1 /*
2 * Real-time clock driver for MPC5121
3 *
4 * Copyright 2007, Domen Puncer <domen.puncer@telargo.com>
5 * Copyright 2008, Freescale Semiconductor, Inc. All rights reserved.
6 * Copyright 2011, Dmitry Eremin-Solenikov
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/rtc.h>
16 #include <linux/of.h>
17 #include <linux/of_address.h>
18 #include <linux/of_device.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_platform.h>
21 #include <linux/io.h>
22 #include <linux/slab.h>
23
24 struct mpc5121_rtc_regs {
25 u8 set_time; /* RTC + 0x00 */
26 u8 hour_set; /* RTC + 0x01 */
27 u8 minute_set; /* RTC + 0x02 */
28 u8 second_set; /* RTC + 0x03 */
29
30 u8 set_date; /* RTC + 0x04 */
31 u8 month_set; /* RTC + 0x05 */
32 u8 weekday_set; /* RTC + 0x06 */
33 u8 date_set; /* RTC + 0x07 */
34
35 u8 write_sw; /* RTC + 0x08 */
36 u8 sw_set; /* RTC + 0x09 */
37 u16 year_set; /* RTC + 0x0a */
38
39 u8 alm_enable; /* RTC + 0x0c */
40 u8 alm_hour_set; /* RTC + 0x0d */
41 u8 alm_min_set; /* RTC + 0x0e */
42 u8 int_enable; /* RTC + 0x0f */
43
44 u8 reserved1;
45 u8 hour; /* RTC + 0x11 */
46 u8 minute; /* RTC + 0x12 */
47 u8 second; /* RTC + 0x13 */
48
49 u8 month; /* RTC + 0x14 */
50 u8 wday_mday; /* RTC + 0x15 */
51 u16 year; /* RTC + 0x16 */
52
53 u8 int_alm; /* RTC + 0x18 */
54 u8 int_sw; /* RTC + 0x19 */
55 u8 alm_status; /* RTC + 0x1a */
56 u8 sw_minute; /* RTC + 0x1b */
57
58 u8 bus_error_1; /* RTC + 0x1c */
59 u8 int_day; /* RTC + 0x1d */
60 u8 int_min; /* RTC + 0x1e */
61 u8 int_sec; /* RTC + 0x1f */
62
63 /*
64 * target_time:
65 * intended to be used for hibernation but hibernation
66 * does not work on silicon rev 1.5 so use it for non-volatile
67 * storage of offset between the actual_time register and linux
68 * time
69 */
70 u32 target_time; /* RTC + 0x20 */
71 /*
72 * actual_time:
73 * readonly time since VBAT_RTC was last connected
74 */
75 u32 actual_time; /* RTC + 0x24 */
76 u32 keep_alive; /* RTC + 0x28 */
77 };
78
79 struct mpc5121_rtc_data {
80 unsigned irq;
81 unsigned irq_periodic;
82 struct mpc5121_rtc_regs __iomem *regs;
83 struct rtc_device *rtc;
84 struct rtc_wkalrm wkalarm;
85 };
86
87 /*
88 * Update second/minute/hour registers.
89 *
90 * This is just so alarm will work.
91 */
mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem * regs,struct rtc_time * tm)92 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
93 struct rtc_time *tm)
94 {
95 out_8(®s->second_set, tm->tm_sec);
96 out_8(®s->minute_set, tm->tm_min);
97 out_8(®s->hour_set, tm->tm_hour);
98
99 /* set time sequence */
100 out_8(®s->set_time, 0x1);
101 out_8(®s->set_time, 0x3);
102 out_8(®s->set_time, 0x1);
103 out_8(®s->set_time, 0x0);
104 }
105
mpc5121_rtc_read_time(struct device * dev,struct rtc_time * tm)106 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
107 {
108 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
109 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
110 unsigned long now;
111
112 /*
113 * linux time is actual_time plus the offset saved in target_time
114 */
115 now = in_be32(®s->actual_time) + in_be32(®s->target_time);
116
117 rtc_time_to_tm(now, tm);
118
119 /*
120 * update second minute hour registers
121 * so alarms will work
122 */
123 mpc5121_rtc_update_smh(regs, tm);
124
125 return rtc_valid_tm(tm);
126 }
127
mpc5121_rtc_set_time(struct device * dev,struct rtc_time * tm)128 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
129 {
130 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
131 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
132 int ret;
133 unsigned long now;
134
135 /*
136 * The actual_time register is read only so we write the offset
137 * between it and linux time to the target_time register.
