drivers/pwm/pwm-fsl-ftm.c

   1 /*
   2  *  Freescale FlexTimer Module (FTM) PWM Driver
   3  *
   4  *  Copyright 2012-2013 Freescale Semiconductor, Inc.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/clk.h>
  13 #include <linux/err.h>
  14 #include <linux/io.h>
  15 #include <linux/kernel.h>
  16 #include <linux/module.h>
  17 #include <linux/mutex.h>
  18 #include <linux/of_address.h>
  19 #include <linux/of_device.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/pm.h>
  22 #include <linux/pwm.h>
  23 #include <linux/regmap.h>
  24 #include <linux/slab.h>
  25
  26 #define FTM_SC          0x00
  27 #define FTM_SC_CLK_MASK_SHIFT   3
  28 #define FTM_SC_CLK_MASK (3 << FTM_SC_CLK_MASK_SHIFT)
  29 #define FTM_SC_CLK(c)   (((c) + 1) << FTM_SC_CLK_MASK_SHIFT)
  30 #define FTM_SC_PS_MASK  0x7
  31
  32 #define FTM_CNT         0x04
  33 #define FTM_MOD         0x08
  34
  35 #define FTM_CSC_BASE    0x0C
  36 #define FTM_CSC_MSB     BIT(5)
  37 #define FTM_CSC_MSA     BIT(4)
  38 #define FTM_CSC_ELSB    BIT(3)
  39 #define FTM_CSC_ELSA    BIT(2)
  40 #define FTM_CSC(_channel)       (FTM_CSC_BASE + ((_channel) * 8))
  41
  42 #define FTM_CV_BASE     0x10
  43 #define FTM_CV(_channel)        (FTM_CV_BASE + ((_channel) * 8))
  44
  45 #define FTM_CNTIN       0x4C
  46 #define FTM_STATUS      0x50
  47
  48 #define FTM_MODE        0x54
  49 #define FTM_MODE_FTMEN  BIT(0)
  50 #define FTM_MODE_INIT   BIT(2)
  51 #define FTM_MODE_PWMSYNC        BIT(3)
  52
  53 #define FTM_SYNC        0x58
  54 #define FTM_OUTINIT     0x5C
  55 #define FTM_OUTMASK     0x60
  56 #define FTM_COMBINE     0x64
  57 #define FTM_DEADTIME    0x68
  58 #define FTM_EXTTRIG     0x6C
  59 #define FTM_POL         0x70
  60 #define FTM_FMS         0x74
  61 #define FTM_FILTER      0x78
  62 #define FTM_FLTCTRL     0x7C
  63 #define FTM_QDCTRL      0x80
  64 #define FTM_CONF        0x84
  65 #define FTM_FLTPOL      0x88
  66 #define FTM_SYNCONF     0x8C
  67 #define FTM_INVCTRL     0x90
  68 #define FTM_SWOCTRL     0x94
  69 #define FTM_PWMLOAD     0x98
  70
  71 enum fsl_pwm_clk {
  72         FSL_PWM_CLK_SYS,
  73         FSL_PWM_CLK_FIX,
  74         FSL_PWM_CLK_EXT,
  75         FSL_PWM_CLK_CNTEN,
  76         FSL_PWM_CLK_MAX
  77 };
  78
  79 struct fsl_ftm_soc {
  80         bool has_enable_bits;
  81 };
  82
  83 struct fsl_pwm_chip {
  84         struct pwm_chip chip;
  85
  86         struct mutex lock;
  87
  88         unsigned int cnt_select;
  89         unsigned int clk_ps;
  90
  91         struct regmap *regmap;
  92
  93         int period_ns;
  94
  95         struct clk *ipg_clk;
  96         struct clk *clk[FSL_PWM_CLK_MAX];
  97
  98         const struct fsl_ftm_soc *soc;
  99 };
 100
 101 static inline struct fsl_pwm_chip *to_fsl_chip(struct pwm_chip *chip)
 102 {
 103         return container_of(chip, struct fsl_pwm_chip, chip);
 104 }
 105
 106 static int fsl_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 107 {
 108         int ret;
 109         struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
 110
 111         ret = clk_prepare_enable(fpc->ipg_clk);
 112         if (!ret && fpc->soc->has_enable_bits) {
 113                 mutex_lock(&fpc->lock);
 114                 regmap_update_bits(fpc->regmap, FTM_SC, BIT(pwm->hwpwm + 16),
 115                                    BIT(pwm->hwpwm + 16));
 116                 mutex_unlock(&fpc->lock);
 117         }
 118
 119         return ret;
 120 }
 121
 122 static void fsl_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 123 {
 124         struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
 125
 126         if (fpc->soc->has_enable_bits) {
 127                 mutex_lock(&fpc->lock);
 128                 regmap_update_bits(fpc->regmap, FTM_SC, BIT(pwm->hwpwm + 16),
 129                                    0);
 130                 mutex_unlock(&fpc->lock);
 131         }
 132
 133         clk_disable_unprepare(fpc->ipg_clk);
 134 }
 135
 136 static int fsl_pwm_calculate_default_ps(struct fsl_pwm_chip *fpc,
 137                                         enum fsl_pwm_clk index)
 138 {
 139         unsigned long sys_rate, cnt_rate;
 140         unsigned long long ratio;
 141
 142         sys_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_SYS]);
 143         if (!sys_rate)
