arch/arm/mach-msm/timer.c

   1 /* linux/arch/arm/mach-msm/timer.c
   2  *
   3  * Copyright (C) 2007 Google, Inc.
   4  *
   5  * This software is licensed under the terms of the GNU General Public
   6  * License version 2, as published by the Free Software Foundation, and
   7  * may be copied, distributed, and modified under those terms.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  */
  15
  16 #include <linux/init.h>
  17 #include <linux/time.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/irq.h>
  20 #include <linux/clk.h>
  21 #include <linux/clockchips.h>
  22 #include <linux/delay.h>
  23 #include <linux/io.h>
  24
  25 #include <asm/mach/time.h>
  26 #include <asm/hardware/gic.h>
  27
  28 #include <mach/msm_iomap.h>
  29 #include <mach/cpu.h>
  30
  31 #define TIMER_MATCH_VAL         0x0000
  32 #define TIMER_COUNT_VAL         0x0004
  33 #define TIMER_ENABLE            0x0008
  34 #define TIMER_ENABLE_CLR_ON_MATCH_EN    2
  35 #define TIMER_ENABLE_EN                 1
  36 #define TIMER_CLEAR             0x000C
  37 #define DGT_CLK_CTL             0x0034
  38 enum {
  39         DGT_CLK_CTL_DIV_1 = 0,
  40         DGT_CLK_CTL_DIV_2 = 1,
  41         DGT_CLK_CTL_DIV_3 = 2,
  42         DGT_CLK_CTL_DIV_4 = 3,
  43 };
  44 #define CSR_PROTECTION          0x0020
  45 #define CSR_PROTECTION_EN               1
  46
  47 #define GPT_HZ 32768
  48
  49 enum timer_location {
  50         LOCAL_TIMER = 0,
  51         GLOBAL_TIMER = 1,
  52 };
  53
  54 #define MSM_GLOBAL_TIMER MSM_CLOCK_DGT
  55
  56 /* TODO: Remove these ifdefs */
  57 #if defined(CONFIG_ARCH_QSD8X50)
  58 #define DGT_HZ (19200000 / 4) /* 19.2 MHz / 4 by default */
  59 #define MSM_DGT_SHIFT (0)
  60 #elif defined(CONFIG_ARCH_MSM7X30)
  61 #define DGT_HZ (24576000 / 4) /* 24.576 MHz (LPXO) / 4 by default */
  62 #define MSM_DGT_SHIFT (0)
  63 #elif defined(CONFIG_ARCH_MSM8X60) || defined(CONFIG_ARCH_MSM8960)
  64 #define DGT_HZ (27000000 / 4) /* 27 MHz (PXO) / 4 by default */
  65 #define MSM_DGT_SHIFT (0)
  66 #else
  67 #define DGT_HZ 19200000 /* 19.2 MHz or 600 KHz after shift */
  68 #define MSM_DGT_SHIFT (5)
  69 #endif
  70
  71 struct msm_clock {
  72         struct clock_event_device   clockevent;
  73         struct clocksource          clocksource;
  74         unsigned int                irq;
  75         void __iomem                *regbase;
  76         uint32_t                    freq;
  77         uint32_t                    shift;
  78         void __iomem                *global_counter;
  79         void __iomem                *local_counter;
  80         union {
  81                 struct clock_event_device               *evt;
  82                 struct clock_event_device __percpu      **percpu_evt;
  83         };
  84 };
  85
  86 enum {
  87         MSM_CLOCK_GPT,
  88         MSM_CLOCK_DGT,
  89         NR_TIMERS,
  90 };
  91
  92
  93 static struct msm_clock msm_clocks[];
  94
  95 static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
  96 {
  97         struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
  98         if (evt->event_handler == NULL)
  99                 return IRQ_HANDLED;
 100         evt->event_handler(evt);
 101         return IRQ_HANDLED;
 102 }
 103
 104 static cycle_t msm_read_timer_count(struct clocksource *cs)
 105 {
 106         struct msm_clock *clk = container_of(cs, struct msm_clock, clocksource);
 107
 108         /*
 109          * Shift timer count down by a constant due to unreliable lower bits
 110          * on some targets.