138 */
139 ret = rtc_tm_to_time(tm, &now);
140 if (ret == 0)
141 out_be32(®s->target_time, now - in_be32(®s->actual_time));
142
143 /*
144 * update second minute hour registers
145 * so alarms will work
146 */
147 mpc5121_rtc_update_smh(regs, tm);
148
149 return 0;
150 }
151
mpc5200_rtc_read_time(struct device * dev,struct rtc_time * tm)152 static int mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm)
153 {
154 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
155 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
156 int tmp;
157
158 tm->tm_sec = in_8(®s->second);
159 tm->tm_min = in_8(®s->minute);
160
161 /* 12 hour format? */
162 if (in_8(®s->hour) & 0x20)
163 tm->tm_hour = (in_8(®s->hour) >> 1) +
164 (in_8(®s->hour) & 1 ? 12 : 0);
165 else
166 tm->tm_hour = in_8(®s->hour);
167
168 tmp = in_8(®s->wday_mday);
169 tm->tm_mday = tmp & 0x1f;
170 tm->tm_mon = in_8(®s->month) - 1;
171 tm->tm_year = in_be16(®s->year) - 1900;
172 tm->tm_wday = (tmp >> 5) % 7;
173 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
174 tm->tm_isdst = 0;
175
176 return 0;
177 }
178
mpc5200_rtc_set_time(struct device * dev,struct rtc_time * tm)179 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm)
180 {
181 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
182 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
183
184 mpc5121_rtc_update_smh(regs, tm);
185
186 /* date */
187 out_8(®s->month_set, tm->tm_mon + 1);
188 out_8(®s->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
189 out_8(®s->date_set, tm->tm_mday);
190 out_be16(®s->year_set, tm->tm_year + 1900);
191
192 /* set date sequence */
193 out_8(®s->set_date, 0x1);
194 out_8(®s->set_date, 0x3);
195 out_8(®s->set_date, 0x1);
196 out_8(®s->set_date, 0x0);
197
198 return 0;
199 }
200
mpc5121_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)201 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
202 {
203 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
204 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
205
206 *alarm = rtc->wkalarm;
207
208 alarm->pending = in_8(®s->alm_status);
209
210 return 0;
211 }
212
mpc5121_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)213 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
214 {
215 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
216 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
217
218 /*
219 * the alarm has no seconds so deal with it
220 */
221 if (alarm->time.tm_sec) {
222 alarm->time.tm_sec = 0;
223 alarm->time.tm_min++;
224 if (alarm->time.tm_min >= 60) {
225 alarm->time.tm_min = 0;
226 alarm->time.tm_hour++;
227 if (alarm->time.tm_hour >= 24)
228 alarm->time.tm_hour = 0;
229 }
230 }
231
232 alarm->time.tm_mday = -1;
233 alarm->time.tm_mon = -1;
234 alarm->time.tm_year = -1;
235
236 out_8(®s->alm_min_set, alarm->time.tm_min);
237 out_8(®s->alm_hour_set, alarm->time.tm_hour);
238
239 out_8(®s->alm_enable, alarm->enabled);
240
241 rtc->wkalarm = *alarm;
242 return 0;
243 }
244
mpc5121_rtc_handler(int irq,void * dev)245 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
246 {
247 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
248 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
249
250 if (in_8(®s->int_alm)) {
251 /* acknowledge and clear status */
252 out_8(®s->int_alm, 1);
253 out_8(®s->alm_status, 1);
254
255 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
256 return IRQ_HANDLED;
257 }
258
259 return IRQ_NONE;
260 }
261
mpc5121_rtc_handler_upd(int irq,void * dev)262 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
263 {
264 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
265 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
266
267 if (in_8(®s->int_sec) && (in_8(®s->int_enable) & 0x1)) {
268 /* acknowledge */
269 out_8(®s->int_sec, 1);
270
271 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
272 return IRQ_HANDLED;
273 }
274
275 return IRQ_NONE;
276 }
277
mpc5121_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)278 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
279 unsigned int enabled)
