blob: 8624f55d05608cabe99e6f91a9e18220be699a13 [file] [log] [blame]
Wu, Bryan8cc75c92007-05-06 14:50:32 -07001/*
2 * Blackfin On-Chip Real Time Clock Driver
Mike Frysinger095b9d52008-02-06 01:38:51 -08003 * Supports BF52[257]/BF53[123]/BF53[467]/BF54[24789]
Wu, Bryan8cc75c92007-05-06 14:50:32 -07004 *
5 * Copyright 2004-2007 Analog Devices Inc.
6 *
7 * Enter bugs at http://blackfin.uclinux.org/
8 *
9 * Licensed under the GPL-2 or later.
10 */
11
12/* The biggest issue we deal with in this driver is that register writes are
13 * synced to the RTC frequency of 1Hz. So if you write to a register and
14 * attempt to write again before the first write has completed, the new write
15 * is simply discarded. This can easily be troublesome if userspace disables
16 * one event (say periodic) and then right after enables an event (say alarm).
17 * Since all events are maintained in the same interrupt mask register, if
18 * we wrote to it to disable the first event and then wrote to it again to
19 * enable the second event, that second event would not be enabled as the
20 * write would be discarded and things quickly fall apart.
21 *
22 * To keep this delay from significantly degrading performance (we, in theory,
23 * would have to sleep for up to 1 second everytime we wanted to write a
24 * register), we only check the write pending status before we start to issue
25 * a new write. We bank on the idea that it doesnt matter when the sync
26 * happens so long as we don't attempt another write before it does. The only
27 * time userspace would take this penalty is when they try and do multiple
28 * operations right after another ... but in this case, they need to take the
29 * sync penalty, so we should be OK.
30 *
31 * Also note that the RTC_ISTAT register does not suffer this penalty; its
32 * writes to clear status registers complete immediately.
33 */
34
Wu, Bryan8cc75c92007-05-06 14:50:32 -070035#include <linux/bcd.h>
Mike Frysinger095b9d52008-02-06 01:38:51 -080036#include <linux/completion.h>
Wu, Bryan8cc75c92007-05-06 14:50:32 -070037#include <linux/delay.h>
Mike Frysinger095b9d52008-02-06 01:38:51 -080038#include <linux/init.h>
39#include <linux/interrupt.h>
40#include <linux/kernel.h>
41#include <linux/module.h>
42#include <linux/platform_device.h>
43#include <linux/rtc.h>
44#include <linux/seq_file.h>
Wu, Bryan8cc75c92007-05-06 14:50:32 -070045
46#include <asm/blackfin.h>
47
Mike Frysinger5438de42008-02-06 01:38:49 -080048#define dev_dbg_stamp(dev) dev_dbg(dev, "%s:%i: here i am\n", __func__, __LINE__)
Wu, Bryan8cc75c92007-05-06 14:50:32 -070049
50struct bfin_rtc {
51 struct rtc_device *rtc_dev;
52 struct rtc_time rtc_alarm;
Mike Frysinger095b9d52008-02-06 01:38:51 -080053 u16 rtc_wrote_regs;
Wu, Bryan8cc75c92007-05-06 14:50:32 -070054};
55
56/* Bit values for the ISTAT / ICTL registers */
57#define RTC_ISTAT_WRITE_COMPLETE 0x8000
58#define RTC_ISTAT_WRITE_PENDING 0x4000
59#define RTC_ISTAT_ALARM_DAY 0x0040
60#define RTC_ISTAT_24HR 0x0020
61#define RTC_ISTAT_HOUR 0x0010
62#define RTC_ISTAT_MIN 0x0008
63#define RTC_ISTAT_SEC 0x0004
64#define RTC_ISTAT_ALARM 0x0002
65#define RTC_ISTAT_STOPWATCH 0x0001
66
67/* Shift values for RTC_STAT register */
68#define DAY_BITS_OFF 17
69#define HOUR_BITS_OFF 12
70#define MIN_BITS_OFF 6
71#define SEC_BITS_OFF 0
72
73/* Some helper functions to convert between the common RTC notion of time
Mike Frysinger5c236342008-02-06 01:38:47 -080074 * and the internal Blackfin notion that is encoded in 32bits.
