diff options
Diffstat (limited to 'arch/sparc/kernel/time_32.c')
-rw-r--r-- | arch/sparc/kernel/time_32.c | 330 |
1 files changed, 330 insertions, 0 deletions
diff --git a/arch/sparc/kernel/time_32.c b/arch/sparc/kernel/time_32.c new file mode 100644 index 00000000000..614ac7b4a9d --- /dev/null +++ b/arch/sparc/kernel/time_32.c @@ -0,0 +1,330 @@ +/* linux/arch/sparc/kernel/time.c + * + * Copyright (C) 1995 David S. Miller (davem@davemloft.net) + * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu) + * + * Chris Davis (cdavis@cois.on.ca) 03/27/1998 + * Added support for the intersil on the sun4/4200 + * + * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998 + * Support for MicroSPARC-IIep, PCI CPU. + * + * This file handles the Sparc specific time handling details. + * + * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 + * "A Kernel Model for Precision Timekeeping" by Dave Mills + */ +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/param.h> +#include <linux/string.h> +#include <linux/mm.h> +#include <linux/interrupt.h> +#include <linux/time.h> +#include <linux/rtc.h> +#include <linux/rtc/m48t59.h> +#include <linux/timex.h> +#include <linux/init.h> +#include <linux/pci.h> +#include <linux/ioport.h> +#include <linux/profile.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> + +#include <asm/oplib.h> +#include <asm/timer.h> +#include <asm/system.h> +#include <asm/irq.h> +#include <asm/io.h> +#include <asm/idprom.h> +#include <asm/machines.h> +#include <asm/page.h> +#include <asm/pcic.h> +#include <asm/irq_regs.h> + +#include "irq.h" + +DEFINE_SPINLOCK(rtc_lock); +EXPORT_SYMBOL(rtc_lock); + +static int set_rtc_mmss(unsigned long); +static int sbus_do_settimeofday(struct timespec *tv); + +unsigned long profile_pc(struct pt_regs *regs) +{ + extern char __copy_user_begin[], __copy_user_end[]; + extern char __atomic_begin[], __atomic_end[]; + extern char __bzero_begin[], __bzero_end[]; + + unsigned long pc = regs->pc; + + if (in_lock_functions(pc) || + (pc >= (unsigned long) __copy_user_begin && + pc < (unsigned long) __copy_user_end) || + (pc >= (unsigned long) __atomic_begin && + pc < (unsigned long) __atomic_end) || + (pc >= (unsigned long) __bzero_begin && + pc < (unsigned long) __bzero_end)) + pc = regs->u_regs[UREG_RETPC]; + return pc; +} + +EXPORT_SYMBOL(profile_pc); + +__volatile__ unsigned int *master_l10_counter; + +/* + * timer_interrupt() needs to keep up the real-time clock, + * as well as call the "do_timer()" routine every clocktick + */ + +#define TICK_SIZE (tick_nsec / 1000) + +static irqreturn_t timer_interrupt(int dummy, void *dev_id) +{ + /* last time the cmos clock got updated */ + static long last_rtc_update; + +#ifndef CONFIG_SMP + profile_tick(CPU_PROFILING); +#endif + + /* Protect counter clear so that do_gettimeoffset works */ + write_seqlock(&xtime_lock); + + clear_clock_irq(); + + do_timer(1); + + /* Determine when to update the Mostek clock. */ + if (ntp_synced() && + xtime.tv_sec > last_rtc_update + 660 && + (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && + (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) { + if (set_rtc_mmss(xtime.tv_sec) == 0) + last_rtc_update = xtime.tv_sec; + else + last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ + } + write_sequnlock(&xtime_lock); + +#ifndef CONFIG_SMP + update_process_times(user_mode(get_irq_regs())); +#endif + return IRQ_HANDLED; +} + +static unsigned char mostek_read_byte(struct device *dev, u32 ofs) +{ + struct platform_device *pdev = to_platform_device(dev); + struct m48t59_plat_data *pdata = pdev->dev.platform_data; + + return readb(pdata->ioaddr + ofs); +} + +static void mostek_write_byte(struct device *dev, u32 ofs, u8 val) +{ + struct platform_device *pdev = to_platform_device(dev); + struct m48t59_plat_data *pdata = pdev->dev.platform_data; + + writeb(val, pdata->ioaddr + ofs); +} + +static struct m48t59_plat_data m48t59_data = { + .read_byte = mostek_read_byte, + .write_byte = mostek_write_byte, +}; + +/* resource is set at runtime */ +static struct platform_device m48t59_rtc = { + .name = "rtc-m48t59", + .id = 0, + .num_resources = 1, + .dev = { + .platform_data = &m48t59_data, + }, +}; + +static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match) +{ + struct device_node *dp = op->node; + const char *model = of_get_property(dp, "model", NULL); + + if (!model) + return -ENODEV; + + m48t59_rtc.resource = &op->resource[0]; + if (!strcmp(model, "mk48t02")) { + /* Map the clock register io area read-only */ + m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0, + 2048, "rtc-m48t59"); + m48t59_data.type = M48T59RTC_TYPE_M48T02; + } else if (!strcmp(model, "mk48t08")) { + m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0, + 8192, "rtc-m48t59"); + m48t59_data.type = M48T59RTC_TYPE_M48T08; + } else + return -ENODEV; + + if (platform_device_register(&m48t59_rtc) < 0) + printk(KERN_ERR "Registering RTC device failed\n"); + + return 0; +} + +static struct of_device_id __initdata clock_match[] = { + { + .name = "eeprom", + }, + {}, +}; + +static struct of_platform_driver clock_driver = { + .match_table = clock_match, + .probe = clock_probe, + .driver = { + .name = "rtc", + }, +}; + + +/* Probe for the mostek real time clock chip. */ +static int __init clock_init(void) +{ + return of_register_driver(&clock_driver, &of_platform_bus_type); +} + +/* Must be after subsys_initcall() so that busses are probed. Must + * be before device_initcall() because things like the RTC driver + * need to see the clock registers. + */ +fs_initcall(clock_init); + +static void __init sbus_time_init(void) +{ + + BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM); + btfixup(); + + sparc_init_timers(timer_interrupt); + + /* Now that OBP ticker has been silenced, it is safe to enable IRQ. */ + local_irq_enable(); +} + +void __init time_init(void) +{ +#ifdef CONFIG_PCI + extern void pci_time_init(void); + if (pcic_present()) { + pci_time_init(); + return; + } +#endif + sbus_time_init(); +} + +static inline unsigned long do_gettimeoffset(void) +{ + unsigned long val = *master_l10_counter; + unsigned long usec = (val >> 10) & 0x1fffff; + + /* Limit hit? */ + if (val & 0x80000000) + usec += 1000000 / HZ; + + return usec; +} + +/* Ok, my cute asm atomicity trick doesn't work anymore. + * There are just too many variables that need to be protected + * now (both members of xtime, et al.) + */ +void do_gettimeofday(struct timeval *tv) +{ + unsigned long flags; + unsigned long seq; + unsigned long usec, sec; + unsigned long max_ntp_tick = tick_usec - tickadj; + + do { + seq = read_seqbegin_irqsave(&xtime_lock, flags); + usec = do_gettimeoffset(); + + /* + * If time_adjust is negative then NTP is slowing the clock + * so make sure not to go into next possible interval. + * Better to lose some accuracy than have time go backwards.. + */ + if (unlikely(time_adjust < 0)) + usec = min(usec, max_ntp_tick); + + sec = xtime.tv_sec; + usec += (xtime.tv_nsec / 1000); + } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); + + while (usec >= 1000000) { + usec -= 1000000; + sec++; + } + + tv->tv_sec = sec; + tv->tv_usec = usec; +} + +EXPORT_SYMBOL(do_gettimeofday); + +int do_settimeofday(struct timespec *tv) +{ + int ret; + + write_seqlock_irq(&xtime_lock); + ret = bus_do_settimeofday(tv); + write_sequnlock_irq(&xtime_lock); + clock_was_set(); + return ret; +} + +EXPORT_SYMBOL(do_settimeofday); + +static int sbus_do_settimeofday(struct timespec *tv) +{ + time_t wtm_sec, sec = tv->tv_sec; + long wtm_nsec, nsec = tv->tv_nsec; + + if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) + return -EINVAL; + + /* + * This is revolting. We need to set "xtime" correctly. However, the + * value in this location is the value at the most recent update of + * wall time. Discover what correction gettimeofday() would have + * made, and then undo it! + */ + nsec -= 1000 * do_gettimeoffset(); + + wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); + wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); + + set_normalized_timespec(&xtime, sec, nsec); + set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); + + ntp_clear(); + return 0; +} + +static int set_rtc_mmss(unsigned long secs) +{ + struct rtc_device *rtc = rtc_class_open("rtc0"); + int err = -1; + + if (rtc) { + err = rtc_set_mmss(rtc, secs); + rtc_class_close(rtc); + } + + return err; +} |