280 {
281 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
282 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
283 int val;
284
285 if (enabled)
286 val = 1;
287 else
288 val = 0;
289
290 out_8(®s->alm_enable, val);
291 rtc->wkalarm.enabled = val;
292
293 return 0;
294 }
295
296 static const struct rtc_class_ops mpc5121_rtc_ops = {
297 .read_time = mpc5121_rtc_read_time,
298 .set_time = mpc5121_rtc_set_time,
299 .read_alarm = mpc5121_rtc_read_alarm,
300 .set_alarm = mpc5121_rtc_set_alarm,
301 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
302 };
303
304 static const struct rtc_class_ops mpc5200_rtc_ops = {
305 .read_time = mpc5200_rtc_read_time,
306 .set_time = mpc5200_rtc_set_time,
307 .read_alarm = mpc5121_rtc_read_alarm,
308 .set_alarm = mpc5121_rtc_set_alarm,
309 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
310 };
311
mpc5121_rtc_probe(struct platform_device * op)312 static int mpc5121_rtc_probe(struct platform_device *op)
313 {
314 struct mpc5121_rtc_data *rtc;
315 int err = 0;
316
317 rtc = devm_kzalloc(&op->dev, sizeof(*rtc), GFP_KERNEL);
318 if (!rtc)
319 return -ENOMEM;
320
321 rtc->regs = of_iomap(op->dev.of_node, 0);
322 if (!rtc->regs) {
323 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
324 return -ENOSYS;
325 }
326
327 device_init_wakeup(&op->dev, 1);
328
329 platform_set_drvdata(op, rtc);
330
331 rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
332 err = request_irq(rtc->irq, mpc5121_rtc_handler, 0,
333 "mpc5121-rtc", &op->dev);
334 if (err) {
335 dev_err(&op->dev, "%s: could not request irq: %i\n",
336 __func__, rtc->irq);
337 goto out_dispose;
338 }
339
340 rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
341 err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
342 0, "mpc5121-rtc_upd", &op->dev);
343 if (err) {
344 dev_err(&op->dev, "%s: could not request irq: %i\n",
345 __func__, rtc->irq_periodic);
346 goto out_dispose2;
347 }
348
349 if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
350 u32 ka;
351 ka = in_be32(&rtc->regs->keep_alive);
352 if (ka & 0x02) {
353 dev_warn(&op->dev,
354 "mpc5121-rtc: Battery or oscillator failure!\n");
355 out_be32(&rtc->regs->keep_alive, ka);
356 }
357
358 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5121-rtc",
359 &mpc5121_rtc_ops, THIS_MODULE);
360 } else {
361 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5200-rtc",
362 &mpc5200_rtc_ops, THIS_MODULE);
363 }
364
365 if (IS_ERR(rtc->rtc)) {
366 err = PTR_ERR(rtc->rtc);
367 goto out_free_irq;
368 }
369 rtc->rtc->uie_unsupported = 1;
370
371 return 0;
372
373 out_free_irq:
374 free_irq(rtc->irq_periodic, &op->dev);
375 out_dispose2:
376 irq_dispose_mapping(rtc->irq_periodic);
377 free_irq(rtc->irq, &op->dev);
378 out_dispose:
379 irq_dispose_mapping(rtc->irq);
380 iounmap(rtc->regs);
381
382 return err;
383 }
384
mpc5121_rtc_remove(struct platform_device * op)385 static int mpc5121_rtc_remove(struct platform_device *op)
386 {
387 struct mpc5121_rtc_data *rtc = platform_get_drvdata(op);
388 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
389
390 /* disable interrupt, so there are no nasty surprises */
391 out_8(®s->alm_enable, 0);
392 out_8(®s->int_enable, in_8(®s->int_enable) & ~0x1);
393
394 iounmap(rtc->regs);
395 free_irq(rtc->irq, &op->dev);
396 free_irq(rtc->irq_periodic, &op->dev);
397 irq_dispose_mapping(rtc->irq);
398 irq_dispose_mapping(rtc->irq_periodic);
399
400 return 0;
401 }
402
403 #ifdef CONFIG_OF
404 static const struct of_device_id mpc5121_rtc_match[] = {
405 { .compatible = "fsl,mpc5121-rtc", },
406 { .compatible = "fsl,mpc5200-rtc", },
407 {},
408 };
409 MODULE_DEVICE_TABLE(of, mpc5121_rtc_match);
410 #endif
411
412 static struct platform_driver mpc5121_rtc_driver = {
413 .driver = {
414 .name = "mpc5121-rtc",
415 .of_match_table = of_match_ptr(mpc5121_rtc_match),
416 },
417 .probe = mpc5121_rtc_probe,
418 .remove = mpc5121_rtc_remove,
419 };
420
421 module_platform_driver(mpc5121_rtc_driver);
422
423 MODULE_LICENSE("GPL");
424 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");
425