linux/drivers/clocksource/sh_mtu2.c
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   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#ifdef CONFIG_SUPERH
  27#include <asm/platform_early.h>
  28#endif
  29
  30struct sh_mtu2_device;
  31
  32struct sh_mtu2_channel {
  33        struct sh_mtu2_device *mtu;
  34        unsigned int index;
  35
  36        void __iomem *base;
  37
  38        struct clock_event_device ced;
  39};
  40
  41struct sh_mtu2_device {
  42        struct platform_device *pdev;
  43
  44        void __iomem *mapbase;
  45        struct clk *clk;
  46
  47        raw_spinlock_t lock; /* Protect the shared registers */
  48
  49        struct sh_mtu2_channel *channels;
  50        unsigned int num_channels;
  51
  52        bool has_clockevent;
  53};
  54
  55#define TSTR -1 /* shared register */
  56#define TCR  0 /* channel register */
  57#define TMDR 1 /* channel register */
  58#define TIOR 2 /* channel register */
  59#define TIER 3 /* channel register */
  60#define TSR  4 /* channel register */
  61#define TCNT 5 /* channel register */
  62#define TGR  6 /* channel register */
  63
  64#define TCR_CCLR_NONE           (0 << 5)
  65#define TCR_CCLR_TGRA           (1 << 5)
  66#define TCR_CCLR_TGRB           (2 << 5)
  67#define TCR_CCLR_SYNC           (3 << 5)
  68#define TCR_CCLR_TGRC           (5 << 5)
  69#define TCR_CCLR_TGRD           (6 << 5)
  70#define TCR_CCLR_MASK           (7 << 5)
  71#define TCR_CKEG_RISING         (0 << 3)
  72#define TCR_CKEG_FALLING        (1 << 3)
  73#define TCR_CKEG_BOTH           (2 << 3)
  74#define TCR_CKEG_MASK           (3 << 3)
  75/* Values 4 to 7 are channel-dependent */
  76#define TCR_TPSC_P1             (0 << 0)
  77#define TCR_TPSC_P4             (1 << 0)
  78#define TCR_TPSC_P16            (2 << 0)
  79#define TCR_TPSC_P64            (3 << 0)
  80#define TCR_TPSC_CH0_TCLKA      (4 << 0)
  81#define TCR_TPSC_CH0_TCLKB      (5 << 0)
  82#define TCR_TPSC_CH0_TCLKC      (6 << 0)
  83#define TCR_TPSC_CH0_TCLKD      (7 << 0)
  84#define TCR_TPSC_CH1_TCLKA      (4 << 0)
  85#define TCR_TPSC_CH1_TCLKB      (5 << 0)
  86#define TCR_TPSC_CH1_P256       (6 << 0)
  87#define TCR_TPSC_CH1_TCNT2      (7 << 0)
  88#define TCR_TPSC_CH2_TCLKA      (4 << 0)
  89#define TCR_TPSC_CH2_TCLKB      (5 << 0)
  90#define TCR_TPSC_CH2_TCLKC      (6 << 0)
  91#define TCR_TPSC_CH2_P1024      (7 << 0)
  92#define TCR_TPSC_CH34_P256      (4 << 0)
  93#define TCR_TPSC_CH34_P1024     (5 << 0)
  94#define TCR_TPSC_CH34_TCLKA     (6 << 0)
  95#define TCR_TPSC_CH34_TCLKB     (7 << 0)
  96#define TCR_TPSC_MASK           (7 << 0)
  97
  98#define TMDR_BFE                (1 << 6)
  99#define TMDR_BFB                (1 << 5)
 100#define TMDR_BFA                (1 << 4)
 101#define TMDR_MD_NORMAL          (0 << 0)
 102#define TMDR_MD_PWM_1           (2 << 0)
 103#define TMDR_MD_PWM_2           (3 << 0)
 104#define TMDR_MD_PHASE_1         (4 << 0)
 105#define TMDR_MD_PHASE_2         (5 << 0)
 106#define TMDR_MD_PHASE_3         (6 << 0)
 107#define TMDR_MD_PHASE_4         (7 << 0)
 108#define TMDR_MD_PWM_SYNC        (8 << 0)
 109#define TMDR_MD_PWM_COMP_CREST  (13 << 0)
 110#define TMDR_MD_PWM_COMP_TROUGH (14 << 0)
 111#define TMDR_MD_PWM_COMP_BOTH   (15 << 0)
 112#define TMDR_MD_MASK            (15 << 0)
 113
 114#define TIOC_IOCH(n)            ((n) << 4)
 115#define TIOC_IOCL(n)            ((n) << 0)
 116#define TIOR_OC_RETAIN          (0 << 0)
 117#define TIOR_OC_0_CLEAR         (1 << 0)
 118#define TIOR_OC_0_SET           (2 << 0)
 119#define TIOR_OC_0_TOGGLE        (3 << 0)
 120#define TIOR_OC_1_CLEAR         (5 << 0)
