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1 | /* linux/arch/sparc/kernel/time.c | |
2 | * | |
3 | * Copyright (C) 1995 David S. Miller (davem@davemloft.net) | |
4 | * Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu) | |
5 | * | |
6 | * Chris Davis (cdavis@cois.on.ca) 03/27/1998 | |
7 | * Added support for the intersil on the sun4/4200 | |
8 | * | |
9 | * Gleb Raiko (rajko@mech.math.msu.su) 08/18/1998 | |
10 | * Support for MicroSPARC-IIep, PCI CPU. | |
11 | * | |
12 | * This file handles the Sparc specific time handling details. | |
13 | * | |
14 | * 1997-09-10 Updated NTP code according to technical memorandum Jan '96 | |
15 | * "A Kernel Model for Precision Timekeeping" by Dave Mills | |
16 | */ | |
17 | #include <linux/errno.h> | |
18 | #include <linux/module.h> | |
19 | #include <linux/sched.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/param.h> | |
22 | #include <linux/string.h> | |
23 | #include <linux/mm.h> | |
24 | #include <linux/interrupt.h> | |
25 | #include <linux/time.h> | |
26 | #include <linux/rtc.h> | |
27 | #include <linux/rtc/m48t59.h> | |
28 | #include <linux/timex.h> | |
29 | #include <linux/init.h> | |
30 | #include <linux/pci.h> | |
31 | #include <linux/ioport.h> | |
32 | #include <linux/profile.h> | |
33 | #include <linux/of.h> | |
34 | #include <linux/of_device.h> | |
35 | #include <linux/platform_device.h> | |
36 | ||
37 | #include <asm/oplib.h> | |
38 | #include <asm/timer.h> | |
39 | #include <asm/system.h> | |
40 | #include <asm/irq.h> | |
41 | #include <asm/io.h> | |
42 | #include <asm/idprom.h> | |
43 | #include <asm/machines.h> | |
44 | #include <asm/page.h> | |
45 | #include <asm/pcic.h> | |
46 | #include <asm/irq_regs.h> | |
47 | ||
48 | #include "irq.h" | |
49 | ||
50 | DEFINE_SPINLOCK(rtc_lock); | |
51 | EXPORT_SYMBOL(rtc_lock); | |
52 | ||
53 | static int set_rtc_mmss(unsigned long); | |
54 | static int sbus_do_settimeofday(struct timespec *tv); | |
55 | ||
56 | unsigned long profile_pc(struct pt_regs *regs) | |
57 | { | |
58 | extern char __copy_user_begin[], __copy_user_end[]; | |
59 | extern char __atomic_begin[], __atomic_end[]; | |
60 | extern char __bzero_begin[], __bzero_end[]; | |
61 | ||
62 | unsigned long pc = regs->pc; | |
63 | ||
64 | if (in_lock_functions(pc) || | |
65 | (pc >= (unsigned long) __copy_user_begin && | |
66 | pc < (unsigned long) __copy_user_end) || | |
67 | (pc >= (unsigned long) __atomic_begin && | |
68 | pc < (unsigned long) __atomic_end) || | |
69 | (pc >= (unsigned long) __bzero_begin && | |
70 | pc < (unsigned long) __bzero_end)) | |
71 | pc = regs->u_regs[UREG_RETPC]; | |
72 | return pc; | |
73 | } | |
74 | ||
75 | EXPORT_SYMBOL(profile_pc); | |
76 | ||
77 | __volatile__ unsigned int *master_l10_counter; | |
78 | ||
79 | /* | |
80 | * timer_interrupt() needs to keep up the real-time clock, | |
81 | * as well as call the "do_timer()" routine every clocktick | |
82 | */ | |
83 | ||
84 | #define TICK_SIZE (tick_nsec / 1000) | |
85 | ||
86 | static irqreturn_t timer_interrupt(int dummy, void *dev_id) | |
87 | { | |
88 | /* last time the cmos clock got updated */ | |
89 | static long last_rtc_update; | |
90 | ||
91 | #ifndef CONFIG_SMP | |
92 | profile_tick(CPU_PROFILING); | |
93 | #endif | |
94 | ||
95 | /* Protect counter clear so that do_gettimeoffset works */ | |
96 | write_seqlock(&xtime_lock); | |
97 | ||
98 | clear_clock_irq(); | |
99 | ||
100 | do_timer(1); | |
101 | ||
102 | /* Determine when to update the Mostek clock. */ | |
103 | if (ntp_synced() && | |
104 | xtime.tv_sec > last_rtc_update + 660 && | |
