1 /*
2 * linux/arch/m68k/atari/time.c
3 *
4 * Atari time and real time clock stuff
5 *
6 * Assembled of parts of former atari/config.c 97-12-18 by Roman Hodek
7 *
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file COPYING in the main directory of this archive
10 * for more details.
11 */
12
13 #include <linux/types.h>
14 #include <linux/mc146818rtc.h>
15 #include <linux/interrupt.h>
16 #include <linux/init.h>
17 #include <linux/rtc.h>
18 #include <linux/bcd.h>
19 #include <linux/clocksource.h>
20 #include <linux/delay.h>
21 #include <linux/export.h>
22
23 #include <asm/atariints.h>
24
25 DEFINE_SPINLOCK(rtc_lock);
26 EXPORT_SYMBOL_GPL(rtc_lock);
27
28 static u64 atari_read_clk(struct clocksource *cs);
29
30 static struct clocksource atari_clk = {
31 .name = "mfp",
32 .rating = 100,
33 .read = atari_read_clk,
34 .mask = CLOCKSOURCE_MASK(32),
35 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
36 };
37
38 static u32 clk_total;
39 static u8 last_timer_count;
40
mfp_timer_c_handler(int irq,void * dev_id)41 static irqreturn_t mfp_timer_c_handler(int irq, void *dev_id)
42 {
43 irq_handler_t timer_routine = dev_id;
44 unsigned long flags;
45
46 local_irq_save(flags);
47 do {
48 last_timer_count = st_mfp.tim_dt_c;
49 } while (last_timer_count == 1);
50 clk_total += INT_TICKS;
51 timer_routine(0, NULL);
52 local_irq_restore(flags);
53
54 return IRQ_HANDLED;
55 }
56
57 void __init
atari_sched_init(irq_handler_t timer_routine)58 atari_sched_init(irq_handler_t timer_routine)
59 {
60 /* set Timer C data Register */
61 st_mfp.tim_dt_c = INT_TICKS;
62 /* start timer C, div = 1:100 */
63 st_mfp.tim_ct_cd = (st_mfp.tim_ct_cd & 15) | 0x60;
64 /* install interrupt service routine for MFP Timer C */
65 if (request_irq(IRQ_MFP_TIMC, mfp_timer_c_handler, IRQF_TIMER, "timer",
66 timer_routine))
67 pr_err("Couldn't register timer interrupt\n");
68
69 clocksource_register_hz(&atari_clk, INT_CLK);
70 }
71
72 /* ++andreas: gettimeoffset fixed to check for pending interrupt */
73
atari_read_clk(struct clocksource * cs)74 static u64 atari_read_clk(struct clocksource *cs)
75 {
76 unsigned long flags;
77 u8 count;
78 u32 ticks;
79
80 local_irq_save(flags);
81 /* Ensure that the count is monotonically decreasing, even though
82 * the result may briefly stop changing after counter wrap-around.
