+ clocksource_register(&clocksource_hpet);
+
+
+ if (id & HPET_ID_LEGSUP) {
+ hpet_enable_int();
+ hpet_reserve_platform_timers(id);
+ /*
+ * Start hpet with the boot cpu mask and make it
+ * global after the IO_APIC has been initialized.
+ */
+ hpet_clockevent.cpumask =cpumask_of_cpu(0);
+ clockevents_register_device(&hpet_clockevent);
+ global_clock_event = &hpet_clockevent;
+ return 1;
+ }
+ return 0;
+
+out_nohpet:
+ iounmap(hpet_virt_address);
+ hpet_virt_address = NULL;
+ boot_hpet_disable = 1;
+ return 0;
+}
+
+
+#ifdef CONFIG_HPET_EMULATE_RTC
+
+/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
+ * is enabled, we support RTC interrupt functionality in software.
+ * RTC has 3 kinds of interrupts:
+ * 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
+ * is updated
+ * 2) Alarm Interrupt - generate an interrupt at a specific time of day
+ * 3) Periodic Interrupt - generate periodic interrupt, with frequencies
+ * 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
+ * (1) and (2) above are implemented using polling at a frequency of
+ * 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
+ * overhead. (DEFAULT_RTC_INT_FREQ)
+ * For (3), we use interrupts at 64Hz or user specified periodic
+ * frequency, whichever is higher.
+ */
+#include <linux/mc146818rtc.h>
+#include <linux/rtc.h>
+
+#define DEFAULT_RTC_INT_FREQ 64
+#define DEFAULT_RTC_SHIFT 6
+#define RTC_NUM_INTS 1
+
+static unsigned long hpet_rtc_flags;
+static unsigned long hpet_prev_update_sec;
+static struct rtc_time hpet_alarm_time;
+static unsigned long hpet_pie_count;
+static unsigned long hpet_t1_cmp;
+static unsigned long hpet_default_delta;
+static unsigned long hpet_pie_delta;
+static unsigned long hpet_pie_limit;
+
+/*
+ * Timer 1 for RTC emulation. We use one shot mode, as periodic mode
+ * is not supported by all HPET implementations for timer 1.
+ *
+ * hpet_rtc_timer_init() is called when the rtc is initialized.
+ */
+int hpet_rtc_timer_init(void)
+{
+ unsigned long cfg, cnt, delta, flags;
+
+ if (!is_hpet_enabled())
+ return 0;
+
+ if (!hpet_default_delta) {
+ uint64_t clc;
+
+ clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
+ clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
+ hpet_default_delta = (unsigned long) clc;
+ }
+
+ if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
+ delta = hpet_default_delta;
+ else
+ delta = hpet_pie_delta;
+
+ local_irq_save(flags);
+
+ cnt = delta + hpet_readl(HPET_COUNTER);
+ hpet_writel(cnt, HPET_T1_CMP);
+ hpet_t1_cmp = cnt;
+
+ cfg = hpet_readl(HPET_T1_CFG);
+ cfg &= ~HPET_TN_PERIODIC;
+ cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
+ hpet_writel(cfg, HPET_T1_CFG);
+
+ local_irq_restore(flags);
+
+ return 1;
+}
+
+/*
+ * The functions below are called from rtc driver.
+ * Return 0 if HPET is not being used.
+ * Otherwise do the necessary changes and return 1.
