_CMT32_CMCSR_CMF, 207 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 208 .read_control = sh_cmt_read16, 209 .write_control = sh_cmt_write16, 210 .read_count = sh_cmt_read32, 211 .write_count = sh_cmt_write32, 212 }, 213 [SH_CMT_48BIT] = { 214 .model = SH_CMT_48BIT, 215 .width = 32, 216 .overflow_bit = SH_CMT32_CMCSR_CMF, 217 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 218 .read_control = sh_cmt_read32, 219 .write_control = sh_cmt_write32, 220 .read_count = sh_cmt_read32, 221 .write_count = sh_cmt_write32, 222 }, 223 [SH_CMT_48BIT_GEN2] = { 224 .model = SH_CMT_48BIT_GEN2, 225 .width = 32, 226 .overflow_bit = SH_CMT32_CMCSR_CMF, 227 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 228 .read_control = sh_cmt_read32, 229 .write_control = sh_cmt_write32, 230 .read_count = sh_cmt_read32, 231 .write_count = sh_cmt_write32, 232 }, 233 }; 234 235 #define CMCSR 0 /* channel register */ 236 #define CMCNT 1 /* channel register */ 237 #define CMCOR 2 /* channel register */ 238 239 static inline unsigned long sh_cmt_read_cmstr(struct sh_cmt_channel *ch) 240 { 241 if (ch->iostart) 242 return ch->cmt->info->read_control(ch->iostart, 0); 243 else 244 return ch->cmt->info->read_control(ch->cmt->mapbase, 0); 245 } 246 247 static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, 248 unsigned long value) 249 { 250 if (ch->iostart) 251 ch->cmt->info->write_control(ch->iostart, 0, value); 252 else 253 ch->cmt->info->write_control(ch->cmt->mapbase, 0, value); 254 } 255 256 static inline unsigned long sh_cmt_read_cmcsr(struct sh_cmt_channel *ch) 257 { 258 return ch->cmt->info->read_control(ch->ioctrl, CMCSR); 259 } 260 261 static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch, 262 unsigned long value) 263 { 264 ch->cmt->info->write_control(ch->ioctrl, CMCSR, value); 265 } 266 267 static inline unsigned long sh_cmt_read_cmcnt(struct sh_cmt_channel *ch) 268 { 269 return ch->cmt->info->read_count(ch->ioctrl, CMCNT); 270 } 271 272 static inline void sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, 273 unsigned long value) 274 { 275 ch->cmt->info->write_count(ch->ioctrl, CMCNT, value); 276 } 277 278 static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch, 279 unsigned long value) 280 { 281 ch->cmt->info->write_count(ch->ioctrl, CMCOR, value); 282 } 283 284 static unsigned long sh_cmt_get_counter(struct sh_cmt_channel *ch, 285 int *has_wrapped) 286 { 287 unsigned long v1, v2, v3; 288 int o1, o2; 289 290 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit; 291 292 /* Make sure the timer value is stable. Stolen from acpi_pm.c */ 293 do { 294 o2 = o1; 295 v1 = sh_cmt_read_cmcnt(ch); 296 v2 = sh_cmt_read_cmcnt(ch); 297 v3 = sh_cmt_read_cmcnt(ch); 298 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit; 299 } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3) 300 || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2))); 301 302 *has_wrapped = o1; 303 return v2; 304 } 305 306 static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start) 307 { 308 unsigned long flags, value; 309 310 /* start stop register shared by multiple timer channels */ 311 raw_spin_lock_irqsave(&ch->cmt->lock, flags); 