--- /dev/null
+/*
+ * linux/include/asm-arm/arch-ebsa285/time.h
+ *
+ * Copyright (C) 1998 Russell King.
+ * Copyright (C) 1998 Phil Blundell
+ *
+ * CATS has a real-time clock, though the evaluation board doesn't.
+ *
+ * Changelog:
+ * 21-Mar-1998 RMK Created
+ * 27-Aug-1998 PJB CATS support
+ * 28-Dec-1998 APH Made leds optional
+ * 20-Jan-1999 RMK Started merge of EBSA285, CATS and NetWinder
+ * 16-Mar-1999 RMK More support for EBSA285-like machines with RTCs in
+ */
+
+#define RTC_PORT(x) (rtc_base+(x))
+#define RTC_ALWAYS_BCD 0
+
+#include <linux/timex.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/sched.h>
+#include <linux/mc146818rtc.h>
+#include <linux/bcd.h>
+
+#include <asm/hardware/dec21285.h>
+
+#include <asm/hardware.h>
+#include <asm/irq.h>
+#include <asm/leds.h>
+#include <asm/mach-types.h>
+#include <asm/io.h>
+#include <asm/hardware/clps7111.h>
+
+#include <asm/mach/time.h>
+
+static int rtc_base;
+
+#define mSEC_10_from_14 ((14318180 + 100) / 200)
+
+static unsigned long isa_gettimeoffset(void)
+{
+ int count;
+
+ static int count_p = (mSEC_10_from_14/6); /* for the first call after boot */
+ static unsigned long jiffies_p = 0;
+
+ /*
+ * cache volatile jiffies temporarily; we have IRQs turned off.
+ */
+ unsigned long jiffies_t;
+
+ /* timer count may underflow right here */
+ outb_p(0x00, 0x43); /* latch the count ASAP */
+
+ count = inb_p(0x40); /* read the latched count */
+
+ /*
+ * We do this guaranteed double memory access instead of a _p
+ * postfix in the previous port access. Wheee, hackady hack
+ */
+ jiffies_t = jiffies;
+
+ count |= inb_p(0x40) << 8;
+
+ /* Detect timer underflows. If we haven't had a timer tick since
+ the last time we were called, and time is apparently going
+ backwards, the counter must have wrapped during this routine. */
+ if ((jiffies_t == jiffies_p) && (count > count_p))
+ count -= (mSEC_10_from_14/6);
+ else
+ jiffies_p = jiffies_t;
+
+ count_p = count;
+
+ count = (((mSEC_10_from_14/6)-1) - count) * (tick_nsec / 1000);
+ count = (count + (mSEC_10_from_14/6)/2) / (mSEC_10_from_14/6);
+
+ return count;
+}
+
+static irqreturn_t
+isa_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ timer_tick(regs);
+
+ return IRQ_HANDLED;
+}
+
+static unsigned long __init get_isa_cmos_time(void)
+{
+ unsigned int year, mon, day, hour, min, sec;
+ int i;
+
+ // check to see if the RTC makes sense.....
+ if ((CMOS_READ(RTC_VALID) & RTC_VRT) == 0)
+ return mktime(1970, 1, 1, 0, 0, 0);
+
+ /* The Linux interpretation of the CMOS clock register contents:
+ * When the Update-In-Progress (UIP) flag goes from 1 to 0, the
+ * RTC registers show the second which has precisely just started.
+ * Let's hope other operating systems interpret the RTC the same way.
