--- /dev/null
+/*
+ * 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 int 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 ((unsigned long)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 int 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 ((unsigned long)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
+
+/* Can't be __init, it's called when suspending and resuming */
+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;
+ struct resource rsrc;
+
+ vias = of_find_node_by_name(NULL, "via-cuda");
+ if (vias == 0)
+ vias = of_find_node_by_name(NULL, "via-pmu");
+ if (vias == 0)
+ vias = of_find_node_by_name(NULL, "via");
+ if (vias == 0 || of_address_to_resource(vias, 0, &rsrc))
+ return 0;
+ via = ioremap(rsrc.start, rsrc.end - rsrc.start + 1);
+ if (via == NULL) {
+ printk(KERN_ERR "Failed to map VIA for timer calibration !\n");
+ return 0;
+ }
+
+ /* 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)
+{
+#if defined(CONFIG_PM) && defined(CONFIG_ADB_PMU)
+ /* XXX why here? */
+ pmu_register_sleep_notifier(&time_sleep_notifier);
+#endif
+
+ 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
+}
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