312 value = sh_cmt_read_cmstr(ch); 313 314 if (start) 315 value |= 1 << ch->timer_bit; 316 else 317 value &= ~(1 << ch->timer_bit); 318 319 sh_cmt_write_cmstr(ch, value); 320 raw_spin_unlock_irqrestore(&ch->cmt->lock, flags); 321 } 322 323 static int sh_cmt_enable(struct sh_cmt_channel *ch, unsigned long *rate) 324 { 325 int k, ret; 326 327 pm_runtime_get_sync(&ch->cmt->pdev->dev); 328 dev_pm_syscore_device(&ch->cmt->pdev->dev, true); 329 330 /* enable clock */ 331 ret = clk_enable(ch->cmt->clk); 332 if (ret) { 333 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot enable clock\n", 334 ch->index); 335 goto err0; 336 } 337 338 /* make sure channel is disabled */ 339 sh_cmt_start_stop_ch(ch, 0); 340 341 /* configure channel, periodic mode and maximum timeout */ 342 if (ch->cmt->info->width == 16) { 343 *rate = clk_get_rate(ch->cmt->clk) / 512; 344 sh_cmt_write_cmcsr(ch, SH_CMT16_CMCSR_CMIE | 345 SH_CMT16_CMCSR_CKS512); 346 } else { 347 *rate = clk_get_rate(ch->cmt->clk) / 8; 348 sh_cmt_write_cmcsr(ch, SH_CMT32_CMCSR_CMM | 349 SH_CMT32_CMCSR_CMTOUT_IE | 350 SH_CMT32_CMCSR_CMR_IRQ | 351 SH_CMT32_CMCSR_CKS_RCLK8); 352 } 353 354 sh_cmt_write_cmcor(ch, 0xffffffff); 355 sh_cmt_write_cmcnt(ch, 0); 356 357 /* 358 * According to the sh73a0 user's manual, as CMCNT can be operated 359 * only by the RCLK (Pseudo 32 KHz), there's one restriction on 360 * modifying CMCNT register; two RCLK cycles are necessary before 361 * this register is either read or any modification of the value 362 * it holds is reflected in the LSI's actual operation. 363 * 364 * While at it, we're supposed to clear out the CMCNT as of this 365 * moment, so make sure it's processed properly here. This will 366 * take RCLKx2 at maximum. 367 */ 368 for (k = 0; k < 100; k++) { 369 if (!sh_cmt_read_cmcnt(ch)) 370 break; 371 udelay(1); 372 } 373 374 if (sh_cmt_read_cmcnt(ch)) { 375 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot clear CMCNT\n", 376 ch->index); 377 ret = -ETIMEDOUT; 378 goto err1; 379 } 380 381 /* enable channel */ 382 sh_cmt_start_stop_ch(ch, 1); 383 return 0; 384 err1: 385 /* stop clock */ 386 clk_disable(ch->cmt->clk); 387 388 err0: 389 return ret; 390 } 391 392 static void sh_cmt_disable(struct sh_cmt_channel *ch) 393 { 394 /* disable channel */ 395 sh_cmt_start_stop_ch(ch, 0); 396 397 /* disable interrupts in CMT block */ 398 sh_cmt_write_cmcsr(ch, 0); 399 400 /* stop clock */ 401 clk_disable(ch->cmt->clk); 402 403 dev_pm_syscore_device(&ch->cmt->pdev->dev, false); 404 pm_runtime_put(&ch->cmt->pdev->dev); 405 } 406 407 /* private flags */ 408 #define FLAG_CLOCKEVENT (1 << 0) 409 #define FLAG_CLOCKSOURCE (1 << 1) 410 #define FLAG_REPROGRAM (1 << 2) 411 #define FLAG_SKIPEVENT (1 << 3) 412 #define FLAG_IRQCONTEXT (1 << 4) 413 414 static void sh_cmt_clock_event_program_verify(struct sh_cmt_channel *ch, 415 int absolute) 416 { 417 unsigned long new_match; 418 unsigned long value = ch->next_match_value; 419 unsigned long delay = 0; 420 unsigned long now = 0; 421 int has_wrapped; 422 423 now = sh_cmt_get_counter(ch, &has_wrapped); 424 ch->flags |= FLAG_REPROGRAM; /* force reprogram */ 425 426 if (has_wrapped) { 427 /* we're competing with the interrupt handler. 