arch/arm/plat-s5p/s5p-time.c

   1 /* linux/arch/arm/plat-s5p/s5p-time.c
   2  *
   3  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
   4  *              http://www.samsung.com/
   5  *
   6  * S5P - Common hr-timer support
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11 */
  12
  13 #include <linux/sched.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/irq.h>
  16 #include <linux/err.h>
  17 #include <linux/clk.h>
  18 #include <linux/clockchips.h>
  19 #include <linux/platform_device.h>
  20
  21 #include <asm/smp_twd.h>
  22 #include <asm/mach/time.h>
  23 #include <asm/mach/arch.h>
  24 #include <asm/mach/map.h>
  25 #include <asm/sched_clock.h>
  26
  27 #include <mach/map.h>
  28 #include <plat/devs.h>
  29 #include <plat/regs-timer.h>
  30 #include <plat/s5p-time.h>
  31
  32 static struct clk *tin_event;
  33 static struct clk *tin_source;
  34 static struct clk *tdiv_event;
  35 static struct clk *tdiv_source;
  36 static struct clk *timerclk;
  37 static struct s5p_timer_source timer_source;
  38 static unsigned long clock_count_per_tick;
  39 static void s5p_timer_resume(void);
  40
  41 static void s5p_time_stop(enum s5p_timer_mode mode)
  42 {
  43         unsigned long tcon;
  44
  45         tcon = __raw_readl(S3C2410_TCON);
  46
  47         switch (mode) {
  48         case S5P_PWM0:
  49                 tcon &= ~S3C2410_TCON_T0START;
  50                 break;
  51
  52         case S5P_PWM1:
  53                 tcon &= ~S3C2410_TCON_T1START;
  54                 break;
  55
  56         case S5P_PWM2:
  57                 tcon &= ~S3C2410_TCON_T2START;
  58                 break;
  59
  60         case S5P_PWM3:
  61                 tcon &= ~S3C2410_TCON_T3START;
  62                 break;
  63
  64         case S5P_PWM4:
  65                 tcon &= ~S3C2410_TCON_T4START;
  66                 break;
  67
  68         default:
  69                 printk(KERN_ERR "Invalid Timer %d\n", mode);
  70                 break;
  71         }
  72         __raw_writel(tcon, S3C2410_TCON);
  73 }
  74
  75 static void s5p_time_setup(enum s5p_timer_mode mode, unsigned long tcnt)
  76 {
  77         unsigned long tcon;
  78
  79         tcon = __raw_readl(S3C2410_TCON);
  80
  81         tcnt--;
  82
  83         switch (mode) {
  84         case S5P_PWM0:
  85                 tcon &= ~(0x0f << 0);
  86                 tcon |= S3C2410_TCON_T0MANUALUPD;
  87                 break;
  88
  89         case S5P_PWM1:
  90                 tcon &= ~(0x0f << 8);
  91                 tcon |= S3C2410_TCON_T1MANUALUPD;
  92                 break;
  93
  94         case S5P_PWM2:
  95                 tcon &= ~(0x0f << 12);
  96                 tcon |= S3C2410_TCON_T2MANUALUPD;
  97                 break;
  98
  99         case S5P_PWM3:
 100                 tcon &= ~(0x0f << 16);
 101                 tcon |= S3C2410_TCON_T3MANUALUPD;
 102                 break;
 103
 104         case S5P_PWM4:
 105                 tcon &= ~(0x07 << 20);
 106                 tcon |= S3C2410_TCON_T4MANUALUPD;
 107                 break;
 108
 109         default:
 110                 printk(KERN_ERR "Invalid Timer %d\n", mode);
 111                 break;
 112         }
 113
 114         __raw_writel(tcnt, S3C2410_TCNTB(mode));
 115         __raw_writel(tcnt, S3C2410_TCMPB(mode));
 116         __raw_writel(tcon, S3C2410_TCON);
 117 }
 118
 119 static void s5p_time_start(enum s5p_timer_mode mode, bool periodic)
 120 {
 121         unsigned long tcon;
 122
 123         tcon  = __raw_readl(S3C2410_TCON);
 124
 125         switch (mode) {
 126         case S5P_PWM0:
 127                 tcon |= S3C2410_TCON_T0START;
 128                 tcon &= ~S3C2410_TCON_T0MANUALUPD;
 129
 130                 if (periodic)
 131                         tcon |= S3C2410_TCON_T0RELOAD;
 132                 else
 133                         tcon &= ~S3C2410_TCON_T0RELOAD;
 134                 break;
 135
 136         case S5P_PWM1:
 137                 tcon |= S3C2410_TCON_T1START;
 138                 tcon &= ~S3C2410_TCON_T1MANUALUPD;
 139
 140                 if (periodic)
 141                         tcon |= S3C2410_TCON_T1RELOAD;
 142                 else
 143                         tcon &= ~S3C2410_TCON_T1RELOAD;
 144                 break;
 145
 146         case S5P_PWM2:
 147                 tcon |= S3C2410_TCON_T2START;
 148                 tcon &= ~S3C2410_TCON_T2MANUALUPD;
 149
 150                 if (periodic)
 151                         tcon |= S3C2410_TCON_T2RELOAD;
 152                 else
