2 * Support for periodic interrupts (100 per second) and for getting
3 * the current time from the RTC on Power Macintoshes.
5 * We use the decrementer register for our periodic interrupts.
7 * Paul Mackerras August 1996.
8 * Copyright (C) 1996 Paul Mackerras.
9 * Copyright (C) 2003-2005 Benjamin Herrenschmidt.
12 #include <linux/config.h>
13 #include <linux/errno.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/param.h>
17 #include <linux/string.h>
19 #include <linux/init.h>
20 #include <linux/time.h>
21 #include <linux/adb.h>
22 #include <linux/cuda.h>
23 #include <linux/pmu.h>
24 #include <linux/interrupt.h>
25 #include <linux/hardirq.h>
26 #include <linux/rtc.h>
28 #include <asm/sections.h>
30 #include <asm/system.h>
32 #include <asm/pgtable.h>
33 #include <asm/machdep.h>
35 #include <asm/nvram.h>
41 #define DBG(x...) printk(x)
46 /* Apparently the RTC stores seconds since 1 Jan 1904 */
47 #define RTC_OFFSET 2082844800
50 * Calibrate the decrementer frequency with the VIA timer 1.
52 #define VIA_TIMER_FREQ_6 4700000 /* time 1 frequency * 6 */
55 #define RS 0x200 /* skip between registers */
56 #define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */
57 #define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */
58 #define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */
59 #define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */
60 #define ACR (11*RS) /* Auxiliary control register */
61 #define IFR (13*RS) /* Interrupt flag register */
64 #define T1MODE 0xc0 /* Timer 1 mode */
65 #define T1MODE_CONT 0x40 /* continuous interrupts */
67 /* Bits in IFR and IER */
68 #define T1_INT 0x40 /* Timer 1 interrupt */
70 long __init pmac_time_init(void)
76 delta = ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x9)) << 16;
77 delta |= ((s32)pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xa)) << 8;
78 delta |= pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0xb);
79 if (delta & 0x00800000UL)
80 delta |= 0xFF000000UL;
81 dst = ((pmac_xpram_read(PMAC_XPRAM_MACHINE_LOC + 0x8) & 0x80) != 0);
82 printk("GMT Delta read from XPRAM: %d minutes, DST: %s\n", delta/60,
88 static void to_rtc_time(unsigned long now, struct rtc_time *tm)
95 static unsigned long from_rtc_time(struct rtc_time *tm)
97 return mktime(tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
98 tm->tm_hour, tm->tm_min, tm->tm_sec);
101 #ifdef CONFIG_ADB_CUDA
102 static unsigned long cuda_get_time(void)
104 struct adb_request req;
107 if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0)
109 while (!req.complete)
111 if (req.reply_len != 7)
112 printk(KERN_ERR "cuda_get_time: got %d byte reply\n",
114 now = (req.reply[3] << 24) + (req.reply[4] << 16)
115 + (req.reply[5] << 8) + req.reply[6];
116 if (now < RTC_OFFSET)
118 return now - RTC_OFFSET;
121 #define cuda_get_rtc_time(tm) to_rtc_time(cuda_get_time(), (tm))
123 static int cuda_set_rtc_time(struct rtc_time *tm)
125 unsigned int nowtime;
126 struct adb_request req;
128 nowtime = from_rtc_time(tm) + RTC_OFFSET;
129 if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
130 nowtime >> 24, nowtime >> 16, nowtime >> 8,
133 while (!req.complete)
135 if ((req.reply_len != 3) && (req.reply_len != 7))
136 printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n",
142 #define cuda_get_time() 0
143 #define cuda_get_rtc_time(tm)
144 #define cuda_set_rtc_time(tm) 0
147 #ifdef CONFIG_ADB_PMU
148 static unsigned long pmu_get_time(void)
150 struct adb_request req;
153 if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
155 pmu_wait_complete(&req);
156 if (req.reply_len != 4)
157 printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n",
159 now = (req.reply[0] << 24) + (req.reply[1] << 16)
160 + (req.reply[2] << 8) + req.reply[3];
161 if (now < RTC_OFFSET)
163 return now - RTC_OFFSET;
166 #define pmu_get_rtc_time(tm) to_rtc_time(pmu_get_time(), (tm))
