diff options
Diffstat (limited to 'arch/i386/kernel/time_hpet.c')
| -rw-r--r-- | arch/i386/kernel/time_hpet.c | 497 |
1 files changed, 0 insertions, 497 deletions
diff --git a/arch/i386/kernel/time_hpet.c b/arch/i386/kernel/time_hpet.c deleted file mode 100644 index 1e4702dfcd0..00000000000 --- a/arch/i386/kernel/time_hpet.c +++ /dev/null @@ -1,497 +0,0 @@ -/* - * linux/arch/i386/kernel/time_hpet.c - * This code largely copied from arch/x86_64/kernel/time.c - * See that file for credits. - * - * 2003-06-30 Venkatesh Pallipadi - Additional changes for HPET support - */ - -#include <linux/errno.h> -#include <linux/kernel.h> -#include <linux/param.h> -#include <linux/string.h> -#include <linux/init.h> -#include <linux/smp.h> - -#include <asm/timer.h> -#include <asm/fixmap.h> -#include <asm/apic.h> - -#include <linux/timex.h> - -#include <asm/hpet.h> -#include <linux/hpet.h> - -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 */ -static void __iomem * hpet_virt_address; /* hpet kernel virtual address */ - -#define FSEC_TO_USEC (1000000000UL) - -int hpet_readl(unsigned long a) -{ - return readl(hpet_virt_address + a); -} - -static void hpet_writel(unsigned long d, unsigned long a) -{ - writel(d, hpet_virt_address + a); -} - -#ifdef CONFIG_X86_LOCAL_APIC -/* - * HPET counters dont wrap around on every tick. They just change the - * comparator value and continue. Next tick can be caught by checking - * for a change in the comparator value. Used in apic.c. - */ -static void __devinit wait_hpet_tick(void) -{ - unsigned int start_cmp_val, end_cmp_val; - - start_cmp_val = hpet_readl(HPET_T0_CMP); - do { - end_cmp_val = hpet_readl(HPET_T0_CMP); - } while (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 id; - unsigned long tick_fsec_low, tick_fsec_high; /* tick in femto sec */ - unsigned long hpet_tick_rem; - - if (boot_hpet_disable) - return -1; - - if (!hpet_address) { - return -1; - } - hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE); - /* - * Read the period, compute tick and quotient. - */ - id = hpet_readl(HPET_ID); - - /* - * 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. - */ -#ifdef CONFIG_HPET_EMULATE_RTC - if (!(id & HPET_ID_NUMBER)) { - iounmap(hpet_virt_address); - hpet_virt_address = NULL; - return -1; - } -#endif - - - hpet_period = hpet_readl(HPET_PERIOD); - if ((hpet_period < HPET_MIN_PERIOD) || (hpet_period > HPET_MAX_PERIOD)) { - iounmap(hpet_virt_address); - hpet_virt_address = NULL; - return -1; - } - - /* - * 64 bit math - * First changing tick into fsec - * Then 64 bit div to find number of hpet clk per tick - */ - ASM_MUL64_REG(tick_fsec_low, tick_fsec_high, - KERNEL_TICK_USEC, FSEC_TO_USEC); - ASM_DIV64_REG(hpet_tick, hpet_tick_rem, - hpet_period, tick_fsec_low, tick_fsec_high); - - if (hpet_tick_rem > (hpet_period >> 1)) - hpet_tick++; /* rounding the result */ - - hpet_use_timer = id & HPET_ID_LEGSUP; - - if (hpet_timer_stop_set_go(hpet_tick)) { - iounmap(hpet_virt_address); - hpet_virt_address = NULL; - return -1; - } - - use_hpet = 1; - -#ifdef CONFIG_HPET - { - struct hpet_data hd; - unsigned int ntimer; - - memset(&hd, 0, sizeof (hd)); - - ntimer = hpet_readl(HPET_ID); - ntimer = (ntimer & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT; - ntimer++; - - /* - * 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; - 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; - if (ntimer > 2) { - struct hpet __iomem *hpet; - struct hpet_timer __iomem *timer; - int i; - - hpet = hpet_virt_address; - - for (i = 2, timer = &hpet->hpet_timers[2]; i < ntimer; - timer++, i++) - hd.hd_irq[i] = (timer->hpet_config & - Tn_INT_ROUTE_CNF_MASK) >> - Tn_INT_ROUTE_CNF_SHIFT; - - } - - hpet_alloc(&hd); - } -#endif - -#ifdef CONFIG_X86_LOCAL_APIC - 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; -} - -int is_hpet_capable(void) -{ - if (!boot_hpet_disable && hpet_address) - return 1; - return 0; -} - -static int __init hpet_setup(char* str) -{ - if (str) { - if (!strncmp("disable", str, 7)) - boot_hpet_disable = 1; - } - return 1; -} - -__setup("hpet=", hpet_setup); - -#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 RTC_NUM_INTS 1 - -static unsigned long UIE_on; -static unsigned long prev_update_sec; - -static unsigned long AIE_on; -static struct rtc_time alarm_time; - -static unsigned long PIE_on; -static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ; -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, - * even