#include <asm/hpet.h>
#include <linux/hpet.h>
-unsigned long hpet_period; /* fsecs / HPET clock */
-unsigned long hpet_tick; /* hpet clks count per tick */
-unsigned long hpet_address; /* hpet memory map physical address */
+static unsigned long hpet_period; /* fsecs / HPET clock */
+unsigned long hpet_tick; /* hpet clks count per tick */
+unsigned long hpet_address; /* hpet memory map physical address */
+int hpet_use_timer;
static int use_hpet; /* can be used for runtime check of hpet */
static int boot_hpet_disable; /* boottime override for HPET timer */
return readl(hpet_virt_address + a);
}
-void hpet_writel(unsigned long d, unsigned long a)
+static void hpet_writel(unsigned long d, unsigned long a)
{
writel(d, hpet_virt_address + a);
}
* comparator value and continue. Next tick can be caught by checking
* for a change in the comparator value. Used in apic.c.
*/
-void __init wait_hpet_tick(void)
+static void __devinit wait_hpet_tick(void)
{
unsigned int start_cmp_val, end_cmp_val;
}
#endif
+static int hpet_timer_stop_set_go(unsigned long tick)
+{
+ unsigned int cfg;
+
+ /*
+ * Stop the timers and reset the main counter.
+ */
+ cfg = hpet_readl(HPET_CFG);
+ cfg &= ~HPET_CFG_ENABLE;
+ hpet_writel(cfg, HPET_CFG);
+ hpet_writel(0, HPET_COUNTER);
+ hpet_writel(0, HPET_COUNTER + 4);
+
+ if (hpet_use_timer) {
+ /*
+ * Set up timer 0, as periodic with first interrupt to happen at
+ * hpet_tick, and period also hpet_tick.
+ */
+ cfg = hpet_readl(HPET_T0_CFG);
+ cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
+ HPET_TN_SETVAL | HPET_TN_32BIT;
+ hpet_writel(cfg, HPET_T0_CFG);
+
+ /*
+ * The first write after writing TN_SETVAL to the config register sets
+ * the counter value, the second write sets the threshold.
+ */
+ hpet_writel(tick, HPET_T0_CMP);
+ hpet_writel(tick, HPET_T0_CMP);
+ }
+ /*
+ * Go!
+ */
+ cfg = hpet_readl(HPET_CFG);
+ if (hpet_use_timer)
+ cfg |= HPET_CFG_LEGACY;
+ cfg |= HPET_CFG_ENABLE;
+ hpet_writel(cfg, HPET_CFG);
+
+ return 0;
+}
+
/*
* Check whether HPET was found by ACPI boot parse. If yes setup HPET
* counter 0 for kernel base timer.
*/
int __init hpet_enable(void)
{
- unsigned int cfg, id;
+ unsigned int id;
unsigned long tick_fsec_low, tick_fsec_high; /* tick in femto sec */
unsigned long hpet_tick_rem;
id = hpet_readl(HPET_ID);
/*
- * We are checking for value '1' or more in number field.
- * So, we are OK with HPET_EMULATE_RTC part too, where we need
- * to have atleast 2 timers.
+ * We are checking for value '1' or more in number field if
+ * CONFIG_HPET_EMULATE_RTC is set because we will need an
+ * additional timer for RTC emulation.
+ * However, we can do with one timer otherwise using the
+ * the single HPET timer for system time.
*/
- if (!(id & HPET_ID_NUMBER) ||
- !(id & HPET_ID_LEGSUP))
+#ifdef CONFIG_HPET_EMULATE_RTC
+ if (!(id & HPET_ID_NUMBER))
return -1;
+#endif
+
hpet_period = hpet_readl(HPET_PERIOD);
if ((hpet_period < HPET_MIN_PERIOD) || (hpet_period > HPET_MAX_PERIOD))
if (hpet_tick_rem > (hpet_period >> 1))
hpet_tick++; /* rounding the result */
- /*
- * Stop the timers and reset the main counter.
