1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * SuperH Timer Support - CMT 4 * 5 * Copyright (C) 2008 Magnus Damm 6 */ 7 8 #include <linux/clk.h> 9 #include <linux/clockchips.h> 10 #include <linux/clocksource.h> 11 #include <linux/delay.h> 12 #include <linux/err.h> 13 #include <linux/init.h> 14 #include <linux/interrupt.h> 15 #include <linux/io.h> 16 #include <linux/ioport.h> 17 #include <linux/irq.h> 18 #include <linux/module.h> 19 #include <linux/of.h> 20 #include <linux/of_device.h> 21 #include <linux/platform_device.h> 22 #include <linux/pm_domain.h> 23 #include <linux/pm_runtime.h> 24 #include <linux/sh_timer.h> 25 #include <linux/slab.h> 26 #include <linux/spinlock.h> 27 28 struct sh_cmt_device; 29 30 /* 31 * The CMT comes in 5 different identified flavours, depending not only on the 32 * SoC but also on the particular instance. The following table lists the main 33 * characteristics of those flavours. 34 * 35 * 16B 32B 32B-F 48B R-Car Gen2 36 * ----------------------------------------------------------------------------- 37 * Channels 2 1/4 1 6 2/8 38 * Control Width 16 16 16 16 32 39 * Counter Width 16 32 32 32/48 32/48 40 * Shared Start/Stop Y Y Y Y N 41 * 42 * The r8a73a4 / R-Car Gen2 version has a per-channel start/stop register 43 * located in the channel registers block. All other versions have a shared 44 * start/stop register located in the global space. 45 * 46 * Channels are indexed from 0 to N-1 in the documentation. The channel index 47 * infers the start/stop bit position in the control register and the channel 48 * registers block address. Some CMT instances have a subset of channels 49 * available, in which case the index in the documentation doesn't match the 50 * "real" index as implemented in hardware. This is for instance the case with 51 * CMT0 on r8a7740, which is a 32-bit variant with a single channel numbered 0 52 * in the documentation but using start/stop bit 5 and having its registers 53 * block at 0x60. 54 * 55 * Similarly CMT0 on r8a73a4, r8a7790 and r8a7791, while implementing 32-bit 56 * channels only, is a 48-bit gen2 CMT with the 48-bit channels unavailable. 57 */ 58 59 enum sh_cmt_model { 60 SH_CMT_16BIT, 61 SH_CMT_32BIT, 62 SH_CMT_48BIT, 63 SH_CMT0_RCAR_GEN2, 64 SH_CMT1_RCAR_GEN2, 65 }; 66 67 struct sh_cmt_info { 68 enum sh_cmt_model model; 69 70 unsigned int channels_mask; 71 72 unsigned long width; /* 16 or 32 bit version of hardware block */ 73 u32 overflow_bit; 74 u32 clear_bits; 75 76 /* callbacks for CMSTR and CMCSR access */ 77 u32 (*read_control)(void __iomem *base, unsigned long offs); 78 void (*write_control)(void __iomem *base, unsigned long offs, 79 u32 value); 80 81 /* callbacks for CMCNT and CMCOR access */ 82 u32 (*read_count)(void __iomem *base, unsigned long offs); 83 void (*write_count)(void __iomem *base, unsigned long offs, u32 value); 84 }; 85 86 struct sh_cmt_channel { 87 struct sh_cmt_device *cmt; 88 89 unsigned int index; /* Index in the documentation */ 90 unsigned int hwidx; /* Real hardware index */ 91 92 void __iomem *iostart; 93 void __iomem *ioctrl; 94 95 unsigned int timer_bit; 96 unsigned long flags; 97 u32 match_value; 98 u32 next_match_value; 99 u32 max_match_value; 100 raw_spinlock_t lock; 101 struct clock_event_device ced; 102 struct clocksource cs; 103 u64 total_cycles; 104 bool cs_enabled; 105 }; 106 107 struct sh_cmt_device { 108 struct platform_device *pdev; 109 110 const struct sh_cmt_info *info; 111 112 void __iomem *mapbase; 113 struct clk *clk; 114 unsigned long rate; 115 116 raw_spinlock_t lock; /* Protect the shared start/stop register */ 117 118 struct sh_cmt_channel *channels; 119 unsigned int num_channels; 120 unsigned int hw_channels; 121 122 bool has_clockevent; 123 bool has_clocksource; 124 }; 125 126 #define SH_CMT16_CMCSR_CMF (1 << 7) 127 #define SH_CMT16_CMCSR_CMIE (1 << 6) 128 #define SH_CMT16_CMCSR_CKS8 (0 << 0) 129 #define SH_CMT16_CMCSR_CKS32 (1 << 0) 130 #define SH_CMT16_CMCSR_CKS128 (2 << 0) 131 #define SH_CMT16_CMCSR_CKS512 (3 << 0) 132 #define SH_CMT16_CMCSR_CKS_MASK (3 << 0) 133 134 #define SH_CMT32_CMCSR_CMF (1 << 15) 135 #define SH_CMT32_CMCSR_OVF (1 << 14) 136 #define SH_CMT32_CMCSR_WRFLG (1 << 13) 137 #define SH_CMT32_CMCSR_STTF (1 << 12) 138 #define SH_CMT32_CMCSR_STPF (1 << 11) 139 #define SH_CMT32_CMCSR_SSIE (1 << 10) 140 #define SH_CMT32_CMCSR_CMS (1 << 9) 141 #define SH_CMT32_CMCSR_CMM (1 << 8) 142 #define SH_CMT32_CMCSR_CMTOUT_IE (1 << 7) 143 #define SH_CMT32_CMCSR_CMR_NONE (0 << 4) 144 #define SH_CMT32_CMCSR_CMR_DMA (1 << 4) 145 #define SH_CMT32_CMCSR_CMR_IRQ (2 << 4) 146 #define SH_CMT32_CMCSR_CMR_MASK (3 << 4) 147 #define SH_CMT32_CMCSR_DBGIVD (1 << 3) 148 #define SH_CMT32_CMCSR_CKS_RCLK8 (4 << 0) 149 #define SH_CMT32_CMCSR_CKS_RCLK32 (5 << 0) 150 #define SH_CMT32_CMCSR_CKS_RCLK128 (6 << 0) 151 #define SH_CMT32_CMCSR_CKS_RCLK1 (7 << 0) 152 #define SH_CMT32_CMCSR_CKS_MASK (7 << 0) 153 154 static u32 sh_cmt_read16(void __iomem *base, unsigned long offs) 155 { 156 return ioread16(base + (offs << 1)); 157 } 158 159 static u32 sh_cmt_read32(void __iomem *base, unsigned long offs) 160 { 161 return ioread32(base + (offs << 2)); 162 } 163 164 static void sh_cmt_write16(void __iomem *base, unsigned long offs, u32 value) 165 { 166 iowrite16(value, base + (offs << 1)); 167 } 168 169 static void sh_cmt_write32(void __iomem *base, unsigned long offs, u32 value) 170 { 171 iowrite32(value, base + (offs << 2)); 172 } 173 174 static const struct sh_cmt_info sh_cmt_info[] = { 175 [SH_CMT_16BIT] = { 176 .model = SH_CMT_16BIT, 177 .width = 16, 178 .overflow_bit = SH_CMT16_CMCSR_CMF, 179 .clear_bits = ~SH_CMT16_CMCSR_CMF, 180 .read_control = sh_cmt_read16, 181 .write_control = sh_cmt_write16, 182 .read_count = sh_cmt_read16, 183 .write_count = sh_cmt_write16, 184 }, 185 [SH_CMT_32BIT] = { 186 .model = SH_CMT_32BIT, 187 .width = 32, 188 .overflow_bit = SH_CMT32_CMCSR_CMF, 189 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 190 .read_control = sh_cmt_read16, 191 .write_control = sh_cmt_write16, 192 .read_count = sh_cmt_read32, 193 .write_count = sh_cmt_write32, 194 }, 195 [SH_CMT_48BIT] = { 196 .model = SH_CMT_48BIT, 197 .channels_mask = 0x3f, 198 .width = 32, 199 .overflow_bit = SH_CMT32_CMCSR_CMF, 200 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 201 .read_control = sh_cmt_read32, 202 .write_control = sh_cmt_write32, 203 .read_count = sh_cmt_read32, 204 .write_count = sh_cmt_write32, 205 }, 206 [SH_CMT0_RCAR_GEN2] = { 207 .model = SH_CMT0_RCAR_GEN2, 208 .channels_mask = 0x60, 209 .width = 32, 210 .overflow_bit = SH_CMT32_CMCSR_CMF, 211 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 212 .read_control = sh_cmt_read32, 213 .write_control = sh_cmt_write32, 214 .read_count = sh_cmt_read32, 215 .write_count = sh_cmt_write32, 216 }, 217 [SH_CMT1_RCAR_GEN2] = { 218 .model = SH_CMT1_RCAR_GEN2, 219 .channels_mask = 0xff, 220 .width = 32, 221 .overflow_bit = SH_CMT32_CMCSR_CMF, 222 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 223 .read_control = sh_cmt_read32, 224 .write_control = sh_cmt_write32, 225 .read_count = sh_cmt_read32, 226 .write_count = sh_cmt_write32, 227 }, 228 }; 229 230 #define CMCSR 0 /* channel register */ 231 #define CMCNT 1 /* channel register */ 232 #define CMCOR 2 /* channel register */ 233 234 static inline u32 sh_cmt_read_cmstr(struct sh_cmt_channel *ch) 235 { 236 if (ch->iostart) 237 return ch->cmt->info->read_control(ch->iostart, 0); 238 else 239 return ch->cmt->info->read_control(ch->cmt->mapbase, 0); 240 } 241 242 static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, u32 value) 243 { 244 if (ch->iostart) 245 ch->cmt->info->write_control(ch->iostart, 0, value); 246 else 247 ch->cmt->info->write_control(ch->cmt->mapbase, 0, value); 248 } 249 250 static inline u32 sh_cmt_read_cmcsr(struct sh_cmt_channel *ch) 251 { 252 return