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/iopoll.h> 17 #include <linux/ioport.h> 18 #include <linux/irq.h> 19 #include <linux/module.h> 20 #include <linux/of.h> 21 #include <linux/of_device.h> 22 #include <linux/platform_device.h> 23 #include <linux/pm_domain.h> 24 #include <linux/pm_runtime.h> 25 #include <linux/sh_timer.h> 26 #include <linux/slab.h> 27 #include <linux/spinlock.h> 28 29 #ifdef CONFIG_SUPERH 30 #include <asm/platform_early.h> 31 #endif 32 33 struct sh_cmt_device; 34 35 /* 36 * The CMT comes in 5 different identified flavours, depending not only on the 37 * SoC but also on the particular instance. The following table lists the main 38 * characteristics of those flavours. 39 * 40 * 16B 32B 32B-F 48B R-Car Gen2 41 * ----------------------------------------------------------------------------- 42 * Channels 2 1/4 1 6 2/8 43 * Control Width 16 16 16 16 32 44 * Counter Width 16 32 32 32/48 32/48 45 * Shared Start/Stop Y Y Y Y N 46 * 47 * The r8a73a4 / R-Car Gen2 version has a per-channel start/stop register 48 * located in the channel registers block. All other versions have a shared 49 * start/stop register located in the global space. 50 * 51 * Channels are indexed from 0 to N-1 in the documentation. The channel index 52 * infers the start/stop bit position in the control register and the channel 53 * registers block address. Some CMT instances have a subset of channels 54 * available, in which case the index in the documentation doesn't match the 55 * "real" index as implemented in hardware. This is for instance the case with 56 * CMT0 on r8a7740, which is a 32-bit variant with a single channel numbered 0 57 * in the documentation but using start/stop bit 5 and having its registers 58 * block at 0x60. 59 * 60 * Similarly CMT0 on r8a73a4, r8a7790 and r8a7791, while implementing 32-bit 61 * channels only, is a 48-bit gen2 CMT with the 48-bit channels unavailable. 62 */ 63 64 enum sh_cmt_model { 65 SH_CMT_16BIT, 66 SH_CMT_32BIT, 67 SH_CMT_48BIT, 68 SH_CMT0_RCAR_GEN2, 69 SH_CMT1_RCAR_GEN2, 70 }; 71 72 struct sh_cmt_info { 73 enum sh_cmt_model model; 74 75 unsigned int channels_mask; 76 77 unsigned long width; /* 16 or 32 bit version of hardware block */ 78 u32 overflow_bit; 79 u32 clear_bits; 80 81 /* callbacks for CMSTR and CMCSR access */ 82 u32 (*read_control)(void __iomem *base, unsigned long offs); 83 void (*write_control)(void __iomem *base, unsigned long offs, 84 u32 value); 85 86 /* callbacks for CMCNT and CMCOR access */ 87 u32 (*read_count)(void __iomem *base, unsigned long offs); 88 void (*write_count)(void __iomem *base, unsigned long offs, u32 value); 89 }; 90 91 struct sh_cmt_channel { 92 struct sh_cmt_device *cmt; 93 94 unsigned int index; /* Index in the documentation */ 95 unsigned int hwidx; /* Real hardware index */ 96 97 void __iomem *iostart; 98 void __iomem *ioctrl; 99 100 unsigned int timer_bit; 101 unsigned long flags; 102 u32 match_value; 103 u32 next_match_value; 104 u32 max_match_value; 105 raw_spinlock_t lock; 106 struct clock_event_device ced; 107 struct clocksource cs; 108 u64 total_cycles; 109 bool cs_enabled; 110 }; 111 112 struct sh_cmt_device { 113 struct platform_device *pdev; 114 115 const struct sh_cmt_info *info; 116 117 void __iomem *mapbase; 118 struct clk *clk; 119 unsigned long rate; 120 unsigned int reg_delay; 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 u32 sh_cmt_read16(void __iomem *base, unsigned long offs) 161 { 162 return ioread16(base + (offs << 1)); 163 } 164 165 static u32 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, u32 value) 171 { 172 iowrite16(value, base + (offs << 1)); 173 } 174 175 static void sh_cmt_write32(void __iomem *base, unsigned long offs, u32 value) 176 { 177 iowrite32(value, base + (offs << 2)); 178 } 179 180 static const struct sh_cmt_info sh_cmt_info[] = { 181 [SH_CMT_16BIT] = { 182 .model = SH_CMT_16BIT, 183 .width = 16, 184 .overflow_bit = SH_CMT16_CMCSR_CMF, 185 .clear_bits = ~SH_CMT16_CMCSR_CMF, 186 .read_control = sh_cmt_read16, 187 .write_control = sh_cmt_write16, 188 .read_count = sh_cmt_read16, 189 .write_count = sh_cmt_write16, 190 }, 191 [SH_CMT_32BIT] = { 192 .model = SH_CMT_32BIT, 193 .width = 32, 194 .overflow_bit = SH_CMT32_CMCSR_CMF, 195 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 196 .read_control = sh_cmt_read16, 197 .write_control = sh_cmt_write16, 198 .read_count = sh_cmt_read32, 199 .write_count = sh_cmt_write32, 200 }, 201 [SH_CMT_48BIT] = { 202 .model = SH_CMT_48BIT, 203 .channels_mask = 0x3f, 204 .width = 32, 205 .overflow_bit = SH_CMT32_CMCSR_CMF, 206 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 207 .read_control = sh_cmt_read32, 208 .write_control = sh_cmt_write32, 209 .read_count = sh_cmt_read32, 210 .write_count = sh_cmt_write32, 211 }, 212 [SH_CMT0_RCAR_GEN2] = { 213 .model = SH_CMT0_RCAR_GEN2, 214 .channels_mask = 0x60, 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_CMT1_RCAR_GEN2] = { 224 .model = SH_CMT1_RCAR_GEN2, 225 .channels_mask = 0xff, 226 .width = 32, 227 .overflow_bit = SH_CMT32_CMCSR_CMF, 228 .clear_bits = ~(SH_CMT32_CMCSR_CMF | SH_CMT32_CMCSR_OVF), 229 .read_control = sh_cmt_read32, 230 .write_control = sh_cmt_write32, 231 .read_count = sh_cmt_read32, 232 .write_count = sh_cmt_write32, 233 }, 234 }; 235 236 #define CMCSR 0 /* channel register */ 237 #define CMCNT 1 /* channel register */ 238 #define CMCOR 2 /* channel register */ 239 240 #define CMCLKE 0x1000 /* CLK Enable Register (R-Car Gen2) */ 241 242 static inline u32 sh_cmt_read_cmstr(struct sh_cmt_channel *ch) 243 { 244 if (ch->iostart) 245 return ch->cmt->info->read_control(ch->iostart, 0); 246 else 247 return ch->cmt->info->read_control(ch->cmt->mapbase, 0); 248 } 249 250 static inline void sh_cmt_write_cmstr(struct sh_cmt_channel *ch, u32 value) 251 { 252 u32 old_value = sh_cmt_read_cmstr(ch); 253 254 if (value != old_value) { 255 if (ch->iostart) { 256 ch->cmt->info->write_control(ch->iostart, 0, value); 257 udelay(ch->cmt->reg_delay); 258 } else { 259 ch->cmt->info->write_control(ch->cmt->mapbase, 0, value); 260 udelay(ch->cmt->reg_delay); 261 } 262 } 263 } 264 265 static inline u32 sh_cmt_read_cmcsr(struct sh_cmt_channel *ch) 266 { 267 return ch->cmt->info->read_control(ch->ioctrl, CMCSR); 268 } 269 270 static inline void sh_cmt_write_cmcsr(struct sh_cmt_channel *ch, u32 value) 271 { 272 u32 old_value = sh_cmt_read_cmcsr(ch); 273 274 if (value != old_value) { 275 ch->cmt->info->write_control(ch->ioctrl, CMCSR, value); 276 udelay(ch->cmt->reg_delay); 277 } 278 } 279 280 static inline u32 sh_cmt_read_cmcnt(struct sh_cmt_channel *ch) 281 { 282 return ch->cmt->info->read_count(ch->ioctrl, CMCNT); 283 } 284 285 static inline int sh_cmt_write_cmcnt(struct sh_cmt_channel *ch, u32 value) 286 { 287 /* Tests showed that we need to wait 3 clocks here */ 288 unsigned int cmcnt_delay = DIV_ROUND_UP(3 * ch->cmt->reg_delay, 2); 289 u32 reg; 290 291 if (ch->cmt->info->model > SH_CMT_16BIT) { 292 int ret = read_poll_timeout_atomic(sh_cmt_read_cmcsr, reg, 293 !(reg & SH_CMT32_CMCSR_WRFLG), 294 1, cmcnt_delay, false, ch); 295 if (ret < 0) 296 return ret; 297 } 298 299 ch->cmt->info->write_count(ch->ioctrl, CMCNT, value); 300 udelay(cmcnt_delay); 301 return 0; 302 } 303 304 static inline void sh_cmt_write_cmcor(struct sh_cmt_channel *ch, u32 value) 305 { 306 u32 old_value = ch->cmt->info->read_count(ch->ioctrl, CMCOR); 307 308 if (value != old_value) { 309 ch->cmt->info->write_count(ch->ioctrl, CMCOR, value); 310 udelay(ch->cmt->reg_delay); 311 } 312 } 313 314 static u32 sh_cmt_get_counter(struct sh_cmt_channel *ch, u32 *has_wrapped) 315 { 316 u32 v1, v2, v3; 317 u32 o1, o2; 318 319 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit; 320 321 /* Make sure the