linux/arch/sparc/kernel/time_32.c
<<
>>
Prefs
   1/* linux/arch/sparc/kernel/time.c
   2 *
   3 * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
   4 * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
   5 *
   6 * Chris Davis (cdavis@cois.on.ca) 03/27/1998
   7 * Added support for the intersil on the sun4/4200
   8 *
   9 * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
  10 * Support for MicroSPARC-IIep, PCI CPU.
  11 *
  12 * This file handles the Sparc specific time handling details.
  13 *
  14 * 1997-09-10   Updated NTP code according to technical memorandum Jan '96
  15 *              "A Kernel Model for Precision Timekeeping" by Dave Mills
  16 */
  17#include <linux/errno.h>
  18#include <linux/module.h>
  19#include <linux/sched.h>
  20#include <linux/kernel.h>
  21#include <linux/param.h>
  22#include <linux/string.h>
  23#include <linux/mm.h>
  24#include <linux/interrupt.h>
  25#include <linux/time.h>
  26#include <linux/rtc.h>
  27#include <linux/rtc/m48t59.h>
  28#include <linux/timex.h>
  29#include <linux/clocksource.h>
  30#include <linux/clockchips.h>
  31#include <linux/init.h>
  32#include <linux/pci.h>
  33#include <linux/ioport.h>
  34#include <linux/profile.h>
  35#include <linux/of.h>
  36#include <linux/of_device.h>
  37#include <linux/platform_device.h>
  38
  39#include <asm/oplib.h>
  40#include <asm/timex.h>
  41#include <asm/timer.h>
  42#include <asm/irq.h>
  43#include <asm/io.h>
  44#include <asm/idprom.h>
  45#include <asm/page.h>
  46#include <asm/pcic.h>
  47#include <asm/irq_regs.h>
  48#include <asm/setup.h>
  49
  50#include "irq.h"
  51
  52static __cacheline_aligned_in_smp DEFINE_SEQLOCK(timer_cs_lock);
  53static __volatile__ u64 timer_cs_internal_counter = 0;
  54static char timer_cs_enabled = 0;
  55
  56static struct clock_event_device timer_ce;
  57static char timer_ce_enabled = 0;
  58
  59#ifdef CONFIG_SMP
  60DEFINE_PER_CPU(struct clock_event_device, sparc32_clockevent);
  61#endif
  62
  63DEFINE_SPINLOCK(rtc_lock);
  64EXPORT_SYMBOL(rtc_lock);
  65
  66static int set_rtc_mmss(unsigned long);
  67
  68unsigned long profile_pc(struct pt_regs *regs)
  69{
  70        extern char __copy_user_begin[], __copy_user_end[];
  71        extern char __bzero_begin[], __bzero_end[];
  72
  73        unsigned long pc = regs->pc;
  74
  75        if (in_lock_functions(pc) ||
  76            (pc >= (unsigned long) __copy_user_begin &&
  77             pc < (unsigned long) __copy_user_end) ||
  78            (pc >= (unsigned long) __bzero_begin &&
  79             pc < (unsigned long) __bzero_end))
  80                pc = regs->u_regs[UREG_RETPC];
  81        return pc;
  82}
  83
  84EXPORT_SYMBOL(profile_pc);
  85
  86__volatile__ unsigned int *master_l10_counter;
  87
  88int update_persistent_clock(struct timespec now)
  89{
  90        return set_rtc_mmss(now.tv_sec);
  91}
  92
  93irqreturn_t notrace timer_interrupt(int dummy, void *dev_id)
  94{
  95        if (timer_cs_enabled) {
  96                write_seqlock(&timer_cs_lock);
  97                timer_cs_internal_counter++;
  98                sparc_config.clear_clock_irq();
  99                write_sequnlock(&timer_cs_lock);
 100        } else {
 101                sparc_config.clear_clock_irq();
 102        }
 103
 104        if (timer_ce_enabled)
 105                timer_ce.event_handler(&timer_ce);
 106
 107        return IRQ_HANDLED;
 108}
 109
 110static void timer_ce_set_mode(enum clock_event_mode mode,
 111                              struct clock_event_device *evt)
 112{
 113        switch (mode) {
 114                case CLOCK_EVT_MODE_PERIODIC:
 115                case CLOCK_EVT_MODE_RESUME:
 116                        timer_ce_enabled = 1;
 117                        break;
 118                case CLOCK_EVT_MODE_SHUTDOWN:
 119                        timer_ce_enabled = 0;
 120                        break;
 121                default:
 122                        break;
 123        }
 124        smp_mb();
 125}
 126
 127static __init void setup_timer_ce(void)
 128{
 129        struct clock_event_device *ce = &timer_ce;
 130
