diff options
Diffstat (limited to 'arch/i386/kernel/hpet.c')
| -rw-r--r-- | arch/i386/kernel/hpet.c | 553 |
1 files changed, 0 insertions, 553 deletions
diff --git a/arch/i386/kernel/hpet.c b/arch/i386/kernel/hpet.c deleted file mode 100644 index 533d4932bc79..000000000000 --- a/arch/i386/kernel/hpet.c +++ /dev/null @@ -1,553 +0,0 @@ -#include <linux/clocksource.h> -#include <linux/clockchips.h> -#include <linux/errno.h> -#include <linux/hpet.h> -#include <linux/init.h> -#include <linux/sysdev.h> -#include <linux/pm.h> -#include <linux/delay.h> - -#include <asm/hpet.h> -#include <asm/io.h> - -extern struct clock_event_device *global_clock_event; - -#define HPET_MASK CLOCKSOURCE_MASK(32) -#define HPET_SHIFT 22 - -/* FSEC = 10^-15 NSEC = 10^-9 */ -#define FSEC_PER_NSEC 1000000 - -/* - * HPET address is set in acpi/boot.c, when an ACPI entry exists - */ -unsigned long hpet_address; -static void __iomem * hpet_virt_address; - -static inline unsigned long hpet_readl(unsigned long a) -{ - return readl(hpet_virt_address + a); -} - -static inline void hpet_writel(unsigned long d, unsigned long a) -{ - writel(d, hpet_virt_address + a); -} - -/* - * HPET command line enable / disable - */ -static int boot_hpet_disable; - -static int __init hpet_setup(char* str) -{ - if (str) { - if (!strncmp("disable", str, 7)) - boot_hpet_disable = 1; - } - return 1; -} -__setup("hpet=", hpet_setup); - -static inline int is_hpet_capable(void) -{ - return (!boot_hpet_disable && hpet_address); -} - -/* - * HPET timer interrupt enable / disable - */ -static int hpet_legacy_int_enabled; - -/** - * is_hpet_enabled - check whether the hpet timer interrupt is enabled - */ -int is_hpet_enabled(void) -{ - return is_hpet_capable() && hpet_legacy_int_enabled; -} - -/* - * When the hpet driver (/dev/hpet) is enabled, we need to reserve - * timer 0 and timer 1 in case of RTC emulation. - */ -#ifdef CONFIG_HPET -static void hpet_reserve_platform_timers(unsigned long id) -{ - struct hpet __iomem *hpet = hpet_virt_address; - struct hpet_timer __iomem *timer = &hpet->hpet_timers[2]; - unsigned int nrtimers, i; - struct hpet_data hd; - - nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1; - - memset(&hd, 0, sizeof (hd)); - hd.hd_phys_address = hpet_address; - hd.hd_address = hpet_virt_address; - hd.hd_nirqs = nrtimers; - hd.hd_flags = HPET_DATA_PLATFORM; - hpet_reserve_timer(&hd, 0); - -#ifdef CONFIG_HPET_EMULATE_RTC - hpet_reserve_timer(&hd, 1); -#endif - - hd.hd_irq[0] = HPET_LEGACY_8254; - hd.hd_irq[1] = HPET_LEGACY_RTC; - - for (i = 2; i < nrtimers; timer++, i++) - hd.hd_irq[i] = (timer->hpet_config & Tn_INT_ROUTE_CNF_MASK) >> - Tn_INT_ROUTE_CNF_SHIFT; - - hpet_alloc(&hd); - -} -#else -static void hpet_reserve_platform_timers(unsigned long id) { } -#endif - -/* - * Common hpet info - */ -static unsigned long hpet_period; - -static void hpet_set_mode(enum clock_event_mode mode, - struct clock_event_device *evt); -static int hpet_next_event(unsigned long delta, - struct clock_event_device *evt); - -/* - * The hpet clock event device - */ -static struct clock_event_device hpet_clockevent = { - .name = "hpet", - .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT, - .set_mode = hpet_set_mode, - .set_next_event = hpet_next_event, - .shift = 32, - .irq = 0, -}; - -static void hpet_start_counter(void) -{ - unsigned long 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); - cfg |= HPET_CFG_ENABLE; - hpet_writel(cfg, HPET_CFG); -} - -static void hpet_enable_int(void) -{ - unsigned long cfg = hpet_readl(HPET_CFG); - - cfg |= HPET_CFG_LEGACY; - hpet_writel(cfg, HPET_CFG); - hpet_legacy_int_enabled = 1; -} - -static void hpet_set_mode(enum clock_event_mode mode, - struct clock_event_device *evt) -{ - unsigned long cfg, cmp, now; - uint64_t delta; - - switch(mode) { - case CLOCK_EVT_MODE_PERIODIC: - delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * hpet_clockevent.mult; - delta >>= hpet_clockevent.shift; - now = hpet_readl(HPET_COUNTER); - cmp = now + (unsigned long) delta; - 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 period. - */ - hpet_writel(cmp, HPET_T0_CMP); - udelay(1); - hpet_writel((unsigned long) delta, HPET_T0_CMP); - break; - - case CLOCK_EVT_MODE_ONESHOT: - cfg = hpet_readl(HPET_T0_CFG); - cfg &= ~HPET_TN_PERIODIC; - cfg |= HPET_TN_ENABLE | HPET_TN_32BIT; - hpet_writel(cfg, HPET_T0_CFG); - break; - - case CLOCK_EVT_MODE_UNUSED: - case CLOCK_EVT_MODE_SHUTDOWN: - cfg = hpet_readl(HPET_T0_CFG); - cfg &= ~HPET_TN_ENABLE; - hpet_writel(cfg, HPET_T0_CFG); - break; - - case CLOCK_EVT_MODE_RESUME: - hpet_enable_int(); - break; - } -} - -static int hpet_next_event(unsigned long delta, - struct clock_event_device *evt) -{ - unsigned long cnt; - - cnt = hpet_readl(HPET_COUNTER); - cnt += delta; - hpet_writel(cnt, HPET_T0_CMP); - - return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0) ? -ETIME : 0; -} - -/* - * Clock source related code - */ -static cycle_t read_hpet(void) -{ - return (cycle_t)hpet_readl(HPET_COUNTER); -} - -static struct clocksource clocksource_hpet = { - .name = "hpet", - .rating = 250, - .read = read_hpet, - .mask = HPET_MASK, - .shift = HPET_SHIFT, - .flags = CLOCK_SOURCE_IS_CONTINUOUS, - .resume = hpet_start_counter, -}; - -/* - * Try to setup the HPET timer - */ -int __init hpet_enable(void) -{ - unsigned long id; - uint64_t hpet_freq; - u64 tmp, start, now; - cycle_t t1; - - if (!is_hpet_capable()) - return 0; - - hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE); - - /* - * Read the period and check for a sane value: - */ - hpet_period = hpet_readl(HPET_PERIOD); - if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD) - goto out_nohpet; - - /* - * The period is a femto seconds value. We need to calculate the - * scaled math multiplication factor for nanosecond to hpet tick - * conversion. - */ - hpet_freq = 1000000000000000ULL; - do_div(hpet_freq, hpet_period); - hpet_clockevent.mult = div_sc((unsigned long) hpet_freq, - NSEC_PER_SEC, 32); - /* Calculate the min / max delta */ - hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF, - &hpet_clockevent); - hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30, - &hpet_clockevent); - - /* - * Read the HPET ID register to retrieve the IRQ routing - * information and the number of channels - */ - id = hpet_readl(HPET_ID); - -#ifdef CONFIG_HPET_EMULATE_RTC - /* - * The legacy routing mode needs at least two channels, tick timer - * and the rtc emulation channel. - */ - if (!(id & HPET_ID_NUMBER)) - goto out_nohpet; -#endif - - /* Start the counter */ - hpet_start_counter(); - - /* Verify whether hpet counter works */ - t1 = read_hpet(); - rdtscll(start); - - /* - * We don't know the TSC frequency yet, but waiting for - * 200000 TSC cycles is safe: - * 4 GHz == 50us - * 1 GHz == 200us - */ - do { - rep_nop(); - rdtscll(now); - } while ((now - start) < 200000UL); - - if (t1 == read_hpet()) { - printk(KERN_WARNING - "HPET counter not counting. HPET disabled\n"); - goto out_nohpet; - } - - /* Initialize and register HPET clocksource - * - * hpet period is in femto seconds per cycle - * so we need to convert this to ns/cyc units - * aproximated by mult/2^shift - * - * fsec/cyc * 1nsec/1000000fsec = nsec/cyc = mult/2^shift - * fsec/cyc * 1ns/1000000fsec * 2^shift = mult - * fsec/cyc * 2^shift * 1nsec/1000000fsec = mult - * (fsec/cyc << shift)/1000000 = mult - * (hpet_period << shift)/FSEC_PER_NSEC = mult - */ - tmp = (u64)hpet_period << HPET_SHIFT; - do_div(tmp, FSEC_PER_NSEC); - clocksource_hpet.mult = (u32)tmp; - - 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(smp_processor_id()); - 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 |