428 * -> let the interrupt handler reprogram the timer. 429 * -> interrupt number two handles the event. 430 */ 431 ch->flags |= FLAG_SKIPEVENT; 432 return; 433 } 434 435 if (absolute) 436 now = 0; 437 438 do { 439 /* reprogram the timer hardware, 440 * but don't save the new match value yet. 441 */ 442 new_match = now + value + delay; 443 if (new_match > ch->max_match_value) 444 new_match = ch->max_match_value; 445 446 sh_cmt_write_cmcor(ch, new_match); 447 448 now = sh_cmt_get_counter(ch, &has_wrapped); 449 if (has_wrapped && (new_match > ch->match_value)) { 450 /* we are changing to a greater match value, 451 * so this wrap must be caused by the counter 452 * matching the old value. 453 * -> first interrupt reprograms the timer. 454 * -> interrupt number two handles the event. 455 */ 456 ch->flags |= FLAG_SKIPEVENT; 457 break; 458 } 459 460 if (has_wrapped) { 461 /* we are changing to a smaller match value, 462 * so the wrap must be caused by the counter 463 * matching the new value. 464 * -> save programmed match value. 465 * -> let isr handle the event. 466 */ 467 ch->match_value = new_match; 468 break; 469 } 470 471 /* be safe: verify hardware settings */ 472 if (now < new_match) { 473 /* timer value is below match value, all good. 474 * this makes sure we won't miss any match events. 475 * -> save programmed match value. 476 * -> let isr handle the event. 477 */ 478 ch->match_value = new_match; 479 break; 480 } 481 482 /* the counter has reached a value greater 483 * than our new match value. and since the 484 * has_wrapped flag isn't set we must have 485 * programmed a too close event. 486 * -> increase delay and retry. 487 */ 488 if (delay) 489 delay <<= 1; 490 else 491 delay = 1; 492 493 if (!delay) 494 dev_warn(&ch->cmt->pdev->dev, "ch%u: too long delay\n", 495 ch->index); 496 497 } while (delay); 498 } 499 500 static void __sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta) 501 { 502 if (delta > ch->max_match_value) 503 dev_warn(&ch->cmt->pdev->dev, "ch%u: delta out of range\n", 504 ch->index); 505 506 ch->next_match_value = delta; 507 sh_cmt_clock_event_program_verify(ch, 0); 508 } 509 510 static void sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta) 511 { 512 unsigned long flags; 513 514 raw_spin_lock_irqsave(&ch->lock, flags); 515 __sh_cmt_set_next(ch, delta); 516 raw_spin_unlock_irqrestore(&ch->lock, flags); 517 } 518 519 static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id) 520 { 521 struct sh_cmt_channel *ch = dev_id; 522 523 /* clear flags */ 524 sh_cmt_write_cmcsr(ch, sh_cmt_read_cmcsr(ch) & 525 ch->cmt->info->clear_bits); 526 527 /* update clock source counter to begin with if enabled 528 * the wrap flag should be cleared by the timer specific 529 * isr before we end up here. 530 */ 531 if (ch->flags & FLAG_CLOCKSOURCE) 532 ch->total_cycles += ch->match_value + 1; 533 534 if (!(ch->flags & FLAG_REPROGRAM)) 535 ch->next_match_value = ch->max_match_value; 536 537 ch->flags |= FLAG_IRQCONTEXT; 538 539 if (ch->flags & FLAG_CLOCKEVENT) { 540 if (!