 131        BUG_ON(smp_processor_id() != boot_cpu_id);
 132
 133        ce->name     = "timer_ce";
 134        ce->rating   = 100;
 135        ce->features = CLOCK_EVT_FEAT_PERIODIC;
 136        ce->set_mode = timer_ce_set_mode;
 137        ce->cpumask  = cpu_possible_mask;
 138        ce->shift    = 32;
 139        ce->mult     = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
 140                              ce->shift);
 141        clockevents_register_device(ce);
 142}
 143
 144static unsigned int sbus_cycles_offset(void)
 145{
 146        unsigned int val, offset;
 147
 148        val = *master_l10_counter;
 149        offset = (val >> TIMER_VALUE_SHIFT) & TIMER_VALUE_MASK;
 150
 151        /* Limit hit? */
 152        if (val & TIMER_LIMIT_BIT)
 153                offset += sparc_config.cs_period;
 154
 155        return offset;
 156}
 157
 158static cycle_t timer_cs_read(struct clocksource *cs)
 159{
 160        unsigned int seq, offset;
 161        u64 cycles;
 162
 163        do {
 164                seq = read_seqbegin(&timer_cs_lock);
 165
 166                cycles = timer_cs_internal_counter;
 167                offset = sparc_config.get_cycles_offset();
 168        } while (read_seqretry(&timer_cs_lock, seq));
 169
 170        /* Count absolute cycles */
 171        cycles *= sparc_config.cs_period;
 172        cycles += offset;
 173
 174        return cycles;
 175}
 176
 177static struct clocksource timer_cs = {
 178        .name   = "timer_cs",
 179        .rating = 100,
 180        .read   = timer_cs_read,
 181        .mask   = CLOCKSOURCE_MASK(64),
 182        .shift  = 2,
 183        .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 184};
 185
 186static __init int setup_timer_cs(void)
 187{
 188        timer_cs_enabled = 1;
 189        timer_cs.mult = clocksource_hz2mult(sparc_config.clock_rate,
 190                                            timer_cs.shift);
 191
 192        return clocksource_register(&timer_cs);
 193}
 194
 195#ifdef CONFIG_SMP
 196static void percpu_ce_setup(enum clock_event_mode mode,
 197                        struct clock_event_device *evt)
 198{
 199        int cpu = __first_cpu(evt->cpumask);
 200
 201        switch (mode) {
 202                case CLOCK_EVT_MODE_PERIODIC:
 203                        sparc_config.load_profile_irq(cpu,
 204                                                      SBUS_CLOCK_RATE / HZ);
 205                        break;
 206                case CLOCK_EVT_MODE_ONESHOT:
 207                case CLOCK_EVT_MODE_SHUTDOWN:
 208                case CLOCK_EVT_MODE_UNUSED:
 209                        sparc_config.load_profile_irq(cpu, 0);
 210                        break;
 211                default:
 212                        break;
 213        }
 214}
 215
 216static int percpu_ce_set_next_event(unsigned long delta,
 217                                    struct clock_event_device *evt)
 218{
 219        int cpu = __first_cpu(evt->cpumask);
 220        unsigned int next = (unsigned int)delta;
 221
 222        sparc_config.load_profile_irq(cpu, next);
 223        return 0;
 224}
 225
 226void register_percpu_ce(int cpu)
 227{
 228        struct clock_event_device *ce = &per_cpu(sparc32_clockevent, cpu);
 229        unsigned int features = CLOCK_EVT_FEAT_PERIODIC;
 230
 231        if (sparc_config.features & FEAT_L14_ONESHOT)
 232                features |= CLOCK_EVT_FEAT_ONESHOT;
 233
 234        ce->name           = "percpu_ce";
 235        ce->rating         = 200;
 236        ce->features       = features;
 237        ce->set_mode       = percpu_ce_setup;
 238        ce->set_next_event = percpu_ce_set_next_event;
 239        ce->cpumask        = cpumask_of(cpu);
 240        ce->shift          = 32;
 241        ce->mult           = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
 242                                    ce->shift);
 243        ce->max_delta_ns   = clockevent_delta2ns(sparc_config.clock_rate, ce);
 244        ce->min_delta_ns   = clockevent_delta2ns(100, ce);
 245
 246        clockevents_register_device(ce);
 247}
 248#endif
 249
 250static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
