summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/rtc.c
diff options
context:
space:
mode:
authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/x86/kernel/rtc.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
downloadFOSSEE-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.c256
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);