arch/sparc/kernel/time_32.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* linux/arch/sparc/kernel/time.c
   3  *
   4  * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
   5  * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
   6  *
   7  * Chris Davis (cdavis@cois.on.ca) 03/27/1998
   8  * Added support for the intersil on the sun4/4200
   9  *
  10  * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998
  11  * Support for MicroSPARC-IIep, PCI CPU.
  12  *
  13  * This file handles the Sparc specific time handling details.
  14  *
  15  * 1997-09-10   Updated NTP code according to technical memorandum Jan '96
  16  *              "A Kernel Model for Precision Timekeeping" by Dave Mills
  17  */
  18 #include <linux/errno.h>
  19 #include <linux/module.h>
  20 #include <linux/sched.h>
  21 #include <linux/kernel.h>
  22 #include <linux/param.h>
  23 #include <linux/string.h>
  24 #include <linux/mm.h>
  25 #include <linux/interrupt.h>
  26 #include <linux/time.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/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
  53 static __cacheline_aligned_in_smp DEFINE_SEQLOCK(timer_cs_lock);
  54 static __volatile__ u64 timer_cs_internal_counter = 0;
  55 static char timer_cs_enabled = 0;
  56
  57 static struct clock_event_device timer_ce;
  58 static char timer_ce_enabled = 0;
  59
  60 #ifdef CONFIG_SMP
  61 DEFINE_PER_CPU(struct clock_event_device, sparc32_clockevent);
  62 #endif
  63
  64 DEFINE_SPINLOCK(rtc_lock);
  65 EXPORT_SYMBOL(rtc_lock);
  66
  67 unsigned 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
  83 EXPORT_SYMBOL(profile_pc);
  84
  85 volatile u32 __iomem *master_l10_counter;
  86
  87 irqreturn_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
 104 static int timer_ce_shutdown(struct clock_event_device *evt)
 105 {
 106         timer_ce_enabled = 0;
 107         smp_mb();
 108         return 0;
 109 }
 110
 111 static int timer_ce_set_periodic(struct clock_event_device *evt)
 112 {
 113         timer_ce_enabled = 1;
 114         smp_mb();
 115         return 0;
 116 }
 117
 118 static __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
 137 static 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
 151 static 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
 170 static 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
 178 static __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
 185 static 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
 193 static 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
 201 static 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
 211 void 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
 239 static 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
 247 static 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
 255 static 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 */
 261 static 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
 270 static 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_property_present(dp, "address"))
 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
 301 static const struct of_device_id clock_match[] = {
 302         {
 303                 .name = "eeprom",
 304         },
 305         {},
 306 };
 307
 308 static 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. */
 318 static 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  */
 326 fs_initcall(clock_init);
 327
 328 static 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
 339 static void __init sbus_time_init(void)
 340 {
 341         sparc_config.get_cycles_offset = sbus_cycles_offset;
 342         sparc_config.init_timers();
 343 }
 344
 345 void __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