1 files changed, 360 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powermac/time.c b/arch/powerpc/platforms/powermac/time.c
new file mode 100644
index 00000000000..5947b21a858
--- /dev/null
+++ b/arch/powerpc/platforms/powermac/time.c
@@ -0,0 +1,360 @@
+/*
+ * 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.
+ * Copyright (C) 2003-2005 Benjamin Herrenschmidt.
+ *
+ */
+#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/interrupt.h>
+#include <linux/hardirq.h>
+#include <linux/rtc.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>
+#include <asm/smu.h>
+
+#undef DEBUG
+
+#ifdef DEBUG
+#define DBG(x...) printk(x)
+#else
+#define DBG(x...)
+#endif
+
+/* 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 */
+
+long __init pmac_time_init(void)
+{
+	s32 delta = 0;
+#ifdef CONFIG_NVRAM
+	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");
+#endif
+	return delta;
+}
+
+static void to_rtc_time(unsigned long now, struct rtc_time *tm)
+{
+	to_tm(now, tm);
+	tm->tm_year -= 1900;
+	tm->tm_mon -= 1;
+}
+
+static unsigned long from_rtc_time(struct rtc_time *tm)
+{
+	return mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
+		      tm->tm_hour, tm->tm_min, tm->tm_sec);
+}
+
+#ifdef CONFIG_ADB_CUDA
+static unsigned long cuda_get_time(void)
+{
+	struct adb_request req;
+	unsigned long now;
+
+	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 "cuda_get_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;
+}
+
+#define cuda_get_rtc_time(tm)	to_rtc_time(cuda_get_time(), (tm))
+
+static int cuda_set_rtc_time(struct rtc_time *tm)
+{
+	unsigned int nowtime;
+	struct adb_request req;
+
+	nowtime = from_rtc_time(tm) + RTC_OFFSET;
+	if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
+			 nowtime >> 24, nowtime >> 16, nowtime >> 8,
+			 nowtime) < 0)
+		return -ENXIO;
+	while (!req.complete)
+		cuda_poll();
+	if ((req.reply_len != 3) && (req.reply_len != 7))
+		printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n",
+		       req.reply_len);
+	return 0;
+}
+
+#else
+#define cuda_get_time()		0
+#define cuda_get_rtc_time(tm)
+#define cuda_set_rtc_time(tm)	0
+#endif
+
+#ifdef CONFIG_ADB_PMU
+static unsigned long pmu_get_time(void)
+{
+	struct adb_request req;
+	unsigned long now;
+
+	if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
+		return 0;
+	pmu_wait_complete(&req);
+	if (req.reply_len != 4)
+		printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n",
+		       req.reply_len);
+	now = (req.reply[0] << 24) + (req.reply[1] << 16)
+		+ (req.reply[2] << 8) + req.reply[3];
+	return now - RTC_OFFSET;
+}
+
+#define pmu_get_rtc_time(tm)	to_rtc_time(pmu_get_time(), (tm))
+
+static int pmu_set_rtc_time(struct rtc_time *tm)
+{
+	unsigned int nowtime;
+	struct adb_request req;
+
+	nowtime = from_rtc_time(tm) + RTC_OFFSET;
+	if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24,
+			nowtime >> 16, nowtime >> 8, nowtime) < 0)
+		return -ENXIO;
+	pmu_wait_complete(&req);
+	if (req.reply_len != 0)
+		printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n",
+		       req.reply_len);
+	return 0;
+}
+
+#else
+#define pmu_get_time()		0
+#define pmu_get_rtc_time(tm)
+#define pmu_set_rtc_time(tm)	0
+#endif
+
+#ifdef CONFIG_PMAC_SMU
+static unsigned long smu_get_time(void)
+{
+	struct rtc_time tm;
+
+	if (smu_get_rtc_time(&tm, 1))
+		return 0;
+	return from_rtc_time(&tm);
+}
+
+#else
+#define smu_get_time()			0
+#define smu_get_rtc_time(tm, spin)
+#define smu_set_rtc_time(tm, spin)	0
+#endif
+
+unsigned long pmac_get_boot_time(void)
+{
+	/* Get the time from the RTC, used only at boot time */
+	switch (sys_ctrler) {
+	case SYS_CTRLER_CUDA:
+		return cuda_get_time();
+	case SYS_CTRLER_PMU:
+		return pmu_get_time();
+	case SYS_CTRLER_SMU:
+		return smu_get_time();
+	default:
+		return 0;
+	}
+}
+
+void pmac_get_rtc_time(struct rtc_time *tm)
+{
+	/* Get the time from the RTC, used only at boot time */
+	switch (sys_ctrler) {
+	case SYS_CTRLER_CUDA:
+		cuda_get_rtc_time(tm);
+		break;
+	case SYS_CTRLER_PMU:
+		pmu_get_rtc_time(tm);
+		break;
+	case SYS_CTRLER_SMU:
+		smu_get_rtc_time(tm, 1);
+		break;
+	default:
+		;
+	}
+}
+
+int pmac_set_rtc_time(struct rtc_time *tm)
+{
+	switch (sys_ctrler) {
+	case SYS_CTRLER_CUDA:
+		return cuda_set_rtc_time(tm);
+	case SYS_CTRLER_PMU:
+		return pmu_set_rtc_time(tm);
+	case SYS_CTRLER_SMU:
+		return smu_set_rtc_time(tm, 1);
+	default:
+		return -ENODEV;
+	}
+}
+
+#ifdef CONFIG_PPC32
+/*
+ * 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();
+
+	ppc_tb_freq = (dstart - dend) * 100 / 6;
+
+	iounmap(via);
+	
+	return 1;
+}
+#endif
+
+#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;
+	struct timespec tv;
+
+	switch (when) {
+	case PBOOK_SLEEP_NOW:
+		do {
+			seq = read_seqbegin_irqsave(&xtime_lock, flags);
+			time_diff = xtime.tv_sec - pmac_get_boot_time();
+		} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
+		break;
+	case PBOOK_WAKE:
+		tv.tv_sec = pmac_get_boot_time() + time_diff;
+		tv.tv_nsec = 0;
+		do_settimeofday(&tv);
+		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.
+ */
+void __init pmac_calibrate_decr(void)
+{
+#ifdef CONFIG_PM
+	/* XXX why here? */
+	pmu_register_sleep_notifier(&time_sleep_notifier);
+#endif /* CONFIG_PM */
+
+	generic_calibrate_decr();
+
+#ifdef CONFIG_PPC32
+	/* 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;
+#endif
+}