1 files changed, 291 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/powermac/time.c b/arch/powerpc/platforms/powermac/time.c
new file mode 100644
index 000000000000..ff6adff36cb8
--- /dev/null
+++ b/arch/powerpc/platforms/powermac/time.c
@@ -0,0 +1,291 @@
+/*
+ * Support for periodic interrupts (100 per second) and for getting
+ * the current time from the RTC on Power Macintoshes.
+ *
+ * We use the decrementer register for our periodic interrupts.
+ *
+ * Paul Mackerras       August 1996.
+ * Copyright (C) 1996 Paul Mackerras.
+ */
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/param.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/adb.h>
+#include <linux/cuda.h>
+#include <linux/pmu.h>
+#include <linux/hardirq.h>
+
+#include <asm/sections.h>
+#include <asm/prom.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/machdep.h>
+#include <asm/time.h>
+#include <asm/nvram.h>
+
+/* Apparently the RTC stores seconds since 1 Jan 1904 */
+#define RTC_OFFSET      2082844800
+
+/*
+ * Calibrate the decrementer frequency with the VIA timer 1.
+ */
+#define VIA_TIMER_FREQ_6        4700000 /* time 1 frequency * 6 */
+
+/* VIA registers */
+#define RS              0x200           /* skip between registers */
+#define T1CL            (4*RS)          /* Timer 1 ctr/latch (low 8 bits) */
+#define T1CH            (5*RS)          /* Timer 1 counter (high 8 bits) */
+#define T1LL            (6*RS)          /* Timer 1 latch (low 8 bits) */
+#define T1LH            (7*RS)          /* Timer 1 latch (high 8 bits) */
+#define ACR             (11*RS)         /* Auxiliary control register */
+#define IFR             (13*RS)         /* Interrupt flag register */
+
+/* Bits in ACR */
+#define T1MODE          0xc0            /* Timer 1 mode */
+#define T1MODE_CONT     0x40            /*  continuous interrupts */
+
+/* Bits in IFR and IER */
+#define T1_INT          0x40            /* Timer 1 interrupt */
+
+extern struct timezone sys_tz;
+
+long __init
+pmac_time_init(void)
+{
+#ifdef CONFIG_NVRAM
+        s32 delta = 0;
+        int dst;
+        
+        delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
+        delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
+        delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
+        if (delta & 0x00800000UL)
+                delta |= 0xFF000000UL;
+        dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
+        printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
+                dst ? "on" : "off");
+        return delta;
+#else
+        return 0;
+#endif
+}
+
+unsigned long
+pmac_get_rtc_time(void)
+{
+#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU)
+        struct adb_request req;
+        unsigned long now;
+#endif
+
+        /* Get the time from the RTC */
+        switch (sys_ctrler) {
+#ifdef CONFIG_ADB_CUDA
+        case SYS_CTRLER_CUDA:
+                if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0)
+                        return 0;
+                while (!req.complete)
+                        cuda_poll();
+                if (req.reply_len != 7)
+                        printk(KERN_ERR "pmac_get_rtc_time: got %d byte reply\n",
+                               req.reply_len);
+                now = (req.reply[3] << 24) + (req.reply[4] << 16)
+                        + (req.reply[5] << 8) + req.reply[6];
+                return now - RTC_OFFSET;
+#endif /* CONFIG_ADB_CUDA */
+#ifdef CONFIG_ADB_PMU
+        case SYS_CTRLER_PMU:
+                if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
+                        return 0;
+                while (!req.complete)
+                        pmu_poll();
+                if (req.reply_len != 4)
+                        printk(KERN_ERR "pmac_get_rtc_time: got %d byte reply\n",
+                               req.reply_len);
+                now = (req.reply[0] << 24) + (req.reply[1] << 16)
+                        + (req.reply[2] << 8) + req.reply[3];
+                return now - RTC_OFFSET;
+#endif /* CONFIG_ADB_PMU */
+        default: ;
+        }
+        return 0;
+}
+
+int
+pmac_set_rtc_time(unsigned long nowtime)
+{
+#if defined(CONFIG_ADB_CUDA) || defined(CONFIG_ADB_PMU)
+        struct adb_request req;
+#endif
+
+        nowtime += RTC_OFFSET;
+
+        switch (sys_ctrler) {
+#ifdef CONFIG_ADB_CUDA
+        case SYS_CTRLER_CUDA:
+                if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
+                                 nowtime >> 24, nowtime >> 16, nowtime >> 8, nowtime) < 0)
+                        return 0;
+                while (!req.complete)
+                        cuda_poll();
+                if ((req.reply_len != 3) && (req.reply_len != 7))
+                        printk(KERN_ERR "pmac_set_rtc_time: got %d byte reply\n",
+                               req.reply_len);
+                return 1;
+#endif /* CONFIG_ADB_CUDA */
+#ifdef CONFIG_ADB_PMU
+        case SYS_CTRLER_PMU:
+                if (pmu_request(&req, NULL, 5, PMU_SET_RTC,
+                                nowtime >> 24, nowtime >> 16, nowtime >> 8, nowtime) < 0)
+                        return 0;
+                while (!req.complete)
+                        pmu_poll();
+                if (req.reply_len != 0)
+                        printk(KERN_ERR "pmac_set_rtc_time: got %d byte reply\n",
+                               req.reply_len);
+                return 1;
+#endif /* CONFIG_ADB_PMU */
+        default:
+                return 0;
+        }
+}
+
+/*
+ * Calibrate the decrementer register using VIA timer 1.