if HPET supports periodic interrupts on Timer 1. - * The reason being, to set up a periodic interrupt in HPET, we need to - * stop the main counter. And if we do that everytime someone diables/enables - * RTC, we will have adverse effect on main kernel timer running on Timer 0. - * So, for the time being, simulate the periodic interrupt in software. - * - * hpet_rtc_timer_init() is called for the first time and during subsequent - * interuppts reinit happens through hpet_rtc_timer_reinit(). - */ -int hpet_rtc_timer_init(void) -{ - unsigned int cfg, cnt; - unsigned long flags; - - if (!is_hpet_enabled()) - return 0; - /* - * Set the counter 1 and enable the interrupts. - */ - if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ)) - hpet_rtc_int_freq = PIE_freq; - else - hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ; - - local_irq_save(flags); - - cnt = hpet_readl(HPET_COUNTER); - cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq); - 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; -} - -static void hpet_rtc_timer_reinit(void) -{ - unsigned int cfg, cnt, ticks_per_int, lost_ints; - - 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; - else - hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ; - - /* It is more accurate to use the comparator value than current count.*/ - ticks_per_int = hpet_tick * HZ / hpet_rtc_int_freq; - hpet_t1_cmp += ticks_per_int; - hpet_writel(hpet_t1_cmp, HPET_T1_CMP); - - /* - * If the interrupt handler was delayed too long, the write above tries - * to schedule the next interrupt in the past and the hardware would - * not interrupt until the counter had wrapped around. - * So we have to check that the comparator wasn't set to a past time. - */ - cnt = hpet_readl(HPET_COUNTER); - if (unlikely((int)(cnt - hpet_t1_cmp) > 0)) { - lost_ints = (cnt - hpet_t1_cmp) / ticks_per_int + 1; - /* Make sure that, even with the time needed to execute - * this code, the next scheduled interrupt has been moved - * back to the future: */ - lost_ints++; - - hpet_t1_cmp += lost_ints * ticks_per_int; - hpet_writel(hpet_t1_cmp, HPET_T1_CMP); - - if (PIE_on) - PIE_count += lost_ints; - - printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n", - hpet_rtc_int_freq); - } -} - -/* - * 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; - - if (bit_mask & RTC_UIE) - UIE_on = 0; - if (bit_mask & RTC_PIE) - PIE_on = 0; - if (bit_mask & RTC_AIE) - AIE_on = 0; - - return 1; -} - -int hpet_set_rtc_irq_bit(unsigned long bit_mask) -{ - int timer_init_reqd = 0; - - if (!is_hpet_enabled()) - return 0; - - if (!(PIE_on | AIE_on | UIE_on)) - timer_init_reqd = 1; - - if (bit_mask & RTC_UIE) { - UIE_on = 1; - } - if (bit_mask & RTC_PIE) { - PIE_on = 1; - PIE_count = 0; - } - if (bit_mask & RTC_AIE) { - AIE_on = 1; - } - - if (timer_init_reqd) - 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; - - alarm_time.tm_hour = hrs; - alarm_time.tm_min = min; - alarm_time.tm_sec = sec; - - return 1; -} - -int hpet_set_periodic_freq(unsigned long freq) -{ - if (!is_hpet_enabled()) - return 0; - - PIE_freq = freq; - PIE_count = 0; - - return 1; -} - -int hpet_rtc_dropped_irq(void) -{ - if (!is_hpet_enabled()) - return 0; - - return 1; -} - -irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id) -{ - struct rtc_time curr_time; - unsigned long rtc_int_flag = 0; - int call_rtc_interrupt = 0; - - hpet_rtc_timer_reinit(); - - if (UIE_on | AIE_on) { - rtc_get_rtc_time(&curr_time); - } - if (UIE_on) { - if (curr_time.tm_sec != prev_update_sec) { - /* Set update int info, call real rtc int routine */ - call_rtc_interrupt = 1; - rtc_int_flag = RTC_UF; - prev_update_sec = curr_time.tm_sec; - } - } - if (PIE_on) { - PIE_count++; - if (PIE_count >= hpet_rtc_int_freq/PIE_freq) { - /* Set periodic int info, call real rtc int routine */ - call_rtc_interrupt = 1; - rtc_int_flag |= RTC_PF; - PIE_count = 0; - } - } - if (AIE_on) { - if ((curr_time.tm_sec == alarm_time.tm_sec) && - (curr_time.tm_min == alarm_time.tm_min) && - (curr_time.tm_hour == alarm_time.tm_hour)) { - /* Set alarm int info, call real rtc int routine */ - call_rtc_interrupt = 1; - rtc_int_flag |= RTC_AF; - } - } - if (call_rtc_interrupt) { - rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8)); - rtc_interrupt(rtc_int_flag, dev_id); - } - return IRQ_HANDLED; -} -#endif - |