(ch->flags & FLAG_SKIPEVENT)) { 541 if (ch->ced.mode == CLOCK_EVT_MODE_ONESHOT) { 542 ch->next_match_value = ch->max_match_value; 543 ch->flags |= FLAG_REPROGRAM; 544 } 545 546 ch->ced.event_handler(&ch->ced); 547 } 548 } 549 550 ch->flags &= ~FLAG_SKIPEVENT; 551 552 if (ch->flags & FLAG_REPROGRAM) { 553 ch->flags &= ~FLAG_REPROGRAM; 554 sh_cmt_clock_event_program_verify(ch, 1); 555 556 if (ch->flags & FLAG_CLOCKEVENT) 557 if ((ch->ced.mode == CLOCK_EVT_MODE_SHUTDOWN) 558 || (ch->match_value == ch->next_match_value)) 559 ch->flags &= ~FLAG_REPROGRAM; 560 } 561 562 ch->flags &= ~FLAG_IRQCONTEXT; 563 564 return IRQ_HANDLED; 565 } 566 567 static int sh_cmt_start(struct sh_cmt_channel *ch, unsigned long flag) 568 { 569 int ret = 0; 570 unsigned long flags; 571 572 raw_spin_lock_irqsave(&ch->lock, flags); 573 574 if (!(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) 575 ret = sh_cmt_enable(ch, &ch->rate); 576 577 if (ret) 578 goto out; 579 ch->flags |= flag; 580 581 /* setup timeout if no clockevent */ 582 if ((flag == FLAG_CLOCKSOURCE) && (!(ch->flags & FLAG_CLOCKEVENT))) 583 __sh_cmt_set_next(ch, ch->max_match_value); 584 out: 585 raw_spin_unlock_irqrestore(&ch->lock, flags); 586 587 return ret; 588 } 589 590 static void sh_cmt_stop(struct sh_cmt_channel *ch, unsigned long flag) 591 { 592 unsigned long flags; 593 unsigned long f; 594 595 raw_spin_lock_irqsave(&ch->lock, flags); 596 597 f = ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE); 598 ch->flags &= ~flag; 599 600 if (f && !(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) 601 sh_cmt_disable(ch); 602 603 /* adjust the timeout to maximum if only clocksource left */ 604 if ((flag == FLAG_CLOCKEVENT) && (ch->flags & FLAG_CLOCKSOURCE)) 605 __sh_cmt_set_next(ch, ch->max_match_value); 606 607 raw_spin_unlock_irqrestore(&ch->lock, flags); 608 } 609 610 static struct sh_cmt_channel *cs_to_sh_cmt(struct clocksource *cs) 611 { 612 return container_of(cs, struct sh_cmt_channel, cs); 613 } 614 615 static cycle_t sh_cmt_clocksource_read(struct clocksource *cs) 616 { 617 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 618 unsigned long flags, raw; 619 unsigned long value; 620 int has_wrapped; 621 622 raw_spin_lock_irqsave(&ch->lock, flags); 623 value = ch->total_cycles; 624 raw = sh_cmt_get_counter(ch, &has_wrapped); 625 626 if (unlikely(has_wrapped)) 627 raw += ch->match_value + 1; 628 raw_spin_unlock_irqrestore(&ch->lock, flags); 629 630 return value + raw; 631 } 632 633 static int sh_cmt_clocksource_enable(struct clocksource *cs) 634 { 635 int ret; 636 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 637 638 WARN_ON(ch->cs_enabled); 639 640 ch->total_cycles = 0; 641 642 ret = sh_cmt_start(ch, FLAG_CLOCKSOURCE); 643 if (!ret) { 644 __clocksource_updatefreq_hz(cs, ch->rate); 645 ch->cs_enabled = true; 646 } 647 return ret; 648 } 649 650 static void sh_cmt_clocksource_disable(struct clocksource *cs) 651 { 652 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 653 654 WARN_ON(!ch->cs_enabled); 655 656 sh_cmt_stop(ch, FLAG_CLOCKSOURCE); 657 ch->cs_enabled = false; 658 } 659 660 static void sh_cmt_clocksource_suspend(struct clocksource *cs) 661 { 662 