ch->cmt->info->read_control(ch->ioctrl, CMCSR); 253 } 254 255 static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch, u32 value) 256 { 257 ch->cmt->info->write_control(ch->ioctrl, CMCSR, value); 258 } 259 260 static inline u32 sh_cmt_read_cmcnt(struct sh_cmt_channel *ch) 261 { 262 return ch->cmt->info->read_count(ch->ioctrl, CMCNT); 263 } 264 265 static inline void sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, u32 value) 266 { 267 ch->cmt->info->write_count(ch->ioctrl, CMCNT, value); 268 } 269 270 static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch, u32 value) 271 { 272 ch->cmt->info->write_count(ch->ioctrl, CMCOR, value); 273 } 274 275 static u32 sh_cmt_get_counter(struct sh_cmt_channel *ch, u32 *has_wrapped) 276 { 277 u32 v1, v2, v3; 278 u32 o1, o2; 279 280 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit; 281 282 /* Make sure the timer value is stable. Stolen from acpi_pm.c */ 283 do { 284 o2 = o1; 285 v1 = sh_cmt_read_cmcnt(ch); 286 v2 = sh_cmt_read_cmcnt(ch); 287 v3 = sh_cmt_read_cmcnt(ch); 288 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit; 289 } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3) 290 || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2))); 291 292 *has_wrapped = o1; 293 return v2; 294 } 295 296 static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start) 297 { 298 unsigned long flags; 299 u32 value; 300 301 /* start stop register shared by multiple timer channels */ 302 raw_spin_lock_irqsave(&ch->cmt->lock, flags); 303 value = sh_cmt_read_cmstr(ch); 304 305 if (start) 306 value |= 1 << ch->timer_bit; 307 else 308 value &= ~(1 << ch->timer_bit); 309 310 sh_cmt_write_cmstr(ch, value); 311 raw_spin_unlock_irqrestore(&ch->cmt->lock, flags); 312 } 313 314 static int sh_cmt_enable(struct sh_cmt_channel *ch) 315 { 316 int k, ret; 317 318 pm_runtime_get_sync(&ch->cmt->pdev->dev); 319 dev_pm_syscore_device(&ch->cmt->pdev->dev, true); 320 321 /* enable clock */ 322 ret = clk_enable(ch->cmt->clk); 323 if (ret) { 324 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot enable clock\n", 325 ch->index); 326 goto err0; 327 } 328 329 /* make sure channel is disabled */ 330 sh_cmt_start_stop_ch(ch, 0); 331 332 /* configure channel, periodic mode and maximum timeout */ 333 if (ch->cmt->info->width == 16) { 334 sh_cmt_write_cmcsr(ch, SH_CMT16_CMCSR_CMIE | 335 SH_CMT16_CMCSR_CKS512); 336 } else { 337 sh_cmt_write_cmcsr(ch, SH_CMT32_CMCSR_CMM | 338 SH_CMT32_CMCSR_CMTOUT_IE | 339 SH_CMT32_CMCSR_CMR_IRQ | 340 SH_CMT32_CMCSR_CKS_RCLK8); 341 } 342 343 sh_cmt_write_cmcor(ch, 0xffffffff); 344 sh_cmt_write_cmcnt(ch, 0); 345 346 /* 347 * According to the sh73a0 user's manual, as CMCNT can be operated 348 * only by the RCLK (Pseudo 32 KHz), there's one restriction on 349 * modifying CMCNT register; two RCLK cycles are necessary before 350 * this register is either read or any modification of the value 351 * it holds is reflected in the LSI's actual operation. 352 * 353 * While at it, we're supposed to clear out the CMCNT as of this 354 * moment, so make sure it's processed properly here. This will 355 * take RCLKx2 at maximum. 356 */ 357 for (k = 0; k < 100; k++) { 358 if (!sh_cmt_read_cmcnt(ch)) 359 break; 360 udelay(1); 361 } 362 363 if (sh_cmt_read_cmcnt(ch)) { 364 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot clear CMCNT\n", 365 ch->index); 366 ret = -ETIMEDOUT; 367 goto err1; 368 } 369 370 /* enable channel */ 371 sh_cmt_start_stop_ch(ch, 1); 372 return 0; 373 err1: 374 /* stop clock */ 375 clk_disable(ch->cmt->clk); 376 377 err0: 378 return ret; 379 } 380 381 static void sh_cmt_disable(struct sh_cmt_channel *ch) 382 { 383 /* disable channel */ 384 sh_cmt_start_stop_ch(ch, 0); 385 386 /* disable interrupts in CMT block */ 387 sh_cmt_write_cmcsr(ch, 0); 388 389 /* stop clock */ 390 clk_disable(ch->cmt->clk); 391 392 dev_pm_syscore_device(&ch->cmt->pdev->dev, false); 393 