1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) Overkiz SAS 2012 4 * 5 * Author: Boris BREZILLON <b.brezillon@overkiz.com> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/init.h> 10 #include <linux/clocksource.h> 11 #include <linux/clockchips.h> 12 #include <linux/interrupt.h> 13 #include <linux/irq.h> 14 15 #include <linux/clk.h> 16 #include <linux/err.h> 17 #include <linux/ioport.h> 18 #include <linux/io.h> 19 #include <linux/mfd/syscon.h> 20 #include <linux/platform_device.h> 21 #include <linux/pwm.h> 22 #include <linux/of_device.h> 23 #include <linux/of_irq.h> 24 #include <linux/regmap.h> 25 #include <linux/slab.h> 26 #include <soc/at91/atmel_tcb.h> 27 28 #define NPWM 2 29 30 #define ATMEL_TC_ACMR_MASK (ATMEL_TC_ACPA | ATMEL_TC_ACPC | \ 31 ATMEL_TC_AEEVT | ATMEL_TC_ASWTRG) 32 33 #define ATMEL_TC_BCMR_MASK (ATMEL_TC_BCPB | ATMEL_TC_BCPC | \ 34 ATMEL_TC_BEEVT | ATMEL_TC_BSWTRG) 35 36 struct atmel_tcb_pwm_device { 37 enum pwm_polarity polarity; /* PWM polarity */ 38 unsigned div; /* PWM clock divider */ 39 unsigned duty; /* PWM duty expressed in clk cycles */ 40 unsigned period; /* PWM period expressed in clk cycles */ 41 }; 42 43 struct atmel_tcb_channel { 44 u32 enabled; 45 u32 cmr; 46 u32 ra; 47 u32 rb; 48 u32 rc; 49 }; 50 51 struct atmel_tcb_pwm_chip { 52 struct pwm_chip chip; 53 spinlock_t lock; 54 u8 channel; 55 u8 width; 56 struct regmap *regmap; 57 struct clk *clk; 58 struct clk *gclk; 59 struct clk *slow_clk; 60 struct atmel_tcb_pwm_device *pwms[NPWM]; 61 struct atmel_tcb_channel bkup; 62 }; 63 64 static const u8 atmel_tcb_divisors[] = { 2, 8, 32, 128, 0, }; 65 66 static inline struct atmel_tcb_pwm_chip *to_tcb_chip(struct pwm_chip *chip) 67 { 68 return container_of(chip, struct atmel_tcb_pwm_chip, chip); 69 } 70 71 static int atmel_tcb_pwm_set_polarity(struct pwm_chip *chip, 72 struct pwm_device *pwm, 73 enum pwm_polarity polarity) 74 { 75 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); 76 struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm]; 77 78 tcbpwm->polarity = polarity; 79 80 return 0; 81 } 82 83 static int atmel_tcb_pwm_request(struct pwm_chip *chip, 84 struct pwm_device *pwm) 85 { 86 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); 87 struct atmel_tcb_pwm_device *tcbpwm; 88 unsigned cmr; 89 int ret; 90 91 tcbpwm = devm_kzalloc(chip->dev, sizeof(*tcbpwm), GFP_KERNEL); 92 if (!tcbpwm) 93 return -ENOMEM; 94 95 ret = clk_prepare_enable(tcbpwmc->clk); 96 if (ret) { 97 devm_kfree(chip->dev, tcbpwm); 98 return ret; 99 } 100 101 tcbpwm->polarity = PWM_POLARITY_NORMAL; 102 tcbpwm->duty = 0; 103 tcbpwm->period = 0; 104 tcbpwm->div = 0; 105 106 spin_lock(&tcbpwmc->lock); 107 regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr); 108 /* 109 * Get init config from Timer Counter registers if 110 * Timer Counter is already configured as a PWM generator. 