105 | (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 && | |
106 | (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) { | |
107 | if (set_rtc_mmss(xtime.tv_sec) == 0) | |
108 | last_rtc_update = xtime.tv_sec; | |
109 | else | |
110 | last_rtc_update = xtime.tv_sec - 600; /* do it again in 60 s */ | |
111 | } | |
112 | write_sequnlock(&xtime_lock); | |
113 | ||
114 | #ifndef CONFIG_SMP | |
115 | update_process_times(user_mode(get_irq_regs())); | |
116 | #endif | |
117 | return IRQ_HANDLED; | |
118 | } | |
119 | ||
120 | static unsigned char mostek_read_byte(struct device *dev, u32 ofs) | |
121 | { | |
122 | struct platform_device *pdev = to_platform_device(dev); | |
123 | struct m48t59_plat_data *pdata = pdev->dev.platform_data; | |
124 | ||
125 | return readb(pdata->ioaddr + ofs); | |
126 | } | |
127 | ||
128 | static void mostek_write_byte(struct device *dev, u32 ofs, u8 val) | |
129 | { | |
130 | struct platform_device *pdev = to_platform_device(dev); | |
131 | struct m48t59_plat_data *pdata = pdev->dev.platform_data; | |
132 | ||
133 | writeb(val, pdata->ioaddr + ofs); | |
134 | } | |
135 | ||
136 | static struct m48t59_plat_data m48t59_data = { | |
137 | .read_byte = mostek_read_byte, | |
138 | .write_byte = mostek_write_byte, | |
139 | }; | |
140 | ||
141 | /* resource is set at runtime */ | |
142 | static struct platform_device m48t59_rtc = { | |
143 | .name = "rtc-m48t59", | |
144 | .id = 0, | |
145 | .num_resources = 1, | |
146 | .dev = { | |
147 | .platform_data = &m48t59_data, | |
148 | }, | |
149 | }; | |
150 | ||
151 | static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match) | |
152 | { | |
153 | struct device_node *dp = op->node; | |
154 | const char *model = of_get_property(dp, "model", NULL); | |
155 | ||
156 | if (!model) | |
157 | return -ENODEV; | |
158 | ||
159 | m48t59_rtc.resource = &op->resource[0]; | |
160 | if (!strcmp(model, "mk48t02")) { | |
161 | /* Map the clock register io area read-only */ | |
162 | m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0, | |
163 | 2048, "rtc-m48t59"); | |
164 | m48t59_data.type = M48T59RTC_TYPE_M48T02; | |
165 | } else if (!strcmp(model, "mk48t08")) { | |
166 | m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0, | |
167 | 8192, "rtc-m48t59"); | |
168 | m48t59_data.type = M48T59RTC_TYPE_M48T08; | |
169 | } else | |
170 | return -ENODEV; | |
171 | ||
172 | if (platform_device_register(&m48t59_rtc) < 0) | |
173 | printk(KERN_ERR "Registering RTC device failed\n"); | |
174 | ||
175 | return 0; | |
176 | } | |
177 | ||
178 | static struct of_device_id __initdata clock_match[] = { | |
179 | { | |
180 | .name = "eeprom", | |
181 | }, | |
182 | {}, | |
183 | }; | |
184 | ||
185 | static struct of_platform_driver clock_driver = { | |
186 | .match_table = clock_match, | |
187 | .probe = clock_probe, | |
188 | .driver = { | |
189 | .name = "rtc", | |
190 | }, | |
191 | }; | |
192 | ||
193 | ||
194 | /* Probe for the mostek real time clock chip. */ | |
195 | static int __init clock_init(void) | |
196 | { | |
197 | return of_register_driver(&clock_driver, &of_platform_bus_type); | |
198 | } | |
199 | ||
200 | /* Must be after subsys_initcall() so that busses are probed. Must | |
201 | * be before device_initcall() because things like the RTC driver | |
202 | * need to see the clock registers. | |
203 | */ | |
204 | fs_initcall(clock_init); | |
205 | ||
206 | static void __init sbus_time_init(void) | |
207 | { | |
208 | ||
209 | BTFIXUPSET_CALL(bus_do_settimeofday, sbus_do_settimeofday, BTFIXUPCALL_NORM); | |
210 | btfixup(); | |
211 | ||
212 | sparc_init_timers(timer_interrupt); | |