pm_runtime_put(&ch->cmt->pdev->dev); 394 } 395 396 /* private flags */ 397 #define FLAG_CLOCKEVENT (1 << 0) 398 #define FLAG_CLOCKSOURCE (1 << 1) 399 #define FLAG_REPROGRAM (1 << 2) 400 #define FLAG_SKIPEVENT (1 << 3) 401 #define FLAG_IRQCONTEXT (1 << 4) 402 403 static void sh_cmt_clock_event_program_verify(struct sh_cmt_channel *ch, 404 int absolute) 405 { 406 u32 value = ch->next_match_value; 407 u32 new_match; 408 u32 delay = 0; 409 u32 now = 0; 410 u32 has_wrapped; 411 412 now = sh_cmt_get_counter(ch, &has_wrapped); 413 ch->flags |= FLAG_REPROGRAM; /* force reprogram */ 414 415 if (has_wrapped) { 416 /* we're competing with the interrupt handler. 417 * -> let the interrupt handler reprogram the timer. 418 * -> interrupt number two handles the event. 419 */ 420 ch->flags |= FLAG_SKIPEVENT; 421 return; 422 } 423 424 if (absolute) 425 now = 0; 426 427 do { 428 /* reprogram the timer hardware, 429 * but don't save the new match value yet. 430 */ 431 new_match = now + value + delay; 432 if (new_match > ch->max_match_value) 433 new_match = ch->max_match_value; 434 435 sh_cmt_write_cmcor(ch, new_match); 436 437 now = sh_cmt_get_counter(ch, &has_wrapped); 438 if (has_wrapped && (new_match > ch->match_value)) { 439 /* we are changing to a greater match value, 440 * so this wrap must be caused by the counter 441 * matching the old value. 442 * -> first interrupt reprograms the timer. 443 * -> interrupt number two handles the event. 444 */ 445 ch->flags |= FLAG_SKIPEVENT; 446 break; 447 } 448 449 if (has_wrapped) { 450 /* we are changing to a smaller match value, 451 * so the wrap must be caused by the counter 452 * matching the new value. 453 * -> save programmed match value. 454 * -> let isr handle the event. 455 */ 456 ch->match_value = new_match; 457 break; 458 } 459 460 /* be safe: verify hardware settings */ 461 if (now < new_match) { 462 /* timer value is below match value, all good. 463 * this makes sure we won't miss any match events. 464 * -> save programmed match value. 465 * -> let isr handle the event. 466 */ 467 ch->match_value = new_match; 468 break; 469 } 470 471 /* the counter has reached a value greater 472 * than our new match value. and since the 473 * has_wrapped flag isn't set we must have 474 * programmed a too close event. 475 * -> increase delay and retry. 476 */ 477 if (delay) 478 delay <<= 1; 479 else 480 delay = 1; 481 482 if (!delay) 483 dev_warn(&ch->cmt->pdev->dev, "ch%u: too long delay\n", 484 ch->index); 485 486 } while (delay); 487 } 488 489 static void __sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta) 490 { 491 if (delta > ch->max_match_value) 492 dev_warn(&ch->cmt->pdev->dev, "ch%u: delta out of range\n", 493 ch->index); 494 495 ch->next_match_value = delta; 496 sh_cmt_clock_event_program_verify(ch, 0); 497 } 498 499 static void sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta) 500 { 501 unsigned long flags; 502 503 raw_spin_lock_irqsave(&ch->lock, flags); 504 __sh_cmt_set_next(ch, delta); 505 raw_spin_unlock_irqrestore(&ch->lock, flags); 506 } 507 508 static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id) 509 { 510 struct sh_cmt_channel *ch = dev_id; 511 512 /* clear flags */ 513 sh_cmt_write_cmcsr(ch, sh_cmt_read_cmcsr(ch) & 514 ch->cmt->info->clear_bits); 515 516 /* update clock source counter to begin with if enabled 517 * the wrap flag should be cleared by the timer specific 518 * isr before we end up here. 519 */ 520 if (ch->flags & FLAG_CLOCKSOURCE) 521 ch->total_cycles += ch->match_value + 1; 522 523 if (!(ch->flags & FLAG_REPROGRAM)) 524 ch->next_match_value = ch->max_match_value; 525 526 ch->flags |= FLAG_IRQCONTEXT; 527 528 if (ch->flags & FLAG_CLOCKEVENT) { 529 if (!