- */
- cfg = hpet_readl(HPET_CFG);
- cfg &= ~HPET_CFG_ENABLE;
- hpet_writel(cfg, HPET_CFG);
- hpet_writel(0, HPET_COUNTER);
- hpet_writel(0, HPET_COUNTER + 4);
-
- /*
- * Set up timer 0, as periodic with first interrupt to happen at
- * hpet_tick, and period also hpet_tick.
- */
- cfg = hpet_readl(HPET_T0_CFG);
- cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
- HPET_TN_SETVAL | HPET_TN_32BIT;
- hpet_writel(cfg, HPET_T0_CFG);
- hpet_writel(hpet_tick, HPET_T0_CMP);
+ hpet_use_timer = id & HPET_ID_LEGSUP;
- /*
- * Go!
- */
- cfg = hpet_readl(HPET_CFG);
- cfg |= HPET_CFG_ENABLE | HPET_CFG_LEGACY;
- hpet_writel(cfg, HPET_CFG);
+ if (hpet_timer_stop_set_go(hpet_tick))
+ return -1;
use_hpet = 1;
* Register with driver.
* Timer0 and Timer1 is used by platform.
*/
+ hd.hd_phys_address = hpet_address;
hd.hd_address = hpet_virt_address;
hd.hd_nirqs = ntimer;
hd.hd_flags = HPET_DATA_PLATFORM;
#endif
#ifdef CONFIG_X86_LOCAL_APIC
- wait_timer_tick = wait_hpet_tick;
+ if (hpet_use_timer)
+ wait_timer_tick = wait_hpet_tick;
#endif
return 0;
}
+int hpet_reenable(void)
+{
+ return hpet_timer_stop_set_go(hpet_tick);
+}
+
int is_hpet_enabled(void)
{
return use_hpet;
#include <linux/mc146818rtc.h>
#include <linux/rtc.h>
-extern irqreturn_t rtc_interrupt(int irq, void *dev_id, struct pt_regs *regs);
-
#define DEFAULT_RTC_INT_FREQ 64
#define RTC_NUM_INTS 1
static unsigned long PIE_count;
static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */
+static unsigned int hpet_t1_cmp; /* cached comparator register */
/*
* Timer 1 for RTC, we do not use periodic interrupt feature,
cnt = hpet_readl(HPET_COUNTER);
cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
hpet_writel(cnt, HPET_T1_CMP);
+ hpet_t1_cmp = cnt;
local_irq_restore(flags);
cfg = hpet_readl(HPET_T1_CFG);
- cfg |= HPET_TN_ENABLE | HPET_TN_SETVAL | HPET_TN_32BIT;
+ cfg &= ~HPET_TN_PERIODIC;
+ cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
hpet_writel(cfg, HPET_T1_CFG);
return 1;
{
unsigned int cfg, cnt;
- if (!(PIE_on | AIE_on | UIE_on))
+ if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
+ cfg = hpet_readl(HPET_T1_CFG);
+ cfg &= ~HPET_TN_ENABLE;
+ hpet_writel(cfg, HPET_T1_CFG);
return;
+ }
if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
hpet_rtc_int_freq = PIE_freq;
hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
/* It is more accurate to use the comparator value than current count.*/
- cnt = hpet_readl(HPET_T1_CMP);
+ cnt = hpet_t1_cmp;
cnt += hpet_tick*HZ/hpet_rtc_int_freq;
hpet_writel(cnt, HPET_T1_CMP);
-
- cfg = hpet_readl(HPET_T1_CFG);
- cfg |= HPET_TN_ENABLE | HPET_TN_SETVAL | HPET_TN_32BIT;
- hpet_writel(cfg, HPET_T1_CFG);
-
- return;
+ hpet_t1_cmp = cnt;
}
/*
git://git.onelab.eu / linux-2.6.git / blobdiff