patch-2.4.20 linux-2.4.20/arch/ppc/platforms/pmac_time.c

• Lines: 285
• Date: Thu Nov 28 15:53:11 2002
• Orig file: linux-2.4.19/arch/ppc/platforms/pmac_time.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -urN linux-2.4.19/arch/ppc/platforms/pmac_time.c linux-2.4.20/arch/ppc/platforms/pmac_time.c
@@ -0,0 +1,284 @@
+/*
+ * BK Id: %F% %I% %G% %U% %#%
+ */
+/*
+ * 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/adb.h>
+#include <linux/cuda.h>
+#include <linux/pmu.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/hardirq.h>
+#include <asm/time.h>
+#include <asm/nvram.h>
+
+extern rwlock_t xtime_lock;
+
+/* 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
+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
+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 *via;
+	int count = VIA_TIMER_FREQ_6 / HZ;
+	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 = (volatile unsigned char *)
+		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;
+	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_PMAC_PBOOK
+/*
+ * Reset the time after a sleep.
+ */
+static int __pmac
+time_sleep_notify(struct pmu_sleep_notifier *self, int when)
+{
+	static unsigned long time_diff;
+	unsigned long flags;
+
+	switch (when) {
+	case PBOOK_SLEEP_NOW:
+		read_lock_irqsave(&xtime_lock, flags);
+		time_diff = xtime.tv_sec - pmac_get_rtc_time();
+		read_unlock_irqrestore(&xtime_lock, flags);
+		break;
+	case PBOOK_WAKE:
+		write_lock_irqsave(&xtime_lock, flags);
+		xtime.tv_sec = pmac_get_rtc_time() + time_diff;
+		xtime.tv_usec = 0;
+		last_rtc_update = xtime.tv_sec;
+		write_unlock_irqrestore(&xtime_lock, flags);
+		break;
+	}
+	return PBOOK_SLEEP_OK;
+}
+
+static struct pmu_sleep_notifier time_sleep_notifier __pmacdata = {
+	time_sleep_notify, SLEEP_LEVEL_MISC,
+};
+#endif /* CONFIG_PMAC_PBOOK */
+
+/*
+ * 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_PMAC_PBOOK
+	pmu_register_sleep_notifier(&time_sleep_notifier);
+#endif /* CONFIG_PMAC_PBOOK */
+
+	/* 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"))
+		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);
+}