drivers/clocksource/sh_cmt.c

   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");