drivers/clocksource/sh_mtu2.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * SuperH Timer Support - MTU2
   4  *
   5  *  Copyright (C) 2009 Magnus Damm
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/clockchips.h>
  10 #include <linux/delay.h>
  11 #include <linux/err.h>
  12 #include <linux/init.h>
  13 #include <linux/interrupt.h>
  14 #include <linux/io.h>
  15 #include <linux/ioport.h>
  16 #include <linux/irq.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/pm_domain.h>
  21 #include <linux/pm_runtime.h>
  22 #include <linux/sh_timer.h>
  23 #include <linux/slab.h>
  24 #include <linux/spinlock.h>
  25
  26 struct sh_mtu2_device;
  27
  28 struct sh_mtu2_channel {
  29         struct sh_mtu2_device *mtu;
  30         unsigned int index;
  31
  32         void __iomem *base;
  33
  34         struct clock_event_device ced;
  35 };
  36
  37 struct sh_mtu2_device {
  38         struct platform_device *pdev;
  39
  40         void __iomem *mapbase;
  41         struct clk *clk;
  42
  43         raw_spinlock_t lock; /* Protect the shared registers */
  44
  45         struct sh_mtu2_channel *channels;
  46         unsigned int num_channels;
  47
  48         bool has_clockevent;
  49 };
  50
  51 #define TSTR -1 /* shared register */
  52 #define TCR  0 /* channel register */
  53 #define TMDR 1 /* channel register */
  54 #define TIOR 2 /* channel register */
  55 #define TIER 3 /* channel register */
  56 #define TSR  4 /* channel register */
  57 #define TCNT 5 /* channel register */
  58 #define TGR  6 /* channel register */
  59
  60 #define TCR_CCLR_NONE           (0 << 5)
  61 #define TCR_CCLR_TGRA           (1 << 5)
  62 #define TCR_CCLR_TGRB           (2 << 5)
  63 #define TCR_CCLR_SYNC           (3 << 5)
  64 #define TCR_CCLR_TGRC           (5 << 5)
  65 #define TCR_CCLR_TGRD           (6 << 5)
  66 #define TCR_CCLR_MASK           (7 << 5)
  67 #define TCR_CKEG_RISING         (0 << 3)
  68 #define TCR_CKEG_FALLING        (1 << 3)
  69 #define TCR_CKEG_BOTH           (2 << 3)
  70 #define TCR_CKEG_MASK           (3 << 3)
  71 /* Values 4 to 7 are channel-dependent */
  72 #define TCR_TPSC_P1             (0 << 0)
  73 #define TCR_TPSC_P4             (1 << 0)
  74 #define TCR_TPSC_P16            (2 << 0)
  75 #define TCR_TPSC_P64            (3 << 0)
  76 #define TCR_TPSC_CH0_TCLKA      (4 << 0)
  77 #define TCR_TPSC_CH0_TCLKB      (5 << 0)
  78 #define TCR_TPSC_CH0_TCLKC      (6 << 0)
  79 #define TCR_TPSC_CH0_TCLKD      (7 << 0)
  80 #define TCR_TPSC_CH1_TCLKA      (4 << 0)
  81 #define TCR_TPSC_CH1_TCLKB      (5 << 0)
  82 #define TCR_TPSC_CH1_P256       (6 << 0)
  83 #define TCR_TPSC_CH1_TCNT2      (7 << 0)
  84 #define TCR_TPSC_CH2_TCLKA      (4 << 0)
  85 #define TCR_TPSC_CH2_TCLKB      (5 << 0)
  86 #define TCR_TPSC_CH2_TCLKC      (6 << 0)
  87 #define TCR_TPSC_CH2_P1024      (7 << 0)
  88 #define TCR_TPSC_CH34_P256      (4 << 0)
  89 #define TCR_TPSC_CH34_P1024     (5 << 0)
  90 #define TCR_TPSC_CH34_TCLKA     (6 << 0)
  91 #define TCR_TPSC_CH34_TCLKB     (7 << 0)
  92 #define TCR_TPSC_MASK           (7 << 0)
  93
  94 #define TMDR_BFE                (1 << 6)
  95 #define TMDR_BFB                (1 << 5)
  96 #define TMDR_BFA                (1 << 4)
  97 #define TMDR_MD_NORMAL          (0 << 0)
  98 #define TMDR_MD_PWM_1           (2 << 0)
  99 #define TMDR_MD_PWM_2           (3 << 0)
 100 #define TMDR_MD_PHASE_1         (4 << 0)
 101 #define TMDR_MD_PHASE_2         (5 << 0)
 102 #define TMDR_MD_PHASE_3         (6 << 0)
 103 #define TMDR_MD_PHASE_4         (7 << 0)