213 | ||
214 | /* Now that OBP ticker has been silenced, it is safe to enable IRQ. */ | |
215 | local_irq_enable(); | |
216 | } | |
217 | ||
218 | void __init time_init(void) | |
219 | { | |
220 | #ifdef CONFIG_PCI | |
221 | extern void pci_time_init(void); | |
222 | if (pcic_present()) { | |
223 | pci_time_init(); | |
224 | return; | |
225 | } | |
226 | #endif | |
227 | sbus_time_init(); | |
228 | } | |
229 | ||
230 | static inline unsigned long do_gettimeoffset(void) | |
231 | { | |
232 | unsigned long val = *master_l10_counter; | |
233 | unsigned long usec = (val >> 10) & 0x1fffff; | |
234 | ||
235 | /* Limit hit? */ | |
236 | if (val & 0x80000000) | |
237 | usec += 1000000 / HZ; | |
238 | ||
239 | return usec; | |
240 | } | |
241 | ||
242 | /* Ok, my cute asm atomicity trick doesn't work anymore. | |
243 | * There are just too many variables that need to be protected | |
244 | * now (both members of xtime, et al.) | |
245 | */ | |
246 | void do_gettimeofday(struct timeval *tv) | |
247 | { | |
248 | unsigned long flags; | |
249 | unsigned long seq; | |
250 | unsigned long usec, sec; | |
251 | unsigned long max_ntp_tick = tick_usec - tickadj; | |
252 | ||
253 | do { | |
254 | seq = read_seqbegin_irqsave(&xtime_lock, flags); | |
255 | usec = do_gettimeoffset(); | |
256 | ||
257 | /* | |
258 | * If time_adjust is negative then NTP is slowing the clock | |
259 | * so make sure not to go into next possible interval. | |
260 | * Better to lose some accuracy than have time go backwards.. | |
261 | */ | |
262 | if (unlikely(time_adjust < 0)) | |
263 | usec = min(usec, max_ntp_tick); | |
264 | ||
265 | sec = xtime.tv_sec; | |
266 | usec += (xtime.tv_nsec / 1000); | |
267 | } while (read_seqretry_irqrestore(&xtime_lock, seq, flags)); | |
268 | ||
269 | while (usec >= 1000000) { | |
270 | usec -= 1000000; | |
271 | sec++; | |
272 | } | |
273 | ||
274 | tv->tv_sec = sec; | |
275 | tv->tv_usec = usec; | |
276 | } | |
277 | ||
278 | EXPORT_SYMBOL(do_gettimeofday); | |
279 | ||
280 | int do_settimeofday(struct timespec *tv) | |
281 | { | |
282 | int ret; | |
283 | ||
284 | write_seqlock_irq(&xtime_lock); | |
285 | ret = bus_do_settimeofday(tv); | |
286 | write_sequnlock_irq(&xtime_lock); | |
287 | clock_was_set(); | |
288 | return ret; | |
289 | } | |
290 | ||
291 | EXPORT_SYMBOL(do_settimeofday); | |
292 | ||
293 | static int sbus_do_settimeofday(struct timespec *tv) | |
294 | { | |
295 | time_t wtm_sec, sec = tv->tv_sec; | |
296 | long wtm_nsec, nsec = tv->tv_nsec; | |
297 | ||
298 | if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) | |
299 | return -EINVAL; | |
300 | ||
301 | /* | |
302 | * This is revolting. We need to set "xtime" correctly. However, the | |
303 | * value in this location is the value at the most recent update of | |
304 | * wall time. Discover what correction gettimeofday() would have | |
305 | * made, and then undo it! | |
306 | */ | |
307 | nsec -= 1000 * do_gettimeoffset(); | |
308 | ||
309 | wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); | |
310 | wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); | |
311 | ||
312 | set_normalized_timespec(&xtime, sec, nsec); | |
313 | set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); | |
314 | ||
315 | ntp_clear(); | |
316 | return 0; | |
317 | } | |
318 | ||
319 | static int set_rtc_mmss(unsigned long secs) | |
320 | { | |
321 | struct rtc_device *rtc = rtc_class_open("rtc0"); | |
322 | int err = -1; | |
323 | ||
324 | if (rtc) { | |
325 | err = rtc_set_mmss(rtc, secs); | |
326 | rtc_class_close(rtc); | |
327 | } | |
328 | ||
329 | return err; | |
330 | } |