1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Real-time clock driver for MPC5121
4 *
5 * Copyright 2007, Domen Puncer <domen.puncer@telargo.com>
6 * Copyright 2008, Freescale Semiconductor, Inc. All rights reserved.
7 * Copyright 2011, Dmitry Eremin-Solenikov
8 */
9
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/rtc.h>
13 #include <linux/of.h>
14 #include <linux/of_address.h>
15 #include <linux/of_device.h>
16 #include <linux/of_irq.h>
17 #include <linux/of_platform.h>
18 #include <linux/io.h>
19 #include <linux/slab.h>
20
21 struct mpc5121_rtc_regs {
22 u8 set_time; /* RTC + 0x00 */
23 u8 hour_set; /* RTC + 0x01 */
24 u8 minute_set; /* RTC + 0x02 */
25 u8 second_set; /* RTC + 0x03 */
26
27 u8 set_date; /* RTC + 0x04 */
28 u8 month_set; /* RTC + 0x05 */
29 u8 weekday_set; /* RTC + 0x06 */
30 u8 date_set; /* RTC + 0x07 */
31
32 u8 write_sw; /* RTC + 0x08 */
33 u8 sw_set; /* RTC + 0x09 */
34 u16 year_set; /* RTC + 0x0a */
35
36 u8 alm_enable; /* RTC + 0x0c */
37 u8 alm_hour_set; /* RTC + 0x0d */
38 u8 alm_min_set; /* RTC + 0x0e */
39 u8 int_enable; /* RTC + 0x0f */
40
41 u8 reserved1;
42 u8 hour; /* RTC + 0x11 */
43 u8 minute; /* RTC + 0x12 */
44 u8 second; /* RTC + 0x13 */
45
46 u8 month; /* RTC + 0x14 */
47 u8 wday_mday; /* RTC + 0x15 */
48 u16 year; /* RTC + 0x16 */
49
50 u8 int_alm; /* RTC + 0x18 */
51 u8 int_sw; /* RTC + 0x19 */
52 u8 alm_status; /* RTC + 0x1a */
53 u8 sw_minute; /* RTC + 0x1b */
54
55 u8 bus_error_1; /* RTC + 0x1c */
56 u8 int_day; /* RTC + 0x1d */
57 u8 int_min; /* RTC + 0x1e */
58 u8 int_sec; /* RTC + 0x1f */
59
60 /*
61 * target_time:
62 * intended to be used for hibernation but hibernation
63 * does not work on silicon rev 1.5 so use it for non-volatile
64 * storage of offset between the actual_time register and linux
65 * time
66 */
67 u32 target_time; /* RTC + 0x20 */
68 /*
69 * actual_time:
70 * readonly time since VBAT_RTC was last connected
71 */
72 u32 actual_time; /* RTC + 0x24 */
73 u32 keep_alive; /* RTC + 0x28 */
74 };
75
76 struct mpc5121_rtc_data {
77 unsigned irq;
78 unsigned irq_periodic;
79 struct mpc5121_rtc_regs __iomem *regs;
80 struct rtc_device *rtc;
81 struct rtc_wkalrm wkalarm;
82 };
83
84 /*
85 * Update second/minute/hour registers.
86 *
87 * This is just so alarm will work.
88 */
mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem * regs,struct rtc_time * tm)89 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
90 struct rtc_time *tm)
91 {
92 out_8(®s->second_set, tm->tm_sec);
93 out_8(®s->minute_set, tm->tm_min);
94 out_8(®s->hour_set, tm->tm_hour);
95
96 /* set time sequence */
97 out_8(®s->set_time, 0x1);
98 out_8(®s->set_time, 0x3);
99 out_8(®s->set_time, 0x1);
100 out_8(®s->set_time, 0x0);
101 }
102
mpc5121_rtc_read_time(struct device * dev,struct rtc_time * tm)103 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
104 {
105 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
106 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
107 unsigned long now;
108
109 /*
110 * linux time is actual_time plus the offset saved in target_time
111 */
112 now = in_be32(®s->actual_time) + in_be32(®s->target_time);
113
114 rtc_time_to_tm(now, tm);
115
116 /*
117 * update second minute hour registers
118 * so alarms will work
119 */
120 mpc5121_rtc_update_smh(regs, tm);
121
122 return 0;
123 }
124
mpc5121_rtc_set_time(struct device * dev,struct rtc_time * tm)125 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
126 {
127 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
128 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
129 int ret;
130 unsigned long now;
131
132 /*
133 * The actual_time register is read only so we write the offset
134 * between it and linux time to the target_time register.
