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