timer value is stable. Stolen from acpi_pm.c */ 322 do { 323 o2 = o1; 324 v1 = sh_cmt_read_cmcnt(ch); 325 v2 = sh_cmt_read_cmcnt(ch); 326 v3 = sh_cmt_read_cmcnt(ch); 327 o1 = sh_cmt_read_cmcsr(ch) & ch->cmt->info->overflow_bit; 328 } while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3) 329 || (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2))); 330 331 *has_wrapped = o1; 332 return v2; 333 } 334 335 static void sh_cmt_start_stop_ch(struct sh_cmt_channel *ch, int start) 336 { 337 unsigned long flags; 338 u32 value; 339 340 /* start stop register shared by multiple timer channels */ 341 raw_spin_lock_irqsave(&ch->cmt->lock, flags); 342 value = sh_cmt_read_cmstr(ch); 343 344 if (start) 345 value |= 1 << ch->timer_bit; 346 else 347 value &= ~(1 << ch->timer_bit); 348 349 sh_cmt_write_cmstr(ch, value); 350 raw_spin_unlock_irqrestore(&ch->cmt->lock, flags); 351 } 352 353 static int sh_cmt_enable(struct sh_cmt_channel *ch) 354 { 355 int ret; 356 357 dev_pm_syscore_device(&ch->cmt->pdev->dev, true); 358 359 /* enable clock */ 360 ret = clk_enable(ch->cmt->clk); 361 if (ret) { 362 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot enable clock\n", 363 ch->index); 364 goto err0; 365 } 366 367 /* make sure channel is disabled */ 368 sh_cmt_start_stop_ch(ch, 0); 369 370 /* configure channel, periodic mode and maximum timeout */ 371 if (ch->cmt->info->width == 16) { 372 sh_cmt_write_cmcsr(ch, SH_CMT16_CMCSR_CMIE | 373 SH_CMT16_CMCSR_CKS512); 374 } else { 375 u32 cmtout = ch->cmt->info->model <= SH_CMT_48BIT ? 376 SH_CMT32_CMCSR_CMTOUT_IE : 0; 377 sh_cmt_write_cmcsr(ch, cmtout | SH_CMT32_CMCSR_CMM | 378 SH_CMT32_CMCSR_CMR_IRQ | 379 SH_CMT32_CMCSR_CKS_RCLK8); 380 } 381 382 sh_cmt_write_cmcor(ch, 0xffffffff); 383 ret = sh_cmt_write_cmcnt(ch, 0); 384 385 if (ret || sh_cmt_read_cmcnt(ch)) { 386 dev_err(&ch->cmt->pdev->dev, "ch%u: cannot clear CMCNT\n", 387 ch->index); 388 ret = -ETIMEDOUT; 389 goto err1; 390 } 391 392 /* enable channel */ 393 sh_cmt_start_stop_ch(ch, 1); 394 return 0; 395 err1: 396 /* stop clock */ 397 clk_disable(ch->cmt->clk); 398 399 err0: 400 return ret; 401 } 402 403 static void sh_cmt_disable(struct sh_cmt_channel *ch) 404 { 405 /* disable channel */ 406 sh_cmt_start_stop_ch(ch, 0); 407 408 /* disable interrupts in CMT block */ 409 sh_cmt_write_cmcsr(ch, 0); 410 411 /* stop clock */ 412 clk_disable(ch->cmt->clk); 413 414 dev_pm_syscore_device(&ch->cmt->pdev->dev, false); 415 } 416 417 /* private flags */ 418 #define FLAG_CLOCKEVENT (1 << 0) 419 #define FLAG_CLOCKSOURCE (1 << 1) 420 #define FLAG_REPROGRAM (1 << 2) 421 #define FLAG_SKIPEVENT (1 << 3) 422 #define FLAG_IRQCONTEXT (1 << 4) 423 424 static void sh_cmt_clock_event_program_verify(struct sh_cmt_channel *ch, 425 int absolute) 426 { 427 u32 value = ch->next_match_value; 428 u32 new_match; 429 u32 delay = 0; 430 u32 now = 0; 431 u32 has_wrapped; 432 433 now = sh_cmt_get_counter(ch, &has_wrapped); 434 ch->flags |= FLAG_REPROGRAM; /* force reprogram */ 435 436 if (has_wrapped) { 437 /* we're competing with the interrupt handler. 438 * -> let the interrupt handler reprogram the timer. 439 * -> interrupt number two handles the event. 440 */ 441 ch->flags |= FLAG_SKIPEVENT; 442 return; 443 } 444 445 if (absolute) 446 now = 0; 447 448 do { 449 /* reprogram the timer hardware, 450 * but don't save the new match value yet. 451 */ 452 new_match = now + value + delay; 453 if (new_match > ch->max_match_value) 454 new_match = ch->max_match_value; 455 456 sh_cmt_write_cmcor(ch, new_match); 457 458 now = sh_cmt_get_counter(ch, &has_wrapped); 459 if (has_wrapped && (new_match > ch->match_value)) { 460 /* we are changing to a greater match value, 461 * so this wrap must be caused by the counter 462 * matching the old value. 463 * -> first interrupt reprograms the timer. 464 * -> interrupt number two handles the event. 