 144                 return -EINVAL;
 145
 146         cnt_rate = clk_get_rate(fpc->clk[fpc->cnt_select]);
 147         if (!cnt_rate)
 148                 return -EINVAL;
 149
 150         switch (index) {
 151         case FSL_PWM_CLK_SYS:
 152                 fpc->clk_ps = 1;
 153                 break;
 154         case FSL_PWM_CLK_FIX:
 155                 ratio = 2 * cnt_rate - 1;
 156                 do_div(ratio, sys_rate);
 157                 fpc->clk_ps = ratio;
 158                 break;
 159         case FSL_PWM_CLK_EXT:
 160                 ratio = 4 * cnt_rate - 1;
 161                 do_div(ratio, sys_rate);
 162                 fpc->clk_ps = ratio;
 163                 break;
 164         default:
 165                 return -EINVAL;
 166         }
 167
 168         return 0;
 169 }
 170
 171 static unsigned long fsl_pwm_calculate_cycles(struct fsl_pwm_chip *fpc,
 172                                               unsigned long period_ns)
 173 {
 174         unsigned long long c, c0;
 175
 176         c = clk_get_rate(fpc->clk[fpc->cnt_select]);
 177         c = c * period_ns;
 178         do_div(c, 1000000000UL);
 179
 180         do {
 181                 c0 = c;
 182                 do_div(c0, (1 << fpc->clk_ps));
 183                 if (c0 <= 0xFFFF)
 184                         return (unsigned long)c0;
 185         } while (++fpc->clk_ps < 8);
 186
 187         return 0;
 188 }
 189
 190 static unsigned long fsl_pwm_calculate_period_cycles(struct fsl_pwm_chip *fpc,
 191                                                      unsigned long period_ns,
 192                                                      enum fsl_pwm_clk index)
 193 {
 194         int ret;
 195
 196         ret = fsl_pwm_calculate_default_ps(fpc, index);
 197         if (ret) {
 198                 dev_err(fpc->chip.dev,
 199                         "failed to calculate default prescaler: %d\n",
 200                         ret);
 201                 return 0;
 202         }
 203
 204         return fsl_pwm_calculate_cycles(fpc, period_ns);
 205 }
 206
 207 static unsigned long fsl_pwm_calculate_period(struct fsl_pwm_chip *fpc,
 208                                               unsigned long period_ns)
 209 {
 210         enum fsl_pwm_clk m0, m1;
 211         unsigned long fix_rate, ext_rate, cycles;
 212
 213         cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns,
 214                         FSL_PWM_CLK_SYS);
 215         if (cycles) {
 216                 fpc->cnt_select = FSL_PWM_CLK_SYS;
 217                 return cycles;
 218         }
 219
 220         fix_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_FIX]);
 221         ext_rate = clk_get_rate(fpc->clk[FSL_PWM_CLK_EXT]);
 222
 223         if (fix_rate > ext_rate) {
 224                 m0 = FSL_PWM_CLK_FIX;
 225                 m1 = FSL_PWM_CLK_EXT;
 226         } else {
 227                 m0 = FSL_PWM_CLK_EXT;
 228                 m1 = FSL_PWM_CLK_FIX;
 229         }
 230
 231         cycles = fsl_pwm_calculate_period_cycles(fpc, period_ns, m0);
 232         if (cycles) {
 233                 fpc->cnt_select = m0;
 234                 return cycles;
 235         }
 236
 237         fpc->cnt_select = m1;
 238
 239         return fsl_pwm_calculate_period_cycles(fpc, period_ns, m1);
 240 }
 241
 242 static unsigned long fsl_pwm_calculate_duty(struct fsl_pwm_chip *fpc,
 243                                             unsigned long period_ns,
 244                                             unsigned long duty_ns)
 245 {
 246         unsigned long long duty;
 247         u32 val;
 248
 249         regmap_read(fpc->regmap, FTM_MOD, &val);
 250         duty = (unsigned long long)duty_ns * (val + 1);
 251         do_div(duty, period_ns);
 252
 253         return (unsigned long)duty;
 254 }
 255
 256 static int fsl_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 257                           int duty_ns, int period_ns)
 258 {
 259         struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
 260         u32 period, duty;
 261
 262         mutex_lock(&fpc->lock);
 263
 264         /*
 265          * The Freescale FTM controller supports only a single period for
 266          * all PWM channels, therefore incompatible changes need to be
 267          * refused.