 104 #define TMDR_MD_PWM_SYNC        (8 << 0)
 105 #define TMDR_MD_PWM_COMP_CREST  (13 << 0)
 106 #define TMDR_MD_PWM_COMP_TROUGH (14 << 0)
 107 #define TMDR_MD_PWM_COMP_BOTH   (15 << 0)
 108 #define TMDR_MD_MASK            (15 << 0)
 109
 110 #define TIOC_IOCH(n)            ((n) << 4)
 111 #define TIOC_IOCL(n)            ((n) << 0)
 112 #define TIOR_OC_RETAIN          (0 << 0)
 113 #define TIOR_OC_0_CLEAR         (1 << 0)
 114 #define TIOR_OC_0_SET           (2 << 0)
 115 #define TIOR_OC_0_TOGGLE        (3 << 0)
 116 #define TIOR_OC_1_CLEAR         (5 << 0)
 117 #define TIOR_OC_1_SET           (6 << 0)
 118 #define TIOR_OC_1_TOGGLE        (7 << 0)
 119 #define TIOR_IC_RISING          (8 << 0)
 120 #define TIOR_IC_FALLING         (9 << 0)
 121 #define TIOR_IC_BOTH            (10 << 0)
 122 #define TIOR_IC_TCNT            (12 << 0)
 123 #define TIOR_MASK               (15 << 0)
 124
 125 #define TIER_TTGE               (1 << 7)
 126 #define TIER_TTGE2              (1 << 6)
 127 #define TIER_TCIEU              (1 << 5)
 128 #define TIER_TCIEV              (1 << 4)
 129 #define TIER_TGIED              (1 << 3)
 130 #define TIER_TGIEC              (1 << 2)
 131 #define TIER_TGIEB              (1 << 1)
 132 #define TIER_TGIEA              (1 << 0)
 133
 134 #define TSR_TCFD                (1 << 7)
 135 #define TSR_TCFU                (1 << 5)
 136 #define TSR_TCFV                (1 << 4)
 137 #define TSR_TGFD                (1 << 3)
 138 #define TSR_TGFC                (1 << 2)
 139 #define TSR_TGFB                (1 << 1)
 140 #define TSR_TGFA                (1 << 0)
 141
 142 static unsigned long mtu2_reg_offs[] = {
 143         [TCR] = 0,
 144         [TMDR] = 1,
 145         [TIOR] = 2,
 146         [TIER] = 4,
 147         [TSR] = 5,
 148         [TCNT] = 6,
 149         [TGR] = 8,
 150 };
 151
 152 static inline unsigned long sh_mtu2_read(struct sh_mtu2_channel *ch, int reg_nr)
 153 {
 154         unsigned long offs;
 155
 156         if (reg_nr == TSTR)
 157                 return ioread8(ch->mtu->mapbase + 0x280);
 158
 159         offs = mtu2_reg_offs[reg_nr];
 160
 161         if ((reg_nr == TCNT) || (reg_nr == TGR))
 162                 return ioread16(ch->base + offs);
 163         else
 164                 return ioread8(ch->base + offs);
 165 }
 166
 167 static inline void sh_mtu2_write(struct sh_mtu2_channel *ch, int reg_nr,
 168                                 unsigned long value)
 169 {
 170         unsigned long offs;
 171
 172         if (reg_nr == TSTR)
 173                 return iowrite8(value, ch->mtu->mapbase + 0x280);
 174
 175         offs = mtu2_reg_offs[reg_nr];
 176
 177         if ((reg_nr == TCNT) || (reg_nr == TGR))
 178                 iowrite16(value, ch->base + offs);
 179         else
 180                 iowrite8(value, ch->base + offs);
 181 }
 182
 183 static void sh_mtu2_start_stop_ch(struct sh_mtu2_channel *ch, int start)
 184 {
 185         unsigned long flags, value;
 186
 187         /* start stop register shared by multiple timer channels */
 188         raw_spin_lock_irqsave(&ch->mtu->lock, flags);
 189         value = sh_mtu2_read(ch, TSTR);
 190
 191         if (start)
 192                 value |= 1 << ch->index;
 193         else
 194                 value &= ~(1 << ch->index);
 195
 196         sh_mtu2_write(ch, TSTR, value);
 197         raw_spin_unlock_irqrestore(&ch->mtu->lock, flags);
 198 }
 199
 200 static int sh_mtu2_enable(struct sh_mtu2_channel *ch)
 201 {
 202         unsigned long periodic;