465 */ 466 ch->flags |= FLAG_SKIPEVENT; 467 break; 468 } 469 470 if (has_wrapped) { 471 /* we are changing to a smaller match value, 472 * so the wrap must be caused by the counter 473 * matching the new value. 474 * -> save programmed match value. 475 * -> let isr handle the event. 476 */ 477 ch->match_value = new_match; 478 break; 479 } 480 481 /* be safe: verify hardware settings */ 482 if (now < new_match) { 483 /* timer value is below match value, all good. 484 * this makes sure we won't miss any match events. 485 * -> save programmed match value. 486 * -> let isr handle the event. 487 */ 488 ch->match_value = new_match; 489 break; 490 } 491 492 /* the counter has reached a value greater 493 * than our new match value. and since the 494 * has_wrapped flag isn't set we must have 495 * programmed a too close event. 496 * -> increase delay and retry. 497 */ 498 if (delay) 499 delay <<= 1; 500 else 501 delay = 1; 502 503 if (!delay) 504 dev_warn(&ch->cmt->pdev->dev, "ch%u: too long delay\n", 505 ch->index); 506 507 } while (delay); 508 } 509 510 static void __sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta) 511 { 512 if (delta > ch->max_match_value) 513 dev_warn(&ch->cmt->pdev->dev, "ch%u: delta out of range\n", 514 ch->index); 515 516 ch->next_match_value = delta; 517 sh_cmt_clock_event_program_verify(ch, 0); 518 } 519 520 static void sh_cmt_set_next(struct sh_cmt_channel *ch, unsigned long delta) 521 { 522 unsigned long flags; 523 524 raw_spin_lock_irqsave(&ch->lock, flags); 525 __sh_cmt_set_next(ch, delta); 526 raw_spin_unlock_irqrestore(&ch->lock, flags); 527 } 528 529 static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id) 530 { 531 struct sh_cmt_channel *ch = dev_id; 532 533 /* clear flags */ 534 sh_cmt_write_cmcsr(ch, sh_cmt_read_cmcsr(ch) & 535 ch->cmt->info->clear_bits); 536 537 /* update clock source counter to begin with if enabled 538 * the wrap flag should be cleared by the timer specific 539 * isr before we end up here. 540 */ 541 if (ch->flags & FLAG_CLOCKSOURCE) 542 ch->total_cycles += ch->match_value + 1; 543 544 if (!(ch->flags & FLAG_REPROGRAM)) 545 ch->next_match_value = ch->max_match_value; 546 547 ch->flags |= FLAG_IRQCONTEXT; 548 549 if (ch->flags & FLAG_CLOCKEVENT) { 550 if (!(ch->flags & FLAG_SKIPEVENT)) { 551 if (clockevent_state_oneshot(&ch->ced)) { 552 ch->next_match_value = ch->max_match_value; 553 ch->flags |= FLAG_REPROGRAM; 554 } 555 556 ch->ced.event_handler(&ch->ced); 557 } 558 } 559 560 ch->flags &= ~FLAG_SKIPEVENT; 561 562 if (ch->flags & FLAG_REPROGRAM) { 563 ch->flags &= ~FLAG_REPROGRAM; 564 sh_cmt_clock_event_program_verify(ch, 1); 565 566 if (ch->flags & FLAG_CLOCKEVENT) 567 if ((clockevent_state_shutdown(&ch->ced)) 568 || (ch->match_value == ch->next_match_value)) 569 ch->flags &= ~FLAG_REPROGRAM; 570 } 571 572 ch->flags &= ~FLAG_IRQCONTEXT; 573 574 return IRQ_HANDLED; 575 } 576 577 static int sh_cmt_start(struct sh_cmt_channel *ch, unsigned long flag) 578 { 579 int ret = 0; 580 unsigned long flags; 581 582 if (flag & FLAG_CLOCKSOURCE) 583 pm_runtime_get_sync(&ch->cmt->pdev->dev); 584 585 raw_spin_lock_irqsave(&ch->lock, flags); 586 587 if (!(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) { 588 if (flag & FLAG_CLOCKEVENT) 589 pm_runtime_get_sync(&ch->cmt->pdev->dev); 590 ret = sh_cmt_enable(ch); 591 } 592 593 if (ret) 594 goto out; 595 ch->flags |= flag; 596 597 /* setup timeout if no clockevent */ 598 if (ch->cmt->num_channels == 1 && 599 flag == FLAG_CLOCKSOURCE && (!(ch->flags & FLAG_CLOCKEVENT))) 600 __sh_cmt_set_next(ch, ch->max_match_value); 601 out: 602 raw_spin_unlock_irqrestore(&ch->lock, flags); 603 604 return ret; 605 } 606 607 static void sh_cmt_stop(struct sh_cmt_channel *ch, unsigned long flag) 608 { 609 unsigned long flags; 610 unsigned long f; 611 612 raw_spin_lock_irqsave(&ch->lock, flags); 613 614 f = ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE); 615 ch->flags &= ~flag; 616 617 if (f && !