Wu, Bryan8cc75c92007-05-06 14:50:32 -070075 */
76static inline u32 rtc_time_to_bfin(unsigned long now)
77{
78 u32 sec = (now % 60);
79 u32 min = (now % (60 * 60)) / 60;
80 u32 hour = (now % (60 * 60 * 24)) / (60 * 60);
81 u32 days = (now / (60 * 60 * 24));
82 return (sec << SEC_BITS_OFF) +
83 (min << MIN_BITS_OFF) +
84 (hour << HOUR_BITS_OFF) +
85 (days << DAY_BITS_OFF);
86}
87static inline unsigned long rtc_bfin_to_time(u32 rtc_bfin)
88{
89 return (((rtc_bfin >> SEC_BITS_OFF) & 0x003F)) +
90 (((rtc_bfin >> MIN_BITS_OFF) & 0x003F) * 60) +
91 (((rtc_bfin >> HOUR_BITS_OFF) & 0x001F) * 60 * 60) +
92 (((rtc_bfin >> DAY_BITS_OFF) & 0x7FFF) * 60 * 60 * 24);
93}
94static inline void rtc_bfin_to_tm(u32 rtc_bfin, struct rtc_time *tm)
95{
96 rtc_time_to_tm(rtc_bfin_to_time(rtc_bfin), tm);
97}
98
Mike Frysinger095b9d52008-02-06 01:38:51 -080099/**
100 * bfin_rtc_sync_pending - make sure pending writes have complete
101 *
102 * Wait for the previous write to a RTC register to complete.
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700103 * Unfortunately, we can't sleep here as that introduces a race condition when
104 * turning on interrupt events. Consider this:
105 * - process sets alarm
106 * - process enables alarm
107 * - process sleeps while waiting for rtc write to sync
108 * - interrupt fires while process is sleeping
109 * - interrupt acks the event by writing to ISTAT
110 * - interrupt sets the WRITE PENDING bit
111 * - interrupt handler finishes
112 * - process wakes up, sees WRITE PENDING bit set, goes to sleep
113 * - interrupt fires while process is sleeping
114 * If anyone can point out the obvious solution here, i'm listening :). This
115 * shouldn't be an issue on an SMP or preempt system as this function should
116 * only be called with the rtc lock held.
Mike Frysinger5c236342008-02-06 01:38:47 -0800117 *
118 * Other options:
119 * - disable PREN so the sync happens at 32.768kHZ ... but this changes the
120 * inc rate for all RTC registers from 1HZ to 32.768kHZ ...
121 * - use the write complete IRQ
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700122 */
Mike Frysinger095b9d52008-02-06 01:38:51 -0800123/*
124static void bfin_rtc_sync_pending_polled(void)
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700125{
Mike Frysinger095b9d52008-02-06 01:38:51 -0800126 while (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_COMPLETE))
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700127 if (!(bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_PENDING))
128 break;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700129 bfin_write_RTC_ISTAT(RTC_ISTAT_WRITE_COMPLETE);
130}
Mike Frysinger095b9d52008-02-06 01:38:51 -0800131*/
132static DECLARE_COMPLETION(bfin_write_complete);
133static void bfin_rtc_sync_pending(struct device *dev)
134{
135 dev_dbg_stamp(dev);
136 while (bfin_read_RTC_ISTAT() & RTC_ISTAT_WRITE_PENDING)
137 wait_for_completion_timeout(&bfin_write_complete, HZ * 5);
138 dev_dbg_stamp(dev);
139}
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700140
Mike Frysinger095b9d52008-02-06 01:38:51 -0800141/**
142 * bfin_rtc_reset - set RTC to sane/known state
143 *
144 * Initialize the RTC. Enable pre-scaler to scale RTC clock
145 * to 1Hz and clear interrupt/status registers.
