linux/arch/sparc/kernel/time_32.c
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   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/m48t59.h>
  27#include <linux/timex.h>
  28#include <linux/clocksource.h>
  29#include <linux/clockchips.h>
  30#include <linux/init.h>
  31#include <linux/pci.h>
  32#include <linux/ioport.h>
  33#include <linux/profile.h>
  34#include <linux/of.h>
  35#include <linux/of_device.h>
  36#include <linux/platform_device.h>
  37
  38#include <asm/mc146818rtc.h>
  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 "kernel.h"
  51#include "irq.h"
  52
  53static __cacheline_aligned_in_smp DEFINE_SEQLOCK(timer_cs_lock);
  54static __volatile__ u64 timer_cs_internal_counter = 0;
  55static char timer_cs_enabled = 0;
  56
  57static struct clock_event_device timer_ce;
  58static char timer_ce_enabled = 0;
  59
  60#ifdef CONFIG_SMP
  61DEFINE_PER_CPU(struct clock_event_device, sparc32_clockevent);
  62#endif
  63
  64DEFINE_SPINLOCK(rtc_lock);
  65EXPORT_SYMBOL(rtc_lock);
  66
  67unsigned long profile_pc(struct pt_regs *regs)
  68{
  69        extern char __copy_user_begin[], __copy_user_end[];
  70        extern char __bzero_begin[], __bzero_end[];
  71
  72        unsigned long pc = regs->pc;
  73
  74        if (in_lock_functions(pc) ||
  75            (pc >= (unsigned long) __copy_user_begin &&
  76             pc < (unsigned long) __copy_user_end) ||
  77            (pc >= (unsigned long) __bzero_begin &&
  78             pc < (unsigned long) __bzero_end))
  79                pc = regs->u_regs[UREG_RETPC];
  80        return pc;
  81}
  82
  83EXPORT_SYMBOL(profile_pc);
  84
  85volatile u32 __iomem *master_l10_counter;
  86
  87irqreturn_t notrace timer_interrupt(int dummy, void *dev_id)
  88{
  89        if (timer_cs_enabled) {
  90                write_seqlock(&timer_cs_lock);
  91                timer_cs_internal_counter++;
  92                sparc_config.clear_clock_irq();
  93                write_sequnlock(&timer_cs_lock);
  94        } else {
  95                sparc_config.clear_clock_irq();
  96        }
  97
  98        if (timer_ce_enabled)
  99                timer_ce.event_handler(&timer_ce);
 100
 101        return IRQ_HANDLED;
 102}
 103
 104static int timer_ce_shutdown(struct clock_event_device *evt)
 105{
 106        timer_ce_enabled = 0;
 107        smp_mb();
 108        return 0;
 109}
 110
 111static int timer_ce_set_periodic(struct clock_event_device *evt)
 112{
 113        timer_ce_enabled = 1;
 114        smp_mb();
 115        return 0;
 116}
 117
 118static __init void setup_timer_ce(void)
 119{
 120        struct clock_event_device *ce = &timer_ce;
 121
 122        BUG_ON(smp_processor_id() != boot_cpu_id);
 123
 124        ce->name     = "timer_ce";
 125        ce->rating   = 100;
 126        ce->features = CLOCK_EVT_FEAT_PERIODIC;
 127        ce->set_state_shutdown = timer_ce_shutdown;
 128        ce->set_state_periodic = timer_ce_set_periodic;
 129        ce->tick_resume = timer_ce_set_periodic;
 130        ce->cpumask  = cpu_possible_mask;
 131        ce->shift    = 32;
 132        ce->mult     = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
 133                              ce->shift);
 134        clockevents_register_device(ce);
 135}
 136
 137static unsigned int sbus_cycles_offset(void)
 138{
 139        u32 val, offset;
 140
 141        val = sbus_readl(master_l10_counter);
 142        offset = (val >> TIMER_VALUE_SHIFT) & TIMER_VALUE_MASK;
 143
 144        /* Limit hit? */
 145        if (val & TIMER_LIMIT_BIT)
 146                offset += sparc_config.cs_period;
 147
 148        return offset;
 149}
 150
 151static u64 timer_cs_read(struct clocksource *cs)
 152{
 153        unsigned int seq, offset;
 154        u64 cycles;
 155
 156        do {
 157                seq = read_seqbegin(&timer_cs_lock);
 158
 159                cycles = timer_cs_internal_counter;
 160                offset = sparc_config.get_cycles_offset();
 161        } while (read_seqretry(&timer_cs_lock, seq));
 162
 163        /* Count absolute cycles */
 164        cycles *= sparc_config.cs_period;
 165        cycles += offset;
 166
 167        return cycles;
 168}
 169
 170static struct clocksource timer_cs = {
 171        .name   = "timer_cs",
 172        .rating = 100,
 173        .read   = timer_cs_read,
 174        .mask   = CLOCKSOURCE_MASK(64),
 175        .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 176};
 177
 178static __init int setup_timer_cs(void)
 179{
 180        timer_cs_enabled = 1;
 181        return clocksource_register_hz(&timer_cs, sparc_config.clock_rate);
 182}
 183
 184#ifdef CONFIG_SMP
 185static int percpu_ce_shutdown(struct clock_event_device *evt)
 186{
 187        int cpu = cpumask_first(evt->cpumask);
 188
 189        sparc_config.load_profile_irq(cpu, 0);
 190        return 0;
 191}
 192
 193static int percpu_ce_set_periodic(struct clock_event_device *evt)
 194{
 195        int cpu = cpumask_first(evt->cpumask);
 196
 197        sparc_config.load_profile_irq(cpu, SBUS_CLOCK_RATE / HZ);
 198        return 0;
 199}
 200
 201static int percpu_ce_set_next_event(unsigned long delta,
 202                                    struct clock_event_device *evt)
