drivers/pwm/pwm-tiehrpwm.c

   1 /*
   2  * EHRPWM PWM driver
   3  *
   4  * Copyright (C) 2012 Texas Instruments, Inc. - http://www.ti.com/
   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  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20
  21 #include <linux/module.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/pwm.h>
  24 #include <linux/io.h>
  25 #include <linux/err.h>
  26 #include <linux/clk.h>
  27 #include <linux/pm_runtime.h>
  28 #include <linux/of_device.h>
  29
  30 #include "pwm-tipwmss.h"
  31
  32 /* EHRPWM registers and bits definitions */
  33
  34 /* Time base module registers */
  35 #define TBCTL                   0x00
  36 #define TBPRD                   0x0A
  37
  38 #define TBCTL_RUN_MASK          (BIT(15) | BIT(14))
  39 #define TBCTL_STOP_NEXT         0
  40 #define TBCTL_STOP_ON_CYCLE     BIT(14)
  41 #define TBCTL_FREE_RUN          (BIT(15) | BIT(14))
  42 #define TBCTL_PRDLD_MASK        BIT(3)
  43 #define TBCTL_PRDLD_SHDW        0
  44 #define TBCTL_PRDLD_IMDT        BIT(3)
  45 #define TBCTL_CLKDIV_MASK       (BIT(12) | BIT(11) | BIT(10) | BIT(9) | \
  46                                 BIT(8) | BIT(7))
  47 #define TBCTL_CTRMODE_MASK      (BIT(1) | BIT(0))
  48 #define TBCTL_CTRMODE_UP        0
  49 #define TBCTL_CTRMODE_DOWN      BIT(0)
  50 #define TBCTL_CTRMODE_UPDOWN    BIT(1)
  51 #define TBCTL_CTRMODE_FREEZE    (BIT(1) | BIT(0))
  52
  53 #define TBCTL_HSPCLKDIV_SHIFT   7
  54 #define TBCTL_CLKDIV_SHIFT      10
  55
  56 #define CLKDIV_MAX              7
  57 #define HSPCLKDIV_MAX           7
  58 #define PERIOD_MAX              0xFFFF
  59
  60 /* compare module registers */
  61 #define CMPA                    0x12
  62 #define CMPB                    0x14
  63
  64 /* Action qualifier module registers */
  65 #define AQCTLA                  0x16
  66 #define AQCTLB                  0x18
  67 #define AQSFRC                  0x1A
  68 #define AQCSFRC                 0x1C
  69
  70 #define AQCTL_CBU_MASK          (BIT(9) | BIT(8))
  71 #define AQCTL_CBU_FRCLOW        BIT(8)
  72 #define AQCTL_CBU_FRCHIGH       BIT(9)
  73 #define AQCTL_CBU_FRCTOGGLE     (BIT(9) | BIT(8))
  74 #define AQCTL_CAU_MASK          (BIT(5) | BIT(4))
  75 #define AQCTL_CAU_FRCLOW        BIT(4)
  76 #define AQCTL_CAU_FRCHIGH       BIT(5)
  77 #define AQCTL_CAU_FRCTOGGLE     (BIT(5) | BIT(4))
  78 #define AQCTL_PRD_MASK          (BIT(3) | BIT(2))
  79 #define AQCTL_PRD_FRCLOW        BIT(2)
  80 #define AQCTL_PRD_FRCHIGH       BIT(3)
  81 #define AQCTL_PRD_FRCTOGGLE     (BIT(3) | BIT(2))
  82 #define AQCTL_ZRO_MASK          (BIT(1) | BIT(0))
  83 #define AQCTL_ZRO_FRCLOW        BIT(0)
  84 #define AQCTL_ZRO_FRCHIGH       BIT(1)
  85 #define AQCTL_ZRO_FRCTOGGLE     (BIT(1) | BIT(0))
  86
  87 #define AQCTL_CHANA_POLNORMAL   (AQCTL_CAU_FRCLOW | AQCTL_PRD_FRCHIGH | \
  88                                 AQCTL_ZRO_FRCHIGH)
  89 #define AQCTL_CHANA_POLINVERSED (AQCTL_CAU_FRCHIGH | AQCTL_PRD_FRCLOW | \
  90                                 AQCTL_ZRO_FRCLOW)
  91 #define AQCTL_CHANB_POLNORMAL   (AQCTL_CBU_FRCLOW | AQCTL_PRD_FRCHIGH | \