+ */
+ /* read RTC exactly on falling edge of update flag */
+ for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */
+ if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)
+ break;
+
+ for (i = 0 ; i < 1000000 ; i++) /* must try at least 2.228 ms */
+ if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
+ break;
+
+ do { /* Isn't this overkill ? UIP above should guarantee consistency */
+ 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);
+ } while (sec != CMOS_READ(RTC_SECONDS));
+
+ if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+ BCD_TO_BIN(sec);
+ BCD_TO_BIN(min);
+ BCD_TO_BIN(hour);
+ BCD_TO_BIN(day);
+ BCD_TO_BIN(mon);
+ BCD_TO_BIN(year);
+ }
+ if ((year += 1900) < 1970)
+ year += 100;
+ return mktime(year, mon, day, hour, min, sec);
+}
+
+static int
+set_isa_cmos_time(void)
+{
+ int retval = 0;
+ int real_seconds, real_minutes, cmos_minutes;
+ unsigned char save_control, save_freq_select;
+ unsigned long nowtime = xtime.tv_sec;
+
+ save_control = CMOS_READ(RTC_CONTROL); /* tell the clock it's being set */
+ CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
+
+ save_freq_select = CMOS_READ(RTC_FREQ_SELECT); /* stop and reset prescaler */
+ 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)
+ BCD_TO_BIN(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;
+ if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
+ real_minutes += 30; /* correct for half hour time zone */
+ real_minutes %= 60;
+
+ if (abs(real_minutes - cmos_minutes) < 30) {
+ if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+ BIN_TO_BCD(real_seconds);
+ BIN_TO_BCD(real_minutes);
+ }
+ CMOS_WRITE(real_seconds,RTC_SECONDS);
+ CMOS_WRITE(real_minutes,RTC_MINUTES);
+ } else
+ 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);
+
+ return retval;
+}
+
+
+static unsigned long timer1_latch;
+
+static unsigned long timer1_gettimeoffset (void)
+{
+ unsigned long value = timer1_latch - *CSR_TIMER1_VALUE;
+
+ return ((tick_nsec / 1000) * value) / timer1_latch;
+}
+
+static irqreturn_t
+timer1_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ *CSR_TIMER1_CLR = 0;
+
+ timer_tick(regs);
+
+ return IRQ_HANDLED;
+}
+
+static struct irqaction footbridge_timer_irq = {
+ .flags = SA_INTERRUPT
+};
+
+/*
+ * Set up timer interrupt.
+ */
+void __init footbridge_init_time(void)
+{
+ if (machine_is_co285() ||
+ machine_is_personal_server())
+ /*
+ * Add-in 21285s shouldn't access the RTC
+ */
+ rtc_base = 0;
+ else
+ rtc_base = 0x70;
+
+ if (rtc_base) {
+ int reg_d, reg_b;
+
+ /*
+ * Probe for the RTC.
+ */
+ reg_d = CMOS_READ(RTC_REG_D);
+
+ /*
+ * make sure the divider is set
+ */
+ CMOS_WRITE(RTC_REF_CLCK_32KHZ, RTC_REG_A);
+
+ /*
+ * Set control reg B
+ * (24 hour mode, update enabled)
+ */
+ reg_b = CMOS_READ(RTC_REG_B) & 0x7f;
+ reg_b |= 2;
+ CMOS_WRITE(reg_b, RTC_REG_B);
+
+ if ((CMOS_READ(RTC_REG_A) & 0x7f) == RTC_REF_CLCK_32KHZ &&
+ CMOS_READ(RTC_REG_B) == reg_b) {
+ struct timespec tv;
+
+ /*
+ * We have a RTC. Check the battery
+ */
+ if ((reg_d & 0x80) == 0)
+ printk(KERN_WARNING "RTC: *** warning: CMOS battery bad\n");
+
+ tv.tv_nsec = 0;
+ tv.tv_sec = get_isa_cmos_time();
+ do_settimeofday(&tv);
+ set_rtc = set_isa_cmos_time;
+ } else
+ rtc_base = 0;
+ }
+
+ if (machine_is_ebsa285() ||
+ machine_is_co285() ||
+ machine_is_personal_server()) {
+ gettimeoffset = timer1_gettimeoffset;
+
+ timer1_latch = (mem_fclk_21285 + 8 * HZ) / (16 * HZ);
+
+ *CSR_TIMER1_CLR = 0;
+ *CSR_TIMER1_LOAD = timer1_latch;
+ *CSR_TIMER1_CNTL = TIMER_CNTL_ENABLE | TIMER_CNTL_AUTORELOAD | TIMER_CNTL_DIV16;
+
+ footbridge_timer_irq.name = "Timer1 Timer Tick";
+ footbridge_timer_irq.handler = timer1_interrupt;
+
+ setup_irq(IRQ_TIMER1, &footbridge_timer_irq);
+
+ } else {
+ /* enable PIT timer */
+ /* set for periodic (4) and LSB/MSB write (0x30) */
+ outb(0x34, 0x43);
+ outb((mSEC_10_from_14/6) & 0xFF, 0x40);
+ outb((mSEC_10_from_14/6) >> 8, 0x40);
+
+ gettimeoffset = isa_gettimeoffset;
+
+ footbridge_timer_irq.name = "ISA Timer Tick";
+ footbridge_timer_irq.handler = isa_timer_interrupt;
+
+ setup_irq(IRQ_ISA_TIMER, &footbridge_timer_irq);
+ }
+}
git://git.onelab.eu / linux-2.6.git / blobdiff