1 /* 2 * SuperH Timer Support - MTU2 3 * 4 * Copyright (C) 2009 Magnus Damm 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 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 */ 15 16 #include <linux/clk.h> 17 #include <linux/clockchips.h> 18 #include <linux/delay.h> 19 #include <linux/err.h> 20 #include <linux/init.h> 21 #include <linux/interrupt.h> 22 #include <linux/io.h> 23 #include <linux/ioport.h> 24 #include <linux/irq.h> 25 #include <linux/module.h> 26 #include <linux/of.h> 27 #include <linux/platform_device.h> 28 #include <linux/pm_domain.h> 29 #include <linux/pm_runtime.h> 30 #include <linux/sh_timer.h> 31 #include <linux/slab.h> 32 #include <linux/spinlock.h> 33 34 struct sh_mtu2_device; 35 36 struct sh_mtu2_channel { 37 struct sh_mtu2_device *mtu; 38 unsigned int index; 39 40 void __iomem *base; 41 42 struct clock_event_device ced; 43 }; 44 45 struct sh_mtu2_device { 46 struct platform_device *pdev; 47 48 void __iomem *mapbase; 49 struct clk *clk; 50 51 raw_spinlock_t lock; /* Protect the shared registers */ 52 53 struct sh_mtu2_channel *channels; 54 unsigned int num_channels; 55 56 bool has_clockevent; 57 }; 58 59 #define TSTR -1 /* shared register */ 60 #define TCR 0 /* channel register */ 61 #define TMDR 1 /* channel register */ 62 #define TIOR 2 /* channel register */ 63 #define TIER 3 /* channel register */ 64 #define TSR 4 /* channel register */ 65 #define TCNT 5 /* channel register */ 66 #define TGR 6 /* channel register */ 67 68 #define TCR_CCLR_NONE (0 << 5) 69 #define TCR_CCLR_TGRA (1 << 5) 70 #define TCR_CCLR_TGRB (2 << 5) 71 #define TCR_CCLR_SYNC (3 << 5) 72 #define TCR_CCLR_TGRC (5 << 5) 73 #define TCR_CCLR_TGRD (6 << 5) 74 #define TCR_CCLR_MASK (7 << 5) 75 #define TCR_CKEG_RISING (0 << 3) 76 #define TCR_CKEG_FALLING (1 << 3) 77 #define TCR_CKEG_BOTH (2 << 3) 78 #define TCR_CKEG_MASK (3 << 3) 79 /* Values 4 to 7 are channel-dependent */ 80 #define TCR_TPSC_P1 (0 << 0) 81 #define TCR_TPSC_P4 (1 << 0) 82 #define TCR_TPSC_P16 (2 << 0) 83 #define TCR_TPSC_P64 (3 << 0) 84 #define TCR_TPSC_CH0_TCLKA (4 << 0) 85 #define TCR_TPSC_CH0_TCLKB (5 << 0) 86 #define TCR_TPSC_CH0_TCLKC (6 << 0) 87 #define TCR_TPSC_CH0_TCLKD (7 << 0) 88 #define TCR_TPSC_CH1_TCLKA (4 << 0) 89 #define TCR_TPSC_CH1_TCLKB (5 << 0) 90 #define TCR_TPSC_CH1_P256 (6 << 0) 91 #define TCR_TPSC_CH1_TCNT2 (7 << 0) 92 #define TCR_TPSC_CH2_TCLKA (4 << 0) 93 #define TCR_TPSC_CH2_TCLKB (5 << 0) 94 #define TCR_TPSC_CH2_TCLKC (6 << 0) 95 #define TCR_TPSC_CH2_P1024 (7 << 0) 96 #define TCR_TPSC_CH34_P256 (4 << 0) 97 #define TCR_TPSC_CH34_P1024 (5 << 0) 98 #define TCR_TPSC_CH34_TCLKA (6 << 0) 99 #define TCR_TPSC_CH34_TCLKB (7 << 0) 100 #define TCR_TPSC_MASK (7 << 0) 101 102 #define TMDR_BFE (1 << 6) 103 #define TMDR_BFB (1 << 5) 104 #define TMDR_BFA (1 << 4) 105 #define TMDR_MD_NORMAL (0 << 0) 106 #define TMDR_MD_PWM_1 (2 << 0) 107 #define TMDR_MD_PWM_2 (3 << 0) 108 #define TMDR_MD_PHASE_1 (4 << 0) 109 #define TMDR_MD_PHASE_2 (5 << 0) 110 #define TMDR_MD_PHASE_3 (6 << 0) 111 #define TMDR_MD_PHASE_4 (7 << 0) 112 #define TMDR_MD_PWM_SYNC (8 << 0) 113 #define TMDR_MD_PWM_COMP_CREST (13 << 0) 114 #define TMDR_MD_PWM_COMP_TROUGH (14 << 0) 115 #define TMDR_MD_PWM_COMP_BOTH (15 << 0) 116 #define TMDR_MD_MASK (15 << 0) 117 118 #define TIOC_IOCH(n) ((n) << 4) 119 #define TIOC_IOCL(n) ((n) << 0) 120 #define TIOR_OC_RETAIN (0 << 0) 121 #define TIOR_OC_0_CLEAR (1 << 0) 122 #define TIOR_OC_0_SET (2 << 0) 123 #define TIOR_OC_0_TOGGLE (3 << 0) 124 #define TIOR_OC_1_CLEAR (5 << 0) 125 #define TIOR_OC_1_SET (6 << 0) 126 #define TIOR_OC_1_TOGGLE (7 << 0) 127 #define TIOR_IC_RISING (8 << 0) 128 #define TIOR_IC_FALLING (9 << 0) 129 #define TIOR_IC_BOTH (10 << 0) 130 #define TIOR_IC_TCNT (12 << 0) 131 #define TIOR_MASK (15 << 0) 132 133 #define TIER_TTGE (1 << 7) 134 #define TIER_TTGE2 (1 << 6) 135 #define TIER_TCIEU (1 << 5) 136 #define TIER_TCIEV (1 << 4) 137 #define TIER_TGIED (1 << 3) 138 #define TIER_TGIEC (1 << 2) 139 #define TIER_TGIEB (1 << 1) 140 #define TIER_TGIEA (1 << 0) 141 142 #define TSR_TCFD (1 << 7) 143 #define TSR_TCFU (1 << 5) 144 #define TSR_TCFV (1 << 4) 145 #define TSR_TGFD (1 << 3) 146 #define TSR_TGFC (1 << 2) 147 #define TSR_TGFB (1 << 1) 148 #define TSR_TGFA (1 << 0) 149 150 static unsigned long mtu2_reg_offs[] = { 151 [TCR] = 0, 152 [TMDR] = 1, 153 [TIOR] = 2, 154 [TIER] = 4, 155 [TSR] = 5, 156 [TCNT] = 6, 157 [TGR] = 8, 158 }; 159 160 static inline unsigned long sh_mtu2_read(struct sh_mtu2_channel *ch, int reg_nr) 161 { 162 unsigned long offs; 163 164 if (reg_nr == TSTR) 165 return ioread8(ch->mtu->mapbase + 0x280); 166 167 offs = mtu2_reg_offs[reg_nr]; 168 169 if ((reg_nr == TCNT) || (reg_nr == TGR)) 170 return ioread16(ch->base + offs); 171 else 172 return ioread8(ch->base + offs); 173 } 174 175 static inline void sh_mtu2_write(struct sh_mtu2_channel *ch, int reg_nr, 176 unsigned long value) 177 { 178 unsigned long offs; 179 180 if (reg_nr == TSTR) 181 return iowrite8(value, ch->mtu->mapbase + 0x280); 182 183 offs = mtu2_reg_offs[reg_nr]; 184 185 if ((reg_nr == TCNT) || (reg_nr == TGR)) 186 iowrite16(value, ch->base + offs); 187 else 188 iowrite8(value, ch->base + offs); 189 } 190 191 static void sh_mtu2_start_stop_ch(struct sh_mtu2_channel *ch, int start) 192 { 193 unsigned long flags, value; 194 195 /* start stop register shared by multiple timer channels */ 196 raw_spin_lock_irqsave(&ch->mtu->lock, flags); 197 value = sh_mtu2_read(ch, TSTR); 198 199 if (start) 200 value |= 1 << ch->index; 201 else 202 value &= ~(1 << ch->index); 203 204 sh_mtu2_write(ch, TSTR, value); 205 raw_spin_unlock_irqrestore(&ch->mtu->lock, flags); 206 } 207 208 static int sh_mtu2_enable(struct sh_mtu2_channel *ch) 209 { 210 unsigned long periodic; 211 unsigned long rate; 212 int ret; 213 214 pm_runtime_get_sync(&ch->mtu->pdev->dev); 215 dev_pm_syscore_device(&ch->mtu->pdev->dev, true); 216 217 /* enable clock */ 218 ret = clk_enable(ch->mtu->clk); 219 if (ret) { 220 dev_err(&ch->mtu->pdev->dev, "ch%u: cannot enable clock\n", 221 ch->index); 222 return ret; 223 } 224 225 /* make sure channel is disabled */ 226 sh_mtu2_start_stop_ch(ch, 0); 227 228 rate = clk_get_rate(ch->mtu->clk) / 64; 229 periodic = (rate + HZ/2) / HZ; 230 231 /* 232 * "Periodic Counter Operation" 233 * Clear on TGRA compare match, divide clock by 64. 234 */ 235 sh_mtu2_write(ch, TCR, TCR_CCLR_TGRA | TCR_TPSC_P64); 236 sh_mtu2_write(ch, TIOR, TIOC_IOCH(TIOR_OC_0_CLEAR) | 237 TIOC_IOCL(TIOR_OC_0_CLEAR)); 238 sh_mtu2_write(ch, TGR, periodic); 239 sh_mtu2_write(ch, TCNT, 0); 240 sh_mtu2_write(ch, TMDR, TMDR_MD_NORMAL); 241 sh_mtu2_write(ch, TIER, TIER_TGIEA); 242 243 /* enable channel */ 244 sh_mtu2_start_stop_ch(ch, 1); 245 246 return 0; 247 } 248 249 static void sh_mtu2_disable(struct sh_mtu2_channel *ch) 250 { 251 /* disable channel */ 252 sh_mtu2_start_stop_ch(ch, 0); 253 254 /* stop clock */ 255 clk_disable(ch->mtu->clk); 256 257 dev_pm_syscore_device(&ch->mtu->pdev->dev, false); 258 pm_runtime_put(&ch->mtu->pdev->dev); 259 } 260 261 static irqreturn_t sh_mtu2_interrupt(int irq, void *dev_id) 262 { 263 struct sh_mtu2_channel *ch = dev_id; 264 265 /* acknowledge interrupt */ 266 sh_mtu2_read(ch, TSR); 267 sh_mtu2_write(ch, TSR, ~TSR_TGFA); 268 269 /* notify clockevent layer */ 270 ch->ced.event_handler(&ch->ced); 271 return IRQ_HANDLED; 272 } 273 274 static struct sh_mtu2_channel *ced_to_sh_mtu2(struct clock_event_device *ced) 275 { 276 return container_of(ced, struct sh_mtu2_channel, ced); 277 } 278 279 static int sh_mtu2_clock_event_shutdown(struct clock_event_device *ced) 280 { 281 struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced); 282 283 sh_mtu2_disable(ch); 284 return 0; 285 } 286 287 static int sh_mtu2_clock_event_set_periodic(struct clock_event_device *ced) 288 { 289 struct sh_mtu2_channel *ch = ced_to_sh_mtu2(ced); 290 291 if (clockevent_state_periodic(ced)) 292 sh_mtu2_disable(ch); 293 294 dev_info(&ch->mtu->pdev->dev, "ch%u: used for periodic clock events\n", 295 ch->index); 296 sh_mtu2_enable(ch); 297 return 0; 298 } 299 300 static void sh_mtu2_clock_event_suspend(struct clock_event_device *ced) 301 { 302 pm_genpd_syscore_poweroff(&ced_to_sh_mtu2(ced)->mtu->pdev->dev); 303 } 304 305 static void sh_mtu2_clock_event_resume(struct clock_event_device *ced) 306 { 307 pm_genpd_syscore_poweron(&ced_to_sh_mtu2(ced)->mtu->pdev->dev); 308 } 309 310 static void sh_mtu2_register_clockevent(struct sh_mtu2_channel *ch, 311 const char *name) 312 { 313 struct clock_event_device *ced = &ch->ced; 314 315 ced->name = name; 316 ced->features = CLOCK_EVT_FEAT_PERIODIC; 317 ced->rating = 200; 318 ced->cpumask = cpu_possible_mask; 319 ced->set_state_shutdown = sh_mtu2_clock_event_shutdown; 320 ced->set_state_periodic = sh_mtu2_clock_event_set_periodic; 321 ced->suspend = sh_mtu2_clock_event_suspend; 322 ced->resume = sh_mtu2_clock_event_resume; 323 324 dev_info(&ch->mtu->pdev->dev, "ch%u: used for clock events\n", 325 ch->index); 326 clockevents_register_device(ced); 327 } 328 329 static int sh_mtu2_register(struct sh_mtu2_channel *ch, const char *name) 330 { 331 ch->mtu->has_clockevent = true; 332 sh_mtu2_register_clockevent(ch, name); 333 334 return 0; 335 } 336 337 static int sh_mtu2_setup_channel(struct sh_mtu2_channel *ch, unsigned int index, 338 struct sh_mtu2_device *mtu) 339 { 340 static const unsigned int channel_offsets[] = { 341 0x300, 0x380, 0x000, 342 }; 343 char name[6]; 344 int irq; 345 int ret; 346 347 ch->mtu = mtu; 348 349 sprintf(name, "tgi%ua", index); 350 irq = platform_get_irq_byname(mtu->pdev, name); 351 if (irq < 0) { 352 /* Skip channels with no declared interrupt. */ 353 return 0; 354 } 355 356 ret = request_irq(irq, sh_mtu2_interrupt, 357 IRQF_TIMER | IRQF_IRQPOLL | IRQF_NOBALANCING, 358 dev_name(&ch->mtu->pdev->dev), ch); 359 if (ret) { 360 dev_err(&ch->mtu->pdev->dev, "ch%u: failed to request irq %d\n", 361 index, irq); 362 return ret; 363 } 364 365 ch->base = mtu->mapbase + channel_offsets[index]; 366 ch->index = index; 367 368 return sh_mtu2_register(ch, dev_name(&mtu->pdev->dev)); 369 } 370 371 static int sh_mtu2_map_memory(struct sh_mtu2_device *mtu) 372 { 373 struct resource *res; 374 375 res = platform_get_resource(mtu->pdev, IORESOURCE_MEM, 0); 376 if (!res) { 377 dev_err(&mtu->pdev->dev, "failed to get I/O memory\n"); 378 return -ENXIO; 379 } 380 381 mtu->mapbase = ioremap_nocache(res->start, resource_size(res)); 382 if (mtu->mapbase == NULL) 383 return -ENXIO; 384 385 return 0; 386 } 387 388 static int sh_mtu2_setup(struct sh_mtu2_device *mtu, 389 struct platform_device *pdev) 390 { 391 unsigned int i; 392 int ret; 393 394 mtu->pdev = pdev; 395 396 raw_spin_lock_init(&mtu->lock); 397 398 /* Get hold of clock. */ 399 mtu->clk = clk_get(&mtu->pdev->dev, "fck"); 400 if (IS_ERR(mtu->clk)) { 401 dev_err(&mtu->pdev->dev, "cannot get clock\n"); 402 return PTR_ERR(mtu->clk); 403 } 404 405 ret = clk_prepare(mtu->clk); 406 if (ret < 0) 407 goto err_clk_put; 408 409 /* Map the memory resource. */ 410 ret = sh_mtu2_map_memory(mtu); 