arch/arm/mach-msm/timer.c

   1 /*
   2  *
   3  * Copyright (C) 2007 Google, Inc.
   4  * Copyright (c) 2009-2012, The Linux Foundation. All rights reserved.
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   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
  17 #include <linux/clocksource.h>
  18 #include <linux/clockchips.h>
  19 #include <linux/init.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/irq.h>
  22 #include <linux/io.h>
  23 #include <linux/of.h>
  24 #include <linux/of_address.h>
  25 #include <linux/of_irq.h>
  26 #include <linux/sched_clock.h>
  27
  28 #include <asm/mach/time.h>
  29 #include <asm/localtimer.h>
  30
  31 #include "common.h"
  32
  33 #define TIMER_MATCH_VAL                 0x0000
  34 #define TIMER_COUNT_VAL                 0x0004
  35 #define TIMER_ENABLE                    0x0008
  36 #define TIMER_ENABLE_CLR_ON_MATCH_EN    BIT(1)
  37 #define TIMER_ENABLE_EN                 BIT(0)
  38 #define TIMER_CLEAR                     0x000C
  39 #define DGT_CLK_CTL                     0x10
  40 #define DGT_CLK_CTL_DIV_4               0x3
  41 #define TIMER_STS_GPT0_CLR_PEND         BIT(10)
  42
  43 #define GPT_HZ 32768
  44
  45 #define MSM_DGT_SHIFT 5
  46
  47 static void __iomem *event_base;
  48 static void __iomem *sts_base;
  49
  50 static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
  51 {
  52         struct clock_event_device *evt = *(struct clock_event_device **)dev_id;
  53         /* Stop the timer tick */
  54         if (evt->mode == CLOCK_EVT_MODE_ONESHOT) {
  55                 u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
  56                 ctrl &= ~TIMER_ENABLE_EN;
  57                 writel_relaxed(ctrl, event_base + TIMER_ENABLE);
  58         }
  59         evt->event_handler(evt);
  60         return IRQ_HANDLED;
  61 }
  62
  63 static int msm_timer_set_next_event(unsigned long cycles,
  64                                     struct clock_event_device *evt)
  65 {
  66         u32 ctrl = readl_relaxed(event_base + TIMER_ENABLE);
  67
  68         ctrl &= ~TIMER_ENABLE_EN;
  69         writel_relaxed(ctrl, event_base + TIMER_ENABLE);
  70
  71         writel_relaxed(ctrl, event_base + TIMER_CLEAR);
  72         writel_relaxed(cycles, event_base + TIMER_MATCH_VAL);
  73
  74         if (sts_base)
  75                 while (readl_relaxed(sts_base) & TIMER_STS_GPT0_CLR_PEND)
  76                         cpu_relax();
  77
  78         writel_relaxed(ctrl | TIMER_ENABLE_EN, event_base + TIMER_ENABLE);
  79         return 0;
  80 }
  81
  82 static void msm_timer_set_mode(enum clock_event_mode mode,
  83                               struct clock_event_device *evt)
  84 {
  85         u32 ctrl;
  86
  87         ctrl = readl_relaxed(event_base + TIMER_ENABLE);
  88         ctrl &= ~(TIMER_ENABLE_EN | TIMER_ENABLE_CLR_ON_MATCH_EN);
  89
  90         switch (mode) {
  91         case CLOCK_EVT_MODE_RESUME:
  92         case CLOCK_EVT_MODE_PERIODIC:
  93                 break;
  94         case CLOCK_EVT_MODE_ONESHOT:
  95                 /* Timer is enabled in set_next_event */
  96                 break;
  97         case CLOCK_EVT_MODE_UNUSED:
  98         case CLOCK_EVT_MODE_SHUTDOWN:
  99                 break;
 100         }
 101         writel_relaxed(ctrl, event_base + TIMER_ENABLE);
 102 }
 103
 104 static struct clock_event_device msm_clockevent = {
 105         .name           = "gp_timer",
 106         .features       = CLOCK_EVT_FEAT_ONESHOT,
 107         .rating         = 200,
 108         .set_next_event = msm_timer_set_next_event,
 109         .set_mode       = msm_timer_set_mode,
 110 };
 111
 112 static union {
 113         struct clock_event_device *evt;
 114         struct clock_event_device * __percpu *percpu_evt;
 115 } msm_evt;
 116
 117 static void __iomem *source_base;
 118
 119 static notrace cycle_t msm_read_timer_count(struct clocksource *cs)
 120 {
 121         return readl_relaxed(source_base + TIMER_COUNT_VAL);
 122 }
 123
 124 static notrace cycle_t msm_read_timer_count_shift(struct clocksource *cs)
 125 {
 126         /*
 127          * Shift timer count down by a constant due to unreliable lower bits
 128          * on some targets.