 268          */
 269         if (fpc->period_ns && fpc->period_ns != period_ns) {
 270                 dev_err(fpc->chip.dev,
 271                         "conflicting period requested for PWM %u\n",
 272                         pwm->hwpwm);
 273                 mutex_unlock(&fpc->lock);
 274                 return -EBUSY;
 275         }
 276
 277         if (!fpc->period_ns && duty_ns) {
 278                 period = fsl_pwm_calculate_period(fpc, period_ns);
 279                 if (!period) {
 280                         dev_err(fpc->chip.dev, "failed to calculate period\n");
 281                         mutex_unlock(&fpc->lock);
 282                         return -EINVAL;
 283                 }
 284
 285                 regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_PS_MASK,
 286                                    fpc->clk_ps);
 287                 regmap_write(fpc->regmap, FTM_MOD, period - 1);
 288
 289                 fpc->period_ns = period_ns;
 290         }
 291
 292         mutex_unlock(&fpc->lock);
 293
 294         duty = fsl_pwm_calculate_duty(fpc, period_ns, duty_ns);
 295
 296         regmap_write(fpc->regmap, FTM_CSC(pwm->hwpwm),
 297                      FTM_CSC_MSB | FTM_CSC_ELSB);
 298         regmap_write(fpc->regmap, FTM_CV(pwm->hwpwm), duty);
 299
 300         return 0;
 301 }
 302
 303 static int fsl_pwm_set_polarity(struct pwm_chip *chip,
 304                                 struct pwm_device *pwm,
 305                                 enum pwm_polarity polarity)
 306 {
 307         struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
 308         u32 val;
 309
 310         regmap_read(fpc->regmap, FTM_POL, &val);
 311
 312         if (polarity == PWM_POLARITY_INVERSED)
 313                 val |= BIT(pwm->hwpwm);
 314         else
 315                 val &= ~BIT(pwm->hwpwm);
 316
 317         regmap_write(fpc->regmap, FTM_POL, val);
 318
 319         return 0;
 320 }
 321
 322 static int fsl_counter_clock_enable(struct fsl_pwm_chip *fpc)
 323 {
 324         int ret;
 325
 326         /* select counter clock source */
 327         regmap_update_bits(fpc->regmap, FTM_SC, FTM_SC_CLK_MASK,
 328                            FTM_SC_CLK(fpc->cnt_select));
 329
 330         ret = clk_prepare_enable(fpc->clk[fpc->cnt_select]);
 331         if (ret)
 332                 return ret;
 333
 334         ret = clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
 335         if (ret) {
 336                 clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
 337                 return ret;
 338         }
 339
 340         return 0;
 341 }
 342
 343 static int fsl_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 344 {
 345         struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
 346         int ret;
 347
 348         mutex_lock(&fpc->lock);
 349         regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm), 0);
 350
 351         ret = fsl_counter_clock_enable(fpc);
 352         mutex_unlock(&fpc->lock);
 353
 354         return ret;
 355 }
 356
 357 static void fsl_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 358 {
 359         struct fsl_pwm_chip *fpc = to_fsl_chip(chip);
 360         u32 val;
 361
 362         mutex_lock(&fpc->lock);
 363         regmap_update_bits(fpc->regmap, FTM_OUTMASK, BIT(pwm->hwpwm),
 364                            BIT(pwm->hwpwm));
 365
 366         clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
 367         clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
 368
 369         regmap_read(fpc->regmap, FTM_OUTMASK, &val);
 370         if ((val & 0xFF) == 0xFF)