(ch->flags & FLAG_SKIPEVENT)) { 530 if (clockevent_state_oneshot(&ch->ced)) { 531 ch->next_match_value = ch->max_match_value; 532 ch->flags |= FLAG_REPROGRAM; 533 } 534 535 ch->ced.event_handler(&ch->ced); 536 } 537 } 538 539 ch->flags &= ~FLAG_SKIPEVENT; 540 541 if (ch->flags & FLAG_REPROGRAM) { 542 ch->flags &= ~FLAG_REPROGRAM; 543 sh_cmt_clock_event_program_verify(ch, 1); 544 545 if (ch->flags & FLAG_CLOCKEVENT) 546 if ((clockevent_state_shutdown(&ch->ced)) 547 || (ch->match_value == ch->next_match_value)) 548 ch->flags &= ~FLAG_REPROGRAM; 549 } 550 551 ch->flags &= ~FLAG_IRQCONTEXT; 552 553 return IRQ_HANDLED; 554 } 555 556 static int sh_cmt_start(struct sh_cmt_channel *ch, unsigned long flag) 557 { 558 int ret = 0; 559 unsigned long flags; 560 561 raw_spin_lock_irqsave(&ch->lock, flags); 562 563 if (!(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) 564 ret = sh_cmt_enable(ch); 565 566 if (ret) 567 goto out; 568 ch->flags |= flag; 569 570 /* setup timeout if no clockevent */ 571 if ((flag == FLAG_CLOCKSOURCE) && (!(ch->flags & FLAG_CLOCKEVENT))) 572 __sh_cmt_set_next(ch, ch->max_match_value); 573 out: 574 raw_spin_unlock_irqrestore(&ch->lock, flags); 575 576 return ret; 577 } 578 579 static void sh_cmt_stop(struct sh_cmt_channel *ch, unsigned long flag) 580 { 581 unsigned long flags; 582 unsigned long f; 583 584 raw_spin_lock_irqsave(&ch->lock, flags); 585 586 f = ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE); 587 ch->flags &= ~flag; 588 589 if (f && !(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) 590 sh_cmt_disable(ch); 591 592 /* adjust the timeout to maximum if only clocksource left */ 593 if ((flag == FLAG_CLOCKEVENT) && (ch->flags & FLAG_CLOCKSOURCE)) 594 __sh_cmt_set_next(ch, ch->max_match_value); 595 596 raw_spin_unlock_irqrestore(&ch->lock, flags); 597 } 598 599 static struct sh_cmt_channel *cs_to_sh_cmt(struct clocksource *cs) 600 { 601 return container_of(cs, struct sh_cmt_channel, cs); 602 } 603 604 static u64 sh_cmt_clocksource_read(struct clocksource *cs) 605 { 606 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 607 unsigned long flags; 608 u32 has_wrapped; 609 u64 value; 610 u32 raw; 611 612 raw_spin_lock_irqsave(&ch->lock, flags); 613 value = ch->total_cycles; 614 raw = sh_cmt_get_counter(ch, &has_wrapped); 615 616 if (unlikely(has_wrapped)) 617 raw += ch->match_value + 1; 618 raw_spin_unlock_irqrestore(&ch->lock, flags); 619 620 return value + raw; 621 } 622 623 static int sh_cmt_clocksource_enable(struct clocksource *cs) 624 { 625 int ret; 626 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 627 628 WARN_ON(ch->cs_enabled); 629 630 ch->total_cycles = 0; 631 632 ret = sh_cmt_start(ch, FLAG_CLOCKSOURCE); 633 if (!ret) 634 ch->cs_enabled = true; 635 636 return ret; 637 } 638 639 static void sh_cmt_clocksource_disable(struct clocksource *cs) 640 { 641 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 642 643 WARN_ON(!ch->cs_enabled); 644 645 sh_cmt_stop(ch, FLAG_CLOCKSOURCE); 646 ch->cs_enabled = false; 647 } 648 649 static void sh_cmt_clocksource_suspend(struct clocksource *cs) 650 { 651 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 652 653 if (!ch->cs_enabled) 654 return; 655 656 sh_cmt_stop(ch, FLAG_CLOCKSOURCE); 657 pm_genpd_syscore_poweroff(&ch->cmt->pdev->dev); 658 } 659 660 static void sh_cmt_clocksource_resume(struct clocksource *cs) 661 { 662 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 663 664 if (!ch->cs_enabled) 665 return; 666 667 pm_genpd_syscore_poweron(&ch->cmt->pdev->dev); 668 sh_cmt_start(ch, FLAG_CLOCKSOURCE); 669 } 670 671 static int sh_cmt_register_clocksource(struct sh_cmt_channel *ch, 672 const char *name) 673 { 674 struct clocksource *cs = &ch->cs; 675 676 cs->name = name; 677 cs->rating = 125; 678 cs->read = sh_cmt_clocksource_read; 679 cs->enable = sh_cmt_clocksource_enable; 680 cs->disable = sh_cmt_clocksource_disable; 681 cs->suspend = sh_cmt_clocksource_suspend; 682 cs->resume = sh_cmt_clocksource_resume; 683 cs->mask = CLOCKSOURCE_MASK(sizeof(u64) * 8); 684 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; 685 686 dev_info(&ch->cmt->pdev->dev, "ch%u: used as clock