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author | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
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committer | Srikant Patnaik | 2015-01-11 12:28:04 +0530 |
commit | 871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch) | |
tree | 8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/x86/kernel/rtc.c | |
parent | 9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff) | |
download | FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2 FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip |
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/x86/kernel/rtc.c')
-rw-r--r-- | arch/x86/kernel/rtc.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c new file mode 100644 index 00000000..af6db6ec --- /dev/null +++ b/arch/x86/kernel/rtc.c @@ -0,0 +1,256 @@ +/* + * RTC related functions + */ +#include <linux/platform_device.h> +#include <linux/mc146818rtc.h> +#include <linux/acpi.h> +#include <linux/bcd.h> +#include <linux/export.h> +#include <linux/pnp.h> +#include <linux/of.h> + +#include <asm/vsyscall.h> +#include <asm/x86_init.h> +#include <asm/time.h> +#include <asm/mrst.h> + +#ifdef CONFIG_X86_32 +/* + * This is a special lock that is owned by the CPU and holds the index + * register we are working with. It is required for NMI access to the + * CMOS/RTC registers. See include/asm-i386/mc146818rtc.h for details. + */ +volatile unsigned long cmos_lock; +EXPORT_SYMBOL(cmos_lock); +#endif /* CONFIG_X86_32 */ + +/* For two digit years assume time is always after that */ +#define CMOS_YEARS_OFFS 2000 + +DEFINE_SPINLOCK(rtc_lock); +EXPORT_SYMBOL(rtc_lock); + +/* + * In order to set the CMOS clock precisely, set_rtc_mmss has to be + * called 500 ms after the second nowtime has started, because when + * nowtime is written into the registers of the CMOS clock, it will + * jump to the next second precisely 500 ms later. Check the Motorola + * MC146818A or Dallas DS12887 data sheet for details. + * + * BUG: This routine does not handle hour overflow properly; it just + * sets the minutes. Usually you'll only notice that after reboot! + */ +int mach_set_rtc_mmss(unsigned long nowtime) +{ + int real_seconds, real_minutes, cmos_minutes; + unsigned char save_control, save_freq_select; + unsigned long flags; + int retval = 0; + + spin_lock_irqsave(&rtc_lock, flags); + + /* tell the clock it's being set */ + save_control = CMOS_READ(RTC_CONTROL); + CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL); + + /* stop and reset prescaler */ + save_freq_select = CMOS_READ(RTC_FREQ_SELECT); + CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT); + + cmos_minutes = CMOS_READ(RTC_MINUTES); + if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) + cmos_minutes = bcd2bin(cmos_minutes); + + /* + * since we're only adjusting minutes and seconds, + * don't interfere with hour overflow. This avoids + * messing with unknown time zones but requires your + * RTC not to be off by more than 15 minutes + */ + real_seconds = nowtime % 60; + real_minutes = nowtime / 60; + /* correct for half hour time zone */ + if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1) + real_minutes += 30; + real_minutes %= 60; + + if (abs(real_minutes - cmos_minutes) < 30) { + if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) { + real_seconds = bin2bcd(real_seconds); + real_minutes = bin2bcd(real_minutes); + } + CMOS_WRITE(real_seconds, RTC_SECONDS); + CMOS_WRITE(real_minutes, RTC_MINUTES); + } else { + printk_once(KERN_NOTICE + "set_rtc_mmss: can't update from %d to %d\n", + cmos_minutes, real_minutes); + retval = -1; + } + + /* The following flags have to be released exactly in this order, + * otherwise the DS12887 (popular MC146818A clone with integrated + * battery and quartz) will