 203         unsigned long rate;
 204         int ret;
 205
 206         pm_runtime_get_sync(&ch->mtu->pdev->dev);
 207         dev_pm_syscore_device(&ch->mtu->pdev->dev, true);
 208
 209         /* enable clock */
 210         ret = clk_enable(ch->mtu->clk);
 211         if (ret) {
 212                 dev_err(&ch->mtu->pdev->dev, "ch%u: cannot enable clock\n",
 213                         ch->index);
 214                 return ret;
 215         }
 216
 217         /* make sure channel is disabled */
 218         sh_mtu2_start_stop_ch(ch, 0);
 219
 220         rate = clk_get_rate(ch->mtu->clk) / 64;
 221         periodic = (rate + HZ/2) / HZ;
 222
 223         /*
 224          * "Periodic Counter Operation"
 225          * Clear on TGRA compare match, divide clock by 64.
 226          */
 227         sh_mtu2_write(ch, TCR, TCR_CCLR_TGRA | TCR_TPSC_P64);
 228         sh_mtu2_write(ch, TIOR, TIOC_IOCH(TIOR_OC_0_CLEAR) |
 229                       TIOC_IOCL(TIOR_OC_0_CLEAR));
 230         sh_mtu2_write(ch, TGR, periodic);
 231         sh_mtu2_write(ch, TCNT, 0);
 232         sh_mtu2_write(ch, TMDR, TMDR_MD_NORMAL);
 233         sh_mtu2_write(ch, TIER, TIER_TGIEA);
 234
 235         /* enable channel */
 236         sh_mtu2_start_stop_ch(ch, 1);
 237
 238         return 0;
 239 }
 240
 241 static void sh_mtu2_disable(struct sh_mtu2_channel *ch)
 242 {
 243         /* disable channel */
 244         sh_mtu2_start_stop_ch(ch, 0);
 245
 246         /* stop clock */
 247         clk_disable(ch->mtu->clk);
 248
 249         dev_pm_syscore_device(&ch->mtu->pdev->dev, false);
 250         pm_runtime_put(&ch->mtu->pdev->dev);
 251 }
 252
 253 static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id)
 254 {
 255         struct sh_mtu2_channel *ch = dev_id;
 256
 257         /* acknowledge interrupt */
 258         sh_mtu2_read(ch, TSR);
 259         sh_mtu2_write(ch, TSR, ~TSR_TGFA);
 260
 261         /* notify clockevent layer */
 262         ch->ced.event_handler(&ch->ced);
 263         return IRQ_HANDLED;
 264 }
 265
 266 static struct sh_mtu2_channel *ced_to_sh_mtu2(struct clock_event_device *ced)
 267 {
 268         return container_of(ced, struct sh_mtu2_channel, ced);
 269 }
 270
 271 static int sh_mtu2_clock_event_shutdown(struct clock_event_device *ced)
 272 {
 273         struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced);
 274
 275         if (clockevent_state_periodic(ced))
 276                 sh_mtu2_disable(ch);
 277
 278         return 0;
 279 }
 280
 281 static int sh_mtu2_clock_event_set_periodic(struct clock_event_device *ced)
 282 {
 283         struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced);
 284
 285         if (clockevent_state_periodic(ced))
 286                 sh_mtu2_disable(ch);
 287
 288         dev_info(&ch->mtu->pdev->dev, "ch%u: used for periodic clock events\n",
 289                  ch->index);
 290         sh_mtu2_enable(ch);
 291         return 0;
 292 }
 293
 294 static void sh_mtu2_clock_event_suspend(struct clock_event_device *ced)
 295 {
 296         pm_genpd_syscore_poweroff(&ced_to_sh_mtu2(ced)->mtu->pdev->dev);
 297 }
 298
 299 static void sh_mtu2_clock_event_resume(struct clock_event_device *ced)
 300 {
 301         pm_genpd_syscore_poweron(&ced_to_sh_mtu2(ced)->mtu->pdev->dev);
 302 }
 303
 304 static void sh_mtu2_register_clockevent(struct sh_mtu2_channel *ch,
 305                                         const char *name)
 306 {
 307         struct clock_event_device *ced = &ch->ced;
 308
 309         ced->name = name;