111 */ 112 if (cmr & ATMEL_TC_WAVE) { 113 if (pwm->hwpwm == 0) 114 regmap_read(tcbpwmc->regmap, 115 ATMEL_TC_REG(tcbpwmc->channel, RA), 116 &tcbpwm->duty); 117 else 118 regmap_read(tcbpwmc->regmap, 119 ATMEL_TC_REG(tcbpwmc->channel, RB), 120 &tcbpwm->duty); 121 122 tcbpwm->div = cmr & ATMEL_TC_TCCLKS; 123 regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC), 124 &tcbpwm->period); 125 cmr &= (ATMEL_TC_TCCLKS | ATMEL_TC_ACMR_MASK | 126 ATMEL_TC_BCMR_MASK); 127 } else 128 cmr = 0; 129 130 cmr |= ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO | ATMEL_TC_EEVT_XC0; 131 regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr); 132 spin_unlock(&tcbpwmc->lock); 133 134 tcbpwmc->pwms[pwm->hwpwm] = tcbpwm; 135 136 return 0; 137 } 138 139 static void atmel_tcb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) 140 { 141 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); 142 struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm]; 143 144 clk_disable_unprepare(tcbpwmc->clk); 145 tcbpwmc->pwms[pwm->hwpwm] = NULL; 146 devm_kfree(chip->dev, tcbpwm); 147 } 148 149 static void atmel_tcb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm) 150 { 151 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); 152 struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm]; 153 unsigned cmr; 154 enum pwm_polarity polarity = tcbpwm->polarity; 155 156 /* 157 * If duty is 0 the timer will be stopped and we have to 158 * configure the output correctly on software trigger: 159 * - set output to high if PWM_POLARITY_INVERSED 160 * - set output to low if PWM_POLARITY_NORMAL 161 * 162 * This is why we're reverting polarity in this case. 163 */ 164 if (tcbpwm->duty == 0) 165 polarity = !polarity; 166 167 spin_lock(&tcbpwmc->lock); 168 regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr); 169 170 /* flush old setting and set the new one */ 171 if (pwm->hwpwm == 0) { 172 cmr &= ~ATMEL_TC_ACMR_MASK; 173 if (polarity == PWM_POLARITY_INVERSED) 174 cmr |= ATMEL_TC_ASWTRG_CLEAR; 175 else 176 cmr |= ATMEL_TC_ASWTRG_SET; 177 } else { 178 cmr &= ~ATMEL_TC_BCMR_MASK; 179 if (polarity == PWM_POLARITY_INVERSED) 180 cmr |= ATMEL_TC_BSWTRG_CLEAR; 181 else 182 cmr |= ATMEL_TC_BSWTRG_SET; 183 } 184 185 regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr); 186 187 /* 188 * Use software trigger to apply the new setting. 189 * If both PWM devices in this group are disabled we stop the clock. 190 */ 191 if (!(cmr & (ATMEL_TC_ACPC | ATMEL_TC_BCPC))) { 192 regmap_write(tcbpwmc->regmap, 193 ATMEL_TC_REG(tcbpwmc->channel, CCR), 194 ATMEL_TC_SWTRG | ATMEL_TC_CLKDIS); 195 tcbpwmc->bkup.enabled = 1; 196 } else { 197 regmap_write(tcbpwmc->regmap, 198 ATMEL_TC_REG(tcbpwmc->channel, CCR), 199 ATMEL_TC_SWTRG); 200 tcbpwmc->bkup.enabled = 0; 201 } 202 203 spin_unlock(&tcbpwmc->lock); 204 } 205 206 static int atmel_tcb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm) 207 { 208 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); 209 struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm]; 210 u32 cmr; 211 enum pwm_polarity polarity = tcbpwm->polarity; 212 213 /* 214 * If duty is 0 the timer will be stopped and we have to 215 * configure the output correctly on software trigger: 216 * - set output to high if PWM_POLARITY_INVERSED 217 * - set output to low if PWM_POLARITY_NORMAL 218 * 219 * This is why we're reverting polarity in this case. 220 */ 221 if (tcbpwm->duty == 0) 222 polarity = !polarity; 223 224 spin_lock(&tcbpwmc->lock); 225 regmap_read(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), &cmr); 226 227 /* flush old setting and set the new one */ 228 cmr &= ~ATMEL_TC_TCCLKS; 229 230 if (pwm->hwpwm == 0) { 231 cmr &= ~ATMEL_TC_ACMR_MASK; 232 233 /* Set CMR flags according to given polarity */ 234 if (polarity == PWM_POLARITY_INVERSED) 235 cmr |= ATMEL_TC_ASWTRG_CLEAR; 236 else 237 cmr |= ATMEL_TC_ASWTRG_SET; 238 } else { 239 cmr &= ~ATMEL_TC_BCMR_MASK; 240 if (polarity == PWM_POLARITY_INVERSED) 241 cmr |= ATMEL_TC_BSWTRG_CLEAR; 242 else 243 cmr |= ATMEL_TC_BSWTRG_SET; 244 } 245 246 /* 247 * If duty is 0 or equal to period there's no need to register 248 * a specific action on RA/RB and RC compare. 