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

   1 /*
   2  * Copyright (c) 2011 Samsung Electronics Co., Ltd.
   3  *              http://www.samsung.com/
   4  *
   5  * samsung - Common hr-timer support (s3c and s5p)
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10 */
  11
  12 #include <linux/interrupt.h>
  13 #include <linux/irq.h>
  14 #include <linux/err.h>
  15 #include <linux/clk.h>
  16 #include <linux/clockchips.h>
  17 #include <linux/platform_device.h>
  18 #include <linux/sched_clock.h>
  19
  20 #include <asm/smp_twd.h>
  21 #include <asm/mach/time.h>
  22 #include <asm/mach/arch.h>
  23 #include <asm/mach/map.h>
  24
  25 #include <mach/map.h>
  26 #include <plat/devs.h>
  27 #include <plat/regs-timer.h>
  28 #include <plat/samsung-time.h>
  29
  30 static struct clk *tin_event;
  31 static struct clk *tin_source;
  32 static struct clk *tdiv_event;
  33 static struct clk *tdiv_source;
  34 static struct clk *timerclk;
  35 static struct samsung_timer_source timer_source;
  36 static unsigned long clock_count_per_tick;
  37 static void samsung_timer_resume(void);
  38
  39 static void samsung_time_stop(enum samsung_timer_mode mode)
  40 {
  41         unsigned long tcon;
  42
  43         tcon = __raw_readl(S3C2410_TCON);
  44
  45         switch (mode) {
  46         case SAMSUNG_PWM0:
  47                 tcon &= ~S3C2410_TCON_T0START;
  48                 break;
  49
  50         case SAMSUNG_PWM1:
  51                 tcon &= ~S3C2410_TCON_T1START;
  52                 break;
  53
  54         case SAMSUNG_PWM2:
  55                 tcon &= ~S3C2410_TCON_T2START;
  56                 break;
  57
  58         case SAMSUNG_PWM3:
  59                 tcon &= ~S3C2410_TCON_T3START;
  60                 break;
  61
  62         case SAMSUNG_PWM4:
  63                 tcon &= ~S3C2410_TCON_T4START;
  64                 break;
  65
  66         default:
  67                 printk(KERN_ERR "Invalid Timer %d\n", mode);
  68                 break;
  69         }
  70         __raw_writel(tcon, S3C2410_TCON);
  71 }
  72
  73 static void samsung_time_setup(enum samsung_timer_mode mode, unsigned long tcnt)
  74 {
  75         unsigned long tcon;
  76
  77         tcon = __raw_readl(S3C2410_TCON);
  78
  79         tcnt--;
  80
  81         switch (mode) {
  82         case SAMSUNG_PWM0:
  83                 tcon &= ~(0x0f << 0);
  84                 tcon |= S3C2410_TCON_T0MANUALUPD;
  85                 break;
  86
  87         case SAMSUNG_PWM1:
  88                 tcon &= ~(0x0f << 8);
  89                 tcon |= S3C2410_TCON_T1MANUALUPD;
  90                 break;
  91
  92         case SAMSUNG_PWM2:
  93                 tcon &= ~(0x0f << 12);
  94                 tcon |= S3C2410_TCON_T2MANUALUPD;
  95                 break;
  96
  97         case SAMSUNG_PWM3:
  98                 tcon &= ~(0x0f << 16);
  99                 tcon |= S3C2410_TCON_T3MANUALUPD;
 100                 break;
 101
 102         case SAMSUNG_PWM4:
 103                 tcon &= ~(0x07 << 20);
 104                 tcon |= S3C2410_TCON_T4MANUALUPD;
 105                 break;
 106
 107         default:
 108                 printk(KERN_ERR "Invalid Timer %d\n", mode);
 109                 break;
 110         }
 111
 112         __raw_writel(tcnt, S3C2410_TCNTB(mode));
 113         __raw_writel(tcnt, S3C2410_TCMPB(mode));
 114         __raw_writel(tcon, S3C2410_TCON);
 115 }
 116
 117 static void samsung_time_start(enum samsung_timer_mode mode, bool periodic)
 118 {
 119         unsigned long tcon;
 120
 121         tcon  = __raw_readl(S3C2410_TCON);
 122
 123         switch (mode) {
 124         case SAMSUNG_PWM0:
 125                 tcon |= S3C2410_TCON_T0START;
 126                 tcon &= ~S3C2410_TCON_T0MANUALUPD;
 127
 128                 if (periodic)
 129                         tcon |= S3C2410_TCON_T0RELOAD;
 130                 else
 131                         tcon &= ~S3C2410_TCON_T0RELOAD;
 132                 break;
 133
 134         case SAMSUNG_PWM1:
 135                 tcon |= S3C2410_TCON_T1START;
 136                 tcon &= ~S3C2410_TCON_T1MANUALUPD;
 137
 138                 if (periodic)
 139                         tcon |= S3C2410_TCON_T1RELOAD;
 140                 else
 141                         tcon &= ~S3C2410_TCON_T1RELOAD;
 142                 break;
 143
 144         case SAMSUNG_PWM2:
 145                 tcon |= S3C2410_TCON_T2START;
 146                 tcon &= ~S3C2410_TCON_T2MANUALUPD;
 147
 148                 if (periodic)
 149                         tcon |= S3C2410_TCON_T2RELOAD;
 150                 else
 151                         tcon &= ~S3C2410_TCON_T2RELOAD;
 152                 break;
 153
 154         case SAMSUNG_PWM3:
 155                 tcon |= S3C2410_TCON_T3START;
 156                 tcon &= ~S3C2410_TCON_T3MANUALUPD;
 157
 158                 if (periodic)
 159                         tcon |= S3C2410_TCON_T3RELOAD;
 160                 else
 161                         tcon &= ~S3C2410_TCON_T3RELOAD;
 162                 break;
 163
 164         case SAMSUNG_PWM4:
 165                 tcon |= S3C2410_TCON_T4START;
 166                 tcon &= ~S3C2410_TCON_T4MANUALUPD;
 167
 168                 if (periodic)
 169                         tcon |= S3C2410_TCON_T4RELOAD;
 170                 else
 171                         tcon &= ~S3C2410_TCON_T4RELOAD;
 172                 break;
 173
 174         default:
 175                 printk(KERN_ERR "Invalid Timer %d\n", mode);
 176                 break;
 177         }
 178         __raw_writel(tcon, S3C2410_TCON);
 179 }
 180
 181 static int samsung_set_next_event(unsigned long cycles,
 182                                 struct clock_event_device *evt)
 183 {
 184         samsung_time_setup(timer_source.event_id, cycles);
 185         samsung_time_start(timer_source.event_id, NON_PERIODIC);
 186
 187         return 0;
 188 }
 189
 190 static void samsung_set_mode(enum clock_event_mode mode,
 191                                 struct clock_event_device *evt)
 192 {
 193         samsung_time_stop(timer_source.event_id);
 194
 195         switch (mode) {
 196         case CLOCK_EVT_MODE_PERIODIC:
 197                 samsung_time_setup(timer_source.event_id, clock_count_per_tick);
 198                 samsung_time_start(timer_source.event_id, PERIODIC);
 199                 break;
 200
 201         case CLOCK_EVT_MODE_ONESHOT:
 202                 break;
 203
 204         case CLOCK_EVT_MODE_UNUSED:
 205         case CLOCK_EVT_MODE_SHUTDOWN:
 206                 break;
 207
 208         case CLOCK_EVT_MODE_RESUME:
 209                 samsung_timer_resume();
 210                 break;
 211         }
 212 }
 213
 214 static void samsung_timer_resume(void)
 215 {
 216         /* event timer restart */
 217         samsung_time_setup(timer_source.event_id, clock_count_per_tick);
 218         samsung_time_start(timer_source.event_id, PERIODIC);
 219
 220         /* source timer restart */
 221         samsung_time_setup(timer_source.source_id, TCNT_MAX);
 222         samsung_time_start(timer_source.source_id, PERIODIC);
 223 }
 224
 225 void __init samsung_set_timer_source(enum samsung_timer_mode event,
 226                                  enum samsung_timer_mode source)
 227 {
 228         s3c_device_timer[event].dev.bus = &platform_bus_type;
 229         s3c_device_timer[source].dev.bus = &platform_bus_type;
 230
 231         timer_source.event_id = event;
 232         timer_source.source_id = source;
 233 }
 234
 235 static struct clock_event_device time_event_device = {
 236         .name           = "samsung_event_timer",
 237         .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
 238         .rating         = 200,
 239         .set_next_event = samsung_set_next_event,
 240         .set_mode       = samsung_set_mode,
 241 };
 242
 243 static irqreturn_t samsung_clock_event_isr(int irq, void *dev_id)
 244 {
 245         struct clock_event_device *evt = dev_id;
 246
 247         evt->event_handler(evt);
 248
 249         return IRQ_HANDLED;
 250 }
 251
 252 static struct irqaction samsung_clock_event_irq = {
 253         .name           = "samsung_time_irq",
 254         .flags          = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
 255         .handler        = samsung_clock_event_isr,
 256         .dev_id         = &time_event_device,
 257 };
 258
 259 static void __init samsung_clockevent_init(void)
 260 {
 261         unsigned long pclk;
 262         unsigned long clock_rate;
 263         unsigned int irq_number;
 264         struct clk *tscaler;
 265
 266         pclk = clk_get_rate(timerclk);
 267
 268         tscaler = clk_get_parent(tdiv_event);
 269
 270         clk_set_rate(tscaler, pclk / TSCALER_DIV);
 271         clk_set_rate(tdiv_event, pclk / TDIV);