 310         ced->features = CLOCK_EVT_FEAT_PERIODIC;
 311         ced->rating = 200;
 312         ced->cpumask = cpu_possible_mask;
 313         ced->set_state_shutdown = sh_mtu2_clock_event_shutdown;
 314         ced->set_state_periodic = sh_mtu2_clock_event_set_periodic;
 315         ced->suspend = sh_mtu2_clock_event_suspend;
 316         ced->resume = sh_mtu2_clock_event_resume;
 317
 318         dev_info(&ch->mtu->pdev->dev, "ch%u: used for clock events\n",
 319                  ch->index);
 320         clockevents_register_device(ced);
 321 }
 322
 323 static int sh_mtu2_register(struct sh_mtu2_channel *ch, const char *name)
 324 {
 325         ch->mtu->has_clockevent = true;
 326         sh_mtu2_register_clockevent(ch, name);
 327
 328         return 0;
 329 }
 330
 331 static const unsigned int sh_mtu2_channel_offsets[] = {
 332         0x300, 0x380, 0x000,
 333 };
 334
 335 static int sh_mtu2_setup_channel(struct sh_mtu2_channel *ch, unsigned int index,
 336                                  struct sh_mtu2_device *mtu)
 337 {
 338         char name[6];
 339         int irq;
 340         int ret;
 341
 342         ch->mtu = mtu;
 343
 344         sprintf(name, "tgi%ua", index);
 345         irq = platform_get_irq_byname(mtu->pdev, name);
 346         if (irq < 0) {
 347                 /* Skip channels with no declared interrupt. */
 348                 return 0;
 349         }
 350
 351         ret = request_irq(irq, sh_mtu2_interrupt,
 352                           IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
 353                           dev_name(&ch->mtu->pdev->dev), ch);
 354         if (ret) {
 355                 dev_err(&ch->mtu->pdev->dev, "ch%u: failed to request irq %d\n",
 356                         index, irq);
 357                 return ret;
 358         }
 359
 360         ch->base = mtu->mapbase + sh_mtu2_channel_offsets[index];
 361         ch->index = index;
 362
 363         return sh_mtu2_register(ch, dev_name(&mtu->pdev->dev));
 364 }
 365
 366 static int sh_mtu2_map_memory(struct sh_mtu2_device *mtu)
 367 {
 368         struct resource *res;
 369
 370         res = platform_get_resource(mtu->pdev, IORESOURCE_MEM, 0);
 371         if (!res) {
 372                 dev_err(&mtu->pdev->dev, "failed to get I/O memory\n");
 373                 return -ENXIO;
 374         }
 375
 376         mtu->mapbase = ioremap_nocache(res->start, resource_size(res));
 377         if (mtu->mapbase == NULL)
 378                 return -ENXIO;
 379
 380         return 0;
 381 }
 382
 383 static int sh_mtu2_setup(struct sh_mtu2_device *mtu,
 384                          struct platform_device *pdev)
 385 {
 386         unsigned int i;
 387         int ret;
 388
 389         mtu->pdev = pdev;
 390
 391         raw_spin_lock_init(&mtu->lock);
 392
 393         /* Get hold of clock. */
 394         mtu->clk = clk_get(&mtu->pdev->dev, "fck");
 395         if (IS_ERR(mtu->clk)) {
 396                 dev_err(&mtu->pdev->dev, "cannot get clock\n");
 397                 return PTR_ERR(mtu->clk);
 398         }
 399
 400         ret = clk_prepare(mtu->clk);
 401         if (ret < 0)
 402                 goto err_clk_put;
 403
 404         /* Map the memory resource. */
 405         ret = sh_mtu2_map_memory(mtu);
 406         if (ret < 0) {
 407                 dev_err(&mtu->pdev->dev, "failed to remap I/O memory\n");
 408                 goto err_clk_unprepare;
 409         }
 410
 411         /* Allocate and setup the channels. */
 412         ret = platform_irq_count(pdev);