  92                                 AQCTL_ZRO_FRCHIGH)
  93 #define AQCTL_CHANB_POLINVERSED (AQCTL_CBU_FRCHIGH | AQCTL_PRD_FRCLOW | \
  94                                 AQCTL_ZRO_FRCLOW)
  95
  96 #define AQSFRC_RLDCSF_MASK      (BIT(7) | BIT(6))
  97 #define AQSFRC_RLDCSF_ZRO       0
  98 #define AQSFRC_RLDCSF_PRD       BIT(6)
  99 #define AQSFRC_RLDCSF_ZROPRD    BIT(7)
 100 #define AQSFRC_RLDCSF_IMDT      (BIT(7) | BIT(6))
 101
 102 #define AQCSFRC_CSFB_MASK       (BIT(3) | BIT(2))
 103 #define AQCSFRC_CSFB_FRCDIS     0
 104 #define AQCSFRC_CSFB_FRCLOW     BIT(2)
 105 #define AQCSFRC_CSFB_FRCHIGH    BIT(3)
 106 #define AQCSFRC_CSFB_DISSWFRC   (BIT(3) | BIT(2))
 107 #define AQCSFRC_CSFA_MASK       (BIT(1) | BIT(0))
 108 #define AQCSFRC_CSFA_FRCDIS     0
 109 #define AQCSFRC_CSFA_FRCLOW     BIT(0)
 110 #define AQCSFRC_CSFA_FRCHIGH    BIT(1)
 111 #define AQCSFRC_CSFA_DISSWFRC   (BIT(1) | BIT(0))
 112
 113 #define NUM_PWM_CHANNEL         2       /* EHRPWM channels */
 114
 115 struct ehrpwm_context {
 116         u16 tbctl;
 117         u16 tbprd;
 118         u16 cmpa;
 119         u16 cmpb;
 120         u16 aqctla;
 121         u16 aqctlb;
 122         u16 aqsfrc;
 123         u16 aqcsfrc;
 124 };
 125
 126 struct ehrpwm_pwm_chip {
 127         struct pwm_chip chip;
 128         unsigned int    clk_rate;
 129         void __iomem    *mmio_base;
 130         unsigned long period_cycles[NUM_PWM_CHANNEL];
 131         enum pwm_polarity polarity[NUM_PWM_CHANNEL];
 132         struct  clk     *tbclk;
 133         struct ehrpwm_context ctx;
 134 };
 135
 136 static inline struct ehrpwm_pwm_chip *to_ehrpwm_pwm_chip(struct pwm_chip *chip)
 137 {
 138         return container_of(chip, struct ehrpwm_pwm_chip, chip);
 139 }
 140
 141 static inline u16 ehrpwm_read(void __iomem *base, int offset)
 142 {
 143         return readw(base + offset);
 144 }
 145
 146 static inline void ehrpwm_write(void __iomem *base, int offset, unsigned int val)
 147 {
 148         writew(val & 0xFFFF, base + offset);
 149 }
 150
 151 static void ehrpwm_modify(void __iomem *base, int offset,
 152                 unsigned short mask, unsigned short val)
 153 {
 154         unsigned short regval;
 155
 156         regval = readw(base + offset);
 157         regval &= ~mask;
 158         regval |= val & mask;
 159         writew(regval, base + offset);
 160 }
 161
 162 /**
 163  * set_prescale_div -   Set up the prescaler divider function
 164  * @rqst_prescaler:     prescaler value min
 165  * @prescale_div:       prescaler value set
 166  * @tb_clk_div:         Time Base Control prescaler bits
 167  */
 168 static int set_prescale_div(unsigned long rqst_prescaler,
 169                 unsigned short *prescale_div, unsigned short *tb_clk_div)
 170 {
 171         unsigned int clkdiv, hspclkdiv;
 172
 173         for (clkdiv = 0; clkdiv <= CLKDIV_MAX; clkdiv++) {
 174                 for (hspclkdiv = 0; hspclkdiv <= HSPCLKDIV_MAX; hspclkdiv++) {
 175
 176                         /*
 177                          * calculations for prescaler value :
 178                          * prescale_div = HSPCLKDIVIDER * CLKDIVIDER.