+ */
+int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
+{
+ if (!is_hpet_enabled())
+ return 0;
+
+ hpet_rtc_flags &= ~bit_mask;
+ return 1;
+}
+
+int hpet_set_rtc_irq_bit(unsigned long bit_mask)
+{
+ unsigned long oldbits = hpet_rtc_flags;
+
+ if (!is_hpet_enabled())
+ return 0;
+
+ hpet_rtc_flags |= bit_mask;
+
+ if (!oldbits)
+ hpet_rtc_timer_init();
+
+ return 1;
+}
+
+int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
+ unsigned char sec)
+{
+ if (!is_hpet_enabled())
+ return 0;
+
+ hpet_alarm_time.tm_hour = hrs;
+ hpet_alarm_time.tm_min = min;
+ hpet_alarm_time.tm_sec = sec;
+
+ return 1;
+}
+
+int hpet_set_periodic_freq(unsigned long freq)
+{
+ uint64_t clc;
+
+ if (!is_hpet_enabled())
+ return 0;
+
+ if (freq <= DEFAULT_RTC_INT_FREQ)
+ hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
+ else {
+ clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
+ do_div(clc, freq);
+ clc >>= hpet_clockevent.shift;
+ hpet_pie_delta = (unsigned long) clc;
+ }
+ return 1;
+}
+
+int hpet_rtc_dropped_irq(void)
+{
+ return is_hpet_enabled();
+}
+
+static void hpet_rtc_timer_reinit(void)
+{
+ unsigned long cfg, delta;
+ int lost_ints = -1;
+
+ if (unlikely(!hpet_rtc_flags)) {
+ cfg = hpet_readl(HPET_T1_CFG);
+ cfg &= ~HPET_TN_ENABLE;
+ hpet_writel(cfg, HPET_T1_CFG);
+ return;
+ }
+
+ if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
+ delta = hpet_default_delta;
+ else
+ delta = hpet_pie_delta;
+
+ /*
+ * Increment the comparator value until we are ahead of the
+ * current count.
+ */
+ do {
+ hpet_t1_cmp += delta;
+ hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
+ lost_ints++;
+ } while ((long)(hpet_readl(HPET_COUNTER) - hpet_t1_cmp) > 0);
+
+ if (lost_ints) {
+ if (hpet_rtc_flags & RTC_PIE)
+ hpet_pie_count += lost_ints;
+ if (printk_ratelimit())
+ printk(KERN_WARNING "rtc: lost %d interrupts\n",
+ lost_ints);
+ }
+}
+
+irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
+{
+ struct rtc_time curr_time;
+ unsigned long rtc_int_flag = 0;
+
+ hpet_rtc_timer_reinit();
+
+ if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
+ rtc_get_rtc_time(&curr_time);
+
+ if (hpet_rtc_flags & RTC_UIE &&
+ curr_time.tm_sec != hpet_prev_update_sec) {
+ rtc_int_flag = RTC_UF;
+ hpet_prev_update_sec = curr_time.tm_sec;
+ }
+
+ if (hpet_rtc_flags & RTC_PIE &&
+ ++hpet_pie_count >= hpet_pie_limit) {
+ rtc_int_flag |= RTC_PF;
+ hpet_pie_count = 0;
+ }
+
+ if (hpet_rtc_flags & RTC_PIE &&
+ (curr_time.tm_sec == hpet_alarm_time.tm_sec) &&
+ (curr_time.tm_min == hpet_alarm_time.tm_min) &&
+ (curr_time.tm_hour == hpet_alarm_time.tm_hour))
+ rtc_int_flag |= RTC_AF;
+
+ if (rtc_int_flag) {
+ rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
+ rtc_interrupt(rtc_int_flag, dev_id);
+ }
+ return IRQ_HANDLED;
+}
+#endif
+
+
+/*
+ * Suspend/resume part
+ */
+
+#ifdef CONFIG_PM
+
+static int hpet_suspend(struct sys_device *sys_device, pm_message_t state)
+{
+ unsigned long cfg = hpet_readl(HPET_CFG);
+
+ cfg &= ~(HPET_CFG_ENABLE|HPET_CFG_LEGACY);
+ hpet_writel(cfg, HPET_CFG);
+
+ return 0;
+}
+
+static int hpet_resume(struct sys_device *sys_device)
+{
+ unsigned int id;
+
+ hpet_start_counter();
+
+ id = hpet_readl(HPET_ID);
+
+ if (id & HPET_ID_LEGSUP)
+ hpet_enable_int();
+
+ return 0;
+}
+
+static struct sysdev_class hpet_class = {
+ set_kset_name("hpet"),
+ .suspend = hpet_suspend,
+ .resume = hpet_resume,
+};
+
+static struct sys_device hpet_device = {
+ .id = 0,
+ .cls = &hpet_class,
+};
+
+
+static __init int hpet_register_sysfs(void)
+{
+ int err;
+
+ if (!is_hpet_capable())
+ return 0;
+
+ err = sysdev_class_register(&hpet_class);
+
+ if (!err) {
+ err = sysdev_register(&hpet_device);
+ if (err)
+ sysdev_class_unregister(&hpet_class);
+ }