source\n", 687 ch->index); 688 689 clocksource_register_hz(cs, ch->cmt->rate); 690 return 0; 691 } 692 693 static struct sh_cmt_channel *ced_to_sh_cmt(struct clock_event_device *ced) 694 { 695 return container_of(ced, struct sh_cmt_channel, ced); 696 } 697 698 static void sh_cmt_clock_event_start(struct sh_cmt_channel *ch, int periodic) 699 { 700 sh_cmt_start(ch, FLAG_CLOCKEVENT); 701 702 if (periodic) 703 sh_cmt_set_next(ch, ((ch->cmt->rate + HZ/2) / HZ) - 1); 704 else 705 sh_cmt_set_next(ch, ch->max_match_value); 706 } 707 708 static int sh_cmt_clock_event_shutdown(struct clock_event_device *ced) 709 { 710 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 711 712 sh_cmt_stop(ch, FLAG_CLOCKEVENT); 713 return 0; 714 } 715 716 static int sh_cmt_clock_event_set_state(struct clock_event_device *ced, 717 int periodic) 718 { 719 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 720 721 /* deal with old setting first */ 722 if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced)) 723 sh_cmt_stop(ch, FLAG_CLOCKEVENT); 724 725 dev_info(&ch->cmt->pdev->dev, "ch%u: used for %s clock events\n", 726 ch->index, periodic ? "periodic" : "oneshot"); 727 sh_cmt_clock_event_start(ch, periodic); 728 return 0; 729 } 730 731 static int sh_cmt_clock_event_set_oneshot(struct clock_event_device *ced) 732 { 733 return sh_cmt_clock_event_set_state(ced, 0); 734 } 735 736 static int sh_cmt_clock_event_set_periodic(struct clock_event_device *ced) 737 { 738 return sh_cmt_clock_event_set_state(ced, 1); 739 } 740 741 static int sh_cmt_clock_event_next(unsigned long delta, 742 struct clock_event_device *ced) 743 { 744 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 745 746 BUG_ON(!clockevent_state_oneshot(ced)); 747 if (likely(ch->flags & FLAG_IRQCONTEXT)) 748 ch->next_match_value = delta - 1; 749 else 750 sh_cmt_set_next(ch, delta - 1); 751 752 return 0; 753 } 754 755 static void sh_cmt_clock_event_suspend(struct clock_event_device *ced) 756 { 757 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 758 759 pm_genpd_syscore_poweroff(&ch->cmt->pdev->dev); 760 clk_unprepare(ch->cmt->clk); 761 } 762 763 static void sh_cmt_clock_event_resume(struct clock_event_device *ced) 764 { 765 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 766 767 clk_prepare(ch->cmt->clk); 768 pm_genpd_syscore_poweron(&ch->cmt->pdev->dev); 769 } 770 771 static int sh_cmt_register_clockevent(struct sh_cmt_channel *ch, 772 const char *name) 773 { 774 struct clock_event_device *ced = &ch->ced; 775 int irq; 776 int ret; 777 778 irq = platform_get_irq(ch->cmt->pdev, ch->index); 779 if (irq < 0) { 780 dev_err(&ch->cmt->pdev->dev, "ch%u: failed to get irq\n", 781 ch->index); 782 return irq; 783 } 784 785 ret = request_irq(irq, sh_cmt_interrupt, 786 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING, 787 dev_name(&ch->cmt->pdev->dev), ch); 788 if (ret) { 789 dev_err(&ch->cmt->pdev->dev, "ch%u: failed to request irq %d\n", 790 ch->index, irq); 791 return ret; 792 } 793 794 ced->name = name; 795 ced->features = CLOCK_EVT_FEAT_PERIODIC; 796 ced->features |= CLOCK_EVT_FEAT_ONESHOT; 797 ced->rating = 125; 798 ced->cpumask = cpu_possible_mask; 799 ced->set_next_event = sh_cmt_clock_event_next; 800 ced->set_state_shutdown = sh_cmt_clock_event_shutdown; 801 ced->set_state_periodic = sh_cmt_clock_event_set_periodic; 802 ced->set_state_oneshot = sh_cmt_clock_event_set_oneshot; 803 ced->suspend = sh_cmt_clock_event_suspend; 804 ced->resume = sh_cmt_clock_event_resume; 805 806 /* TODO: calculate good shift from rate and counter bit width */ 807 ced->shift = 32; 808 ced->mult = div_sc(ch->cmt->rate, NSEC_PER_SEC, ced->shift); 809 ced->max_delta_ns = clockevent_delta2ns(ch->max_match_value, ced); 810 ced->max_delta_ticks = ch->max_match_value; 811 ced->min_delta_ns = clockevent_delta2ns(0x1f, ced); 812 ced->min_delta_ticks = 0x1f; 813 814 dev_info(&ch->cmt->pdev->dev, "ch%u: used for clock