 111          */
 112         return readl(clk->global_counter) >> clk->shift;
 113 }
 114
 115 static struct msm_clock *clockevent_to_clock(struct clock_event_device *evt)
 116 {
 117 #ifdef CONFIG_SMP
 118         int i;
 119         for (i = 0; i < NR_TIMERS; i++)
 120                 if (evt == &(msm_clocks[i].clockevent))
 121                         return &msm_clocks[i];
 122         return &msm_clocks[MSM_GLOBAL_TIMER];
 123 #else
 124         return container_of(evt, struct msm_clock, clockevent);
 125 #endif
 126 }
 127
 128 static int msm_timer_set_next_event(unsigned long cycles,
 129                                     struct clock_event_device *evt)
 130 {
 131         struct msm_clock *clock = clockevent_to_clock(evt);
 132         uint32_t now = readl(clock->local_counter);
 133         uint32_t alarm = now + (cycles << clock->shift);
 134
 135         writel(alarm, clock->regbase + TIMER_MATCH_VAL);
 136         return 0;
 137 }
 138
 139 static void msm_timer_set_mode(enum clock_event_mode mode,
 140                               struct clock_event_device *evt)
 141 {
 142         struct msm_clock *clock = clockevent_to_clock(evt);
 143
 144         switch (mode) {
 145         case CLOCK_EVT_MODE_RESUME:
 146         case CLOCK_EVT_MODE_PERIODIC:
 147                 break;
 148         case CLOCK_EVT_MODE_ONESHOT:
 149                 writel(TIMER_ENABLE_EN, clock->regbase + TIMER_ENABLE);
 150                 break;
 151         case CLOCK_EVT_MODE_UNUSED:
 152         case CLOCK_EVT_MODE_SHUTDOWN:
 153                 writel(0, clock->regbase + TIMER_ENABLE);
 154                 break;
 155         }
 156 }
 157
 158 static struct msm_clock msm_clocks[] = {
 159         [MSM_CLOCK_GPT] = {
 160                 .clockevent = {
 161                         .name           = "gp_timer",
 162                         .features       = CLOCK_EVT_FEAT_ONESHOT,
 163                         .shift          = 32,
 164                         .rating         = 200,
 165                         .set_next_event = msm_timer_set_next_event,
 166                         .set_mode       = msm_timer_set_mode,
 167                 },
 168                 .clocksource = {
 169                         .name           = "gp_timer",
 170                         .rating         = 200,
 171                         .read           = msm_read_timer_count,
 172                         .mask           = CLOCKSOURCE_MASK(32),
 173                         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 174                 },
 175                 .irq = INT_GP_TIMER_EXP,
 176                 .freq = GPT_HZ,
 177         },
 178         [MSM_CLOCK_DGT] = {
 179                 .clockevent = {
 180                         .name           = "dg_timer",
 181                         .features       = CLOCK_EVT_FEAT_ONESHOT,
 182                         .shift          = 32 + MSM_DGT_SHIFT,
 183                         .rating         = 300,
 184                         .set_next_event = msm_timer_set_next_event,
 185                         .set_mode       = msm_timer_set_mode,
 186                 },
 187                 .clocksource = {
 188                         .name           = "dg_timer",
 189                         .rating         = 300,
 190                         .read           = msm_read_timer_count,
 191                         .mask           = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT)),
 192                         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 193                 },
 194                 .irq = INT_DEBUG_TIMER_EXP,
 195                 .freq = DGT_HZ >> MSM_DGT_SHIFT,
 196                 .shift = MSM_DGT_SHIFT,
 197         }
 198 };
 199
 200 static void __init msm_timer_init(void)
 201 {
 202         int i;
 203         int res;
 204         int global_offset = 0;
 205
 206         if (cpu_is_msm7x01()) {
 207                 msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE;
 208                 msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x10;
 209         } else if (cpu_is_msm7x30()) {
 210                 msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE + 0x04;
 211                 msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x24;
 212         } else if (cpu_is_qsd8x50()) {
 213                 msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE;
 214                 msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x10;
 215         } else if (cpu_is_msm8x60() || cpu_is_msm8960()) {
 216                 msm_clocks[MSM_CLOCK_GPT].regbase = MSM_TMR_BASE + 0x04;
 217                 msm_clocks[MSM_CLOCK_DGT].regbase = MSM_TMR_BASE + 0x24;
 218
 219                 /* Use CPU0's timer as the global timer. */