146 */
147static void bfin_rtc_reset(struct device *dev)
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700148{
Mike Frysinger5438de42008-02-06 01:38:49 -0800149 struct bfin_rtc *rtc = dev_get_drvdata(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800150 dev_dbg_stamp(dev);
151 bfin_rtc_sync_pending(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700152 bfin_write_RTC_PREN(0x1);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800153 bfin_write_RTC_ICTL(RTC_ISTAT_WRITE_COMPLETE);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700154 bfin_write_RTC_SWCNT(0);
155 bfin_write_RTC_ALARM(0);
156 bfin_write_RTC_ISTAT(0xFFFF);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800157 rtc->rtc_wrote_regs = 0;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700158}
159
Mike Frysinger095b9d52008-02-06 01:38:51 -0800160/**
161 * bfin_rtc_interrupt - handle interrupt from RTC
162 *
163 * Since we handle all RTC events here, we have to make sure the requested
164 * interrupt is enabled (in RTC_ICTL) as the event status register (RTC_ISTAT)
165 * always gets updated regardless of the interrupt being enabled. So when one
166 * even we care about (e.g. stopwatch) goes off, we don't want to turn around
167 * and say that other events have happened as well (e.g. second). We do not
168 * have to worry about pending writes to the RTC_ICTL register as interrupts
169 * only fire if they are enabled in the RTC_ICTL register.
170 */
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700171static irqreturn_t bfin_rtc_interrupt(int irq, void *dev_id)
172{
Mike Frysingerd7827d82008-02-06 01:38:47 -0800173 struct device *dev = dev_id;
174 struct bfin_rtc *rtc = dev_get_drvdata(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700175 unsigned long events = 0;
Mike Frysinger095b9d52008-02-06 01:38:51 -0800176 bool write_complete = false;
177 u16 rtc_istat, rtc_ictl;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700178
Mike Frysinger5438de42008-02-06 01:38:49 -0800179 dev_dbg_stamp(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700180
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700181 rtc_istat = bfin_read_RTC_ISTAT();
Mike Frysinger095b9d52008-02-06 01:38:51 -0800182 rtc_ictl = bfin_read_RTC_ICTL();
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700183
Mike Frysinger095b9d52008-02-06 01:38:51 -0800184 if (rtc_istat & RTC_ISTAT_WRITE_COMPLETE) {
185 bfin_write_RTC_ISTAT(RTC_ISTAT_WRITE_COMPLETE);
186 write_complete = true;
187 complete(&bfin_write_complete);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700188 }
189
Mike Frysinger095b9d52008-02-06 01:38:51 -0800190 if (rtc_ictl & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) {
191 if (rtc_istat & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY)) {
192 bfin_write_RTC_ISTAT(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY);
193 events |= RTC_AF | RTC_IRQF;
194 }
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700195 }
196
Mike Frysinger095b9d52008-02-06 01:38:51 -0800197 if (rtc_ictl & RTC_ISTAT_STOPWATCH) {
198 if (rtc_istat & RTC_ISTAT_STOPWATCH) {
199 bfin_write_RTC_ISTAT(RTC_ISTAT_STOPWATCH);
200 events |= RTC_PF | RTC_IRQF;
201 bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq);
202 }
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700203 }
204
Mike Frysinger095b9d52008-02-06 01:38:51 -0800205 if (rtc_ictl & RTC_ISTAT_SEC) {
206 if (rtc_istat & RTC_ISTAT_SEC) {
207 bfin_write_RTC_ISTAT(RTC_ISTAT_SEC);
208 events |= RTC_UF | RTC_IRQF;
209 }
210 }
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700211
Mike Frysinger095b9d52008-02-06 01:38:51 -0800212 if (events)
213 rtc_update_irq(rtc->rtc_dev, 1, events);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700214
Mike Frysinger095b9d52008-02-06 01:38:51 -0800215 if (write_complete || events)
216 return IRQ_HANDLED;
217 else
218 return IRQ_NONE;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700219}