83 */
84 count = min(st_mfp.tim_dt_c, last_timer_count);
85 last_timer_count = count;
86
87 ticks = INT_TICKS - count;
88 ticks += clk_total;
89 local_irq_restore(flags);
90
91 return ticks;
92 }
93
94
mste_read(struct MSTE_RTC * val)95 static void mste_read(struct MSTE_RTC *val)
96 {
97 #define COPY(v) val->v=(mste_rtc.v & 0xf)
98 do {
99 COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
100 COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
101 COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
102 COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
103 COPY(year_tens) ;
104 /* prevent from reading the clock while it changed */
105 } while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
106 #undef COPY
107 }
108
mste_write(struct MSTE_RTC * val)109 static void mste_write(struct MSTE_RTC *val)
110 {
111 #define COPY(v) mste_rtc.v=val->v
112 do {
113 COPY(sec_ones) ; COPY(sec_tens) ; COPY(min_ones) ;
114 COPY(min_tens) ; COPY(hr_ones) ; COPY(hr_tens) ;
115 COPY(weekday) ; COPY(day_ones) ; COPY(day_tens) ;
116 COPY(mon_ones) ; COPY(mon_tens) ; COPY(year_ones) ;
117 COPY(year_tens) ;
118 /* prevent from writing the clock while it changed */
119 } while (val->sec_ones != (mste_rtc.sec_ones & 0xf));
120 #undef COPY
121 }
122
123 #define RTC_READ(reg) \
124 ({ unsigned char __val; \
125 (void) atari_writeb(reg,&tt_rtc.regsel); \
126 __val = tt_rtc.data; \
127 __val; \
128 })
129
130 #define RTC_WRITE(reg,val) \
131 do { \
132 atari_writeb(reg,&tt_rtc.regsel); \
133 tt_rtc.data = (val); \
134 } while(0)
135
136
137 #define HWCLK_POLL_INTERVAL 5
138
atari_mste_hwclk(int op,struct rtc_time * t)139 int atari_mste_hwclk( int op, struct rtc_time *t )
140 {
141 int hour, year;
142 int hr24=0;
143 struct MSTE_RTC val;
144
145 mste_rtc.mode=(mste_rtc.mode | 1);
146 hr24=mste_rtc.mon_tens & 1;
147 mste_rtc.mode=(mste_rtc.mode & ~1);
148
149 if (op) {
150 /* write: prepare values */
151
152 val.sec_ones = t->tm_sec % 10;
153 val.sec_tens = t->tm_sec / 10;
154 val.min_ones = t->tm_min % 10;
155 val.min_tens = t->tm_min / 10;
156 hour = t->tm_hour;
157 if (!hr24) {
158 if (hour > 11)
159 hour += 20 - 12;
160 if (hour == 0 || hour == 20)
161 hour += 12;
162 }
163 val.hr_ones = hour % 10;
164 val.hr_tens = hour / 10;
165 val.day_ones = t->tm_mday % 10;
166 val.day_tens = t->tm_mday / 10;
167 val.mon_ones = (t->tm_mon+1) % 10;
168 val.mon_tens = (t->tm_mon+1) / 10;
169 year = t->tm_year - 80;
170 val.year_ones = year % 10;
171 val.year_tens = year / 10;
172 val.weekday = t->tm_wday;
173 mste_write(&val);
174 mste_rtc.mode=(mste_rtc.mode | 1);
175 val.year_ones = (year % 4); /* leap year register */
176 mste_rtc.mode=(mste_rtc.mode & ~1);
177 }
178 else {
179 mste_read(&val);
180 t->tm_sec = val.sec_ones + val.sec_tens * 10;
181 t->tm_min = val.min_ones + val.min_tens * 10;
182 hour = val.hr_ones + val.hr_tens * 10;
183 if (!hr24) {
184 if (hour == 12 || hour == 12 + 20)
185 hour -= 12;
186 if (hour >= 20)
187 hour += 12 - 20;
188 }
189 t->tm_hour = hour;
190 t->tm_mday = val.day_ones + val.day_tens * 10;
191 t->tm_mon = val.mon_ones + val.mon_tens * 10 - 1;
192 t->tm_year = val.year_ones + val.year_tens * 10 + 80;
193 t->tm_wday = val.weekday;
194 }
195 return 0;
196 }
197
atari_tt_hwclk(int op,struct rtc_time * t)198 int atari_tt_hwclk( int op, struct rtc_time *t )
199 {
200 int sec=0, min=0, hour=0, day=0, mon=0, year=0, wday=0;
201 unsigned long flags;
202 unsigned char ctrl;
203 int pm = 0;
204
205 ctrl = RTC_READ(RTC_CONTROL); /* control registers are
206 * independent from the UIP */
207
208 if (op) {
209 /* write: prepare values */
210
211 sec = t->tm_sec;
212 min = t->tm_min;
213 hour = t->tm_hour;
214 day = t->tm_mday;
215 mon = t->tm_mon + 1;
216 year = t->tm_year - atari_rtc_year_offset;
217 wday = t->tm_wday + (t->tm_wday >= 0);
218
219 if (!(ctrl & RTC_24H)) {
220 if (hour > 11) {
221 pm = 0x80;
222 if (hour != 12)
223 hour -= 12;
224 }
225 else if (hour == 0)
226 hour = 12;
227 }
228
229 if (!(ctrl & RTC_DM_BINARY)) {
230 sec = bin2bcd(sec);
231 min = bin2bcd(min);
232 hour = bin2bcd(hour);
233 day = bin2bcd(day);
234 mon = bin2bcd(mon);
235 year = bin2bcd(year);
236 if (wday >= 0)
237 wday = bin2bcd(wday);
238 }
239 }
240
241 /* Reading/writing the clock registers is a bit critical due to
242 * the regular update cycle of the RTC. While an update is in
243 * progress, registers 0..9 shouldn't be touched.