 203{
 204        int cpu = cpumask_first(evt->cpumask);
 205        unsigned int next = (unsigned int)delta;
 206
 207        sparc_config.load_profile_irq(cpu, next);
 208        return 0;
 209}
 210
 211void register_percpu_ce(int cpu)
 212{
 213        struct clock_event_device *ce = &per_cpu(sparc32_clockevent, cpu);
 214        unsigned int features = CLOCK_EVT_FEAT_PERIODIC;
 215
 216        if (sparc_config.features & FEAT_L14_ONESHOT)
 217                features |= CLOCK_EVT_FEAT_ONESHOT;
 218
 219        ce->name           = "percpu_ce";
 220        ce->rating         = 200;
 221        ce->features       = features;
 222        ce->set_state_shutdown = percpu_ce_shutdown;
 223        ce->set_state_periodic = percpu_ce_set_periodic;
 224        ce->set_state_oneshot = percpu_ce_shutdown;
 225        ce->set_next_event = percpu_ce_set_next_event;
 226        ce->cpumask        = cpumask_of(cpu);
 227        ce->shift          = 32;
 228        ce->mult           = div_sc(sparc_config.clock_rate, NSEC_PER_SEC,
 229                                    ce->shift);
 230        ce->max_delta_ns   = clockevent_delta2ns(sparc_config.clock_rate, ce);
 231        ce->max_delta_ticks = (unsigned long)sparc_config.clock_rate;
 232        ce->min_delta_ns   = clockevent_delta2ns(100, ce);
 233        ce->min_delta_ticks = 100;
 234
 235        clockevents_register_device(ce);
 236}
 237#endif
 238
 239static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
 240{
 241        struct platform_device *pdev = to_platform_device(dev);
 242        struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 243
 244        return readb(pdata->ioaddr + ofs);
 245}
 246
 247static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
 248{
 249        struct platform_device *pdev = to_platform_device(dev);
 250        struct m48t59_plat_data *pdata = pdev->dev.platform_data;
 251
 252        writeb(val, pdata->ioaddr + ofs);
 253}
 254
 255static struct m48t59_plat_data m48t59_data = {
 256        .read_byte = mostek_read_byte,
 257        .write_byte = mostek_write_byte,
 258};
 259
 260/* resource is set at runtime */
 261static struct platform_device m48t59_rtc = {
 262        .name           = "rtc-m48t59",
 263        .id             = 0,
 264        .num_resources  = 1,
 265        .dev    = {
 266                .platform_data = &m48t59_data,
 267        },
 268};
 269
 270static int clock_probe(struct platform_device *op)
 271{
 272        struct device_node *dp = op->dev.of_node;
 273        const char *model = of_get_property(dp, "model", NULL);
 274
 275        if (!model)
 276                return -ENODEV;
 277
 278        /* Only the primary RTC has an address property */
 279        if (!of_find_property(dp, "address", NULL))
 280                return -ENODEV;
 281
 282        m48t59_rtc.resource = &op->resource[0];
 283        if (!strcmp(model, "mk48t02")) {
 284                /* Map the clock register io area read-only */
 285                m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
 286                                                2048, "rtc-m48t59");
 287                m48t59_data.type = M48T59RTC_TYPE_M48T02;
 288        } else if (!strcmp(model, "mk48t08")) {
 289                m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
 290                                                8192, "rtc-m48t59");
 291                m48t59_data.type = M48T59RTC_TYPE_M48T08;
 292        } else
 293                return -ENODEV;
 294
 295        if (platform_device_register(&m48t59_rtc) < 0)
 296                printk(KERN_ERR "Registering RTC device failed\n");
 297
 298        return 0;
 299}
 300
 301static struct of_device_id clock_match[] = {
 302        {
 303                .name = "eeprom",
 304        },
 305        {},
 306};
 307
 308static struct platform_driver clock_driver = {
 309        .probe          = clock_probe,
 310        .driver = {
 311                .name = "rtc",
 312                .of_match_table = clock_match,
 313        },
 314};
 315
 316
 317/* Probe for the mostek real time clock chip. */
 318static int __init clock_init(void)
 319{
 320        return platform_driver_register(&clock_driver);
 321}
 322/* Must be after subsys_initcall() so that busses are probed.  Must
 323 * be before device_initcall() because things like the RTC driver
 324 * need to see the clock registers.
 325 */
 326fs_initcall(clock_init);
 327
 328static void __init sparc32_late_time_init(void)
 329{
 330        if (sparc_config.features & FEAT_L10_CLOCKEVENT)
 331                setup_timer_ce();
 332        if (sparc_config.features & FEAT_L10_CLOCKSOURCE)
 333                setup_timer_cs();
 334#ifdef CONFIG_SMP
 335        register_percpu_ce(smp_processor_id());
 336#endif
 337}
 338
 339static void __init sbus_time_init(void)
 340{
 341        sparc_config.get_cycles_offset = sbus_cycles_offset;
 342        sparc_config.init_timers();
 343}
 344
 345void __init time_init(void)
 346{
 347        sparc_config.features = 0;
 348        late_time_init = sparc32_late_time_init;
 349
 350        if (pcic_present())
 351                pci_time_init();
 352        else
 353                sbus_time_init();
 354}
 355
 356