events\n", 815 ch->index); 816 clockevents_register_device(ced); 817 818 return 0; 819 } 820 821 static int sh_cmt_register(struct sh_cmt_channel *ch, const char *name, 822 bool clockevent, bool clocksource) 823 { 824 int ret; 825 826 if (clockevent) { 827 ch->cmt->has_clockevent = true; 828 ret = sh_cmt_register_clockevent(ch, name); 829 if (ret < 0) 830 return ret; 831 } 832 833 if (clocksource) { 834 ch->cmt->has_clocksource = true; 835 sh_cmt_register_clocksource(ch, name); 836 } 837 838 return 0; 839 } 840 841 static int sh_cmt_setup_channel(struct sh_cmt_channel *ch, unsigned int index, 842 unsigned int hwidx, bool clockevent, 843 bool clocksource, struct sh_cmt_device *cmt) 844 { 845 int ret; 846 847 /* Skip unused channels. */ 848 if (!clockevent && !clocksource) 849 return 0; 850 851 ch->cmt = cmt; 852 ch->index = index; 853 ch->hwidx = hwidx; 854 ch->timer_bit = hwidx; 855 856 /* 857 * Compute the address of the channel control register block. For the 858 * timers with a per-channel start/stop register, compute its address 859 * as well. 860 */ 861 switch (cmt->info->model) { 862 case SH_CMT_16BIT: 863 ch->ioctrl = cmt->mapbase + 2 + ch->hwidx * 6; 864 break; 865 case SH_CMT_32BIT: 866 case SH_CMT_48BIT: 867 ch->ioctrl = cmt->mapbase + 0x10 + ch->hwidx * 0x10; 868 break; 869 case SH_CMT0_RCAR_GEN2: 870 case SH_CMT1_RCAR_GEN2: 871 ch->iostart = cmt->mapbase + ch->hwidx * 0x100; 872 ch->ioctrl = ch->iostart + 0x10; 873 ch->timer_bit = 0; 874 break; 875 } 876 877 if (cmt->info->width == (sizeof(ch->max_match_value) * 8)) 878 ch->max_match_value = ~0; 879 else 880 ch->max_match_value = (1 << cmt->info->width) - 1; 881 882 ch->match_value = ch->max_match_value; 883 raw_spin_lock_init(&ch->lock); 884 885 ret = sh_cmt_register(ch, dev_name(&cmt->pdev->dev), 886 clockevent, clocksource); 887 if (ret) { 888 dev_err(&cmt->pdev->dev, "ch%u: registration failed\n", 889 ch->index); 890 return ret; 891 } 892 ch->cs_enabled = false; 893 894 return 0; 895 } 896 897 static int sh_cmt_map_memory(struct sh_cmt_device *cmt) 898 { 899 struct resource *mem; 900 901 mem = platform_get_resource(cmt->pdev, IORESOURCE_MEM, 0); 902 if (!mem) { 903 dev_err(&cmt->pdev->dev, "failed to get I/O memory\n"); 904 return -ENXIO; 905 } 906 907 cmt->mapbase = ioremap_nocache(mem->start, resource_size(mem)); 908 if (cmt->mapbase == NULL) { 909 dev_err(&cmt->pdev->dev, "failed to remap I/O memory\n"); 910 return -ENXIO; 911 } 912 913 return 0; 914 } 915 916 static const struct platform_device_id sh_cmt_id_table[] = { 917 { "sh-cmt-16", (kernel_ulong_t)&sh_cmt_info[SH_CMT_16BIT] }, 918 { "sh-cmt-32", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT] }, 919 { } 920 }; 921 MODULE_DEVICE_TABLE(platform, sh_cmt_id_table); 922 923 static const struct of_device_id sh_cmt_of_table[] __maybe_unused = { 924 { .compatible = "renesas,cmt-48", .data = &sh_cmt_info[SH_CMT_48BIT] }, 925 { 926 /* deprecated, preserved for backward compatibility */ 927 .compatible = "renesas,cmt-48-gen2", 928 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2] 929 }, 930 { 931 .compatible = "renesas,rcar-gen2-cmt0", 932 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2] 933 }, 934 { 935 .compatible = "renesas,rcar-gen2-cmt1", 936 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2] 937 }, 938 { 939 .compatible = "renesas,rcar-gen3-cmt0", 940 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2] 941 }, 942 { 943 .compatible = "renesas,rcar-gen3-cmt1", 944 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2] 945 }, 946 { } 947 }; 948 MODULE_DEVICE_TABLE(of, sh_cmt_of_table); 949 950 static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev) 951 { 952 unsigned int mask; 953 unsigned int i; 954 int ret; 955 956 cmt->pdev = pdev; 957 raw_spin_lock_init(&cmt->lock); 958 959 if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) { 960 cmt->info = of_device_get_match_data(&pdev->dev); 961 