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 663 664 sh_cmt_stop(ch, FLAG_CLOCKSOURCE); 665 pm_genpd_syscore_poweroff(&ch->cmt->pdev->dev); 666 } 667 668 static void sh_cmt_clocksource_resume(struct clocksource *cs) 669 { 670 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 671 672 pm_genpd_syscore_poweron(&ch->cmt->pdev->dev); 673 sh_cmt_start(ch, FLAG_CLOCKSOURCE); 674 } 675 676 static int sh_cmt_register_clocksource(struct sh_cmt_channel *ch, 677 const char *name) 678 { 679 struct clocksource *cs = &ch->cs; 680 681 cs->name = name; 682 cs->rating = 125; 683 cs->read = sh_cmt_clocksource_read; 684 cs->enable = sh_cmt_clocksource_enable; 685 cs->disable = sh_cmt_clocksource_disable; 686 cs->suspend = sh_cmt_clocksource_suspend; 687 cs->resume = sh_cmt_clocksource_resume; 688 cs->mask = CLOCKSOURCE_MASK(sizeof(unsigned long) * 8); 689 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; 690 691 dev_info(&ch->cmt->pdev->dev, "ch%u: used as clock source\n", 692 ch->index); 693 694 /* Register with dummy 1 Hz value, gets updated in ->enable() */ 695 clocksource_register_hz(cs, 1); 696 return 0; 697 } 698 699 static struct sh_cmt_channel *ced_to_sh_cmt(struct clock_event_device *ced) 700 { 701 return container_of(ced, struct sh_cmt_channel, ced); 702 } 703 704 static void sh_cmt_clock_event_start(struct sh_cmt_channel *ch, int periodic) 705 { 706 struct clock_event_device *ced = &ch->ced; 707 708 sh_cmt_start(ch, FLAG_CLOCKEVENT); 709 710 /* TODO: calculate good shift from rate and counter bit width */ 711 712 ced->shift = 32; 713 ced->mult = div_sc(ch->rate, NSEC_PER_SEC, ced->shift); 714 ced->max_delta_ns = clockevent_delta2ns(ch->max_match_value, ced); 715 ced->min_delta_ns = clockevent_delta2ns(0x1f, ced); 716 717 if (periodic) 718 sh_cmt_set_next(ch, ((ch->rate + HZ/2) / HZ) - 1); 719 else 720 sh_cmt_set_next(ch, ch->max_match_value); 721 } 722 723 static void sh_cmt_clock_event_mode(enum clock_event_mode mode, 724 struct clock_event_device *ced) 725 { 726 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 727 728 /* deal with old setting first */ 729 switch (ced->mode) { 730 case CLOCK_EVT_MODE_PERIODIC: 731 case CLOCK_EVT_MODE_ONESHOT: 732 sh_cmt_stop(ch, FLAG_CLOCKEVENT); 733 break; 734 default: 735 break; 736 } 737 738 switch (mode) { 739 case CLOCK_EVT_MODE_PERIODIC: 740 dev_info(&ch->cmt->pdev->dev, 741 "ch%u: used for periodic clock events\n", ch->index); 742 sh_cmt_clock_event_start(ch, 1); 743 break; 744 case CLOCK_EVT_MODE_ONESHOT: 745 dev_info(&ch->cmt->pdev->dev, 746 "ch%u: used for oneshot clock events\n", ch->index); 747 sh_cmt_clock_event_start(ch, 0); 748 break; 749 case CLOCK_EVT_MODE_SHUTDOWN: 750 case CLOCK_EVT_MODE_UNUSED: 751 sh_cmt_stop(ch, FLAG_CLOCKEVENT); 752 break; 753 default: 754 break; 755 } 756 } 757 758 static int sh_cmt_clock_event_next(unsigned long delta, 759 struct clock_event_device *ced) 760 { 761 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 762 763 BUG_ON(ced->mode != CLOCK_EVT_MODE_ONESHOT); 764 if (likely(ch->flags & FLAG_IRQCONTEXT)) 765 ch->next_match_value = delta - 1; 766 else 767 sh_cmt_set_next(ch, delta - 1); 768 769 return 0; 770 } 771 772 static