 121#define TIOR_OC_1_SET           (6 << 0)
 122#define TIOR_OC_1_TOGGLE        (7 << 0)
 123#define TIOR_IC_RISING          (8 << 0)
 124#define TIOR_IC_FALLING         (9 << 0)
 125#define TIOR_IC_BOTH            (10 << 0)
 126#define TIOR_IC_TCNT            (12 << 0)
 127#define TIOR_MASK               (15 << 0)
 128
 129#define TIER_TTGE               (1 << 7)
 130#define TIER_TTGE2              (1 << 6)
 131#define TIER_TCIEU              (1 << 5)
 132#define TIER_TCIEV              (1 << 4)
 133#define TIER_TGIED              (1 << 3)
 134#define TIER_TGIEC              (1 << 2)
 135#define TIER_TGIEB              (1 << 1)
 136#define TIER_TGIEA              (1 << 0)
 137
 138#define TSR_TCFD                (1 << 7)
 139#define TSR_TCFU                (1 << 5)
 140#define TSR_TCFV                (1 << 4)
 141#define TSR_TGFD                (1 << 3)
 142#define TSR_TGFC                (1 << 2)
 143#define TSR_TGFB                (1 << 1)
 144#define TSR_TGFA                (1 << 0)
 145
 146static unsigned long mtu2_reg_offs[] = {
 147        [TCR] = 0,
 148        [TMDR] = 1,
 149        [TIOR] = 2,
 150        [TIER] = 4,
 151        [TSR] = 5,
 152        [TCNT] = 6,
 153        [TGR] = 8,
 154};
 155
 156static inline unsigned long sh_mtu2_read(struct sh_mtu2_channel *ch, int reg_nr)
 157{
 158        unsigned long offs;
 159
 160        if (reg_nr == TSTR)
 161                return ioread8(ch->mtu->mapbase + 0x280);
 162
 163        offs = mtu2_reg_offs[reg_nr];
 164
 165        if ((reg_nr == TCNT) || (reg_nr == TGR))
 166                return ioread16(ch->base + offs);
 167        else
 168                return ioread8(ch->base + offs);
 169}
 170
 171static inline void sh_mtu2_write(struct sh_mtu2_channel *ch, int reg_nr,
 172                                unsigned long value)
 173{
 174        unsigned long offs;
 175
 176        if (reg_nr == TSTR)
 177                return iowrite8(value, ch->mtu->mapbase + 0x280);
 178
 179        offs = mtu2_reg_offs[reg_nr];
 180
 181        if ((reg_nr == TCNT) || (reg_nr == TGR))
 182                iowrite16(value, ch->base + offs);
 183        else
 184                iowrite8(value, ch->base + offs);
 185}
 186
 187static void sh_mtu2_start_stop_ch(struct sh_mtu2_channel *ch, int start)
 188{
 189        unsigned long flags, value;
 190
 191        /* start stop register shared by multiple timer channels */
 192        raw_spin_lock_irqsave(&ch->mtu->lock, flags);
 193        value = sh_mtu2_read(ch, TSTR);
 194
 195        if (start)
 196                value |= 1 << ch->index;
 197        else
 198                value &= ~(1 << ch->index);
 199
 200        sh_mtu2_write(ch, TSTR, value);
 201        raw_spin_unlock_irqrestore(&ch->mtu->lock, flags);
 202}
 203
 204static int sh_mtu2_enable(struct sh_mtu2_channel *ch)
 205{
 206        unsigned long periodic;
 207        unsigned long rate;
 208        int ret;
 209
 210        pm_runtime_get_sync(&ch->mtu->pdev->dev);
 211        dev_pm_syscore_device(&ch->mtu->pdev->dev, true);
 212
 213        /* enable clock */
 214        ret = clk_enable(ch->mtu->clk);
 215        if (ret) {
 216                dev_err(&ch->mtu->pdev->dev, "ch%u: cannot enable clock\n",
 217                        ch->index);
 218                return ret;
 219        }
 220
 221        /* make sure channel is disabled */
 222        sh_mtu2_start_stop_ch(ch, 0);
 223
 224        rate = clk_get_rate(ch->mtu->clk) / 64;
 225        periodic = (rate + HZ/2) / HZ;
 226
 227        /*
 228         * "Periodic Counter Operation"
 229         * Clear on TGRA compare match, divide clock by 64.
