blob: 83b2bb480a16da8586d67fc1275499efc8a82d94 [file] [log] [blame]
Richard Purdiee842f1c2006-03-27 01:16:46 -08001/*
2 * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx
3 *
4 * Copyright (c) 2000 Nils Faerber
5 *
6 * Based on rtc.c by Paul Gortmaker
7 *
8 * Original Driver by Nils Faerber <nils@kernelconcepts.de>
9 *
10 * Modifications from:
11 * CIH <cih@coventive.com>
12 * Nicolas Pitre <nico@cam.org>
13 * Andrew Christian <andrew.christian@hp.com>
14 *
15 * Converted to the RTC subsystem and Driver Model
16 * by Richard Purdie <rpurdie@rpsys.net>
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
23
24#include <linux/platform_device.h>
25#include <linux/module.h>
26#include <linux/rtc.h>
27#include <linux/init.h>
28#include <linux/fs.h>
29#include <linux/interrupt.h>
30#include <linux/string.h>
31#include <linux/pm.h>
32
33#include <asm/bitops.h>
34#include <asm/hardware.h>
35#include <asm/irq.h>
36#include <asm/rtc.h>
37
38#ifdef CONFIG_ARCH_PXA
39#include <asm/arch/pxa-regs.h>
40#endif
41
42#define TIMER_FREQ CLOCK_TICK_RATE
43#define RTC_DEF_DIVIDER 32768 - 1
44#define RTC_DEF_TRIM 0
45
46static unsigned long rtc_freq = 1024;
47static struct rtc_time rtc_alarm;
48static spinlock_t sa1100_rtc_lock = SPIN_LOCK_UNLOCKED;
49
50static int rtc_update_alarm(struct rtc_time *alrm)
51{
52 struct rtc_time alarm_tm, now_tm;
53 unsigned long now, time;
54 int ret;
55
56 do {
57 now = RCNR;
58 rtc_time_to_tm(now, &now_tm);
59 rtc_next_alarm_time(&alarm_tm, &now_tm, alrm);
60 ret = rtc_tm_to_time(&alarm_tm, &time);
61 if (ret != 0)
62 break;
63
64 RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL);
65 RTAR = time;
66 } while (now != RCNR);
67
68 return ret;
69}
70
71static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id,
72 struct pt_regs *regs)
73{
74 struct platform_device *pdev = to_platform_device(dev_id);
75 struct rtc_device *rtc = platform_get_drvdata(pdev);
76 unsigned int rtsr;
77 unsigned long events = 0;
78
79 spin_lock(&sa1100_rtc_lock);
80
81 rtsr = RTSR;
82 /* clear interrupt sources */
83 RTSR = 0;
84 RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
85
86 /* clear alarm interrupt if it has occurred */
87 if (rtsr & RTSR_AL)
88 rtsr &= ~RTSR_ALE;
89 RTSR = rtsr & (RTSR_ALE | RTSR_HZE);
90
91 /* update irq data & counter */
92 if (rtsr & RTSR_AL)
93 events |= RTC_AF | RTC_IRQF;
94 if (rtsr & RTSR_HZ)
95 events |= RTC_UF | RTC_IRQF;
96
97 rtc_update_irq(&rtc->class_dev, 1, events);
98
99 if (rtsr & RTSR_AL && rtc_periodic_alarm(&rtc_alarm))
100 rtc_update_alarm(&rtc_alarm);
101
102 spin_unlock(&sa1100_rtc_lock);
103
104 return IRQ_HANDLED;
105}
106
107static int rtc_timer1_count;
108
109static irqreturn_t timer1_interrupt(int irq, void *dev_id,
110 struct pt_regs *regs)
111{
112 struct platform_device *pdev = to_platform_device(dev_id);
113 struct rtc_device *rtc = platform_get_drvdata(pdev);
114
115 /*
116 * If we match for the first time, rtc_timer1_count will be 1.
117 * Otherwise, we wrapped around (very unlikely but
118 * still possible) so compute the amount of missed periods.
119 * The match reg is updated only when the data is actually retrieved
120 * to avoid unnecessary interrupts.