void sh_cmt_clock_event_suspend(struct clock_event_device *ced) 773 { 774 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 775 776 pm_genpd_syscore_poweroff(&ch->cmt->pdev->dev); 777 clk_unprepare(ch->cmt->clk); 778 } 779 780 static void sh_cmt_clock_event_resume(struct clock_event_device *ced) 781 { 782 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 783 784 clk_prepare(ch->cmt->clk); 785 pm_genpd_syscore_poweron(&ch->cmt->pdev->dev); 786 } 787 788 static int sh_cmt_register_clockevent(struct sh_cmt_channel *ch, 789 const char *name) 790 { 791 struct clock_event_device *ced = &ch->ced; 792 int irq; 793 int ret; 794 795 irq = platform_get_irq(ch->cmt->pdev, ch->index); 796 if (irq < 0) { 797 dev_err(&ch->cmt->pdev->dev, "ch%u: failed to get irq\n", 798 ch->index); 799 return irq; 800 } 801 802 ret = request_irq(irq, sh_cmt_interrupt, 803 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING, 804 dev_name(&ch->cmt->pdev->dev), ch); 805 if (ret) { 806 dev_err(&ch->cmt->pdev->dev, "ch%u: failed to request irq %d\n", 807 ch->index, irq); 808 return ret; 809 } 810 811 ced->name = name; 812 ced->features = CLOCK_EVT_FEAT_PERIODIC; 813 ced->features |= CLOCK_EVT_FEAT_ONESHOT; 814 ced->rating = 125; 815 ced->cpumask = cpu_possible_mask; 816 ced->set_next_event = sh_cmt_clock_event_next; 817 ced->set_mode = sh_cmt_clock_event_mode; 818 ced->suspend = sh_cmt_clock_event_suspend; 819 ced->resume = sh_cmt_clock_event_resume; 820 821 dev_info(&ch->cmt->pdev->dev, "ch%u: used for clock events\n", 822 ch->index); 823 clockevents_register_device(ced); 824 825 return 0; 826 } 827 828 static int sh_cmt_register(struct sh_cmt_channel *ch, const char *name, 829 bool clockevent, bool clocksource) 830 { 831 int ret; 832 833 if (clockevent) { 834 ch->cmt->has_clockevent = true; 835 ret = sh_cmt_register_clockevent(ch, name); 836 if (ret < 0) 837 return ret; 838 } 839 840 if (clocksource) { 841 ch->cmt->has_clocksource = true; 842 sh_cmt_register_clocksource(ch, name); 843 } 844 845 return 0; 846 } 847 848 static int sh_cmt_setup_channel(struct sh_cmt_channel *ch, unsigned int index, 849 unsigned int hwidx, bool clockevent, 850 bool clocksource, struct sh_cmt_device *cmt) 851 { 852 int ret; 853 854 /* Skip unused channels. */ 855 if (!clockevent && !clocksource) 856 return 0; 857 858 ch->cmt = cmt; 859 ch->index = index; 860 ch->hwidx = hwidx; 861 862 /* 863 * Compute the address of the channel control register block. For the 864 * timers with a per-channel start/stop register, compute its address 865 * as well. 866 */ 867 switch (cmt->info->model) { 868 case SH_CMT_16BIT: 869 ch->ioctrl = cmt->mapbase + 2 + ch->hwidx * 6; 870 break; 871 case SH_CMT_32BIT: 872 case SH_CMT_48BIT: 873 ch->ioctrl = cmt->mapbase + 0x10 + ch->hwidx * 0x10; 874 break; 875 case SH_CMT_32BIT_FAST: 876 /* 877 * The 32-bit "fast" timer has a single channel at hwidx 5 but 878 * is located at offset 0x40 instead of 0x60 for some reason. 