 129          */
 130         return msm_read_timer_count(cs) >> MSM_DGT_SHIFT;
 131 }
 132
 133 static struct clocksource msm_clocksource = {
 134         .name   = "dg_timer",
 135         .rating = 300,
 136         .read   = msm_read_timer_count,
 137         .mask   = CLOCKSOURCE_MASK(32),
 138         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 139 };
 140
 141 #ifdef CONFIG_LOCAL_TIMERS
 142 static int msm_local_timer_setup(struct clock_event_device *evt)
 143 {
 144         /* Use existing clock_event for cpu 0 */
 145         if (!smp_processor_id())
 146                 return 0;
 147
 148         evt->irq = msm_clockevent.irq;
 149         evt->name = "local_timer";
 150         evt->features = msm_clockevent.features;
 151         evt->rating = msm_clockevent.rating;
 152         evt->set_mode = msm_timer_set_mode;
 153         evt->set_next_event = msm_timer_set_next_event;
 154
 155         *__this_cpu_ptr(msm_evt.percpu_evt) = evt;
 156         clockevents_config_and_register(evt, GPT_HZ, 4, 0xf0000000);
 157         enable_percpu_irq(evt->irq, IRQ_TYPE_EDGE_RISING);
 158         return 0;
 159 }
 160
 161 static void msm_local_timer_stop(struct clock_event_device *evt)
 162 {
 163         evt->set_mode(CLOCK_EVT_MODE_UNUSED, evt);
 164         disable_percpu_irq(evt->irq);
 165 }
 166
 167 static struct local_timer_ops msm_local_timer_ops = {
 168         .setup  = msm_local_timer_setup,
 169         .stop   = msm_local_timer_stop,
 170 };
 171 #endif /* CONFIG_LOCAL_TIMERS */
 172
 173 static notrace u32 msm_sched_clock_read(void)
 174 {
 175         return msm_clocksource.read(&msm_clocksource);
 176 }
 177
 178 static void __init msm_timer_init(u32 dgt_hz, int sched_bits, int irq,
 179                                   bool percpu)
 180 {
 181         struct clock_event_device *ce = &msm_clockevent;
 182         struct clocksource *cs = &msm_clocksource;
 183         int res;
 184
 185         ce->cpumask = cpumask_of(0);
 186         ce->irq = irq;
 187
 188         clockevents_config_and_register(ce, GPT_HZ, 4, 0xffffffff);
 189         if (percpu) {
 190                 msm_evt.percpu_evt = alloc_percpu(struct clock_event_device *);
 191                 if (!msm_evt.percpu_evt) {
 192                         pr_err("memory allocation failed for %s\n", ce->name);
 193                         goto err;
 194                 }
 195                 *__this_cpu_ptr(msm_evt.percpu_evt) = ce;
 196                 res = request_percpu_irq(ce->irq, msm_timer_interrupt,
 197                                          ce->name, msm_evt.percpu_evt);
 198                 if (!res) {
 199                         enable_percpu_irq(ce->irq, IRQ_TYPE_EDGE_RISING);
 200 #ifdef CONFIG_LOCAL_TIMERS
 201                         local_timer_register(&msm_local_timer_ops);
 202 #endif
 203                 }
 204         } else {
 205                 msm_evt.evt = ce;
 206                 res = request_irq(ce->irq, msm_timer_interrupt,
 207                                   IRQF_TIMER | IRQF_NOBALANCING |
 208                                   IRQF_TRIGGER_RISING, ce->name, &msm_evt.evt);
 209         }
 210
 211         if (res)
 212                 pr_err("request_irq failed for %s\n", ce->name);
 213 err:
 214         writel_relaxed(TIMER_ENABLE_EN, source_base + TIMER_ENABLE);
 215         res = clocksource_register_hz(cs, dgt_hz);
 216         if (res)
 217                 pr_err("clocksource_register failed\n");
 218         setup_sched_clock(msm_sched_clock_read, sched_bits, dgt_hz);
 219 }
 220