 413         if (ret < 0)
 414                 goto err_unmap;
 415
 416         mtu->num_channels = min_t(unsigned int, ret,
 417                                   ARRAY_SIZE(sh_mtu2_channel_offsets));
 418
 419         mtu->channels = kcalloc(mtu->num_channels, sizeof(*mtu->channels),
 420                                 GFP_KERNEL);
 421         if (mtu->channels == NULL) {
 422                 ret = -ENOMEM;
 423                 goto err_unmap;
 424         }
 425
 426         for (i = 0; i < mtu->num_channels; ++i) {
 427                 ret = sh_mtu2_setup_channel(&mtu->channels[i], i, mtu);
 428                 if (ret < 0)
 429                         goto err_unmap;
 430         }
 431
 432         platform_set_drvdata(pdev, mtu);
 433
 434         return 0;
 435
 436 err_unmap:
 437         kfree(mtu->channels);
 438         iounmap(mtu->mapbase);
 439 err_clk_unprepare:
 440         clk_unprepare(mtu->clk);
 441 err_clk_put:
 442         clk_put(mtu->clk);
 443         return ret;
 444 }
 445
 446 static int sh_mtu2_probe(struct platform_device *pdev)
 447 {
 448         struct sh_mtu2_device *mtu = platform_get_drvdata(pdev);
 449         int ret;
 450
 451         if (!is_early_platform_device(pdev)) {
 452                 pm_runtime_set_active(&pdev->dev);
 453                 pm_runtime_enable(&pdev->dev);
 454         }
 455
 456         if (mtu) {
 457                 dev_info(&pdev->dev, "kept as earlytimer\n");
 458                 goto out;
 459         }
 460
 461         mtu = kzalloc(sizeof(*mtu), GFP_KERNEL);
 462         if (mtu == NULL)
 463                 return -ENOMEM;
 464
 465         ret = sh_mtu2_setup(mtu, pdev);
 466         if (ret) {
 467                 kfree(mtu);
 468                 pm_runtime_idle(&pdev->dev);
 469                 return ret;
 470         }
 471         if (is_early_platform_device(pdev))
 472                 return 0;
 473
 474  out:
 475         if (mtu->has_clockevent)
 476                 pm_runtime_irq_safe(&pdev->dev);
 477         else
 478                 pm_runtime_idle(&pdev->dev);
 479
 480         return 0;
 481 }
 482
 483 static int sh_mtu2_remove(struct platform_device *pdev)
 484 {
 485         return -EBUSY; /* cannot unregister clockevent */
 486 }
 487
 488 static const struct platform_device_id sh_mtu2_id_table[] = {
 489         { "sh-mtu2", 0 },
 490         { },
 491 };
 492 MODULE_DEVICE_TABLE(platform, sh_mtu2_id_table);
 493
 494 static const struct of_device_id sh_mtu2_of_table[] __maybe_unused = {
 495         { .compatible = "renesas,mtu2" },
 496         { }
 497 };
 498 MODULE_DEVICE_TABLE(of, sh_mtu2_of_table);
 499
 500 static struct platform_driver sh_mtu2_device_driver = {
 501         .probe          = sh_mtu2_probe,
 502         .remove         = sh_mtu2_remove,
 503         .driver         = {
 504                 .name   = "sh_mtu2",
 505                 .of_match_table = of_match_ptr(sh_mtu2_of_table),
 506         },
 507         .id_table       = sh_mtu2_id_table,
 508 };
 509
 510 static int __init sh_mtu2_init(void)
 511 {
 512         return platform_driver_register(&sh_mtu2_device_driver);
 513 }
 514
 515 static void __exit sh_mtu2_exit(void)
 516 {
 517         platform_driver_unregister(&sh_mtu2_device_driver);
 518 }
 519
 520 early_platform_init("earlytimer", &sh_mtu2_device_driver);
 521 subsys_initcall(sh_mtu2_init);
 522 module_exit(sh_mtu2_exit);
 523
 524 MODULE_AUTHOR("Magnus Damm");
 525 MODULE_DESCRIPTION("SuperH MTU2 Timer Driver");
 526 MODULE_LICENSE("GPL v2");