(ch->flags & (FLAG_CLOCKEVENT | FLAG_CLOCKSOURCE))) { 618 sh_cmt_disable(ch); 619 if (flag & FLAG_CLOCKEVENT) 620 pm_runtime_put(&ch->cmt->pdev->dev); 621 } 622 623 /* adjust the timeout to maximum if only clocksource left */ 624 if ((flag == FLAG_CLOCKEVENT) && (ch->flags & FLAG_CLOCKSOURCE)) 625 __sh_cmt_set_next(ch, ch->max_match_value); 626 627 raw_spin_unlock_irqrestore(&ch->lock, flags); 628 629 if (flag & FLAG_CLOCKSOURCE) 630 pm_runtime_put(&ch->cmt->pdev->dev); 631 } 632 633 static struct sh_cmt_channel *cs_to_sh_cmt(struct clocksource *cs) 634 { 635 return container_of(cs, struct sh_cmt_channel, cs); 636 } 637 638 static u64 sh_cmt_clocksource_read(struct clocksource *cs) 639 { 640 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 641 u32 has_wrapped; 642 643 if (ch->cmt->num_channels == 1) { 644 unsigned long flags; 645 u64 value; 646 u32 raw; 647 648 raw_spin_lock_irqsave(&ch->lock, flags); 649 value = ch->total_cycles; 650 raw = sh_cmt_get_counter(ch, &has_wrapped); 651 652 if (unlikely(has_wrapped)) 653 raw += ch->match_value + 1; 654 raw_spin_unlock_irqrestore(&ch->lock, flags); 655 656 return value + raw; 657 } 658 659 return sh_cmt_get_counter(ch, &has_wrapped); 660 } 661 662 static int sh_cmt_clocksource_enable(struct clocksource *cs) 663 { 664 int ret; 665 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 666 667 WARN_ON(ch->cs_enabled); 668 669 ch->total_cycles = 0; 670 671 ret = sh_cmt_start(ch, FLAG_CLOCKSOURCE); 672 if (!ret) 673 ch->cs_enabled = true; 674 675 return ret; 676 } 677 678 static void sh_cmt_clocksource_disable(struct clocksource *cs) 679 { 680 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 681 682 WARN_ON(!ch->cs_enabled); 683 684 sh_cmt_stop(ch, FLAG_CLOCKSOURCE); 685 ch->cs_enabled = false; 686 } 687 688 static void sh_cmt_clocksource_suspend(struct clocksource *cs) 689 { 690 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 691 692 if (!ch->cs_enabled) 693 return; 694 695 sh_cmt_stop(ch, FLAG_CLOCKSOURCE); 696 dev_pm_genpd_suspend(&ch->cmt->pdev->dev); 697 } 698 699 static void sh_cmt_clocksource_resume(struct clocksource *cs) 700 { 701 struct sh_cmt_channel *ch = cs_to_sh_cmt(cs); 702 703 if (!ch->cs_enabled) 704 return; 705 706 dev_pm_genpd_resume(&ch->cmt->pdev->dev); 707 sh_cmt_start(ch, FLAG_CLOCKSOURCE); 708 } 709 710 static int sh_cmt_register_clocksource(struct sh_cmt_channel *ch, 711 const char *name) 712 { 713 struct clocksource *cs = &ch->cs; 714 715 cs->name = name; 716 cs->rating = 125; 717 cs->read = sh_cmt_clocksource_read; 718 cs->enable = sh_cmt_clocksource_enable; 719 cs->disable = sh_cmt_clocksource_disable; 720 cs->suspend = sh_cmt_clocksource_suspend; 721 cs->resume = sh_cmt_clocksource_resume; 722 cs->mask = CLOCKSOURCE_MASK(ch->cmt->info->width); 723 cs->flags = CLOCK_SOURCE_IS_CONTINUOUS; 724 725 dev_info(&ch->cmt->pdev->dev, "ch%u: used as clock source\n", 726 ch->index); 727 728 clocksource_register_hz(cs, ch->cmt->rate); 729 return 0; 730 } 731 732 static struct sh_cmt_channel *ced_to_sh_cmt(struct clock_event_device *ced) 733 { 734 return container_of(ced, struct sh_cmt_channel, ced); 735 } 736 737 static void sh_cmt_clock_event_start(struct sh_cmt_channel *ch, int periodic) 738 { 739 sh_cmt_start(ch, FLAG_CLOCKEVENT); 740 741 if (periodic) 742 sh_cmt_set_next(ch, ((ch->cmt->rate + HZ/2) / HZ) - 1); 743 else 744 sh_cmt_set_next(ch, ch->max_match_value); 745 } 746 747 static int sh_cmt_clock_event_shutdown(struct clock_event_device *ced) 748 { 749 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 750 751 sh_cmt_stop(ch, FLAG_CLOCKEVENT); 752 return 0; 753 } 754 755 static int sh_cmt_clock_event_set_state(struct clock_event_device *ced, 756 int periodic) 757 { 758 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 759 760 /* deal with