 371                 fpc->period_ns = 0;
 372
 373         mutex_unlock(&fpc->lock);
 374 }
 375
 376 static const struct pwm_ops fsl_pwm_ops = {
 377         .request = fsl_pwm_request,
 378         .free = fsl_pwm_free,
 379         .config = fsl_pwm_config,
 380         .set_polarity = fsl_pwm_set_polarity,
 381         .enable = fsl_pwm_enable,
 382         .disable = fsl_pwm_disable,
 383         .owner = THIS_MODULE,
 384 };
 385
 386 static int fsl_pwm_init(struct fsl_pwm_chip *fpc)
 387 {
 388         int ret;
 389
 390         ret = clk_prepare_enable(fpc->ipg_clk);
 391         if (ret)
 392                 return ret;
 393
 394         regmap_write(fpc->regmap, FTM_CNTIN, 0x00);
 395         regmap_write(fpc->regmap, FTM_OUTINIT, 0x00);
 396         regmap_write(fpc->regmap, FTM_OUTMASK, 0xFF);
 397
 398         clk_disable_unprepare(fpc->ipg_clk);
 399
 400         return 0;
 401 }
 402
 403 static bool fsl_pwm_volatile_reg(struct device *dev, unsigned int reg)
 404 {
 405         switch (reg) {
 406         case FTM_CNT:
 407                 return true;
 408         }
 409         return false;
 410 }
 411
 412 static const struct regmap_config fsl_pwm_regmap_config = {
 413         .reg_bits = 32,
 414         .reg_stride = 4,
 415         .val_bits = 32,
 416
 417         .max_register = FTM_PWMLOAD,
 418         .volatile_reg = fsl_pwm_volatile_reg,
 419         .cache_type = REGCACHE_FLAT,
 420 };
 421
 422 static int fsl_pwm_probe(struct platform_device *pdev)
 423 {
 424         struct fsl_pwm_chip *fpc;
 425         struct resource *res;
 426         void __iomem *base;
 427         int ret;
 428
 429         fpc = devm_kzalloc(&pdev->dev, sizeof(*fpc), GFP_KERNEL);
 430         if (!fpc)
 431                 return -ENOMEM;
 432
 433         mutex_init(&fpc->lock);
 434
 435         fpc->soc = of_device_get_match_data(&pdev->dev);
 436         fpc->chip.dev = &pdev->dev;
 437
 438         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 439         base = devm_ioremap_resource(&pdev->dev, res);
 440         if (IS_ERR(base))
 441                 return PTR_ERR(base);
 442
 443         fpc->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "ftm_sys", base,
 444                                                 &fsl_pwm_regmap_config);
 445         if (IS_ERR(fpc->regmap)) {
 446                 dev_err(&pdev->dev, "regmap init failed\n");
 447                 return PTR_ERR(fpc->regmap);
 448         }
 449
 450         fpc->clk[FSL_PWM_CLK_SYS] = devm_clk_get(&pdev->dev, "ftm_sys");
 451         if (IS_ERR(fpc->clk[FSL_PWM_CLK_SYS])) {
 452                 dev_err(&pdev->dev, "failed to get \"ftm_sys\" clock\n");
 453                 return PTR_ERR(fpc->clk[FSL_PWM_CLK_SYS]);
 454         }
 455
 456         fpc->clk[FSL_PWM_CLK_FIX] = devm_clk_get(fpc->chip.dev, "ftm_fix");
 457         if (IS_ERR(fpc->clk[FSL_PWM_CLK_FIX]))
 458                 return PTR_ERR(fpc->clk[FSL_PWM_CLK_FIX]);
 459
 460         fpc->clk[FSL_PWM_CLK_EXT] = devm_clk_get(fpc->chip.dev, "ftm_ext");
 461         if (IS_ERR(fpc->clk[FSL_PWM_CLK_EXT]))
 462                 return PTR_ERR(fpc->clk[FSL_PWM_CLK_EXT]);
 463
 464         fpc->clk[FSL_PWM_CLK_CNTEN] =
 465                                 devm_clk_get(fpc->chip.dev, "ftm_cnt_clk_en");
 466         if (IS_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]))
 467                 return PTR_ERR(fpc->clk[FSL_PWM_CLK_CNTEN]);
 468
 469         /*
 470          * ipg_clk is the interface clock for the IP. If not provided, use the
 471          * ftm_sys clock as the default.