220
221static int bfin_rtc_open(struct device *dev)
222{
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700223 int ret;
224
Mike Frysinger5438de42008-02-06 01:38:49 -0800225 dev_dbg_stamp(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700226
Mike Frysinger095b9d52008-02-06 01:38:51 -0800227 ret = request_irq(IRQ_RTC, bfin_rtc_interrupt, IRQF_SHARED, to_platform_device(dev)->name, dev);
228 if (!ret)
229 bfin_rtc_reset(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700230
231 return ret;
232}
233
234static void bfin_rtc_release(struct device *dev)
235{
Mike Frysinger5438de42008-02-06 01:38:49 -0800236 dev_dbg_stamp(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800237 bfin_rtc_reset(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700238 free_irq(IRQ_RTC, dev);
239}
240
Mike Frysinger095b9d52008-02-06 01:38:51 -0800241static void bfin_rtc_int_set(struct bfin_rtc *rtc, u16 rtc_int)
242{
243 bfin_write_RTC_ISTAT(rtc_int);
244 bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() | rtc_int);
245}
246static void bfin_rtc_int_clear(struct bfin_rtc *rtc, u16 rtc_int)
247{
248 bfin_write_RTC_ICTL(bfin_read_RTC_ICTL() & rtc_int);
249}
250static void bfin_rtc_int_set_alarm(struct bfin_rtc *rtc)
251{
252 /* Blackfin has different bits for whether the alarm is
253 * more than 24 hours away.
254 */
255 bfin_rtc_int_set(rtc, (rtc->rtc_alarm.tm_yday == -1 ? RTC_ISTAT_ALARM : RTC_ISTAT_ALARM_DAY));
256}
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700257static int bfin_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
258{
259 struct bfin_rtc *rtc = dev_get_drvdata(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800260 int ret = 0;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700261
Mike Frysinger5438de42008-02-06 01:38:49 -0800262 dev_dbg_stamp(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700263
Mike Frysinger095b9d52008-02-06 01:38:51 -0800264 bfin_rtc_sync_pending(dev);
265
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700266 switch (cmd) {
267 case RTC_PIE_ON:
Mike Frysinger5438de42008-02-06 01:38:49 -0800268 dev_dbg_stamp(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800269 bfin_rtc_int_set(rtc, RTC_ISTAT_STOPWATCH);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700270 bfin_write_RTC_SWCNT(rtc->rtc_dev->irq_freq);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800271 break;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700272 case RTC_PIE_OFF:
Mike Frysinger5438de42008-02-06 01:38:49 -0800273 dev_dbg_stamp(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800274 bfin_rtc_int_clear(rtc, ~RTC_ISTAT_STOPWATCH);
275 break;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700276
277 case RTC_UIE_ON:
Mike Frysinger5438de42008-02-06 01:38:49 -0800278 dev_dbg_stamp(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800279 bfin_rtc_int_set(rtc, RTC_ISTAT_SEC);
280 break;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700281 case RTC_UIE_OFF:
Mike Frysinger5438de42008-02-06 01:38:49 -0800282 dev_dbg_stamp(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800283 bfin_rtc_int_clear(rtc, ~RTC_ISTAT_SEC);
284 break;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700285
Mike Frysinger095b9d52008-02-06 01:38:51 -0800286 case RTC_AIE_ON:
Mike Frysinger5438de42008-02-06 01:38:49 -0800287 dev_dbg_stamp(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800288 bfin_rtc_int_set_alarm(rtc);
289 break;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700290 case RTC_AIE_OFF:
Mike Frysinger5438de42008-02-06 01:38:49 -0800291 dev_dbg_stamp(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800292 bfin_rtc_int_clear(rtc, ~(RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
293 break;
294
295 default:
296 dev_dbg_stamp(dev);
297 ret = -ENOIOCTLCMD;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700298 }
299
Mike Frysinger095b9d52008-02-06 01:38:51 -0800300 return ret;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700301}