879 */ 880 ch->ioctrl = cmt->mapbase + 0x40; 881 break; 882 case SH_CMT_48BIT_GEN2: 883 ch->iostart = cmt->mapbase + ch->hwidx * 0x100; 884 ch->ioctrl = ch->iostart + 0x10; 885 break; 886 } 887 888 if (cmt->info->width == (sizeof(ch->max_match_value) * 8)) 889 ch->max_match_value = ~0; 890 else 891 ch->max_match_value = (1 << cmt->info->width) - 1; 892 893 ch->match_value = ch->max_match_value; 894 raw_spin_lock_init(&ch->lock); 895 896 ch->timer_bit = cmt->info->model == SH_CMT_48BIT_GEN2 ? 0 : ch->hwidx; 897 898 ret = sh_cmt_register(ch, dev_name(&cmt->pdev->dev), 899 clockevent, clocksource); 900 if (ret) { 901 dev_err(&cmt->pdev->dev, "ch%u: registration failed\n", 902 ch->index); 903 return ret; 904 } 905 ch->cs_enabled = false; 906 907 return 0; 908 } 909 910 static int sh_cmt_map_memory(struct sh_cmt_device *cmt) 911 { 912 struct resource *mem; 913 914 mem = platform_get_resource(cmt->pdev, IORESOURCE_MEM, 0); 915 if (!mem) { 916 dev_err(&cmt->pdev->dev, "failed to get I/O memory\n"); 917 return -ENXIO; 918 } 919 920 cmt->mapbase = ioremap_nocache(mem->start, resource_size(mem)); 921 if (cmt->mapbase == NULL) { 922 dev_err(&cmt->pdev->dev, "failed to remap I/O memory\n"); 923 return -ENXIO; 924 } 925 926 return 0; 927 } 928 929 static const struct platform_device_id sh_cmt_id_table[] = { 930 { "sh-cmt-16", (kernel_ulong_t)&sh_cmt_info[SH_CMT_16BIT] }, 931 { "sh-cmt-32", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT] }, 932 { "sh-cmt-32-fast", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT_FAST] }, 933 { "sh-cmt-48", (kernel_ulong_t)&sh_cmt_info[SH_CMT_48BIT] }, 934 { "sh-cmt-48-gen2", (kernel_ulong_t)&sh_cmt_info[SH_CMT_48BIT_GEN2] }, 935 { } 936 }; 937 MODULE_DEVICE_TABLE(platform, sh_cmt_id_table); 938 939 static const struct of_device_id sh_cmt_of_table[] __maybe_unused = { 940 { .compatible = "renesas,cmt-32", .data = &sh_cmt_info[SH_CMT_32BIT] }, 941 { .compatible = "renesas,cmt-32-fast", .data = &sh_cmt_info[SH_CMT_32BIT_FAST] }, 942 { .compatible = "renesas,cmt-48", .data = &sh_cmt_info[SH_CMT_48BIT] }, 943 { .compatible = "renesas,cmt-48-gen2", .data = &sh_cmt_info[SH_CMT_48BIT_GEN2] }, 944 { } 945 }; 946 MODULE_DEVICE_TABLE(of, sh_cmt_of_table); 947 948 static int sh_cmt_parse_dt(struct sh_cmt_device *cmt) 949 { 950 struct device_node *np = cmt->pdev->dev.of_node; 951 952 return of_property_read_u32(np, "renesas,channels-mask", 953 &cmt->hw_channels); 954 } 955 956 static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev) 957 { 958 unsigned int mask; 959 unsigned int i; 960 int ret; 961 962 memset(cmt, 0, sizeof(*cmt)); 963 cmt->pdev = pdev; 964 raw_spin_lock_init(&cmt->lock); 965 966 if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) { 967 const struct of_device_id *id; 968 969 id = of_match_node(sh_cmt_of_table, pdev->dev.of_node); 970 cmt->info = id->data; 971 972 ret = sh_cmt_parse_dt(cmt); 973 if (ret < 0) 974 return ret; 975 } else if (pdev->dev.platform_data) { 976 struct sh_timer_config *cfg = pdev->dev.platform_data; 977 const struct platform_device_id *id = pdev->id_entry; 978 979 cmt->info = (const struct sh_cmt_info *)id->driver_data; 980 cmt->hw_channels = cfg->channels_mask; 981 } else { 982 dev_err(&cmt->pdev->dev, "missing platform data\n"); 983 return -ENXIO; 984 } 985 986 /* Get hold of clock. */ 987 cmt->clk = clk_get(&cmt->pdev->dev, "fck"); 