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 <mach/msm_iomap.h>
  27 #include <mach/cpu.h>
  28
  29 #define TIMER_MATCH_VAL         0x0000
  30 #define TIMER_COUNT_VAL         0x0004
  31 #define TIMER_ENABLE            0x0008
  32 #define TIMER_ENABLE_CLR_ON_MATCH_EN    2
  33 #define TIMER_ENABLE_EN                 1
  34 #define TIMER_CLEAR             0x000C
  35 #define DGT_CLK_CTL             0x0034
  36 enum {
  37         DGT_CLK_CTL_DIV_1 = 0,
  38         DGT_CLK_CTL_DIV_2 = 1,
  39         DGT_CLK_CTL_DIV_3 = 2,
  40         DGT_CLK_CTL_DIV_4 = 3,
  41 };
  42 #define CSR_PROTECTION          0x0020
  43 #define CSR_PROTECTION_EN               1
  44
  45 #define GPT_HZ 32768
  46
  47 enum timer_location {
  48         LOCAL_TIMER = 0,
  49         GLOBAL_TIMER = 1,
  50 };
  51
  52 #define MSM_GLOBAL_TIMER MSM_CLOCK_DGT
  53
  54 /* TODO: Remove these ifdefs */
  55 #if defined(CONFIG_ARCH_QSD8X50)
  56 #define DGT_HZ (19200000 / 4) /* 19.2 MHz / 4 by default */
  57 #define MSM_DGT_SHIFT (0)
  58 #elif defined(CONFIG_ARCH_MSM7X30) || defined(CONFIG_ARCH_MSM8X60) || \
  59                                       defined(CONFIG_ARCH_MSM8960)
  60 #define DGT_HZ (24576000 / 4) /* 24.576 MHz (LPXO) / 4 by default */
  61 #define MSM_DGT_SHIFT (0)
  62 #else
  63 #define DGT_HZ 19200000 /* 19.2 MHz or 600 KHz after shift */
  64 #define MSM_DGT_SHIFT (5)
  65 #endif
  66
  67 struct msm_clock {
  68         struct clock_event_device   clockevent;
  69         struct clocksource          clocksource;
  70         struct irqaction            irq;
  71         void __iomem                *regbase;
  72         uint32_t                    freq;
  73         uint32_t                    shift;
  74         void __iomem                *global_counter;
  75         void __iomem                *local_counter;
  76 };
  77
  78 enum {
  79         MSM_CLOCK_GPT,
  80         MSM_CLOCK_DGT,
  81         NR_TIMERS,
  82 };
  83
  84
  85 static struct msm_clock msm_clocks[];
  86 static struct clock_event_device *local_clock_event;
  87
  88 static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
  89 {
  90         struct clock_event_device *evt = dev_id;
  91         if (smp_processor_id() != 0)
  92                 evt = local_clock_event;
  93         if (evt->event_handler == NULL)
  94                 return IRQ_HANDLED;
  95         evt->event_handler(evt);
  96         return IRQ_HANDLED;
  97 }
  98
  99 static cycle_t msm_read_timer_count(struct clocksource *cs)
 100 {
 101         struct msm_clock *clk = container_of(cs, struct msm_clock, clocksource);
 102
 103         return readl(clk->global_counter);
 104 }
 105
 106 static struct msm_clock *clockevent_to_clock(struct clock_event_device *evt)
 107 {
 108 #ifdef CONFIG_SMP
 109         int i;
 110         for (i = 0; i < NR_TIMERS; i++)
 111                 if (evt == &(msm_clocks[i].clockevent))
 112                         return &msm_clocks[i];
 113         return &msm_clocks[MSM_GLOBAL_TIMER];
 114 #else
 115         return container_of(evt, struct msm_clock, clockevent);
 116 #endif
 117 }
 118
 119 static int msm_timer_set_next_event(unsigned long cycles,
 120                                     struct clock_event_device *evt)
 121 {
 122         struct msm_clock *clock = clockevent_to_clock(evt);
 123         uint32_t now = readl(clock->local_counter);
 124         uint32_t alarm = now + (cycles << clock->shift);
 125
 126         writel(alarm, clock->regbase + TIMER_MATCH_VAL);
 127         return 0;
 128 }
 129
 130 static void msm_timer_set_mode(enum clock_event_mode mode,
 131                               struct clock_event_device *evt)
 132 {
 133         struct msm_clock *clock = clockevent_to_clock(evt);
 134
 135         switch (mode) {
 136         case CLOCK_EVT_MODE_RESUME:
 137         case CLOCK_EVT_MODE_PERIODIC:
 138                 break;
 139         case CLOCK_EVT_MODE_ONESHOT:
 140                 writel(TIMER_ENABLE_EN, clock->regbase + TIMER_ENABLE);
 141                 break;
 142         case CLOCK_EVT_MODE_UNUSED:
 143         case CLOCK_EVT_MODE_SHUTDOWN:
 144                 writel(0, clock->regbase + TIMER_ENABLE);
 145                 break;
 146         }
 147 }
 148
 149 static struct msm_clock msm_clocks[] = {
 150         [MSM_CLOCK_GPT] = {
 151                 .clockevent = {
 152                         .name           = "gp_timer",
 153                         .features       = CLOCK_EVT_FEAT_ONESHOT,
 154                         .shift          = 32,
 155                         .rating         = 200,
 156                         .set_next_event = msm_timer_set_next_event,
 157                         .set_mode       = msm_timer_set_mode,
 158                 },
 159                 .clocksource = {
 160                         .name           = "gp_timer",
 161                         .rating         = 200,
 162                         .read           = msm_read_timer_count,
 163                         .mask           = CLOCKSOURCE_MASK(32),
 164                         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 165                 },
 166                 .irq = {
 167                         .name    = "gp_timer",
 168                         .flags   = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_RISING,
 169                         .handler = msm_timer_interrupt,
 170                         .dev_id  = &msm_clocks[0].clockevent,
 171                         .irq     = INT_GP_TIMER_EXP
 172                 },
 173                 .freq = GPT_HZ,
 174         },
 175         [MSM_CLOCK_DGT] = {
 176                 .clockevent = {
 177                         .name           = "dg_timer",
 178                         .features       = CLOCK_EVT_FEAT_ONESHOT,
 179                         .shift          = 32 + MSM_DGT_SHIFT,
 180                         .rating         = 300,
 181                         .set_next_event = msm_timer_set_next_event,
 182                         .set_mode       = msm_timer_set_mode,
 183                 },
 184                 .clocksource = {
 185                         .name           = "dg_timer",
 186                         .rating         = 300,
 187                         .read           = msm_read_timer_count,
 188                         .mask           = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT)),
 189                         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 190                 },
 191                 .irq = {
 192                         .name    = "dg_timer",
 193                         .flags   = IRQF_DISABLED | IRQF_TIMER | IRQF_TRIGGER_RISING,
 194                         .handler = msm_timer_interrupt,
 195                         .dev_id  = &msm_clocks[1].clockevent,
 196                         .irq     = INT_DEBUG_TIMER_EXP
 197                 },
 198                 .freq = DGT_HZ >> MSM_DGT_SHIFT,
 199                 .shift = MSM_DGT_SHIFT,
 200         }
 201 };
 202
 203 static void __init msm_timer_init(void)
 204 {
 205         int i;
 206         int res;
 207         int global_offset = 0;
 208
 209         if (cpu_is_msm7x01()) {
 210                 msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE;
 211                 msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x10;
 212         } else if (cpu_is_msm7x30()) {
 213                 msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE + 0x04;
 214                 msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x24;
 215         } else if (cpu_is_qsd8x50()) {
 216                 msm_clocks[MSM_CLOCK_GPT].regbase = MSM_CSR_BASE;