 230         */
 231        sh_mtu2_write(ch, TCR, TCR_CCLR_TGRA | TCR_TPSC_P64);
 232        sh_mtu2_write(ch, TIOR, TIOC_IOCH(TIOR_OC_0_CLEAR) |
 233                      TIOC_IOCL(TIOR_OC_0_CLEAR));
 234        sh_mtu2_write(ch, TGR, periodic);
 235        sh_mtu2_write(ch, TCNT, 0);
 236        sh_mtu2_write(ch, TMDR, TMDR_MD_NORMAL);
 237        sh_mtu2_write(ch, TIER, TIER_TGIEA);
 238
 239        /* enable channel */
 240        sh_mtu2_start_stop_ch(ch, 1);
 241
 242        return 0;
 243}
 244
 245static void sh_mtu2_disable(struct sh_mtu2_channel *ch)
 246{
 247        /* disable channel */
 248        sh_mtu2_start_stop_ch(ch, 0);
 249
 250        /* stop clock */
 251        clk_disable(ch->mtu->clk);
 252
 253        dev_pm_syscore_device(&ch->mtu->pdev->dev, false);
 254        pm_runtime_put(&ch->mtu->pdev->dev);
 255}
 256
 257static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id)
 258{
 259        struct sh_mtu2_channel *ch = dev_id;
 260
 261        /* acknowledge interrupt */
 262        sh_mtu2_read(ch, TSR);
 263        sh_mtu2_write(ch, TSR, ~TSR_TGFA);
 264
 265        /* notify clockevent layer */
 266        ch->ced.event_handler(&ch->ced);
 267        return IRQ_HANDLED;
 268}
 269
 270static struct sh_mtu2_channel *ced_to_sh_mtu2(struct clock_event_device *ced)
 271{
 272        return container_of(ced, struct sh_mtu2_channel, ced);
 273}
 274
 275static int sh_mtu2_clock_event_shutdown(struct clock_event_device *ced)
 276{
 277        struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced);
 278
 279        if (clockevent_state_periodic(ced))
 280                sh_mtu2_disable(ch);
 281
 282        return 0;
 283}
 284
 285static int sh_mtu2_clock_event_set_periodic(struct clock_event_device *ced)
 286{
 287        struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced);
 288
 289        if (clockevent_state_periodic(ced))
 290                sh_mtu2_disable(ch);
 291
 292        dev_info(&ch->mtu->pdev->dev, "ch%u: used for periodic clock events\n",
 293                 ch->index);
 294        sh_mtu2_enable(ch);
 295        return 0;
 296}
 297
 298static void sh_mtu2_clock_event_suspend(struct clock_event_device *ced)
 299{
 300        dev_pm_genpd_suspend(&ced_to_sh_mtu2(ced)->mtu->pdev->dev);
 301}
 302
 303static void sh_mtu2_clock_event_resume(struct clock_event_device *ced)
 304{
 305        dev_pm_genpd_resume(&ced_to_sh_mtu2(ced)->mtu->pdev->dev);
 306}
 307
 308static void sh_mtu2_register_clockevent(struct sh_mtu2_channel *ch,
 309                                        const char *name)
 310{
 311        struct clock_event_device *ced = &ch->ced;
 312
 313        ced->name = name;
 314        ced->features = CLOCK_EVT_FEAT_PERIODIC;
 315        ced->rating = 200;
 316        ced->cpumask = cpu_possible_mask;
 317        ced->set_state_shutdown = sh_mtu2_clock_event_shutdown;
 318        ced->set_state_periodic = sh_mtu2_clock_event_set_periodic;
 319        ced->suspend = sh_mtu2_clock_event_suspend;
 320        ced->resume = sh_mtu2_clock_event_resume;
 321
 322        dev_info(&ch->mtu->pdev->dev, "ch%u: used for clock events\n",
 323                 ch->index);
 324        clockevents_register_device(ced);