old setting first */ 761 if (clockevent_state_oneshot(ced) || clockevent_state_periodic(ced)) 762 sh_cmt_stop(ch, FLAG_CLOCKEVENT); 763 764 dev_info(&ch->cmt->pdev->dev, "ch%u: used for %s clock events\n", 765 ch->index, periodic ? "periodic" : "oneshot"); 766 sh_cmt_clock_event_start(ch, periodic); 767 return 0; 768 } 769 770 static int sh_cmt_clock_event_set_oneshot(struct clock_event_device *ced) 771 { 772 return sh_cmt_clock_event_set_state(ced, 0); 773 } 774 775 static int sh_cmt_clock_event_set_periodic(struct clock_event_device *ced) 776 { 777 return sh_cmt_clock_event_set_state(ced, 1); 778 } 779 780 static int sh_cmt_clock_event_next(unsigned long delta, 781 struct clock_event_device *ced) 782 { 783 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 784 785 BUG_ON(!clockevent_state_oneshot(ced)); 786 if (likely(ch->flags & FLAG_IRQCONTEXT)) 787 ch->next_match_value = delta - 1; 788 else 789 sh_cmt_set_next(ch, delta - 1); 790 791 return 0; 792 } 793 794 static void sh_cmt_clock_event_suspend(struct clock_event_device *ced) 795 { 796 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 797 798 dev_pm_genpd_suspend(&ch->cmt->pdev->dev); 799 clk_unprepare(ch->cmt->clk); 800 } 801 802 static void sh_cmt_clock_event_resume(struct clock_event_device *ced) 803 { 804 struct sh_cmt_channel *ch = ced_to_sh_cmt(ced); 805 806 clk_prepare(ch->cmt->clk); 807 dev_pm_genpd_resume(&ch->cmt->pdev->dev); 808 } 809 810 static int sh_cmt_register_clockevent(struct sh_cmt_channel *ch, 811 const char *name) 812 { 813 struct clock_event_device *ced = &ch->ced; 814 int irq; 815 int ret; 816 817 irq = platform_get_irq(ch->cmt->pdev, ch->index); 818 if (irq < 0) 819 return irq; 820 821 ret = request_irq(irq, sh_cmt_interrupt, 822 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING, 823 dev_name(&ch->cmt->pdev->dev), ch); 824 if (ret) { 825 dev_err(&ch->cmt->pdev->dev, "ch%u: failed to request irq %d\n", 826 ch->index, irq); 827 return ret; 828 } 829 830 ced->name = name; 831 ced->features = CLOCK_EVT_FEAT_PERIODIC; 832 ced->features |= CLOCK_EVT_FEAT_ONESHOT; 833 ced->rating = 125; 834 ced->cpumask = cpu_possible_mask; 835 ced->set_next_event = sh_cmt_clock_event_next; 836 ced->set_state_shutdown = sh_cmt_clock_event_shutdown; 837 ced->set_state_periodic = sh_cmt_clock_event_set_periodic; 838 ced->set_state_oneshot = sh_cmt_clock_event_set_oneshot; 839 ced->suspend = sh_cmt_clock_event_suspend; 840 ced->resume = sh_cmt_clock_event_resume; 841 842 /* TODO: calculate good shift from rate and counter bit width */ 843 ced->shift = 32; 844 ced->mult = div_sc(ch->cmt->rate, NSEC_PER_SEC, ced->shift); 845 ced->max_delta_ns = clockevent_delta2ns(ch->max_match_value, ced); 846 ced->max_delta_ticks = ch->max_match_value; 847 ced->min_delta_ns = clockevent_delta2ns(0x1f, ced); 848 ced->min_delta_ticks = 0x1f; 849 850 dev_info(&ch->cmt->pdev->dev, "ch%u: used for clock events\n", 851 ch->index); 852 clockevents_register_device(ced); 853 854 return 0; 855 } 856 857 static int sh_cmt_register(struct sh_cmt_channel *ch, const char *name, 858 bool clockevent, bool clocksource) 859 { 860 int ret; 861 862 if (clockevent) { 863 ch->cmt->has_clockevent = true; 864 ret = sh_cmt_register_clockevent(ch, name); 865 if (ret < 0) 866 return ret; 867 } 868 869 if (clocksource) { 870 ch->cmt->has_clocksource = true; 871 sh_cmt_register_clocksource(ch, name); 872 } 873 874 return 0; 875 } 876 877 static int sh_cmt_setup_channel(struct sh_cmt_channel *ch, unsigned int index, 878 unsigned int hwidx, bool clockevent, 879 bool clocksource, struct sh_cmt_device *cmt) 880 { 881 u32 value; 882 int ret; 883 884 /* Skip unused channels. */ 885 if (!clockevent && !clocksource) 886 return 0; 887 888 ch->cmt = cmt; 889 ch->index = index; 890 ch->hwidx = hwidx; 891 ch->timer_bit = hwidx; 892 893 /* 894 * Compute the address of the channel control