 179                          * HSPCLKDIVIDER =  2 ** hspclkdiv
 180                          * CLKDIVIDER = (1),            if clkdiv == 0 *OR*
 181                          *              (2 * clkdiv),   if clkdiv != 0
 182                          *
 183                          * Configure prescale_div value such that period
 184                          * register value is less than 65535.
 185                          */
 186
 187                         *prescale_div = (1 << clkdiv) *
 188                                         (hspclkdiv ? (hspclkdiv * 2) : 1);
 189                         if (*prescale_div > rqst_prescaler) {
 190                                 *tb_clk_div = (clkdiv << TBCTL_CLKDIV_SHIFT) |
 191                                         (hspclkdiv << TBCTL_HSPCLKDIV_SHIFT);
 192                                 return 0;
 193                         }
 194                 }
 195         }
 196         return 1;
 197 }
 198
 199 static void configure_polarity(struct ehrpwm_pwm_chip *pc, int chan)
 200 {
 201         int aqctl_reg;
 202         unsigned short aqctl_val, aqctl_mask;
 203
 204         /*
 205          * Configure PWM output to HIGH/LOW level on counter
 206          * reaches compare register value and LOW/HIGH level
 207          * on counter value reaches period register value and
 208          * zero value on counter
 209          */
 210         if (chan == 1) {
 211                 aqctl_reg = AQCTLB;
 212                 aqctl_mask = AQCTL_CBU_MASK;
 213
 214                 if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
 215                         aqctl_val = AQCTL_CHANB_POLINVERSED;
 216                 else
 217                         aqctl_val = AQCTL_CHANB_POLNORMAL;
 218         } else {
 219                 aqctl_reg = AQCTLA;
 220                 aqctl_mask = AQCTL_CAU_MASK;
 221
 222                 if (pc->polarity[chan] == PWM_POLARITY_INVERSED)
 223                         aqctl_val = AQCTL_CHANA_POLINVERSED;
 224                 else
 225                         aqctl_val = AQCTL_CHANA_POLNORMAL;
 226         }
 227
 228         aqctl_mask |= AQCTL_PRD_MASK | AQCTL_ZRO_MASK;
 229         ehrpwm_modify(pc->mmio_base, aqctl_reg, aqctl_mask, aqctl_val);
 230 }
 231
 232 /*
 233  * period_ns = 10^9 * (ps_divval * period_cycles) / PWM_CLK_RATE
 234  * duty_ns   = 10^9 * (ps_divval * duty_cycles) / PWM_CLK_RATE
 235  */
 236 static int ehrpwm_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 237                 int duty_ns, int period_ns)
 238 {
 239         struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
 240         unsigned long long c;
 241         unsigned long period_cycles, duty_cycles;
 242         unsigned short ps_divval, tb_divval;
 243         int i, cmp_reg;
 244
 245         if (period_ns > NSEC_PER_SEC)
 246                 return -ERANGE;
 247
 248         c = pc->clk_rate;
 249         c = c * period_ns;
 250         do_div(c, NSEC_PER_SEC);
 251         period_cycles = (unsigned long)c;
 252
 253         if (period_cycles < 1) {
 254                 period_cycles = 1;
 255                 duty_cycles = 1;
 256         } else {
 257                 c = pc->clk_rate;
 258                 c = c * duty_ns;
 259                 do_div(c, NSEC_PER_SEC);
 260                 duty_cycles = (unsigned long)c;
 261         }
 262
 263         /*
 264          * Period values should be same for multiple PWM channels as IP uses
 265          * same period register for multiple channels.