411 if (ret < 0) { 412 dev_err(&mtu->pdev->dev, "failed to remap I/O memory\n"); 413 goto err_clk_unprepare; 414 } 415 416 /* Allocate and setup the channels. */ 417 mtu->num_channels = 3; 418 419 mtu->channels = kzalloc(sizeof(*mtu->channels) * mtu->num_channels, 420 GFP_KERNEL); 421 if (mtu->channels == NULL) { 422 ret = -ENOMEM; 423 goto err_unmap; 424 } 425 426 for (i = 0; i < mtu->num_channels; ++i) { 427 ret = sh_mtu2_setup_channel(&mtu->channels[i], i, mtu); 428 if (ret < 0) 429 goto err_unmap; 430 } 431 432 platform_set_drvdata(pdev, mtu); 433 434 return 0; 435 436 err_unmap: 437 kfree(mtu->channels); 438 iounmap(mtu->mapbase); 439 err_clk_unprepare: 440 clk_unprepare(mtu->clk); 441 err_clk_put: 442 clk_put(mtu->clk); 443 return ret; 444 } 445 446 static int sh_mtu2_probe(struct platform_device *pdev) 447 { 448 struct sh_mtu2_device *mtu = platform_get_drvdata(pdev); 449 int ret; 450 451 if (!is_early_platform_device(pdev)) { 452 pm_runtime_set_active(&pdev->dev); 453 pm_runtime_enable(&pdev->dev); 454 } 455 456 if (mtu) { 457 dev_info(&pdev->dev, "kept as earlytimer\n"); 458 goto out; 459 } 460 461 mtu = kzalloc(sizeof(*mtu), GFP_KERNEL); 462 if (mtu == NULL) 463 return -ENOMEM; 464 465 ret = sh_mtu2_setup(mtu, pdev); 466 if (ret) { 467 kfree(mtu); 468 pm_runtime_idle(&pdev->dev); 469 return ret; 470 } 471 if (is_early_platform_device(pdev)) 472 return 0; 473 474 out: 475 if (mtu->has_clockevent) 476 pm_runtime_irq_safe(&pdev->dev); 477 else 478 pm_runtime_idle(&pdev->dev); 479 480 return 0; 481 } 482 483 static int sh_mtu2_remove(struct platform_device *pdev) 484 { 485 return -EBUSY; /* cannot unregister clockevent */ 486 } 487 488 static const struct platform_device_id sh_mtu2_id_table[] = { 489 { "sh-mtu2", 0 }, 490 { }, 491 }; 492 MODULE_DEVICE_TABLE(platform, sh_mtu2_id_table); 493 494 static const struct of_device_id sh_mtu2_of_table[] __maybe_unused = { 495 { .compatible = "renesas,mtu2" }, 496 { } 497 }; 498 MODULE_DEVICE_TABLE(of, sh_mtu2_of_table); 499 500 static struct platform_driver sh_mtu2_device_driver = { 501 .probe = sh_mtu2_probe, 502 .remove = sh_mtu2_remove, 503 .driver = { 504 .name = "sh_mtu2", 505 .of_match_table = of_match_ptr(sh_mtu2_of_table), 506 }, 507 .id_table = sh_mtu2_id_table, 508 }; 509 510 static int __init sh_mtu2_init(void) 511 { 512 return platform_driver_register(&sh_mtu2_device_driver); 513 } 514 515 static void __exit sh_mtu2_exit(void) 516 { 517 platform_driver_unregister(&sh_mtu2_device_driver); 518 } 519 520 early_platform_init("earlytimer", &sh_mtu2_device_driver); 521 subsys_initcall(sh_mtu2_init); 522 module_exit(sh_mtu2_exit); 523 524 MODULE_AUTHOR("Magnus Damm"); 525 MODULE_DESCRIPTION("SuperH MTU2 Timer Driver"); 526 MODULE_LICENSE("GPL v2"); 527