244 * The problem is solved like that: If an update is currently in
245 * progress (the UIP bit is set), the process sleeps for a while
246 * (50ms). This really should be enough, since the update cycle
247 * normally needs 2 ms.
248 * If the UIP bit reads as 0, we have at least 244 usecs until the
249 * update starts. This should be enough... But to be sure,
250 * additionally the RTC_SET bit is set to prevent an update cycle.
251 */
252
253 while( RTC_READ(RTC_FREQ_SELECT) & RTC_UIP ) {
254 if (in_atomic() || irqs_disabled())
255 mdelay(1);
256 else
257 schedule_timeout_interruptible(HWCLK_POLL_INTERVAL);
258 }
259
260 local_irq_save(flags);
261 RTC_WRITE( RTC_CONTROL, ctrl | RTC_SET );
262 if (!op) {
263 sec = RTC_READ( RTC_SECONDS );
264 min = RTC_READ( RTC_MINUTES );
265 hour = RTC_READ( RTC_HOURS );
266 day = RTC_READ( RTC_DAY_OF_MONTH );
267 mon = RTC_READ( RTC_MONTH );
268 year = RTC_READ( RTC_YEAR );
269 wday = RTC_READ( RTC_DAY_OF_WEEK );
270 }
271 else {
272 RTC_WRITE( RTC_SECONDS, sec );
273 RTC_WRITE( RTC_MINUTES, min );
274 RTC_WRITE( RTC_HOURS, hour + pm);
275 RTC_WRITE( RTC_DAY_OF_MONTH, day );
276 RTC_WRITE( RTC_MONTH, mon );
277 RTC_WRITE( RTC_YEAR, year );
278 if (wday >= 0) RTC_WRITE( RTC_DAY_OF_WEEK, wday );
279 }
280 RTC_WRITE( RTC_CONTROL, ctrl & ~RTC_SET );
281 local_irq_restore(flags);
282
283 if (!op) {
284 /* read: adjust values */
285
286 if (hour & 0x80) {
287 hour &= ~0x80;
288 pm = 1;
289 }
290
291 if (!(ctrl & RTC_DM_BINARY)) {
292 sec = bcd2bin(sec);
293 min = bcd2bin(min);
294 hour = bcd2bin(hour);
295 day = bcd2bin(day);
296 mon = bcd2bin(mon);
297 year = bcd2bin(year);
298 wday = bcd2bin(wday);
299 }
300
301 if (!(ctrl & RTC_24H)) {
302 if (!pm && hour == 12)
303 hour = 0;
304 else if (pm && hour != 12)
305 hour += 12;
306 }
307
308 t->tm_sec = sec;
309 t->tm_min = min;
310 t->tm_hour = hour;
311 t->tm_mday = day;
312 t->tm_mon = mon - 1;
313 t->tm_year = year + atari_rtc_year_offset;
314 t->tm_wday = wday - 1;
315 }
316
317 return( 0 );
318 }
319
320 /*
321 * Local variables:
322 * c-indent-level: 4
323 * tab-width: 8
324 * End:
325 */
326