135 */
136 ret = rtc_tm_to_time(tm, &now);
137 if (ret == 0)
138 out_be32(®s->target_time, now - in_be32(®s->actual_time));
139
140 /*
141 * update second minute hour registers
142 * so alarms will work
143 */
144 mpc5121_rtc_update_smh(regs, tm);
145
146 return 0;
147 }
148
mpc5200_rtc_read_time(struct device * dev,struct rtc_time * tm)149 static int mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm)
150 {
151 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
152 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
153 int tmp;
154
155 tm->tm_sec = in_8(®s->second);
156 tm->tm_min = in_8(®s->minute);
157
158 /* 12 hour format? */
159 if (in_8(®s->hour) & 0x20)
160 tm->tm_hour = (in_8(®s->hour) >> 1) +
161 (in_8(®s->hour) & 1 ? 12 : 0);
162 else
163 tm->tm_hour = in_8(®s->hour);
164
165 tmp = in_8(®s->wday_mday);
166 tm->tm_mday = tmp & 0x1f;
167 tm->tm_mon = in_8(®s->month) - 1;
168 tm->tm_year = in_be16(®s->year) - 1900;
169 tm->tm_wday = (tmp >> 5) % 7;
170 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
171 tm->tm_isdst = 0;
172
173 return 0;
174 }
175
mpc5200_rtc_set_time(struct device * dev,struct rtc_time * tm)176 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm)
177 {
178 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
179 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
180
181 mpc5121_rtc_update_smh(regs, tm);
182
183 /* date */
184 out_8(®s->month_set, tm->tm_mon + 1);
185 out_8(®s->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
186 out_8(®s->date_set, tm->tm_mday);
187 out_be16(®s->year_set, tm->tm_year + 1900);
188
189 /* set date sequence */
190 out_8(®s->set_date, 0x1);
191 out_8(®s->set_date, 0x3);
192 out_8(®s->set_date, 0x1);
193 out_8(®s->set_date, 0x0);
194
195 return 0;
196 }
197
mpc5121_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)198 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
199 {
200 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
201 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
202
203 *alarm = rtc->wkalarm;
204
205 alarm->pending = in_8(®s->alm_status);
206
207 return 0;
208 }
209
mpc5121_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)210 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
211 {
212 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
213 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
214
215 /*
216 * the alarm has no seconds so deal with it
217 */
218 if (alarm->time.tm_sec) {
219 alarm->time.tm_sec = 0;
220 alarm->time.tm_min++;
221 if (alarm->time.tm_min >= 60) {
222 alarm->time.tm_min = 0;
223 alarm->time.tm_hour++;
224 if (alarm->time.tm_hour >= 24)
225 alarm->time.tm_hour = 0;
226 }
227 }
228
229 alarm->time.tm_mday = -1;
230 alarm->time.tm_mon = -1;
231 alarm->time.tm_year = -1;
232
233 out_8(®s->alm_min_set, alarm->time.tm_min);
234 out_8(®s->alm_hour_set, alarm->time.tm_hour);
235
236 out_8(®s->alm_enable, alarm->enabled);
237
238 rtc->wkalarm = *alarm;
239 return 0;
240 }
241
mpc5121_rtc_handler(int irq,void * dev)242 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
243 {
244 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
245 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
246
247 if (in_8(®s->int_alm)) {
248 /* acknowledge and clear status */
249 out_8(®s->int_alm, 1);
250 out_8(®s->alm_status, 1);
251
252 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
253 return IRQ_HANDLED;
254 }