121 */
122 OSSR = OSSR_M1; /* clear match on timer1 */
123
124 rtc_update_irq(&rtc->class_dev, rtc_timer1_count, RTC_PF | RTC_IRQF);
125
126 if (rtc_timer1_count == 1)
127 rtc_timer1_count = (rtc_freq * ((1<<30)/(TIMER_FREQ>>2)));
128
129 return IRQ_HANDLED;
130}
131
132static int sa1100_rtc_read_callback(struct device *dev, int data)
133{
134 if (data & RTC_PF) {
135 /* interpolate missed periods and set match for the next */
136 unsigned long period = TIMER_FREQ/rtc_freq;
137 unsigned long oscr = OSCR;
138 unsigned long osmr1 = OSMR1;
139 unsigned long missed = (oscr - osmr1)/period;
140 data += missed << 8;
141 OSSR = OSSR_M1; /* clear match on timer 1 */
142 OSMR1 = osmr1 + (missed + 1)*period;
143 /* Ensure we didn't miss another match in the mean time.
144 * Here we compare (match - OSCR) 8 instead of 0 --
145 * see comment in pxa_timer_interrupt() for explanation.
146 */
147 while( (signed long)((osmr1 = OSMR1) - OSCR) <= 8 ) {
148 data += 0x100;
149 OSSR = OSSR_M1; /* clear match on timer 1 */
150 OSMR1 = osmr1 + period;
151 }
152 }
153 return data;
154}
155
156static int sa1100_rtc_open(struct device *dev)
157{
158 int ret;
159
160 ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, SA_INTERRUPT,
161 "rtc 1Hz", dev);
162 if (ret) {
163 printk(KERN_ERR "rtc: IRQ%d already in use.\n", IRQ_RTC1Hz);
164 goto fail_ui;
165 }
166 ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, SA_INTERRUPT,
167 "rtc Alrm", dev);
168 if (ret) {
169 printk(KERN_ERR "rtc: IRQ%d already in use.\n", IRQ_RTCAlrm);
170 goto fail_ai;
171 }
172 ret = request_irq(IRQ_OST1, timer1_interrupt, SA_INTERRUPT,
173 "rtc timer", dev);
174 if (ret) {
175 printk(KERN_ERR "rtc: IRQ%d already in use.\n", IRQ_OST1);
176 goto fail_pi;
177 }
178 return 0;
179
180 fail_pi:
181 free_irq(IRQ_RTCAlrm, NULL);
182 fail_ai:
183 free_irq(IRQ_RTC1Hz, NULL);
184 fail_ui:
185 return ret;
186}
187
188static void sa1100_rtc_release(struct device *dev)
189{
190 spin_lock_irq(&sa1100_rtc_lock);
191 RTSR = 0;
192 OIER &= ~OIER_E1;
193 OSSR = OSSR_M1;
194 spin_unlock_irq(&sa1100_rtc_lock);
195
196 free_irq(IRQ_OST1, dev);
197 free_irq(IRQ_RTCAlrm, dev);
198 free_irq(IRQ_RTC1Hz, dev);
199}
200
201
202static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd,
203 unsigned long arg)
204{
205 switch(cmd) {
206 case RTC_AIE_OFF:
207 spin_lock_irq(&sa1100_rtc_lock);
208 RTSR &= ~RTSR_ALE;
209 spin_unlock_irq(&sa1100_rtc_lock);
210 return 0;
211 case RTC_AIE_ON:
212 spin_lock_irq(&sa1100_rtc_lock);
213 RTSR |= RTSR_ALE;
214 spin_unlock_irq(&sa1100_rtc_lock);
215 return 0;
216 case RTC_UIE_OFF:
217 spin_lock_irq(&sa1100_rtc_lock);
218 RTSR &= ~RTSR_HZE;
219 spin_unlock_irq(&sa1100_rtc_lock);
220 return 0;
221 case RTC_UIE_ON:
222 spin_lock_irq(&sa1100_rtc_lock);
223 RTSR |= RTSR_HZE;
224 spin_unlock_irq(&sa1100_rtc_lock);
225 return 0;
226 case RTC_PIE_OFF:
227 spin_lock_irq(&sa1100_rtc_lock);
228 OIER &= ~OIER_E1;
229 spin_unlock_irq(&sa1100_rtc_lock);
230 return 0;
231 case RTC_PIE_ON:
232 if ((rtc_freq > 64) && !capable(CAP_SYS_RESOURCE))
233 return -EACCES;
234 spin_lock_irq(&sa1100_rtc_lock);
235 OSMR1 = TIMER_FREQ/rtc_freq + OSCR;
236 OIER |= OIER_E1;
237 rtc_timer1_count = 1;
238 spin_unlock_irq(&sa1100_rtc_lock);
239 return 0;
240 case RTC_IRQP_READ:
241 return put_user(rtc_freq, (unsigned long *)arg);
242 case RTC_IRQP_SET:
243 if (arg < 1 || arg > TIMER_FREQ)
244 return -EINVAL;
245 if ((arg > 64) && (!capable(CAP_SYS_RESOURCE)))
246 return -EACCES;
247 rtc_freq = arg;
248 return 0;
249 }
250 return -EINVAL;
251}
252
253static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