+ * This is used both on powermacs and CHRP machines.
+ */
+int __init
+via_calibrate_decr(void)
+{
+        struct device_node *vias;
+        volatile unsigned char __iomem *via;
+        int count = VIA_TIMER_FREQ_6 / 100;
+        unsigned int dstart, dend;
+
+        vias = find_devices("via-cuda");
+        if (vias == 0)
+                vias = find_devices("via-pmu");
+        if (vias == 0)
+                vias = find_devices("via");
+        if (vias == 0 || vias->n_addrs == 0)
+                return 0;
+        via = ioremap(vias->addrs[0].address, vias->addrs[0].size);
+
+        /* set timer 1 for continuous interrupts */
+        out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT);
+        /* set the counter to a small value */
+        out_8(&via[T1CH], 2);
+        /* set the latch to `count' */
+        out_8(&via[T1LL], count);
+        out_8(&via[T1LH], count >> 8);
+        /* wait until it hits 0 */
+        while ((in_8(&via[IFR]) & T1_INT) == 0)
+                ;
+        dstart = get_dec();
+        /* clear the interrupt & wait until it hits 0 again */
+        in_8(&via[T1CL]);
+        while ((in_8(&via[IFR]) & T1_INT) == 0)
+                ;
+        dend = get_dec();
+
+        tb_ticks_per_jiffy = (dstart - dend) / (6 * (HZ/100));
+        tb_to_us = mulhwu_scale_factor(dstart - dend, 60000);
+
+        printk(KERN_INFO "via_calibrate_decr: ticks per jiffy = %u (%u ticks)\n",
+               tb_ticks_per_jiffy, dstart - dend);
+
+        iounmap(via);
+        
+        return 1;
+}
+
+#ifdef CONFIG_PM
+/*
+ * Reset the time after a sleep.
+ */
+static int
+time_sleep_notify(struct pmu_sleep_notifier *self, int when)
+{
+        static unsigned long time_diff;
+        unsigned long flags;
+        unsigned long seq;
+
+        switch (when) {
+        case PBOOK_SLEEP_NOW:
+                do {
+                        seq = read_seqbegin_irqsave(&xtime_lock, flags);
+                        time_diff = xtime.tv_sec - pmac_get_rtc_time();
+                } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
+                break;
+        case PBOOK_WAKE:
+                write_seqlock_irqsave(&xtime_lock, flags);
+                xtime.tv_sec = pmac_get_rtc_time() + time_diff;
+                xtime.tv_nsec = 0;
+                last_rtc_update = xtime.tv_sec;
+                write_sequnlock_irqrestore(&xtime_lock, flags);
+                break;
+        }
+        return PBOOK_SLEEP_OK;
+}
+
+static struct pmu_sleep_notifier time_sleep_notifier = {
+        time_sleep_notify, SLEEP_LEVEL_MISC,
+};
+#endif /* CONFIG_PM */
+
+/*
+ * Query the OF and get the decr frequency.
+ * This was taken from the pmac time_init() when merging the prep/pmac
+ * time functions.
+ */
+void __init
+pmac_calibrate_decr(void)
+{
+        struct device_node *cpu;
+        unsigned int freq, *fp;
+
+#ifdef CONFIG_PM
+        pmu_register_sleep_notifier(&time_sleep_notifier);
+#endif /* CONFIG_PM */
+
+        /* We assume MacRISC2 machines have correct device-tree
+         * calibration. That's better since the VIA itself seems
+         * to be slightly off. --BenH
+         */
+        if (!machine_is_compatible("MacRISC2") &&
+            !machine_is_compatible("MacRISC3") &&
+            !machine_is_compatible("MacRISC4"))
+                if (via_calibrate_decr())
+                        return;
+
+        /* Special case: QuickSilver G4s seem to have a badly calibrated
+         * timebase-frequency in OF, VIA is much better on these. We should
+         * probably implement calibration based on the KL timer on these
+         * machines anyway... -BenH
+         */
+        if (machine_is_compatible("PowerMac3,5"))
+                if (via_calibrate_decr())
+                        return;
+        /*
+         * The cpu node should have a timebase-frequency property
+         * to tell us the rate at which the decrementer counts.
+         */
+        cpu = find_type_devices("cpu");
+        if (cpu == 0)
+                panic("can't find cpu node in time_init");
+        fp = (unsigned int *) get_property(cpu, "timebase-frequency", NULL);
+        if (fp == 0)
+                panic("can't get cpu timebase frequency");
+        freq = *fp;
+        printk("time_init: decrementer frequency = %u.%.6u MHz\n",
+               freq/1000000, freq%1000000);
+        tb_ticks_per_jiffy = freq / HZ;
+        tb_to_us = mulhwu_scale_factor(freq, 1000000);
+}