 266          */
 267         for (i = 0; i < NUM_PWM_CHANNEL; i++) {
 268                 if (pc->period_cycles[i] &&
 269                                 (pc->period_cycles[i] != period_cycles)) {
 270                         /*
 271                          * Allow channel to reconfigure period if no other
 272                          * channels being configured.
 273                          */
 274                         if (i == pwm->hwpwm)
 275                                 continue;
 276
 277                         dev_err(chip->dev, "Period value conflicts with channel %d\n",
 278                                         i);
 279                         return -EINVAL;
 280                 }
 281         }
 282
 283         pc->period_cycles[pwm->hwpwm] = period_cycles;
 284
 285         /* Configure clock prescaler to support Low frequency PWM wave */
 286         if (set_prescale_div(period_cycles/PERIOD_MAX, &ps_divval,
 287                                 &tb_divval)) {
 288                 dev_err(chip->dev, "Unsupported values\n");
 289                 return -EINVAL;
 290         }
 291
 292         pm_runtime_get_sync(chip->dev);
 293
 294         /* Update clock prescaler values */
 295         ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CLKDIV_MASK, tb_divval);
 296
 297         /* Update period & duty cycle with presacler division */
 298         period_cycles = period_cycles / ps_divval;
 299         duty_cycles = duty_cycles / ps_divval;
 300
 301         /* Configure shadow loading on Period register */
 302         ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_PRDLD_MASK, TBCTL_PRDLD_SHDW);
 303
 304         ehrpwm_write(pc->mmio_base, TBPRD, period_cycles);
 305
 306         /* Configure ehrpwm counter for up-count mode */
 307         ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_CTRMODE_MASK,
 308                         TBCTL_CTRMODE_UP);
 309
 310         if (pwm->hwpwm == 1)
 311                 /* Channel 1 configured with compare B register */
 312                 cmp_reg = CMPB;
 313         else
 314                 /* Channel 0 configured with compare A register */
 315                 cmp_reg = CMPA;
 316
 317         ehrpwm_write(pc->mmio_base, cmp_reg, duty_cycles);
 318
 319         pm_runtime_put_sync(chip->dev);
 320         return 0;
 321 }
 322
 323 static int ehrpwm_pwm_set_polarity(struct pwm_chip *chip,
 324                 struct pwm_device *pwm, enum pwm_polarity polarity)
 325 {
 326         struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
 327
 328         /* Configuration of polarity in hardware delayed, do at enable */
 329         pc->polarity[pwm->hwpwm] = polarity;
 330         return 0;
 331 }
 332
 333 static int ehrpwm_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 334 {
 335         struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
 336         unsigned short aqcsfrc_val, aqcsfrc_mask;
 337         int ret;
 338
 339         /* Leave clock enabled on enabling PWM */
 340         pm_runtime_get_sync(chip->dev);
 341
 342         /* Disabling Action Qualifier on PWM output */
 343         if (pwm->hwpwm) {
 344                 aqcsfrc_val = AQCSFRC_CSFB_FRCDIS;
 345                 aqcsfrc_mask = AQCSFRC_CSFB_MASK;