302
303static int bfin_rtc_read_time(struct device *dev, struct rtc_time *tm)
304{
305 struct bfin_rtc *rtc = dev_get_drvdata(dev);
306
Mike Frysinger5438de42008-02-06 01:38:49 -0800307 dev_dbg_stamp(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700308
Mike Frysinger095b9d52008-02-06 01:38:51 -0800309 if (rtc->rtc_wrote_regs & 0x1)
310 bfin_rtc_sync_pending(dev);
311
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700312 rtc_bfin_to_tm(bfin_read_RTC_STAT(), tm);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700313
314 return 0;
315}
316
317static int bfin_rtc_set_time(struct device *dev, struct rtc_time *tm)
318{
319 struct bfin_rtc *rtc = dev_get_drvdata(dev);
320 int ret;
321 unsigned long now;
322
Mike Frysinger5438de42008-02-06 01:38:49 -0800323 dev_dbg_stamp(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700324
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700325 ret = rtc_tm_to_time(tm, &now);
326 if (ret == 0) {
Mike Frysinger095b9d52008-02-06 01:38:51 -0800327 if (rtc->rtc_wrote_regs & 0x1)
328 bfin_rtc_sync_pending(dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700329 bfin_write_RTC_STAT(rtc_time_to_bfin(now));
Mike Frysinger095b9d52008-02-06 01:38:51 -0800330 rtc->rtc_wrote_regs = 0x1;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700331 }
332
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700333 return ret;
334}
335
336static int bfin_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
337{
338 struct bfin_rtc *rtc = dev_get_drvdata(dev);
Mike Frysinger5438de42008-02-06 01:38:49 -0800339 dev_dbg_stamp(dev);
Mike Frysinger48c1a562008-02-06 01:38:50 -0800340 alrm->time = rtc->rtc_alarm;
Mike Frysinger095b9d52008-02-06 01:38:51 -0800341 bfin_rtc_sync_pending(dev);
Mike Frysinger68db3042008-02-06 01:38:49 -0800342 alrm->enabled = !!(bfin_read_RTC_ICTL() & (RTC_ISTAT_ALARM | RTC_ISTAT_ALARM_DAY));
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700343 return 0;
344}
345
346static int bfin_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
347{
348 struct bfin_rtc *rtc = dev_get_drvdata(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800349 unsigned long rtc_alarm;
350
Mike Frysinger5438de42008-02-06 01:38:49 -0800351 dev_dbg_stamp(dev);
Mike Frysinger095b9d52008-02-06 01:38:51 -0800352
353 if (rtc_tm_to_time(&alrm->time, &rtc_alarm))
354 return -EINVAL;
355
Mike Frysinger68db3042008-02-06 01:38:49 -0800356 rtc->rtc_alarm = alrm->time;
Mike Frysinger095b9d52008-02-06 01:38:51 -0800357
358 bfin_rtc_sync_pending(dev);
359 bfin_write_RTC_ALARM(rtc_time_to_bfin(rtc_alarm));
360 if (alrm->enabled)
361 bfin_rtc_int_set_alarm(rtc);
362
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700363 return 0;
364}
365
366static int bfin_rtc_proc(struct device *dev, struct seq_file *seq)
367{
Mike Frysinger64061162008-02-06 01:38:48 -0800368#define yesno(x) ((x) ? "yes" : "no")
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700369 u16 ictl = bfin_read_RTC_ICTL();
Mike Frysinger5438de42008-02-06 01:38:49 -0800370 dev_dbg_stamp(dev);
Mike Frysinger64061162008-02-06 01:38:48 -0800371 seq_printf(seq,
372 "alarm_IRQ\t: %s\n"
373 "wkalarm_IRQ\t: %s\n"
374 "seconds_IRQ\t: %s\n"
375 "periodic_IRQ\t: %s\n",
376 yesno(ictl & RTC_ISTAT_ALARM),
377 yesno(ictl & RTC_ISTAT_ALARM_DAY),
378 yesno(ictl & RTC_ISTAT_SEC),
379 yesno(ictl & RTC_ISTAT_STOPWATCH));
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700380 return 0;
Mike Frysinger64061162008-02-06 01:38:48 -0800381#undef yesno
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700382}
383
Mike Frysinger5c236342008-02-06 01:38:47 -0800384/**
385 * bfin_irq_set_freq - make sure hardware supports requested freq
386 * @dev: pointer to RTC device structure
387 * @freq: requested frequency rate
388 *
389 * The Blackfin RTC can only generate periodic events at 1 per
390 * second (1 Hz), so reject any attempt at changing it.
