1 files changed, 180 insertions, 0 deletions

diff --git a/arch/arm/mach-footbridge/time.c b/arch/arm/mach-footbridge/time.c
new file mode 100644
index 000000000000..2c64a0b0502e
--- /dev/null
+++ b/arch/arm/mach-footbridge/time.c
@@ -0,0 +1,180 @@
+/*
+ *  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/sched.h>
+#include <linux/mc146818rtc.h>
+#include <linux/bcd.h>
+
+#include <asm/hardware.h>
+#include <asm/io.h>
+
+#include <asm/mach/time.h>
+#include "common.h"
+
+static int rtc_base;
+
+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;
+}
+
+void __init isa_rtc_init(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;
+        }
+}