 272         clk_set_parent(tin_event, tdiv_event);
 273
 274         clock_rate = clk_get_rate(tin_event);
 275         clock_count_per_tick = clock_rate / HZ;
 276
 277         time_event_device.cpumask = cpumask_of(0);
 278         clockevents_config_and_register(&time_event_device, clock_rate, 1, -1);
 279
 280         irq_number = timer_source.event_id + IRQ_TIMER0;
 281         setup_irq(irq_number, &samsung_clock_event_irq);
 282 }
 283
 284 static void __iomem *samsung_timer_reg(void)
 285 {
 286         unsigned long offset = 0;
 287
 288         switch (timer_source.source_id) {
 289         case SAMSUNG_PWM0:
 290         case SAMSUNG_PWM1:
 291         case SAMSUNG_PWM2:
 292         case SAMSUNG_PWM3:
 293                 offset = (timer_source.source_id * 0x0c) + 0x14;
 294                 break;
 295
 296         case SAMSUNG_PWM4:
 297                 offset = 0x40;
 298                 break;
 299
 300         default:
 301                 printk(KERN_ERR "Invalid Timer %d\n", timer_source.source_id);
 302                 return NULL;
 303         }
 304
 305         return S3C_TIMERREG(offset);
 306 }
 307
 308 /*
 309  * Override the global weak sched_clock symbol with this
 310  * local implementation which uses the clocksource to get some
 311  * better resolution when scheduling the kernel. We accept that
 312  * this wraps around for now, since it is just a relative time
 313  * stamp. (Inspired by U300 implementation.)
 314  */
 315 static u32 notrace samsung_read_sched_clock(void)
 316 {
 317         void __iomem *reg = samsung_timer_reg();
 318
 319         if (!reg)
 320                 return 0;
 321
 322         return ~__raw_readl(reg);
 323 }
 324
 325 static void __init samsung_clocksource_init(void)
 326 {
 327         unsigned long pclk;
 328         unsigned long clock_rate;
 329
 330         pclk = clk_get_rate(timerclk);
 331
 332         clk_set_rate(tdiv_source, pclk / TDIV);
 333         clk_set_parent(tin_source, tdiv_source);
 334
 335         clock_rate = clk_get_rate(tin_source);
 336
 337         samsung_time_setup(timer_source.source_id, TCNT_MAX);
 338         samsung_time_start(timer_source.source_id, PERIODIC);
 339
 340         setup_sched_clock(samsung_read_sched_clock, TSIZE, clock_rate);
 341
 342         if (clocksource_mmio_init(samsung_timer_reg(), "samsung_clocksource_timer",
 343                         clock_rate, 250, TSIZE, clocksource_mmio_readl_down))
 344                 panic("samsung_clocksource_timer: can't register clocksource\n");
 345 }
 346
 347 static void __init samsung_timer_resources(void)
 348 {
 349
 350         unsigned long event_id = timer_source.event_id;
 351         unsigned long source_id = timer_source.source_id;
 352         char devname[15];
 353
 354         timerclk = clk_get(NULL, "timers");
 355         if (IS_ERR(timerclk))
 356                 panic("failed to get timers clock for timer");
 357
 358         clk_enable(timerclk);
 359
 360         sprintf(devname, "s3c24xx-pwm.%lu", event_id);
 361         s3c_device_timer[event_id].id = event_id;
 362         s3c_device_timer[event_id].dev.init_name = devname;
 363
 364         tin_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tin");
 365         if (IS_ERR(tin_event))
 366                 panic("failed to get pwm-tin clock for event timer");
 367
 368         tdiv_event = clk_get(&s3c_device_timer[event_id].dev, "pwm-tdiv");
 369         if (IS_ERR(tdiv_event))
 370                 panic("failed to get pwm-tdiv clock for event timer");
 371
 372         clk_enable(tin_event);
 373
 374         sprintf(devname, "s3c24xx-pwm.%lu", source_id);
 375         s3c_device_timer[source_id].id = source_id;
 376         s3c_device_timer[source_id].dev.init_name = devname;
 377
 378         tin_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tin");
 379         if (IS_ERR(tin_source))
 380                 panic("failed to get pwm-tin clock for source timer");
 381
 382         tdiv_source = clk_get(&s3c_device_timer[source_id].dev, "pwm-tdiv");
 383         if (IS_ERR(tdiv_source))
 384                 panic("failed to get pwm-tdiv clock for source timer");
 385
 386         clk_enable(tin_source);
 387 }
 388
 389 void __init samsung_timer_init(void)
 390 {
 391         samsung_timer_resources();
 392         samsung_clockevent_init();
 393         samsung_clocksource_init();
 394 }