register block. For the 895 * timers with a per-channel start/stop register, compute its address 896 * as well. 897 */ 898 switch (cmt->info->model) { 899 case SH_CMT_16BIT: 900 ch->ioctrl = cmt->mapbase + 2 + ch->hwidx * 6; 901 break; 902 case SH_CMT_32BIT: 903 case SH_CMT_48BIT: 904 ch->ioctrl = cmt->mapbase + 0x10 + ch->hwidx * 0x10; 905 break; 906 case SH_CMT0_RCAR_GEN2: 907 case SH_CMT1_RCAR_GEN2: 908 ch->iostart = cmt->mapbase + ch->hwidx * 0x100; 909 ch->ioctrl = ch->iostart + 0x10; 910 ch->timer_bit = 0; 911 912 /* Enable the clock supply to the channel */ 913 value = ioread32(cmt->mapbase + CMCLKE); 914 value |= BIT(hwidx); 915 iowrite32(value, cmt->mapbase + CMCLKE); 916 break; 917 } 918 919 if (cmt->info->width == (sizeof(ch->max_match_value) * 8)) 920 ch->max_match_value = ~0; 921 else 922 ch->max_match_value = (1 << cmt->info->width) - 1; 923 924 ch->match_value = ch->max_match_value; 925 raw_spin_lock_init(&ch->lock); 926 927 ret = sh_cmt_register(ch, dev_name(&cmt->pdev->dev), 928 clockevent, clocksource); 929 if (ret) { 930 dev_err(&cmt->pdev->dev, "ch%u: registration failed\n", 931 ch->index); 932 return ret; 933 } 934 ch->cs_enabled = false; 935 936 return 0; 937 } 938 939 static int sh_cmt_map_memory(struct sh_cmt_device *cmt) 940 { 941 struct resource *mem; 942 943 mem = platform_get_resource(cmt->pdev, IORESOURCE_MEM, 0); 944 if (!mem) { 945 dev_err(&cmt->pdev->dev, "failed to get I/O memory\n"); 946 return -ENXIO; 947 } 948 949 cmt->mapbase = ioremap(mem->start, resource_size(mem)); 950 if (cmt->mapbase == NULL) { 951 dev_err(&cmt->pdev->dev, "failed to remap I/O memory\n"); 952 return -ENXIO; 953 } 954 955 return 0; 956 } 957 958 static const struct platform_device_id sh_cmt_id_table[] = { 959 { "sh-cmt-16", (kernel_ulong_t)&sh_cmt_info[SH_CMT_16BIT] }, 960 { "sh-cmt-32", (kernel_ulong_t)&sh_cmt_info[SH_CMT_32BIT] }, 961 { } 962 }; 963 MODULE_DEVICE_TABLE(platform, sh_cmt_id_table); 964 965 static const struct of_device_id sh_cmt_of_table[] __maybe_unused = { 966 { 967 /* deprecated, preserved for backward compatibility */ 968 .compatible = "renesas,cmt-48", 969 .data = &sh_cmt_info[SH_CMT_48BIT] 970 }, 971 { 972 /* deprecated, preserved for backward compatibility */ 973 .compatible = "renesas,cmt-48-gen2", 974 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2] 975 }, 976 { 977 .compatible = "renesas,r8a7740-cmt1", 978 .data = &sh_cmt_info[SH_CMT_48BIT] 979 }, 980 { 981 .compatible = "renesas,sh73a0-cmt1", 982 .data = &sh_cmt_info[SH_CMT_48BIT] 983 }, 984 { 985 .compatible = "renesas,rcar-gen2-cmt0", 986 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2] 987 }, 988 { 989 .compatible = "renesas,rcar-gen2-cmt1", 990 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2] 991 }, 992 { 993 .compatible = "renesas,rcar-gen3-cmt0", 994 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2] 995 }, 996 { 997 .compatible = "renesas,rcar-gen3-cmt1", 998 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2] 999 }, 1000 { 1001 .compatible = "renesas,rcar-gen4-cmt0", 1002 .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2] 1003 }, 1004 { 1005 .compatible = "renesas,rcar-gen4-cmt1", 1006 .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2] 1007 }, 1008 { } 1009 }; 1010 MODULE_DEVICE_TABLE(of, sh_cmt_of_table); 1011 1012 static int sh_cmt_setup(struct sh_cmt_device *cmt, struct platform_device *pdev) 1013 { 1014 unsigned int mask, i; 1015 unsigned long rate; 1016 int ret; 1017 1018 cmt->pdev = pdev; 1019 raw_spin_lock_init(&cmt->lock); 1020 1021 if (IS_ENABLED(CONFIG_OF) && pdev->dev.of_node) { 1022 cmt->info = of_device_get_match_data(&pdev->dev); 1023 cmt->hw_channels = cmt->info->channels_mask; 1024 } else if (pdev->dev.platform_data) { 1025 struct sh_timer_config *cfg = pdev->dev.platform_data; 1026 const struct platform_device_id *id = pdev->id_entry; 1027 1028 