cmt->hw_channels = cmt->info->channels_mask; 962 } else if (pdev->dev.platform_data) { 963 struct sh_timer_config *cfg = pdev->dev.platform_data; 964 const struct platform_device_id *id = pdev->id_entry; 965 966 cmt->info = (const struct sh_cmt_info *)id->driver_data; 967 cmt->hw_channels = cfg->channels_mask; 968 } else { 969 dev_err(&cmt->pdev->dev, "missing platform data\n"); 970 return -ENXIO; 971 } 972 973 /* Get hold of clock. */ 974 cmt->clk = clk_get(&cmt->pdev->dev, "fck"); 975 if (IS_ERR(cmt->clk)) { 976 dev_err(&cmt->pdev->dev, "cannot get clock\n"); 977 return PTR_ERR(cmt->clk); 978 } 979 980 ret = clk_prepare(cmt->clk); 981 if (ret < 0) 982 goto err_clk_put; 983 984 /* Determine clock rate. */ 985 ret = clk_enable(cmt->clk); 986 if (ret < 0) 987 goto err_clk_unprepare; 988 989 if (cmt->info->width == 16) 990 cmt->rate = clk_get_rate(cmt->clk) / 512; 991 else 992 cmt->rate = clk_get_rate(cmt->clk) / 8; 993 994 clk_disable(cmt->clk); 995 996 /* Map the memory resource(s). */ 997 ret = sh_cmt_map_memory(cmt); 998 if (ret < 0) 999 goto err_clk_unprepare; 1000 1001 /* Allocate and setup the channels. */ 1002 cmt->num_channels = hweight8(cmt->hw_channels); 1003 cmt->channels = kcalloc(cmt->num_channels, sizeof(*cmt->channels), 1004 GFP_KERNEL); 1005 if (cmt->channels == NULL) { 1006 ret = -ENOMEM; 1007 goto err_unmap; 1008 } 1009 1010 /* 1011 * Use the first channel as a clock event device and the second channel 1012 * as a clock source. If only one channel is available use it for both. 1013 */ 1014 for (i = 0, mask = cmt->hw_channels; i < cmt->num_channels; ++i) { 1015 unsigned int hwidx = ffs(mask) - 1; 1016 bool clocksource = i == 1 || cmt->num_channels == 1; 1017 bool clockevent = i == 0; 1018 1019 ret = sh_cmt_setup_channel(&cmt->channels[i], i, hwidx, 1020 clockevent, clocksource, cmt); 1021 if (ret < 0) 1022 goto err_unmap; 1023 1024 mask &= ~(1 << hwidx); 1025 } 1026 1027 platform_set_drvdata(pdev, cmt); 1028 1029 return 0; 1030 1031 err_unmap: 1032 kfree(cmt->channels); 1033 iounmap(cmt->mapbase); 1034 err_clk_unprepare: 1035 clk_unprepare(cmt->clk); 1036 err_clk_put: 1037 clk_put(cmt->clk); 1038 return ret; 1039 } 1040 1041 static int sh_cmt_probe(struct platform_device *pdev) 1042 { 1043 struct sh_cmt_device *cmt = platform_get_drvdata(pdev); 1044 int ret; 1045 1046 if (!is_early_platform_device(pdev)) { 1047 pm_runtime_set_active(&pdev->dev); 1048 pm_runtime_enable(&pdev->dev); 1049 } 1050 1051 if (cmt) { 1052 dev_info(&pdev->dev, "kept as earlytimer\n"); 1053 goto out; 1054 } 1055 1056 cmt = kzalloc(sizeof(*cmt), GFP_KERNEL); 1057 if (cmt == NULL) 1058 return -ENOMEM; 1059 1060 ret = sh_cmt_setup(cmt, pdev); 1061 if (ret) { 1062 kfree(cmt); 1063 pm_runtime_idle(&pdev->dev); 1064 return ret; 1065 } 1066 if (is_early_platform_device(pdev)) 1067 return 0; 1068 1069 out: 1070 if (cmt->has_clockevent || cmt->has_clocksource) 1071 pm_runtime_irq_safe(&pdev->dev); 1072 else 1073 pm_runtime_idle(&pdev->dev); 1074 1075 return 0; 1076 } 1077 1078 static int sh_cmt_remove(struct platform_device *pdev) 1079 { 1080 return -EBUSY; /* cannot unregister clockevent and clocksource */ 1081 } 1082 1083 static struct platform_driver sh_cmt_device_driver = { 1084 .probe = sh_cmt_probe, 1085 .remove = sh_cmt_remove, 1086 .driver = { 1087 .name = "sh_cmt", 1088 .of_match_table = of_match_ptr(sh_cmt_of_table), 1089 }, 1090 .id_table = sh_cmt_id_table, 1091 }; 1092 1093 static int __init sh_cmt_init(void) 1094 { 1095 return platform_driver_register(&sh_cmt_device_driver); 1096 } 1097 1098 static void __exit sh_cmt_exit(void) 1099 { 1100 platform_driver_unregister(&sh_cmt_device_driver); 1101 } 1102 1103 early_platform_init("earlytimer", &sh_cmt_device_driver); 1104 subsys_initcall(sh_cmt_init); 1105 module_exit(sh_cmt_exit); 1106 1107 MODULE_AUTHOR("Magnus Damm"); 1108 MODULE_DESCRIPTION("SuperH CMT Timer Driver"); 1109 MODULE_LICENSE("GPL v2"); 1110