 325}
 326
 327static int sh_mtu2_register(struct sh_mtu2_channel *ch, const char *name)
 328{
 329        ch->mtu->has_clockevent = true;
 330        sh_mtu2_register_clockevent(ch, name);
 331
 332        return 0;
 333}
 334
 335static const unsigned int sh_mtu2_channel_offsets[] = {
 336        0x300, 0x380, 0x000,
 337};
 338
 339static int sh_mtu2_setup_channel(struct sh_mtu2_channel *ch, unsigned int index,
 340                                 struct sh_mtu2_device *mtu)
 341{
 342        char name[6];
 343        int irq;
 344        int ret;
 345
 346        ch->mtu = mtu;
 347
 348        sprintf(name, "tgi%ua", index);
 349        irq = platform_get_irq_byname(mtu->pdev, name);
 350        if (irq < 0) {
 351                /* Skip channels with no declared interrupt. */
 352                return 0;
 353        }
 354
 355        ret = request_irq(irq, sh_mtu2_interrupt,
 356                          IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING,
 357                          dev_name(&ch->mtu->pdev->dev), ch);
 358        if (ret) {
 359                dev_err(&ch->mtu->pdev->dev, "ch%u: failed to request irq %d\n",
 360                        index, irq);
 361                return ret;
 362        }
 363
 364        ch->base = mtu->mapbase + sh_mtu2_channel_offsets[index];
 365        ch->index = index;
 366
 367        return sh_mtu2_register(ch, dev_name(&mtu->pdev->dev));
 368}
 369
 370static int sh_mtu2_map_memory(struct sh_mtu2_device *mtu)
 371{
 372        struct resource *res;
 373
 374        res = platform_get_resource(mtu->pdev, IORESOURCE_MEM, 0);
 375        if (!res) {
 376                dev_err(&mtu->pdev->dev, "failed to get I/O memory\n");
 377                return -ENXIO;
 378        }
 379
 380        mtu->mapbase = ioremap(res->start, resource_size(res));
 381        if (mtu->mapbase == NULL)
 382                return -ENXIO;
 383
 384        return 0;
 385}
 386
 387static int sh_mtu2_setup(struct sh_mtu2_device *mtu,
 388                         struct platform_device *pdev)
 389{
 390        unsigned int i;
 391        int ret;
 392
 393        mtu->pdev = pdev;
 394
 395        raw_spin_lock_init(&mtu->lock);
 396
 397        /* Get hold of clock. */
 398        mtu->clk = clk_get(&mtu->pdev->dev, "fck");
 399        if (IS_ERR(mtu->clk)) {
 400                dev_err(&mtu->pdev->dev, "cannot get clock\n");
 401                return PTR_ERR(mtu->clk);
 402        }
 403
 404        ret = clk_prepare(mtu->clk);
 405        if (ret < 0)
 406                goto err_clk_put;
 407
 408        /* Map the memory resource. */
 409        ret = sh_mtu2_map_memory(mtu);
 410        if (ret < 0) {
 411                dev_err(&mtu->pdev->dev, "failed to remap I/O memory\n");
 412                goto err_clk_unprepare;
 413        }
 414
 415        /* Allocate and setup the channels. */
 416        ret = platform_irq_count(pdev);
 417        if (ret < 0)
 418                goto err_unmap;
 419
 420        mtu->num_channels = min_t(unsigned int, ret,
 421                                  ARRAY_SIZE(sh_mtu2_channel_offsets));
 422
 423        mtu->channels = kcalloc(mtu->num_channels, sizeof(*mtu->channels),