cmt->info = (const struct sh_cmt_info *)id->driver_data; 1029 cmt->hw_channels = cfg->channels_mask; 1030 } else { 1031 dev_err(&cmt->pdev->dev, "missing platform data\n"); 1032 return -ENXIO; 1033 } 1034 1035 /* Get hold of clock. */ 1036 cmt->clk = clk_get(&cmt->pdev->dev, "fck"); 1037 if (IS_ERR(cmt->clk)) { 1038 dev_err(&cmt->pdev->dev, "cannot get clock\n"); 1039 return PTR_ERR(cmt->clk); 1040 } 1041 1042 ret = clk_prepare(cmt->clk); 1043 if (ret < 0) 1044 goto err_clk_put; 1045 1046 /* Determine clock rate. */ 1047 ret = clk_enable(cmt->clk); 1048 if (ret < 0) 1049 goto err_clk_unprepare; 1050 1051 rate = clk_get_rate(cmt->clk); 1052 if (!rate) { 1053 ret = -EINVAL; 1054 goto err_clk_disable; 1055 } 1056 1057 /* We shall wait 2 input clks after register writes */ 1058 if (cmt->info->model >= SH_CMT_48BIT) 1059 cmt->reg_delay = DIV_ROUND_UP(2UL * USEC_PER_SEC, rate); 1060 cmt->rate = rate / (cmt->info->width == 16 ? 512 : 8); 1061 1062 /* Map the memory resource(s). */ 1063 ret = sh_cmt_map_memory(cmt); 1064 if (ret < 0) 1065 goto err_clk_disable; 1066 1067 /* Allocate and setup the channels. */ 1068 cmt->num_channels = hweight8(cmt->hw_channels); 1069 cmt->channels = kcalloc(cmt->num_channels, sizeof(*cmt->channels), 1070 GFP_KERNEL); 1071 if (cmt->channels == NULL) { 1072 ret = -ENOMEM; 1073 goto err_unmap; 1074 } 1075 1076 /* 1077 * Use the first channel as a clock event device and the second channel 1078 * as a clock source. If only one channel is available use it for both. 1079 */ 1080 for (i = 0, mask = cmt->hw_channels; i < cmt->num_channels; ++i) { 1081 unsigned int hwidx = ffs(mask) - 1; 1082 bool clocksource = i == 1 || cmt->num_channels == 1; 1083 bool clockevent = i == 0; 1084 1085 ret = sh_cmt_setup_channel(&cmt->channels[i], i, hwidx, 1086 clockevent, clocksource, cmt); 1087 if (ret < 0) 1088 goto err_unmap; 1089 1090 mask &= ~(1 << hwidx); 1091 } 1092 1093 clk_disable(cmt->clk); 1094 1095 platform_set_drvdata(pdev, cmt); 1096 1097 return 0; 1098 1099 err_unmap: 1100 kfree(cmt->channels); 1101 iounmap(cmt->mapbase); 1102 err_clk_disable: 1103 clk_disable(cmt->clk); 1104 err_clk_unprepare: 1105 clk_unprepare(cmt->clk); 1106 err_clk_put: 1107 clk_put(cmt->clk); 1108 return ret; 1109 } 1110 1111 static int sh_cmt_probe(struct platform_device *pdev) 1112 { 1113 struct sh_cmt_device *cmt = platform_get_drvdata(pdev); 1114 int ret; 1115 1116 if (!is_sh_early_platform_device(pdev)) { 1117 pm_runtime_set_active(&pdev->dev); 1118 pm_runtime_enable(&pdev->dev); 1119 } 1120 1121 if (cmt) { 1122 dev_info(&pdev->dev, "kept as earlytimer\n"); 1123 goto out; 1124 } 1125 1126 cmt = kzalloc(sizeof(*cmt), GFP_KERNEL); 1127 if (cmt == NULL) 1128 return -ENOMEM; 1129 1130 ret = sh_cmt_setup(cmt, pdev); 1131 if (ret) { 1132 kfree(cmt); 1133 pm_runtime_idle(&pdev->dev); 1134 return ret; 1135 } 1136 if (is_sh_early_platform_device(pdev)) 1137 return 0; 1138 1139 out: 1140 if (cmt->has_clockevent || cmt->has_clocksource) 1141 pm_runtime_irq_safe(&pdev->dev); 1142 else 1143 pm_runtime_idle(&pdev->dev); 1144 1145 return 0; 1146 } 1147 1148 static struct platform_driver sh_cmt_device_driver = { 1149 .probe = sh_cmt_probe, 1150 .driver = { 1151 .name = "sh_cmt", 1152 .of_match_table = of_match_ptr(sh_cmt_of_table), 1153 .suppress_bind_attrs = true, 1154 }, 1155 .id_table = sh_cmt_id_table, 1156 }; 1157 1158 static int __init sh_cmt_init(void) 1159 { 1160 return platform_driver_register(&sh_cmt_device_driver); 1161 } 1162 1163 static void __exit sh_cmt_exit(void) 1164 { 1165 platform_driver_unregister(&sh_cmt_device_driver); 1166 } 1167 1168 #ifdef CONFIG_SUPERH 1169 sh_early_platform_init("earlytimer", &sh_cmt_device_driver); 1170 #endif 1171 1172 subsys_initcall(sh_cmt_init); 1173 module_exit(sh_cmt_exit); 1174 1175 MODULE_AUTHOR("Magnus Damm"); 1176 MODULE_DESCRIPTION("SuperH CMT Timer Driver"); 1177