988 if (IS_ERR(cmt->clk)) { 989 dev_err(&cmt->pdev->dev, "cannot get clock\n"); 990 return PTR_ERR(cmt->clk); 991 } 992 993 ret = clk_prepare(cmt->clk); 994 if (ret < 0) 995 goto err_clk_put; 996 997 /* Map the memory resource(s). */ 998 ret = sh_cmt_map_memory(cmt); 999 if (ret < 0) 1000 goto err_clk_unprepare; 1001 1002 /* Allocate and setup the channels. */ 1003 cmt->num_channels = hweight8(cmt->hw_channels); 1004 cmt->channels = kzalloc(cmt->num_channels * sizeof(*cmt->channels), 1005 GFP_KERNEL); 1006 if (cmt->channels == NULL) { 1007 ret = -ENOMEM; 1008 goto err_unmap; 1009 } 1010 1011 /* 1012 * Use the first channel as a clock event device and the second channel 1013 * as a clock source. If only one channel is available use it for both. 1014 */ 1015 for (i = 0, mask = cmt->hw_channels; i < cmt->num_channels; ++i) { 1016 unsigned int hwidx = ffs(mask) - 1; 1017 bool clocksource = i == 1 || cmt->num_channels == 1; 1018 bool clockevent = i == 0; 1019 1020 ret = sh_cmt_setup_channel(&cmt->channels[i], i, hwidx, 1021 clockevent, clocksource, cmt); 1022 if (ret < 0) 1023 goto err_unmap; 1024 1025 mask &= ~(1 << hwidx); 1026 } 1027 1028 platform_set_drvdata(pdev, cmt); 1029 1030 return 0; 1031 1032 err_unmap: 1033 kfree(cmt->channels); 1034 iounmap(cmt->mapbase); 1035 err_clk_unprepare: 1036 clk_unprepare(cmt->clk); 1037 err_clk_put: 1038 clk_put(cmt->clk); 1039 return ret; 1040 } 1041 1042 static int sh_cmt_probe(struct platform_device *pdev) 1043 { 1044 struct sh_cmt_device *cmt = platform_get_drvdata(pdev); 1045 int ret; 1046 1047 if (!is_early_platform_device(pdev)) { 1048 pm_runtime_set_active(&pdev->dev); 1049 pm_runtime_enable(&pdev->dev); 1050 } 1051 1052 if (cmt) { 1053 dev_info(&pdev->dev, "kept as earlytimer\n"); 1054 goto out; 1055 } 1056 1057 cmt = kzalloc(sizeof(*cmt), GFP_KERNEL); 1058 if (cmt == NULL) 1059 return -ENOMEM; 1060 1061 ret = sh_cmt_setup(cmt, pdev); 1062 if (ret) { 1063 kfree(cmt); 1064 pm_runtime_idle(&pdev->dev); 1065 return ret; 1066 } 1067 if (is_early_platform_device(pdev)) 1068 return 0; 1069 1070 out: 1071 if (cmt->has_clockevent || cmt->has_clocksource) 1072 pm_runtime_irq_safe(&pdev->dev); 1073 else 1074 pm_runtime_idle(&pdev->dev); 1075 1076 return 0; 1077 } 1078 1079 static int sh_cmt_remove(struct platform_device *pdev) 1080 { 1081 return -EBUSY; /* cannot unregister clockevent and clocksource */ 1082 } 1083 1084 static struct platform_driver sh_cmt_device_driver = { 1085 .probe = sh_cmt_probe, 1086 .remove = sh_cmt_remove, 1087 .driver = { 1088 .name = "sh_cmt", 1089 .of_match_table = of_match_ptr(sh_cmt_of_table), 1090 }, 1091 .id_table = sh_cmt_id_table, 1092 }; 1093 1094 static int __init sh_cmt_init(void) 1095 { 1096 return platform_driver_register(&sh_cmt_device_driver); 1097 } 1098 1099 static void __exit sh_cmt_exit(void) 1100 { 1101 platform_driver_unregister(&sh_cmt_device_driver); 1102 } 1103 1104 early_platform_init("earlytimer", &sh_cmt_device_driver); 1105 subsys_initcall(sh_cmt_init); 1106 module_exit(sh_cmt_exit); 1107 1108 MODULE_AUTHOR("Magnus Damm"); 1109 MODULE_DESCRIPTION("SuperH CMT Timer Driver"); 1110 MODULE_LICENSE("GPL v2"); 1111