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 return now - RTC_OFFSET;
119 #define cuda_get_rtc_time(tm) to_rtc_time(cuda_get_time(), (tm))
121 static int cuda_set_rtc_time(struct rtc_time *tm)
123 unsigned int nowtime;
124 struct adb_request req;
126 nowtime = from_rtc_time(tm) + RTC_OFFSET;
127 if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME,
128 nowtime >> 24, nowtime >> 16, nowtime >> 8,
131 while (!req.complete)
133 if ((req.reply_len != 3) && (req.reply_len != 7))
134 printk(KERN_ERR "cuda_set_rtc_time: got %d byte reply\n",
140 #define cuda_get_time() 0
141 #define cuda_get_rtc_time(tm)
142 #define cuda_set_rtc_time(tm) 0
145 #ifdef CONFIG_ADB_PMU
146 static unsigned long pmu_get_time(void)
148 struct adb_request req;
151 if (pmu_request(&req, NULL, 1, PMU_READ_RTC) < 0)
153 pmu_wait_complete(&req);
154 if (req.reply_len != 4)
155 printk(KERN_ERR "pmu_get_time: got %d byte reply from PMU\n",
157 now = (req.reply[0] << 24) + (req.reply[1] << 16)
158 + (req.reply[2] << 8) + req.reply[3];
159 return now - RTC_OFFSET;
162 #define pmu_get_rtc_time(tm) to_rtc_time(pmu_get_time(), (tm))
164 static int pmu_set_rtc_time(struct rtc_time *tm)
166 unsigned int nowtime;
167 struct adb_request req;
169 nowtime = from_rtc_time(tm) + RTC_OFFSET;
170 if (pmu_request(&req, NULL, 5, PMU_SET_RTC, nowtime >> 24,
171 nowtime >> 16, nowtime >> 8, nowtime) < 0)
173 pmu_wait_complete(&req);
174 if (req.reply_len != 0)
175 printk(KERN_ERR "pmu_set_rtc_time: %d byte reply from PMU\n",
181 #define pmu_get_time() 0
182 #define pmu_get_rtc_time(tm)
183 #define pmu_set_rtc_time(tm) 0
186 #ifdef CONFIG_PMAC_SMU
187 static unsigned long smu_get_time(void)
191 if (smu_get_rtc_time(&tm, 1))
193 return from_rtc_time(&tm);
197 #define smu_get_time() 0
198 #define smu_get_rtc_time(tm, spin)
199 #define smu_set_rtc_time(tm, spin) 0
202 unsigned long pmac_get_boot_time(void)
204 /* Get the time from the RTC, used only at boot time */
205 switch (sys_ctrler) {
206 case SYS_CTRLER_CUDA:
207 return cuda_get_time();
209 return pmu_get_time();
211 return smu_get_time();
217 void pmac_get_rtc_time(struct rtc_time *tm)
219 /* Get the time from the RTC, used only at boot time */
220 switch (sys_ctrler) {
221 case SYS_CTRLER_CUDA:
222 cuda_get_rtc_time(tm);
225 pmu_get_rtc_time(tm);
228 smu_get_rtc_time(tm, 1);
235 int pmac_set_rtc_time(struct rtc_time *tm)
237 switch (sys_ctrler) {
238 case SYS_CTRLER_CUDA:
239 return cuda_set_rtc_time(tm);
241 return pmu_set_rtc_time(tm);
243 return smu_set_rtc_time(tm, 1);
251 * Calibrate the decrementer register using VIA timer 1.
252 * This is used both on powermacs and CHRP machines.
254 int __init via_calibrate_decr(void)
256 struct device_node *vias;
257 volatile unsigned char __iomem *via;
258 int count = VIA_TIMER_FREQ_6 / 100;
259 unsigned int dstart, dend;
261 vias = find_devices("via-cuda");
263 vias = find_devices("via-pmu");
265 vias = find_devices("via");
266 if (vias == 0 || vias->n_addrs == 0)
268 via = ioremap(vias->addrs[0].address, vias->addrs[0].size);
270 /* set timer 1 for continuous interrupts */
271 out_8(&via[ACR], (via[ACR] & ~T1MODE) | T1MODE_CONT);
272 /* set the counter to a small value */
273 out_8(&via[T1CH], 2);
274 /* set the latch to `count' */
275 out_8(&via[T1LL], count);
276 out_8(&via[T1LH], count >> 8);
277 /* wait until it hits 0 */
278 while ((in_8(&via[IFR]) & T1_INT) == 0)
281 /* clear the interrupt & wait until it hits 0 again */
283 while ((in_8(&via[IFR]) & T1_INT) == 0)
287 ppc_tb_freq = (dstart - dend) * 100 / 6;
297 * Reset the time after a sleep.
300 time_sleep_notify(struct pmu_sleep_notifier *self, int when)
302 static unsigned long time_diff;
308 case PBOOK_SLEEP_NOW:
310 seq = read_seqbegin_irqsave(&xtime_lock, flags);
311 time_diff = xtime.tv_sec - pmac_get_boot_time();
312 } while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
315 tv.tv_sec = pmac_get_boot_time() + time_diff;
317 do_settimeofday(&tv);
320 return PBOOK_SLEEP_OK;
323 static struct pmu_sleep_notifier time_sleep_notifier = {
324 time_sleep_notify, SLEEP_LEVEL_MISC,
326 #endif /* CONFIG_PM */
329 * Query the OF and get the decr frequency.
331 void __init pmac_calibrate_decr(void)
335 pmu_register_sleep_notifier(&time_sleep_notifier);
336 #endif /* CONFIG_PM */
338 generic_calibrate_decr();
341 /* We assume MacRISC2 machines have correct device-tree
342 * calibration. That's better since the VIA itself seems
343 * to be slightly off. --BenH
345 if (!machine_is_compatible("MacRISC2") &&
346 !machine_is_compatible("MacRISC3") &&
347 !machine_is_compatible("MacRISC4"))
348 if (via_calibrate_decr())
351 /* Special case: QuickSilver G4s seem to have a badly calibrated
352 * timebase-frequency in OF, VIA is much better on these. We should
353 * probably implement calibration based on the KL timer on these
354 * machines anyway... -BenH
356 if (machine_is_compatible("PowerMac3,5"))
357 if (via_calibrate_decr())