 472          */
 473         fpc->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
 474         if (IS_ERR(fpc->ipg_clk))
 475                 fpc->ipg_clk = fpc->clk[FSL_PWM_CLK_SYS];
 476
 477
 478         fpc->chip.ops = &fsl_pwm_ops;
 479         fpc->chip.of_xlate = of_pwm_xlate_with_flags;
 480         fpc->chip.of_pwm_n_cells = 3;
 481         fpc->chip.base = -1;
 482         fpc->chip.npwm = 8;
 483
 484         ret = pwmchip_add(&fpc->chip);
 485         if (ret < 0) {
 486                 dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
 487                 return ret;
 488         }
 489
 490         platform_set_drvdata(pdev, fpc);
 491
 492         return fsl_pwm_init(fpc);
 493 }
 494
 495 static int fsl_pwm_remove(struct platform_device *pdev)
 496 {
 497         struct fsl_pwm_chip *fpc = platform_get_drvdata(pdev);
 498
 499         return pwmchip_remove(&fpc->chip);
 500 }
 501
 502 #ifdef CONFIG_PM_SLEEP
 503 static int fsl_pwm_suspend(struct device *dev)
 504 {
 505         struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
 506         int i;
 507
 508         regcache_cache_only(fpc->regmap, true);
 509         regcache_mark_dirty(fpc->regmap);
 510
 511         for (i = 0; i < fpc->chip.npwm; i++) {
 512                 struct pwm_device *pwm = &fpc->chip.pwms[i];
 513
 514                 if (!test_bit(PWMF_REQUESTED, &pwm->flags))
 515                         continue;
 516
 517                 clk_disable_unprepare(fpc->ipg_clk);
 518
 519                 if (!pwm_is_enabled(pwm))
 520                         continue;
 521
 522                 clk_disable_unprepare(fpc->clk[FSL_PWM_CLK_CNTEN]);
 523                 clk_disable_unprepare(fpc->clk[fpc->cnt_select]);
 524         }
 525
 526         return 0;
 527 }
 528
 529 static int fsl_pwm_resume(struct device *dev)
 530 {
 531         struct fsl_pwm_chip *fpc = dev_get_drvdata(dev);
 532         int i;
 533
 534         for (i = 0; i < fpc->chip.npwm; i++) {
 535                 struct pwm_device *pwm = &fpc->chip.pwms[i];
 536
 537                 if (!test_bit(PWMF_REQUESTED, &pwm->flags))
 538                         continue;
 539
 540                 clk_prepare_enable(fpc->ipg_clk);
 541
 542                 if (!pwm_is_enabled(pwm))
 543                         continue;
 544
 545                 clk_prepare_enable(fpc->clk[fpc->cnt_select]);
 546                 clk_prepare_enable(fpc->clk[FSL_PWM_CLK_CNTEN]);
 547         }
 548
 549         /* restore all registers from cache */
 550         regcache_cache_only(fpc->regmap, false);
 551         regcache_sync(fpc->regmap);
 552
 553         return 0;
 554 }
 555 #endif
 556
 557 static const struct dev_pm_ops fsl_pwm_pm_ops = {
 558         SET_SYSTEM_SLEEP_PM_OPS(fsl_pwm_suspend, fsl_pwm_resume)
 559 };
 560
 561 static const struct fsl_ftm_soc vf610_ftm_pwm = {
 562         .has_enable_bits = false,
 563 };
 564
 565 static const struct fsl_ftm_soc imx8qm_ftm_pwm = {
 566         .has_enable_bits = true,
 567 };
 568
 569 static const struct of_device_id fsl_pwm_dt_ids[] = {
 570         { .compatible = "fsl,vf610-ftm-pwm", .data = &vf610_ftm_pwm },
 571         { .compatible = "fsl,imx8qm-ftm-pwm", .data = &imx8qm_ftm_pwm },
 572         { /* sentinel */ }
 573 };
 574 MODULE_DEVICE_TABLE(of, fsl_pwm_dt_ids);
 575
 576 static struct platform_driver fsl_pwm_driver = {
 577         .driver = {
 578                 .name = "fsl-ftm-pwm",
 579                 .of_match_table = fsl_pwm_dt_ids,
 580                 .pm = &fsl_pwm_pm_ops,
 581         },
 582         .probe = fsl_pwm_probe,
 583         .remove = fsl_pwm_remove,
 584 };
 585 module_platform_driver(fsl_pwm_driver);
 586
 587 MODULE_DESCRIPTION("Freescale FlexTimer Module PWM Driver");
 588 MODULE_AUTHOR("Xiubo Li <Li.Xiubo@freescale.com>");
 589 MODULE_ALIAS("platform:fsl-ftm-pwm");
 590 MODULE_LICENSE("GPL");