 424                                GFP_KERNEL);
 425        if (mtu->channels == NULL) {
 426                ret = -ENOMEM;
 427                goto err_unmap;
 428        }
 429
 430        for (i = 0; i < mtu->num_channels; ++i) {
 431                ret = sh_mtu2_setup_channel(&mtu->channels[i], i, mtu);
 432                if (ret < 0)
 433                        goto err_unmap;
 434        }
 435
 436        platform_set_drvdata(pdev, mtu);
 437
 438        return 0;
 439
 440err_unmap:
 441        kfree(mtu->channels);
 442        iounmap(mtu->mapbase);
 443err_clk_unprepare:
 444        clk_unprepare(mtu->clk);
 445err_clk_put:
 446        clk_put(mtu->clk);
 447        return ret;
 448}
 449
 450static int sh_mtu2_probe(struct platform_device *pdev)
 451{
 452        struct sh_mtu2_device *mtu = platform_get_drvdata(pdev);
 453        int ret;
 454
 455        if (!is_sh_early_platform_device(pdev)) {
 456                pm_runtime_set_active(&pdev->dev);
 457                pm_runtime_enable(&pdev->dev);
 458        }
 459
 460        if (mtu) {
 461                dev_info(&pdev->dev, "kept as earlytimer\n");
 462                goto out;
 463        }
 464
 465        mtu = kzalloc(sizeof(*mtu), GFP_KERNEL);
 466        if (mtu == NULL)
 467                return -ENOMEM;
 468
 469        ret = sh_mtu2_setup(mtu, pdev);
 470        if (ret) {
 471                kfree(mtu);
 472                pm_runtime_idle(&pdev->dev);
 473                return ret;
 474        }
 475        if (is_sh_early_platform_device(pdev))
 476                return 0;
 477
 478 out:
 479        if (mtu->has_clockevent)
 480                pm_runtime_irq_safe(&pdev->dev);
 481        else
 482                pm_runtime_idle(&pdev->dev);
 483
 484        return 0;
 485}
 486
 487static int sh_mtu2_remove(struct platform_device *pdev)
 488{
 489        return -EBUSY; /* cannot unregister clockevent */
 490}
 491
 492static const struct platform_device_id sh_mtu2_id_table[] = {
 493        { "sh-mtu2", 0 },
 494        { },
 495};
 496MODULE_DEVICE_TABLE(platform, sh_mtu2_id_table);
 497
 498static const struct of_device_id sh_mtu2_of_table[] __maybe_unused = {
 499        { .compatible = "renesas,mtu2" },
 500        { }
 501};
 502MODULE_DEVICE_TABLE(of, sh_mtu2_of_table);
 503
 504static struct platform_driver sh_mtu2_device_driver = {
 505        .probe          = sh_mtu2_probe,
 506        .remove         = sh_mtu2_remove,
 507        .driver         = {
 508                .name   = "sh_mtu2",
 509                .of_match_table = of_match_ptr(sh_mtu2_of_table),
 510        },
 511        .id_table       = sh_mtu2_id_table,
 512};
 513
 514static int __init sh_mtu2_init(void)
 515{
 516        return platform_driver_register(&sh_mtu2_device_driver);
 517}
 518
 519static void __exit sh_mtu2_exit(void)
 520{
 521        platform_driver_unregister(&sh_mtu2_device_driver);
 522}
 523
 524#ifdef CONFIG_SUPERH
 525sh_early_platform_init("earlytimer", &sh_mtu2_device_driver);
 526#endif
 527
 528subsys_initcall(sh_mtu2_init);
 529module_exit(sh_mtu2_exit);
 530
 531MODULE_AUTHOR("Magnus Damm");
 532MODULE_DESCRIPTION("SuperH MTU2 Timer Driver");
 533MODULE_LICENSE("GPL v2");
 534