249 * The output will be configured on software trigger and keep 250 * this config till next config call. 251 */ 252 if (tcbpwm->duty != tcbpwm->period && tcbpwm->duty > 0) { 253 if (pwm->hwpwm == 0) { 254 if (polarity == PWM_POLARITY_INVERSED) 255 cmr |= ATMEL_TC_ACPA_SET | ATMEL_TC_ACPC_CLEAR; 256 else 257 cmr |= ATMEL_TC_ACPA_CLEAR | ATMEL_TC_ACPC_SET; 258 } else { 259 if (polarity == PWM_POLARITY_INVERSED) 260 cmr |= ATMEL_TC_BCPB_SET | ATMEL_TC_BCPC_CLEAR; 261 else 262 cmr |= ATMEL_TC_BCPB_CLEAR | ATMEL_TC_BCPC_SET; 263 } 264 } 265 266 cmr |= (tcbpwm->div & ATMEL_TC_TCCLKS); 267 268 regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CMR), cmr); 269 270 if (pwm->hwpwm == 0) 271 regmap_write(tcbpwmc->regmap, 272 ATMEL_TC_REG(tcbpwmc->channel, RA), 273 tcbpwm->duty); 274 else 275 regmap_write(tcbpwmc->regmap, 276 ATMEL_TC_REG(tcbpwmc->channel, RB), 277 tcbpwm->duty); 278 279 regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, RC), 280 tcbpwm->period); 281 282 /* Use software trigger to apply the new setting */ 283 regmap_write(tcbpwmc->regmap, ATMEL_TC_REG(tcbpwmc->channel, CCR), 284 ATMEL_TC_SWTRG | ATMEL_TC_CLKEN); 285 tcbpwmc->bkup.enabled = 1; 286 spin_unlock(&tcbpwmc->lock); 287 return 0; 288 } 289 290 static int atmel_tcb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm, 291 int duty_ns, int period_ns) 292 { 293 struct atmel_tcb_pwm_chip *tcbpwmc = to_tcb_chip(chip); 294 struct atmel_tcb_pwm_device *tcbpwm = tcbpwmc->pwms[pwm->hwpwm]; 295 struct atmel_tcb_pwm_device *atcbpwm = NULL; 296 int i = 0; 297 int slowclk = 0; 298 unsigned period; 299 unsigned duty; 300 unsigned rate = clk_get_rate(tcbpwmc->clk); 301 unsigned long long min; 302 unsigned long long max; 303 304 /* 305 * Find best clk divisor: 306 * the smallest divisor which can fulfill the period_ns requirements. 307 * If there is a gclk, the first divisor is actually the gclk selector 308 */ 309 if (tcbpwmc->gclk) 310 i = 1; 311 for (; i < ARRAY_SIZE(atmel_tcb_divisors); ++i) { 312 if (atmel_tcb_divisors[i] == 0) { 313 slowclk = i; 314 continue; 315 } 316 min = div_u64((u64)NSEC_PER_SEC * atmel_tcb_divisors[i], rate); 317 max = min << tcbpwmc->width; 318 if (max >= period_ns) 319 break; 320 } 321 322 /* 323 * If none of the divisor are small enough to represent period_ns 324 * take slow clock (32KHz). 325 */ 326 if (i == ARRAY_SIZE(atmel_tcb_divisors)) { 327 i = slowclk; 328 rate = clk_get_rate(tcbpwmc->slow_clk); 329 min = div_u64(NSEC_PER_SEC, rate); 330 max = min << tcbpwmc->width; 331 332 /* If period is too big return ERANGE error */ 333 if (max < period_ns) 334 return -ERANGE; 335 } 336 337 duty = div_u64(duty_ns, min); 338 period = div_u64(period_ns, min); 339 340 if (pwm->hwpwm == 0) 341 atcbpwm = tcbpwmc->pwms[1]; 342 else 343 atcbpwm = tcbpwmc->pwms[0]; 344 345 /* 346 * PWM devices provided by the TCB driver are grouped by 2. 