254{
255 rtc_time_to_tm(RCNR, tm);
256 return 0;
257}
258
259static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
260{
261 unsigned long time;
262 int ret;
263
264 ret = rtc_tm_to_time(tm, &time);
265 if (ret == 0)
266 RCNR = time;
267 return ret;
268}
269
270static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
271{
272 memcpy(&alrm->time, &rtc_alarm, sizeof(struct rtc_time));
273 alrm->pending = RTSR & RTSR_AL ? 1 : 0;
274 return 0;
275}
276
277static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
278{
279 int ret;
280
281 spin_lock_irq(&sa1100_rtc_lock);
282 ret = rtc_update_alarm(&alrm->time);
283 if (ret == 0) {
284 memcpy(&rtc_alarm, &alrm->time, sizeof(struct rtc_time));
285
286 if (alrm->enabled)
287 enable_irq_wake(IRQ_RTCAlrm);
288 else
289 disable_irq_wake(IRQ_RTCAlrm);
290 }
291 spin_unlock_irq(&sa1100_rtc_lock);
292
293 return ret;
294}
295
296static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
297{
298 seq_printf(seq, "trim/divider\t: 0x%08x\n", RTTR);
299 seq_printf(seq, "alarm_IRQ\t: %s\n",
300 (RTSR & RTSR_ALE) ? "yes" : "no" );
301 seq_printf(seq, "update_IRQ\t: %s\n",
302 (RTSR & RTSR_HZE) ? "yes" : "no");
303 seq_printf(seq, "periodic_IRQ\t: %s\n",
304 (OIER & OIER_E1) ? "yes" : "no");
305 seq_printf(seq, "periodic_freq\t: %ld\n", rtc_freq);
306
307 return 0;
308}
309
310static struct rtc_class_ops sa1100_rtc_ops = {
311 .open = sa1100_rtc_open,
312 .read_callback = sa1100_rtc_read_callback,
313 .release = sa1100_rtc_release,
314 .ioctl = sa1100_rtc_ioctl,
315 .read_time = sa1100_rtc_read_time,
316 .set_time = sa1100_rtc_set_time,
317 .read_alarm = sa1100_rtc_read_alarm,
318 .set_alarm = sa1100_rtc_set_alarm,
319 .proc = sa1100_rtc_proc,
320};
321
322static int sa1100_rtc_probe(struct platform_device *pdev)
323{
324 struct rtc_device *rtc;
325
326 /*
327 * According to the manual we should be able to let RTTR be zero
328 * and then a default diviser for a 32.768KHz clock is used.
329 * Apparently this doesn't work, at least for my SA1110 rev 5.
330 * If the clock divider is uninitialized then reset it to the
331 * default value to get the 1Hz clock.
332 */
333 if (RTTR == 0) {
334 RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
335 printk(KERN_WARNING "rtc: warning: initializing default clock divider/trim value\n");
336 /* The current RTC value probably doesn't make sense either */
337 RCNR = 0;
338 }
339
340 rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
341 THIS_MODULE);
342
343 if (IS_ERR(rtc)) {
344 dev_err(&pdev->dev, "Unable to register the RTC device\n");
345 return PTR_ERR(rtc);
346 }
347
348 platform_set_drvdata(pdev, rtc);
349
350 dev_info(&pdev->dev, "SA11xx/PXA2xx RTC Registered\n");
351
352 return 0;
353}
354
355static int sa1100_rtc_remove(struct platform_device *pdev)
356{
357 struct rtc_device *rtc = platform_get_drvdata(pdev);
358
359 if (rtc)
360 rtc_device_unregister(rtc);
361
362 return 0;
363}
364
365static struct platform_driver sa1100_rtc_driver = {
366 .probe = sa1100_rtc_probe,
367 .remove = sa1100_rtc_remove,
368 .driver = {
369 .name = "sa1100-rtc",
370 },
371};
372
373static int __init sa1100_rtc_init(void)
374{
375 return platform_driver_register(&sa1100_rtc_driver);
376}
377
378static void __exit sa1100_rtc_exit(void)
379{
380 platform_driver_unregister(&sa1100_rtc_driver);
381}
382
383module_init(sa1100_rtc_init);
384module_exit(sa1100_rtc_exit);
385
386MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
387MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
388MODULE_LICENSE("GPL");