 346         } else {
 347                 aqcsfrc_val = AQCSFRC_CSFA_FRCDIS;
 348                 aqcsfrc_mask = AQCSFRC_CSFA_MASK;
 349         }
 350
 351         /* Changes to shadow mode */
 352         ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
 353                         AQSFRC_RLDCSF_ZRO);
 354
 355         ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
 356
 357         /* Channels polarity can be configured from action qualifier module */
 358         configure_polarity(pc, pwm->hwpwm);
 359
 360         /* Enable TBCLK before enabling PWM device */
 361         ret = clk_enable(pc->tbclk);
 362         if (ret) {
 363                 dev_err(chip->dev, "Failed to enable TBCLK for %s\n",
 364                         dev_name(pc->chip.dev));
 365                 return ret;
 366         }
 367
 368         /* Enable time counter for free_run */
 369         ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_FREE_RUN);
 370         return 0;
 371 }
 372
 373 static void ehrpwm_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 374 {
 375         struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
 376         unsigned short aqcsfrc_val, aqcsfrc_mask;
 377
 378         /* Action Qualifier puts PWM output low forcefully */
 379         if (pwm->hwpwm) {
 380                 aqcsfrc_val = AQCSFRC_CSFB_FRCLOW;
 381                 aqcsfrc_mask = AQCSFRC_CSFB_MASK;
 382         } else {
 383                 aqcsfrc_val = AQCSFRC_CSFA_FRCLOW;
 384                 aqcsfrc_mask = AQCSFRC_CSFA_MASK;
 385         }
 386
 387         /*
 388          * Changes to immediate action on Action Qualifier. This puts
 389          * Action Qualifier control on PWM output from next TBCLK
 390          */
 391         ehrpwm_modify(pc->mmio_base, AQSFRC, AQSFRC_RLDCSF_MASK,
 392                         AQSFRC_RLDCSF_IMDT);
 393
 394         ehrpwm_modify(pc->mmio_base, AQCSFRC, aqcsfrc_mask, aqcsfrc_val);
 395
 396         /* Disabling TBCLK on PWM disable */
 397         clk_disable(pc->tbclk);
 398
 399         /* Stop Time base counter */
 400         ehrpwm_modify(pc->mmio_base, TBCTL, TBCTL_RUN_MASK, TBCTL_STOP_NEXT);
 401
 402         /* Disable clock on PWM disable */
 403         pm_runtime_put_sync(chip->dev);
 404 }
 405
 406 static void ehrpwm_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 407 {
 408         struct ehrpwm_pwm_chip *pc = to_ehrpwm_pwm_chip(chip);
 409
 410         if (test_bit(PWMF_ENABLED, &pwm->flags)) {
 411                 dev_warn(chip->dev, "Removing PWM device without disabling\n");
 412                 pm_runtime_put_sync(chip->dev);
 413         }
 414
 415         /* set period value to zero on free */
 416         pc->period_cycles[pwm->hwpwm] = 0;
 417 }
 418
 419 static const struct pwm_ops ehrpwm_pwm_ops = {
 420         .free           = ehrpwm_pwm_free,
 421         .config         = ehrpwm_pwm_config,
 422         .set_polarity   = ehrpwm_pwm_set_polarity,
 423         .enable         = ehrpwm_pwm_enable,
 424         .disable        = ehrpwm_pwm_disable,
 425         .owner          = THIS_MODULE,
 426 };
 427
 428 static const struct of_device_id ehrpwm_of_match[] = {
 429         { .compatible   = "ti,am33xx-ehrpwm" },