347 * PWM devices in a given group must be configured with the 348 * same period_ns. 349 * 350 * We're checking the period value of the second PWM device 351 * in this group before applying the new config. 352 */ 353 if ((atcbpwm && atcbpwm->duty > 0 && 354 atcbpwm->duty != atcbpwm->period) && 355 (atcbpwm->div != i || atcbpwm->period != period)) { 356 dev_err(chip->dev, 357 "failed to configure period_ns: PWM group already configured with a different value\n"); 358 return -EINVAL; 359 } 360 361 tcbpwm->period = period; 362 tcbpwm->div = i; 363 tcbpwm->duty = duty; 364 365 return 0; 366 } 367 368 static int atmel_tcb_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, 369 const struct pwm_state *state) 370 { 371 int duty_cycle, period; 372 int ret; 373 374 /* This function only sets a flag in driver data */ 375 atmel_tcb_pwm_set_polarity(chip, pwm, state->polarity); 376 377 if (!state->enabled) { 378 atmel_tcb_pwm_disable(chip, pwm); 379 return 0; 380 } 381 382 period = state->period < INT_MAX ? state->period : INT_MAX; 383 duty_cycle = state->duty_cycle < INT_MAX ? state->duty_cycle : INT_MAX; 384 385 ret = atmel_tcb_pwm_config(chip, pwm, duty_cycle, period); 386 if (ret) 387 return ret; 388 389 return atmel_tcb_pwm_enable(chip, pwm); 390 } 391 392 static const struct pwm_ops atmel_tcb_pwm_ops = { 393 .request = atmel_tcb_pwm_request, 394 .free = atmel_tcb_pwm_free, 395 .apply = atmel_tcb_pwm_apply, 396 .owner = THIS_MODULE, 397 }; 398 399 static struct atmel_tcb_config tcb_rm9200_config = { 400 .counter_width = 16, 401 }; 402 403 static struct atmel_tcb_config tcb_sam9x5_config = { 404 .counter_width = 32, 405 }; 406 407 static struct atmel_tcb_config tcb_sama5d2_config = { 408 .counter_width = 32, 409 .has_gclk = 1, 410 }; 411 412 static const struct of_device_id atmel_tcb_of_match[] = { 413 { .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, }, 414 { .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, }, 415 { .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, }, 416 { /* sentinel */ } 417 }; 418 419 static int atmel_tcb_pwm_probe(struct platform_device *pdev) 420 { 421 const struct of_device_id *match; 422 struct atmel_tcb_pwm_chip *tcbpwm; 423 const struct atmel_tcb_config *config; 424 struct device_node *np = pdev->dev.of_node; 425 struct regmap *regmap; 426 struct clk *clk, *gclk = NULL; 427 struct clk *slow_clk; 428 char clk_name[] = "t0_clk"; 429 int err; 430 int channel; 431 432 err = of_property_read_u32(np, "reg", &channel); 433 if (err < 0) { 434 dev_err(&pdev->dev, 435 "failed to get Timer Counter Block channel from device tree (error: %d)\n", 436 err); 437 return err; 438 } 439 440 regmap = syscon_node_to_regmap(np->parent); 441 if (IS_ERR(regmap)) 442 return PTR_ERR(regmap); 443 444 slow_clk = of_clk_get_by_name(np->parent, "slow_clk"); 445 if (IS_ERR(slow_clk)) 446 return PTR_ERR(slow_clk); 447 448 clk_name[1] += channel; 449 clk = of_clk_get_by_name(np->parent, clk_name); 450 if (IS_ERR(clk)) 451 clk = of_clk_get_by_name(np->parent, "t0_clk"); 452 if (IS_ERR(clk)) 453 return PTR_ERR(clk); 454 455 match = of_match_node(atmel_tcb_of_match, np->parent); 456 config = match->data; 457 458 if (config->has_gclk) { 459 gclk = of_clk_get_by_name(np->parent, "gclk"); 