 217                 msm_clocks[MSM_CLOCK_DGT].regbase = MSM_CSR_BASE + 0x10;
 218         } else if (cpu_is_msm8x60() || cpu_is_msm8960()) {
 219                 msm_clocks[MSM_CLOCK_GPT].regbase = MSM_TMR_BASE + 0x04;
 220                 msm_clocks[MSM_CLOCK_DGT].regbase = MSM_TMR_BASE + 0x24;
 221
 222                 /* Use CPU0's timer as the global timer. */
 223                 global_offset = MSM_TMR0_BASE - MSM_TMR_BASE;
 224         } else
 225                 BUG();
 226
 227 #ifdef CONFIG_ARCH_MSM_SCORPIONMP
 228         writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
 229 #endif
 230
 231         for (i = 0; i < ARRAY_SIZE(msm_clocks); i++) {
 232                 struct msm_clock *clock = &msm_clocks[i];
 233                 struct clock_event_device *ce = &clock->clockevent;
 234                 struct clocksource *cs = &clock->clocksource;
 235
 236                 clock->local_counter = clock->regbase + TIMER_COUNT_VAL;
 237                 clock->global_counter = clock->local_counter + global_offset;
 238
 239                 writel(0, clock->regbase + TIMER_ENABLE);
 240                 writel(0, clock->regbase + TIMER_CLEAR);
 241                 writel(~0, clock->regbase + TIMER_MATCH_VAL);
 242
 243                 ce->mult = div_sc(clock->freq, NSEC_PER_SEC, ce->shift);
 244                 /* allow at least 10 seconds to notice that the timer wrapped */
 245                 ce->max_delta_ns =
 246                         clockevent_delta2ns(0xf0000000 >> clock->shift, ce);
 247                 /* 4 gets rounded down to 3 */
 248                 ce->min_delta_ns = clockevent_delta2ns(4, ce);
 249                 ce->cpumask = cpumask_of(0);
 250
 251                 res = clocksource_register_hz(cs, clock->freq);
 252                 if (res)
 253                         printk(KERN_ERR "msm_timer_init: clocksource_register "
 254                                "failed for %s\n", cs->name);
 255
 256                 res = setup_irq(clock->irq.irq, &clock->irq);
 257                 if (res)
 258                         printk(KERN_ERR "msm_timer_init: setup_irq "
 259                                "failed for %s\n", cs->name);
 260
 261                 clockevents_register_device(ce);
 262         }
 263 }
 264
 265 #ifdef CONFIG_SMP
 266 void __cpuinit local_timer_setup(struct clock_event_device *evt)
 267 {
 268         struct msm_clock *clock = &msm_clocks[MSM_GLOBAL_TIMER];
 269
 270         /* Use existing clock_event for cpu 0 */
 271         if (!smp_processor_id())
 272                 return;
 273
 274         writel(DGT_CLK_CTL_DIV_4, MSM_TMR_BASE + DGT_CLK_CTL);
 275
 276         if (!local_clock_event) {
 277                 writel(0, clock->regbase  + TIMER_ENABLE);
 278                 writel(0, clock->regbase + TIMER_CLEAR);
 279                 writel(~0, clock->regbase + TIMER_MATCH_VAL);
 280         }
 281         evt->irq = clock->irq.irq;
 282         evt->name = "local_timer";
 283         evt->features = CLOCK_EVT_FEAT_ONESHOT;
 284         evt->rating = clock->clockevent.rating;
 285         evt->set_mode = msm_timer_set_mode;
 286         evt->set_next_event = msm_timer_set_next_event;
 287         evt->shift = clock->clockevent.shift;
 288         evt->mult = div_sc(clock->freq, NSEC_PER_SEC, evt->shift);
 289         evt->max_delta_ns =
 290                 clockevent_delta2ns(0xf0000000 >> clock->shift, evt);
 291         evt->min_delta_ns = clockevent_delta2ns(4, evt);
 292
 293         local_clock_event = evt;
 294
 295         gic_enable_ppi(clock->irq.irq);
 296
 297         clockevents_register_device(evt);
 298 }
 299
 300 inline int local_timer_ack(void)
 301 {
 302         return 1;
 303 }
 304
 305 #endif
 306
 307 struct sys_timer msm_timer = {
 308         .init = msm_timer_init
 309 };