 430         {},
 431 };
 432 MODULE_DEVICE_TABLE(of, ehrpwm_of_match);
 433
 434 static int ehrpwm_pwm_probe(struct platform_device *pdev)
 435 {
 436         int ret;
 437         struct resource *r;
 438         struct clk *clk;
 439         struct ehrpwm_pwm_chip *pc;
 440         u16 status;
 441
 442         pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
 443         if (!pc)
 444                 return -ENOMEM;
 445
 446         clk = devm_clk_get(&pdev->dev, "fck");
 447         if (IS_ERR(clk)) {
 448                 dev_err(&pdev->dev, "failed to get clock\n");
 449                 return PTR_ERR(clk);
 450         }
 451
 452         pc->clk_rate = clk_get_rate(clk);
 453         if (!pc->clk_rate) {
 454                 dev_err(&pdev->dev, "failed to get clock rate\n");
 455                 return -EINVAL;
 456         }
 457
 458         pc->chip.dev = &pdev->dev;
 459         pc->chip.ops = &ehrpwm_pwm_ops;
 460         pc->chip.of_xlate = of_pwm_xlate_with_flags;
 461         pc->chip.of_pwm_n_cells = 3;
 462         pc->chip.base = -1;
 463         pc->chip.npwm = NUM_PWM_CHANNEL;
 464
 465         r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 466         pc->mmio_base = devm_ioremap_resource(&pdev->dev, r);
 467         if (IS_ERR(pc->mmio_base))
 468                 return PTR_ERR(pc->mmio_base);
 469
 470         /* Acquire tbclk for Time Base EHRPWM submodule */
 471         pc->tbclk = devm_clk_get(&pdev->dev, "tbclk");
 472         if (IS_ERR(pc->tbclk)) {
 473                 dev_err(&pdev->dev, "Failed to get tbclk\n");
 474                 return PTR_ERR(pc->tbclk);
 475         }
 476
 477         ret = clk_prepare(pc->tbclk);
 478         if (ret < 0) {
 479                 dev_err(&pdev->dev, "clk_prepare() failed: %d\n", ret);
 480                 return ret;
 481         }
 482
 483         ret = pwmchip_add(&pc->chip);
 484         if (ret < 0) {
 485                 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
 486                 return ret;
 487         }
 488
 489         pm_runtime_enable(&pdev->dev);
 490         pm_runtime_get_sync(&pdev->dev);
 491
 492         status = pwmss_submodule_state_change(pdev->dev.parent,
 493                         PWMSS_EPWMCLK_EN);
 494         if (!(status & PWMSS_EPWMCLK_EN_ACK)) {
 495                 dev_err(&pdev->dev, "PWMSS config space clock enable failed\n");
 496                 ret = -EINVAL;
 497                 goto pwmss_clk_failure;
 498         }
 499
 500         pm_runtime_put_sync(&pdev->dev);
 501
 502         platform_set_drvdata(pdev, pc);
 503         return 0;
 504
 505 pwmss_clk_failure:
 506         pm_runtime_put_sync(&pdev->dev);
 507         pm_runtime_disable(&pdev->dev);
 508         pwmchip_remove(&pc->chip);
 509         clk_unprepare(pc->tbclk);
 510         return ret;
 511 }
 512
 513 static int ehrpwm_pwm_remove(struct platform_device *pdev)
 514 {
 515         struct ehrpwm_pwm_chip *pc = platform_get_drvdata(pdev);
 516
 517         clk_unprepare(pc->tbclk);
 518
 519         pm_runtime_get_sync(&pdev->dev);
 520         /*
 521          * Due to hardware misbehaviour, acknowledge of the stop_req
 522          * is missing. Hence checking of the status bit skipped.