391 */
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700392static int bfin_irq_set_freq(struct device *dev, int freq)
393{
Mike Frysinger5438de42008-02-06 01:38:49 -0800394 dev_dbg_stamp(dev);
Mike Frysinger5c236342008-02-06 01:38:47 -0800395 return -ENOTTY;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700396}
397
398static struct rtc_class_ops bfin_rtc_ops = {
399 .open = bfin_rtc_open,
400 .release = bfin_rtc_release,
401 .ioctl = bfin_rtc_ioctl,
402 .read_time = bfin_rtc_read_time,
403 .set_time = bfin_rtc_set_time,
404 .read_alarm = bfin_rtc_read_alarm,
405 .set_alarm = bfin_rtc_set_alarm,
406 .proc = bfin_rtc_proc,
407 .irq_set_freq = bfin_irq_set_freq,
408};
409
410static int __devinit bfin_rtc_probe(struct platform_device *pdev)
411{
412 struct bfin_rtc *rtc;
413 int ret = 0;
414
Mike Frysinger5438de42008-02-06 01:38:49 -0800415 dev_dbg_stamp(&pdev->dev);
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700416
417 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
418 if (unlikely(!rtc))
419 return -ENOMEM;
420
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700421 rtc->rtc_dev = rtc_device_register(pdev->name, &pdev->dev, &bfin_rtc_ops, THIS_MODULE);
Hirofumi Nakagawa801678c2008-04-29 01:03:09 -0700422 if (IS_ERR(rtc)) {
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700423 ret = PTR_ERR(rtc->rtc_dev);
424 goto err;
425 }
Mike Frysinger5c236342008-02-06 01:38:47 -0800426 rtc->rtc_dev->irq_freq = 1;
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700427
428 platform_set_drvdata(pdev, rtc);
429
430 return 0;
431
Mike Frysinger5c236342008-02-06 01:38:47 -0800432 err:
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700433 kfree(rtc);
434 return ret;
435}
436
437static int __devexit bfin_rtc_remove(struct platform_device *pdev)
438{
439 struct bfin_rtc *rtc = platform_get_drvdata(pdev);
440
441 rtc_device_unregister(rtc->rtc_dev);
442 platform_set_drvdata(pdev, NULL);
443 kfree(rtc);
444
445 return 0;
446}
447
448static struct platform_driver bfin_rtc_driver = {
449 .driver = {
450 .name = "rtc-bfin",
451 .owner = THIS_MODULE,
452 },
453 .probe = bfin_rtc_probe,
454 .remove = __devexit_p(bfin_rtc_remove),
455};
456
457static int __init bfin_rtc_init(void)
458{
Wu, Bryan8cc75c92007-05-06 14:50:32 -0700459 return platform_driver_register(&bfin_rtc_driver);
460}
461
462static void __exit bfin_rtc_exit(void)
463{
464 platform_driver_unregister(&bfin_rtc_driver);
465}
466
467module_init(bfin_rtc_init);
468module_exit(bfin_rtc_exit);
469
470MODULE_DESCRIPTION("Blackfin On-Chip Real Time Clock Driver");
471MODULE_AUTHOR("Mike Frysinger <vapier@gentoo.org>");
472MODULE_LICENSE("GPL");
Kay Sieversad28a072008-04-10 21:29:25 -0700473MODULE_ALIAS("platform:rtc-bfin");