 251{
 252        struct platform_device *pdev = to_platform_device(dev);
 253        struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 254
 255        return readb(pdata->ioaddr + ofs);
 256}
 257
 258static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
 259{
 260        struct platform_device *pdev = to_platform_device(dev);
 261        struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 262
 263        writeb(val, pdata->ioaddr + ofs);
 264}
 265
 266static struct m48t59_plat_data m48t59_data = {
 267        .read_byte = mostek_read_byte,
 268        .write_byte = mostek_write_byte,
 269};
 270
 271/* resource is set at runtime */
 272static struct platform_device m48t59_rtc = {
 273        .name           = "rtc-m48t59",
 274        .id             = 0,
 275        .num_resources  = 1,
 276        .dev    = {
 277                .platform_data = &m48t59_data,
 278        },
 279};
 280
 281static int clock_probe(struct platform_device *op)
 282{
 283        struct device_node *dp = op->dev.of_node;
 284        const char *model = of_get_property(dp, "model", NULL);
 285
 286        if (!model)
 287                return -ENODEV;
 288
 289        /* Only the primary RTC has an address property */
 290        if (!of_find_property(dp, "address", NULL))
 291                return -ENODEV;
 292
 293        m48t59_rtc.resource = &op->resource[0];
 294        if (!strcmp(model, "mk48t02")) {
 295                /* Map the clock register io area read-only */
 296                m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
 297                                                2048, "rtc-m48t59");
 298                m48t59_data.type = M48T59RTC_TYPE_M48T02;
 299        } else if (!strcmp(model, "mk48t08")) {
 300                m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
 301                                                8192, "rtc-m48t59");
 302                m48t59_data.type = M48T59RTC_TYPE_M48T08;
 303        } else
 304                return -ENODEV;
 305
 306        if (platform_device_register(&m48t59_rtc) < 0)
 307                printk(KERN_ERR "Registering RTC device failed\n");
 308
 309        return 0;
 310}
 311
 312static struct of_device_id clock_match[] = {
 313        {
 314                .name = "eeprom",
 315        },
 316        {},
 317};
 318
 319static struct platform_driver clock_driver = {
 320        .probe          = clock_probe,
 321        .driver = {
 322                .name = "rtc",
 323                .owner = THIS_MODULE,
 324                .of_match_table = clock_match,
 325        },
 326};
 327
 328
 329/* Probe for the mostek real time clock chip. */
 330static int __init clock_init(void)
 331{
 332        return platform_driver_register(&clock_driver);
 333}
 334/* Must be after subsys_initcall() so that busses are probed.  Must
 335 * be before device_initcall() because things like the RTC driver
 336 * need to see the clock registers.
 337 */
 338fs_initcall(clock_init);
 339
 340static void __init sparc32_late_time_init(void)
 341{
 342        if (sparc_config.features & FEAT_L10_CLOCKEVENT)
 343                setup_timer_ce();
 344        if (sparc_config.features & FEAT_L10_CLOCKSOURCE)
 345                setup_timer_cs();
 346#ifdef CONFIG_SMP
 347        register_percpu_ce(smp_processor_id());
 348#endif
 349}
 350
 351static void __init sbus_time_init(void)
 352{
 353        sparc_config.get_cycles_offset = sbus_cycles_offset;
 354        sparc_config.init_timers();
 355}
 356
 357void __init time_init(void)
 358{
 359        sparc_config.features = 0;
 360        late_time_init = sparc32_late_time_init;
 361
 362        if (pcic_present())
 363                pci_time_init();
 364        else
 365                sbus_time_init();
 366}
 367
 368
 369static int set_rtc_mmss(unsigned long secs)
 370{
 371        struct rtc_device *rtc = rtc_class_open("rtc0");
 372        int err = -1;
 373
 374        if (rtc) {
 375                err = rtc_set_mmss(rtc, secs);
 376                rtc_class_close(rtc);
 377        }
 378
 379        return err;
 380}
 381