 523          */
 524         pwmss_submodule_state_change(pdev->dev.parent, PWMSS_EPWMCLK_STOP_REQ);
 525         pm_runtime_put_sync(&pdev->dev);
 526
 527         pm_runtime_put_sync(&pdev->dev);
 528         pm_runtime_disable(&pdev->dev);
 529         return pwmchip_remove(&pc->chip);
 530 }
 531
 532 #ifdef CONFIG_PM_SLEEP
 533 static void ehrpwm_pwm_save_context(struct ehrpwm_pwm_chip *pc)
 534 {
 535         pm_runtime_get_sync(pc->chip.dev);
 536         pc->ctx.tbctl = ehrpwm_read(pc->mmio_base, TBCTL);
 537         pc->ctx.tbprd = ehrpwm_read(pc->mmio_base, TBPRD);
 538         pc->ctx.cmpa = ehrpwm_read(pc->mmio_base, CMPA);
 539         pc->ctx.cmpb = ehrpwm_read(pc->mmio_base, CMPB);
 540         pc->ctx.aqctla = ehrpwm_read(pc->mmio_base, AQCTLA);
 541         pc->ctx.aqctlb = ehrpwm_read(pc->mmio_base, AQCTLB);
 542         pc->ctx.aqsfrc = ehrpwm_read(pc->mmio_base, AQSFRC);
 543         pc->ctx.aqcsfrc = ehrpwm_read(pc->mmio_base, AQCSFRC);
 544         pm_runtime_put_sync(pc->chip.dev);
 545 }
 546
 547 static void ehrpwm_pwm_restore_context(struct ehrpwm_pwm_chip *pc)
 548 {
 549         ehrpwm_write(pc->mmio_base, TBPRD, pc->ctx.tbprd);
 550         ehrpwm_write(pc->mmio_base, CMPA, pc->ctx.cmpa);
 551         ehrpwm_write(pc->mmio_base, CMPB, pc->ctx.cmpb);
 552         ehrpwm_write(pc->mmio_base, AQCTLA, pc->ctx.aqctla);
 553         ehrpwm_write(pc->mmio_base, AQCTLB, pc->ctx.aqctlb);
 554         ehrpwm_write(pc->mmio_base, AQSFRC, pc->ctx.aqsfrc);
 555         ehrpwm_write(pc->mmio_base, AQCSFRC, pc->ctx.aqcsfrc);
 556         ehrpwm_write(pc->mmio_base, TBCTL, pc->ctx.tbctl);
 557 }
 558
 559 static int ehrpwm_pwm_suspend(struct device *dev)
 560 {
 561         struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
 562         int i;
 563
 564         ehrpwm_pwm_save_context(pc);
 565         for (i = 0; i < pc->chip.npwm; i++) {
 566                 struct pwm_device *pwm = &pc->chip.pwms[i];
 567
 568                 if (!test_bit(PWMF_ENABLED, &pwm->flags))
 569                         continue;
 570
 571                 /* Disable explicitly if PWM is running */
 572                 pm_runtime_put_sync(dev);
 573         }
 574         return 0;
 575 }
 576
 577 static int ehrpwm_pwm_resume(struct device *dev)
 578 {
 579         struct ehrpwm_pwm_chip *pc = dev_get_drvdata(dev);
 580         int i;
 581
 582         for (i = 0; i < pc->chip.npwm; i++) {
 583                 struct pwm_device *pwm = &pc->chip.pwms[i];
 584
 585                 if (!test_bit(PWMF_ENABLED, &pwm->flags))
 586                         continue;
 587
 588                 /* Enable explicitly if PWM was running */
 589                 pm_runtime_get_sync(dev);
 590         }
 591         ehrpwm_pwm_restore_context(pc);
 592         return 0;
 593 }
 594 #endif
 595
 596 static SIMPLE_DEV_PM_OPS(ehrpwm_pwm_pm_ops, ehrpwm_pwm_suspend,
 597                 ehrpwm_pwm_resume);
 598
 599 static struct platform_driver ehrpwm_pwm_driver = {
 600         .driver = {
 601                 .name   = "ehrpwm",
 602                 .of_match_table = ehrpwm_of_match,
 603                 .pm     = &ehrpwm_pwm_pm_ops,
 604         },
 605         .probe = ehrpwm_pwm_probe,
 606         .remove = ehrpwm_pwm_remove,
 607 };
 608
 609 module_platform_driver(ehrpwm_pwm_driver);
 610
 611 MODULE_DESCRIPTION("EHRPWM PWM driver");
 612 MODULE_AUTHOR("Texas Instruments");
 613 MODULE_LICENSE("GPL");