168 static int pmu_set_rtc_time(struct rtc_time *tm)
170 unsigned int nowtime;
171 struct adb_request req;
173 nowtime = from_rtc_time(tm) + RTC_OFFSET;
174 if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24,
175 nowtime >> 16, nowtime >> 8, nowtime) < 0)
177 pmu_wait_complete(&req);
178 if (req.reply_len != 0)
179 printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n",
185 #define pmu_get_time() 0
186 #define pmu_get_rtc_time(tm)
187 #define pmu_set_rtc_time(tm) 0
190 #ifdef CONFIG_PMAC_SMU
191 static unsigned long smu_get_time(void)
195 if (smu_get_rtc_time(&tm, 1))
197 return from_rtc_time(&tm);
201 #define smu_get_time() 0
202 #define smu_get_rtc_time(tm, spin)
203 #define smu_set_rtc_time(tm, spin) 0
206 unsigned long pmac_get_boot_time(void)
208 /* Get the time from the RTC, used only at boot time */
209 switch (sys_ctrler) {
210 case SYS_CTRLER_CUDA:
211 return cuda_get_time();
213 return pmu_get_time();
215 return smu_get_time();
221 void pmac_get_rtc_time(struct rtc_time *tm)
223 /* Get the time from the RTC, used only at boot time */
224 switch (sys_ctrler) {
225 case SYS_CTRLER_CUDA:
226 cuda_get_rtc_time(tm);
229 pmu_get_rtc_time(tm);
232 smu_get_rtc_time(tm, 1);
239 int pmac_set_rtc_time(struct rtc_time *tm)
241 switch (sys_ctrler) {
242 case SYS_CTRLER_CUDA:
243 return cuda_set_rtc_time(tm);
245 return pmu_set_rtc_time(tm);
247 return smu_set_rtc_time(tm, 1);
255 * Calibrate the decrementer register using VIA timer 1.
256 * This is used both on powermacs and CHRP machines.
258 int __init via_calibrate_decr(void)
260 struct device_node *vias;
261 volatile unsigned char __iomem *via;
262 int count = VIA_TIMER_FREQ_6 / 100;
263 unsigned int dstart, dend;
265 vias = find_devices("via-cuda");
267 vias = find_devices("via-pmu");
269 vias = find_devices("via");
270 if (vias == 0 || vias->n_addrs == 0)
272 via = ioremap(vias->addrs[0].address, vias->addrs[0].size);
274 /* set timer 1 for continuous interrupts */
275 out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT);
276 /* set the counter to a small value */
277 out_8(&via[T1CH], 2);
278 /* set the latch to `count' */
279 out_8(&via[T1LL], count);
280 out_8(&via[T1LH], count >> 8);
281 /* wait until it hits 0 */
282 while ((in_8(&via[IFR]) & T1_INT) == 0)
285 /* clear the interrupt & wait until it hits 0 again */
287 while ((in_8(&via[IFR]) & T1_INT) == 0)
291 ppc_tb_freq = (dstart - dend) * 100 / 6;
301 * Reset the time after a sleep.
304 time_sleep_notify(struct pmu_sleep_notifier *self, int when)
306 static unsigned long time_diff;
312 case PBOOK_SLEEP_NOW:
314 seq = read_seqbegin_irqsave(&xtime_lock, flags);
315 time_diff = xtime.tv_sec - pmac_get_boot_time();
316 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
319 tv.tv_sec = pmac_get_boot_time() + time_diff;
321 do_settimeofday(&tv);
324 return PBOOK_SLEEP_OK;
327 static struct pmu_sleep_notifier time_sleep_notifier = {
328 time_sleep_notify, SLEEP_LEVEL_MISC,
330 #endif /* CONFIG_PM */
333 * Query the OF and get the decr frequency.
335 void __init pmac_calibrate_decr(void)
339 pmu_register_sleep_notifier(&time_sleep_notifier);
340 #endif /* CONFIG_PM */
342 generic_calibrate_decr();
345 /* We assume MacRISC2 machines have correct device-tree
346 * calibration. That's better since the VIA itself seems
347 * to be slightly off. --BenH
349 if (!machine_is_compatible("MacRISC2") &&
350 !machine_is_compatible("MacRISC3") &&
351 !machine_is_compatible("MacRISC4"))
352 if (via_calibrate_decr())
355 /* Special case: QuickSilver G4s seem to have a badly calibrated
356 * timebase-frequency in OF, VIA is much better on these. We should
357 * probably implement calibration based on the KL timer on these
358 * machines anyway... -BenH
360 if (machine_is_compatible("PowerMac3,5"))
361 if (via_calibrate_decr())