 153                         tcon &= ~S3C2410_TCON_T2RELOAD;
 154                 break;
 155
 156         case S5P_PWM3:
 157                 tcon |= S3C2410_TCON_T3START;
 158                 tcon &= ~S3C2410_TCON_T3MANUALUPD;
 159
 160                 if (periodic)
 161                         tcon |= S3C2410_TCON_T3RELOAD;
 162                 else
 163                         tcon &= ~S3C2410_TCON_T3RELOAD;
 164                 break;
 165
 166         case S5P_PWM4:
 167                 tcon |= S3C2410_TCON_T4START;
 168                 tcon &= ~S3C2410_TCON_T4MANUALUPD;
 169
 170                 if (periodic)
 171                         tcon |= S3C2410_TCON_T4RELOAD;
 172                 else
 173                         tcon &= ~S3C2410_TCON_T4RELOAD;
 174                 break;
 175
 176         default:
 177                 printk(KERN_ERR "Invalid Timer %d\n", mode);
 178                 break;
 179         }
 180         __raw_writel(tcon, S3C2410_TCON);
 181 }
 182
 183 static int s5p_set_next_event(unsigned long cycles,
 184                                 struct clock_event_device *evt)
 185 {
 186         s5p_time_setup(timer_source.event_id, cycles);
 187         s5p_time_start(timer_source.event_id, NON_PERIODIC);
 188
 189         return 0;
 190 }
 191
 192 static void s5p_set_mode(enum clock_event_mode mode,
 193                                 struct clock_event_device *evt)
 194 {
 195         s5p_time_stop(timer_source.event_id);
 196
 197         switch (mode) {
 198         case CLOCK_EVT_MODE_PERIODIC:
 199                 s5p_time_setup(timer_source.event_id, clock_count_per_tick);
 200                 s5p_time_start(timer_source.event_id, PERIODIC);
 201                 break;
 202
 203         case CLOCK_EVT_MODE_ONESHOT:
 204                 break;
 205
 206         case CLOCK_EVT_MODE_UNUSED:
 207         case CLOCK_EVT_MODE_SHUTDOWN:
 208                 break;
 209
 210         case CLOCK_EVT_MODE_RESUME:
 211                 s5p_timer_resume();
 212                 break;
 213         }
 214 }
 215
 216 static void s5p_timer_resume(void)
 217 {
 218         /* event timer restart */
 219         s5p_time_setup(timer_source.event_id, clock_count_per_tick);
 220         s5p_time_start(timer_source.event_id, PERIODIC);
 221
 222         /* source timer restart */
 223         s5p_time_setup(timer_source.source_id, TCNT_MAX);
 224         s5p_time_start(timer_source.source_id, PERIODIC);
 225 }
 226
 227 void __init s5p_set_timer_source(enum s5p_timer_mode event,
 228                                  enum s5p_timer_mode source)
 229 {
 230         s3c_device_timer[event].dev.bus = &platform_bus_type;
 231         s3c_device_timer[source].dev.bus = &platform_bus_type;
 232
 233         timer_source.event_id = event;
 234         timer_source.source_id = source;
 235 }
 236
 237 static struct clock_event_device time_event_device = {
 238         .name           = "s5p_event_timer",
 239         .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 240         .rating         = 200,
 241         .set_next_event = s5p_set_next_event,
 242         .set_mode       = s5p_set_mode,
 243 };
 244
 245 static irqreturn_t s5p_clock_event_isr(int irq, void *dev_id)
 246 {
 247         struct clock_event_device *evt = dev_id;
 248
 249         evt->event_handler(evt);
 250
 251         return IRQ_HANDLED;
 252 }
 253
 254 static struct irqaction s5p_clock_event_irq = {
 255         .name           = "s5p_time_irq",
 256         .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
 257         .handler        = s5p_clock_event_isr,
 258         .dev_id         = &time_event_device,
 259 };
 260
 261 static void __init s5p_clockevent_init(void)
 262 {
 263         unsigned long pclk;
 264         unsigned long clock_rate;
 265         unsigned int irq_number;
 266         struct clk *tscaler;
 267
 268         pclk = clk_get_rate(timerclk);
 269
 270         tscaler = clk_get_parent(tdiv_event);
 271
 272         clk_set_rate(tscaler, pclk / 2);
 273         clk_set_rate(tdiv_event, pclk / 2);
 274         clk_set_parent(tin_event, tdiv_event);
 275
 276         clock_rate = clk_get_rate(tin_event);
 277         clock_count_per_tick = clock_rate / HZ;
 278
 279         clockevents_calc_mult_shift(&time_event_device,
 280                                     clock_rate, S5PTIMER_MIN_RANGE);
 281         time_event_device.max_delta_ns =
 282                 clockevent_delta2ns(-1, &time_event_device);
 283         time_event_device.min_delta_ns =
 284                 clockevent_delta2ns(1, &time_event_device);