 221 #ifdef CONFIG_OF
 222 static const struct of_device_id msm_timer_match[] __initconst = {
 223         { .compatible = "qcom,kpss-timer" },
 224         { .compatible = "qcom,scss-timer" },
 225         { },
 226 };
 227
 228 void __init msm_dt_timer_init(void)
 229 {
 230         struct device_node *np;
 231         u32 freq;
 232         int irq;
 233         struct resource res;
 234         u32 percpu_offset;
 235         void __iomem *base;
 236         void __iomem *cpu0_base;
 237
 238         np = of_find_matching_node(NULL, msm_timer_match);
 239         if (!np) {
 240                 pr_err("Can't find msm timer DT node\n");
 241                 return;
 242         }
 243
 244         base = of_iomap(np, 0);
 245         if (!base) {
 246                 pr_err("Failed to map event base\n");
 247                 return;
 248         }
 249
 250         /* We use GPT0 for the clockevent */
 251         irq = irq_of_parse_and_map(np, 1);
 252         if (irq <= 0) {
 253                 pr_err("Can't get irq\n");
 254                 return;
 255         }
 256
 257         /* We use CPU0's DGT for the clocksource */
 258         if (of_property_read_u32(np, "cpu-offset", &percpu_offset))
 259                 percpu_offset = 0;
 260
 261         if (of_address_to_resource(np, 0, &res)) {
 262                 pr_err("Failed to parse DGT resource\n");
 263                 return;
 264         }
 265
 266         cpu0_base = ioremap(res.start + percpu_offset, resource_size(&res));
 267         if (!cpu0_base) {
 268                 pr_err("Failed to map source base\n");
 269                 return;
 270         }
 271
 272         if (of_property_read_u32(np, "clock-frequency", &freq)) {
 273                 pr_err("Unknown frequency\n");
 274                 return;
 275         }
 276         of_node_put(np);
 277
 278         event_base = base + 0x4;
 279         sts_base = base + 0x88;
 280         source_base = cpu0_base + 0x24;
 281         freq /= 4;
 282         writel_relaxed(DGT_CLK_CTL_DIV_4, source_base + DGT_CLK_CTL);
 283
 284         msm_timer_init(freq, 32, irq, !!percpu_offset);
 285 }
 286 #endif
 287
 288 static int __init msm_timer_map(phys_addr_t addr, u32 event, u32 source,
 289                                 u32 sts)
 290 {
 291         void __iomem *base;
 292
 293         base = ioremap(addr, SZ_256);
 294         if (!base) {
 295                 pr_err("Failed to map timer base\n");
 296                 return -ENOMEM;
 297         }
 298         event_base = base + event;
 299         source_base = base + source;
 300         if (sts)
 301                 sts_base = base + sts;
 302
 303         return 0;
 304 }
 305
 306 void __init msm7x01_timer_init(void)
 307 {
 308         struct clocksource *cs = &msm_clocksource;
 309
 310         if (msm_timer_map(0xc0100000, 0x0, 0x10, 0x0))
 311                 return;
 312         cs->read = msm_read_timer_count_shift;
 313         cs->mask = CLOCKSOURCE_MASK((32 - MSM_DGT_SHIFT));
 314         /* 600 KHz */
 315         msm_timer_init(19200000 >> MSM_DGT_SHIFT, 32 - MSM_DGT_SHIFT, 7,
 316                         false);
 317 }
 318
 319 void __init msm7x30_timer_init(void)
 320 {
 321         if (msm_timer_map(0xc0100000, 0x4, 0x24, 0x80))
 322                 return;
 323         msm_timer_init(24576000 / 4, 32, 1, false);
 324 }
 325
 326 void __init qsd8x50_timer_init(void)
 327 {
 328         if (msm_timer_map(0xAC100000, 0x0, 0x10, 0x34))
 329                 return;
 330         msm_timer_init(19200000 / 4, 32, 7, false);
 331 }