 220                 global_offset = MSM_TMR0_BASE - MSM_TMR_BASE;
 221         } else
 222                 BUG();
 223
 224 #ifdef CONFIG_ARCH_MSM_SCORPIONMP
 225         writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
 226 #endif
 227
 228         for (i = 0; i < ARRAY_SIZE(msm_clocks); i++) {
 229                 struct msm_clock *clock = &msm_clocks[i];
 230                 struct clock_event_device *ce = &clock->clockevent;
 231                 struct clocksource *cs = &clock->clocksource;
 232
 233                 clock->local_counter = clock->regbase + TIMER_COUNT_VAL;
 234                 clock->global_counter = clock->local_counter + global_offset;
 235
 236                 writel(0, clock->regbase + TIMER_ENABLE);
 237                 writel(0, clock->regbase + TIMER_CLEAR);
 238                 writel(~0, clock->regbase + TIMER_MATCH_VAL);
 239
 240                 ce->mult = div_sc(clock->freq, NSEC_PER_SEC, ce->shift);
 241                 /* allow at least 10 seconds to notice that the timer wrapped */
 242                 ce->max_delta_ns =
 243                         clockevent_delta2ns(0xf0000000 >> clock->shift, ce);
 244                 /* 4 gets rounded down to 3 */
 245                 ce->min_delta_ns = clockevent_delta2ns(4, ce);
 246                 ce->cpumask = cpumask_of(0);
 247
 248                 res = clocksource_register_hz(cs, clock->freq);
 249                 if (res)
 250                         printk(KERN_ERR "msm_timer_init: clocksource_register "
 251                                "failed for %s\n", cs->name);
 252
 253                 ce->irq = clock->irq;
 254                 if (cpu_is_msm8x60() || cpu_is_msm8960()) {
 255                         clock->percpu_evt = alloc_percpu(struct clock_event_device *);
 256                         if (!clock->percpu_evt) {
 257                                 pr_err("msm_timer_init: memory allocation "
 258                                        "failed for %s\n", ce->name);
 259                                 continue;
 260                         }
 261
 262                         *__this_cpu_ptr(clock->percpu_evt) = ce;
 263                         res = request_percpu_irq(ce->irq, msm_timer_interrupt,
 264                                                  ce->name, clock->percpu_evt);
 265                         if (!res)
 266                                 enable_percpu_irq(ce->irq, 0);
 267                 } else {
 268                         clock->evt = ce;
 269                         res = request_irq(ce->irq, msm_timer_interrupt,
 270                                           IRQF_TIMER | IRQF_NOBALANCING | IRQF_TRIGGER_RISING,
 271                                           ce->name, &clock->evt);
 272                 }
 273
 274                 if (res)
 275                         pr_err("msm_timer_init: request_irq failed for %s\n",
 276                                ce->name);
 277
 278                 clockevents_register_device(ce);
 279         }
 280 }
 281
 282 #ifdef CONFIG_SMP
 283 int __cpuinit local_timer_setup(struct clock_event_device *evt)
 284 {
 285         static bool local_timer_inited;
 286         struct msm_clock *clock = &msm_clocks[MSM_GLOBAL_TIMER];
 287
 288         /* Use existing clock_event for cpu 0 */
 289         if (!smp_processor_id())
 290                 return 0;
 291
 292         writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
 293
 294         if (!local_timer_inited) {
 295                 writel(0, clock->regbase  + TIMER_ENABLE);
 296                 writel(0, clock->regbase + TIMER_CLEAR);
 297                 writel(~0, clock->regbase + TIMER_MATCH_VAL);
 298                 local_timer_inited = true;
 299         }
 300         evt->irq = clock->irq;
 301         evt->name = "local_timer";
 302         evt->features = CLOCK_EVT_FEAT_ONESHOT;
 303         evt->rating = clock->clockevent.rating;
 304         evt->set_mode = msm_timer_set_mode;
 305         evt->set_next_event = msm_timer_set_next_event;
 306         evt->shift = clock->clockevent.shift;
 307         evt->mult = div_sc(clock->freq, NSEC_PER_SEC, evt->shift);
 308         evt->max_delta_ns =
 309                 clockevent_delta2ns(0xf0000000 >> clock->shift, evt);
 310         evt->min_delta_ns = clockevent_delta2ns(4, evt);
 311
 312         *__this_cpu_ptr(clock->percpu_evt) = evt;
 313         enable_percpu_irq(evt->irq, 0);
 314
 315         clockevents_register_device(evt);
 316         return 0;
 317 }
 318
 319 void local_timer_stop(struct clock_event_device *evt)
 320 {
 321         evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
 322         disable_percpu_irq(evt->irq);
 323 }
 324
 325 #endif
 326
 327 struct sys_timer msm_timer = {
 328         .init = msm_timer_init
 329 };