 285
 286         time_event_device.cpumask = cpumask_of(0);
 287         clockevents_register_device(&time_event_device);
 288
 289         irq_number = timer_source.event_id + IRQ_TIMER0;
 290         setup_irq(irq_number, &s5p_clock_event_irq);
 291 }
 292
 293 static void __iomem *s5p_timer_reg(void)
 294 {
 295         unsigned long offset = 0;
 296
 297         switch (timer_source.source_id) {
 298         case S5P_PWM0:
 299         case S5P_PWM1:
 300         case S5P_PWM2:
 301         case S5P_PWM3:
 302                 offset = (timer_source.source_id * 0x0c) + 0x14;
 303                 break;
 304
 305         case S5P_PWM4:
 306                 offset = 0x40;
 307                 break;
 308
 309         default:
 310                 printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id);
 311                 return NULL;
 312         }
 313
 314         return S3C_TIMERREG(offset);
 315 }
 316
 317 static cycle_t s5p_timer_read(struct clocksource *cs)
 318 {
 319         void __iomem *reg = s5p_timer_reg();
 320
 321         return (cycle_t) (reg ? ~__raw_readl(reg) : 0);
 322 }
 323
 324 /*
 325  * Override the global weak sched_clock symbol with this
 326  * local implementation which uses the clocksource to get some
 327  * better resolution when scheduling the kernel. We accept that
 328  * this wraps around for now, since it is just a relative time
 329  * stamp. (Inspired by U300 implementation.)
 330  */
 331 static DEFINE_CLOCK_DATA(cd);
 332
 333 unsigned long long notrace sched_clock(void)
 334 {
 335         void __iomem *reg = s5p_timer_reg();
 336
 337         if (!reg)
 338                 return 0;
 339
 340         return cyc_to_sched_clock(&cd, ~__raw_readl(reg), (u32)~0);
 341 }
 342
 343 static void notrace s5p_update_sched_clock(void)
 344 {
 345         void __iomem *reg = s5p_timer_reg();
 346
 347         if (!reg)
 348                 return;
 349
 350         update_sched_clock(&cd, ~__raw_readl(reg), (u32)~0);
 351 }
 352
 353 struct clocksource time_clocksource = {
 354         .name           = "s5p_clocksource_timer",
 355         .rating         = 250,
 356         .read           = s5p_timer_read,
 357         .mask           = CLOCKSOURCE_MASK(32),
 358         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 359 };
 360
 361 static void __init s5p_clocksource_init(void)
 362 {
 363         unsigned long pclk;
 364         unsigned long clock_rate;
 365
 366         pclk = clk_get_rate(timerclk);
 367
 368         clk_set_rate(tdiv_source, pclk / 2);
 369         clk_set_parent(tin_source, tdiv_source);
 370
 371         clock_rate = clk_get_rate(tin_source);
 372
 373         init_sched_clock(&cd, s5p_update_sched_clock, 32, clock_rate);
 374
 375         s5p_time_setup(timer_source.source_id, TCNT_MAX);
 376         s5p_time_start(timer_source.source_id, PERIODIC);
 377
 378         if (clocksource_register_hz(&time_clocksource, clock_rate))
 379                 panic("%s: can't register clocksource\n", time_clocksource.name);
 380 }
 381
 382 static void __init s5p_timer_resources(void)
 383 {
 384
 385         unsigned long event_id = timer_source.event_id;
 386         unsigned long source_id = timer_source.source_id;
 387
 388         timerclk = clk_get(NULL, "timers");
 389         if (IS_ERR(timerclk))
 390                 panic("failed to get timers clock for timer");
 391
 392         clk_enable(timerclk);
 393
 394         tin_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tin");
 395         if (IS_ERR(tin_event))
 396                 panic("failed to get pwm-tin clock for event timer");
 397
 398         tdiv_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tdiv");
 399         if (IS_ERR(tdiv_event))
 400                 panic("failed to get pwm-tdiv clock for event timer");
 401
 402         clk_enable(tin_event);
 403
 404         tin_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tin");
 405         if (IS_ERR(tin_source))
 406                 panic("failed to get pwm-tin clock for source timer");
 407
 408         tdiv_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tdiv");
 409         if (IS_ERR(tdiv_source))
 410                 panic("failed to get pwm-tdiv clock for source timer");
 411
 412         clk_enable(tin_source);
 413 }
 414
 415 static void __init s5p_timer_init(void)
 416 {
 417         s5p_timer_resources();
 418         s5p_clockevent_init();
 419         s5p_clocksource_init();
 420 }
 421
 422 struct sys_timer s5p_timer = {
 423         .init           = s5p_timer_init,
 424 };