460 if (IS_ERR(gclk)) 461 return PTR_ERR(gclk); 462 } 463 464 tcbpwm = devm_kzalloc(&pdev->dev, sizeof(*tcbpwm), GFP_KERNEL); 465 if (tcbpwm == NULL) { 466 err = -ENOMEM; 467 goto err_slow_clk; 468 } 469 470 tcbpwm->chip.dev = &pdev->dev; 471 tcbpwm->chip.ops = &atmel_tcb_pwm_ops; 472 tcbpwm->chip.npwm = NPWM; 473 tcbpwm->channel = channel; 474 tcbpwm->regmap = regmap; 475 tcbpwm->clk = clk; 476 tcbpwm->gclk = gclk; 477 tcbpwm->slow_clk = slow_clk; 478 tcbpwm->width = config->counter_width; 479 480 err = clk_prepare_enable(slow_clk); 481 if (err) 482 goto err_slow_clk; 483 484 spin_lock_init(&tcbpwm->lock); 485 486 err = pwmchip_add(&tcbpwm->chip); 487 if (err < 0) 488 goto err_disable_clk; 489 490 platform_set_drvdata(pdev, tcbpwm); 491 492 return 0; 493 494 err_disable_clk: 495 clk_disable_unprepare(tcbpwm->slow_clk); 496 497 err_slow_clk: 498 clk_put(slow_clk); 499 500 return err; 501 } 502 503 static void atmel_tcb_pwm_remove(struct platform_device *pdev) 504 { 505 struct atmel_tcb_pwm_chip *tcbpwm = platform_get_drvdata(pdev); 506 507 pwmchip_remove(&tcbpwm->chip); 508 509 clk_disable_unprepare(tcbpwm->slow_clk); 510 clk_put(tcbpwm->slow_clk); 511 clk_put(tcbpwm->clk); 512 } 513 514 static const struct of_device_id atmel_tcb_pwm_dt_ids[] = { 515 { .compatible = "atmel,tcb-pwm", }, 516 { /* sentinel */ } 517 }; 518 MODULE_DEVICE_TABLE(of, atmel_tcb_pwm_dt_ids); 519 520 #ifdef CONFIG_PM_SLEEP 521 static int atmel_tcb_pwm_suspend(struct device *dev) 522 { 523 struct atmel_tcb_pwm_chip *tcbpwm = dev_get_drvdata(dev); 524 struct atmel_tcb_channel *chan = &tcbpwm->bkup; 525 unsigned int channel = tcbpwm->channel; 526 527 regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, CMR), &chan->cmr); 528 regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RA), &chan->ra); 529 regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RB), &chan->rb); 530 regmap_read(tcbpwm->regmap, ATMEL_TC_REG(channel, RC), &chan->rc); 531 532 return 0; 533 } 534 535 static int atmel_tcb_pwm_resume(struct device *dev) 536 { 537 struct atmel_tcb_pwm_chip *tcbpwm = dev_get_drvdata(dev); 538 struct atmel_tcb_channel *chan = &tcbpwm->bkup; 539 unsigned int channel = tcbpwm->channel; 540 541 regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, CMR), chan->cmr); 542 regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RA), chan->ra); 543 regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RB), chan->rb); 544 regmap_write(tcbpwm->regmap, ATMEL_TC_REG(channel, RC), chan->rc); 545 546 if (chan->enabled) 547 regmap_write(tcbpwm->regmap, 548 ATMEL_TC_CLKEN | ATMEL_TC_SWTRG, 549 ATMEL_TC_REG(channel, CCR)); 550 551 return 0; 552 } 553 #endif 554 555 static SIMPLE_DEV_PM_OPS(atmel_tcb_pwm_pm_ops, atmel_tcb_pwm_suspend, 556 atmel_tcb_pwm_resume); 557 558 static struct platform_driver atmel_tcb_pwm_driver = { 559 .driver = { 560 .name = "atmel-tcb-pwm", 561 .of_match_table = atmel_tcb_pwm_dt_ids, 562 .pm = &atmel_tcb_pwm_pm_ops, 563 }, 564 .probe = atmel_tcb_pwm_probe, 565 .remove_new = atmel_tcb_pwm_remove, 566 }; 567 module_platform_driver(atmel_tcb_pwm_driver); 568 569 MODULE_AUTHOR("Boris BREZILLON <b.brezillon@overkiz.com>"); 570 MODULE_DESCRIPTION("Atmel Timer Counter Pulse Width Modulation Driver"); 571 MODULE_LICENSE("GPL v2"); 572