not reset the oscillator and will not + * update precisely 500 ms later. You won't find this mentioned in + * the Dallas Semiconductor data sheets, but who believes data + * sheets anyway ... -- Markus Kuhn + */ + CMOS_WRITE(save_control, RTC_CONTROL); + CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT); + + spin_unlock_irqrestore(&rtc_lock, flags); + + return retval; +} + +unsigned long mach_get_cmos_time(void) +{ + unsigned int status, year, mon, day, hour, min, sec, century = 0; + unsigned long flags; + + spin_lock_irqsave(&rtc_lock, flags); + + /* + * If UIP is clear, then we have >= 244 microseconds before + * RTC registers will be updated. Spec sheet says that this + * is the reliable way to read RTC - registers. If UIP is set + * then the register access might be invalid. + */ + while ((CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)) + cpu_relax(); + + sec = CMOS_READ(RTC_SECONDS); + min = CMOS_READ(RTC_MINUTES); + hour = CMOS_READ(RTC_HOURS); + day = CMOS_READ(RTC_DAY_OF_MONTH); + mon = CMOS_READ(RTC_MONTH); + year = CMOS_READ(RTC_YEAR); + +#ifdef CONFIG_ACPI + if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID && + acpi_gbl_FADT.century) + century = CMOS_READ(acpi_gbl_FADT.century); +#endif + + status = CMOS_READ(RTC_CONTROL); + WARN_ON_ONCE(RTC_ALWAYS_BCD && (status & RTC_DM_BINARY)); + + spin_unlock_irqrestore(&rtc_lock, flags); + + if (RTC_ALWAYS_BCD || !(status & RTC_DM_BINARY)) { + sec = bcd2bin(sec); + min = bcd2bin(min); + hour = bcd2bin(hour); + day = bcd2bin(day); + mon = bcd2bin(mon); + year = bcd2bin(year); + } + + if (century) { + century = bcd2bin(century); + year += century * 100; + printk(KERN_INFO "Extended CMOS year: %d\n", century * 100); + } else + year += CMOS_YEARS_OFFS; + + return mktime(year, mon, day, hour, min, sec); +} + +/* Routines for accessing the CMOS RAM/RTC. */ +unsigned char rtc_cmos_read(unsigned char addr) +{ + unsigned char val; + + lock_cmos_prefix(addr); + outb(addr, RTC_PORT(0)); + val = inb(RTC_PORT(1)); + lock_cmos_suffix(addr); + + return val; +} +EXPORT_SYMBOL(rtc_cmos_read); + +void rtc_cmos_write(unsigned char val, unsigned char addr) +{ + lock_cmos_prefix(addr); + outb(addr, RTC_PORT(0)); + outb(val, RTC_PORT(1)); + lock_cmos_suffix(addr); +} +EXPORT_SYMBOL(rtc_cmos_write); + +int update_persistent_clock(struct timespec now) +{ + return x86_platform.set_wallclock(now.tv_sec); +} + +/* not static: needed by APM */ +void read_persistent_clock(struct timespec *ts) +{ + unsigned long retval; + + retval = x86_platform.get_wallclock(); + + ts->tv_sec = retval; + ts->tv_nsec = 0; +} + +unsigned long long native_read_tsc(void) +{ + return __native_read_tsc(); +} +EXPORT_SYMBOL(native_read_tsc); + + +static struct resource rtc_resources[] = { + [0] = { + .start = RTC_PORT(0), + .end = RTC_PORT(1), + .flags = IORESOURCE_IO, + }, + [1] = { + .start = RTC_IRQ, + .end = RTC_IRQ, + .flags = IORESOURCE_IRQ, + } +}; + +static struct platform_device rtc_device = { + .name = "rtc_cmos", + .id = -1, + .resource = rtc_resources, + .num_resources = ARRAY_SIZE(rtc_resources), +}; + +static __init int add_rtc_cmos(void) +{ +#ifdef CONFIG_PNP + static const char *ids[] __initconst = + { "PNP0b00", "PNP0b01", "PNP0b02", }; + struct pnp_dev *dev; + struct pnp_id *id; + int i; + + pnp_for_each_dev(dev) { + for (id = dev->id; id; id = id->next) { + for (i = 0; i < ARRAY_SIZE(ids); i++) { + if (compare_pnp_id(id, ids[i]) != 0) + return 0; + } + } + } +#endif + if (of_have_populated_dt()) + return 0; + + /* Intel MID platforms don't have ioport rtc */ + if (mrst_identify_cpu()) + return -ENODEV; + + platform_device_register(&rtc_device); + dev_info(&rtc_device.dev, + "registered platform RTC device (no PNP device found)\n"); + + return 0; +} +device_initcall(add_rtc_cmos); |