255
256 return IRQ_NONE;
257 }
258
mpc5121_rtc_handler_upd(int irq,void * dev)259 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
260 {
261 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
262 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
263
264 if (in_8(®s->int_sec) && (in_8(®s->int_enable) & 0x1)) {
265 /* acknowledge */
266 out_8(®s->int_sec, 1);
267
268 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
269 return IRQ_HANDLED;
270 }
271
272 return IRQ_NONE;
273 }
274
mpc5121_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)275 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
276 unsigned int enabled)
277 {
278 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
279 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
280 int val;
281
282 if (enabled)
283 val = 1;
284 else
285 val = 0;
286
287 out_8(®s->alm_enable, val);
288 rtc->wkalarm.enabled = val;
289
290 return 0;
291 }
292
293 static const struct rtc_class_ops mpc5121_rtc_ops = {
294 .read_time = mpc5121_rtc_read_time,
295 .set_time = mpc5121_rtc_set_time,
296 .read_alarm = mpc5121_rtc_read_alarm,
297 .set_alarm = mpc5121_rtc_set_alarm,
298 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
299 };
300
301 static const struct rtc_class_ops mpc5200_rtc_ops = {
302 .read_time = mpc5200_rtc_read_time,
303 .set_time = mpc5200_rtc_set_time,
304 .read_alarm = mpc5121_rtc_read_alarm,
305 .set_alarm = mpc5121_rtc_set_alarm,
306 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
307 };
308
mpc5121_rtc_probe(struct platform_device * op)309 static int mpc5121_rtc_probe(struct platform_device *op)
310 {
311 struct mpc5121_rtc_data *rtc;
312 int err = 0;
313
314 rtc = devm_kzalloc(&op->dev, sizeof(*rtc), GFP_KERNEL);
315 if (!rtc)
316 return -ENOMEM;
317
318 rtc->regs = of_iomap(op->dev.of_node, 0);
319 if (!rtc->regs) {
320 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
321 return -ENOSYS;
322 }
323
324 device_init_wakeup(&op->dev, 1);
325
326 platform_set_drvdata(op, rtc);
327
328 rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
329 err = request_irq(rtc->irq, mpc5121_rtc_handler, 0,
330 "mpc5121-rtc", &op->dev);
331 if (err) {
332 dev_err(&op->dev, "%s: could not request irq: %i\n",
333 __func__, rtc->irq);
334 goto out_dispose;
335 }
336
337 rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
338 err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
339 0, "mpc5121-rtc_upd", &op->dev);
340 if (err) {
341 dev_err(&op->dev, "%s: could not request irq: %i\n",
342 __func__, rtc->irq_periodic);
343 goto out_dispose2;
344 }
345
346 if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
347 u32 ka;
348 ka = in_be32(&rtc->regs->keep_alive);
349 if (ka & 0x02) {
350 dev_warn(&op->dev,
351 "mpc5121-rtc: Battery or oscillator failure!\n");
352 out_be32(&rtc->regs->keep_alive, ka);
353 }
354
355 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5121-rtc",
356 &mpc5121_rtc_ops, THIS_MODULE);
357 } else {
358 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5200-rtc",
359 &mpc5200_rtc_ops, THIS_MODULE);
360 }
361
362 if (IS_ERR(rtc->rtc)) {
363 err = PTR_ERR(rtc->rtc);
364 goto out_free_irq;
365 }
366 rtc->rtc->uie_unsupported = 1;
367
368 return 0;
369
370 out_free_irq:
371 free_irq(rtc->irq_periodic, &op->dev);
372 out_dispose2:
373 irq_dispose_mapping(rtc->irq_periodic);
374 free_irq(rtc->irq, &op->dev);
375 out_dispose:
376 irq_dispose_mapping(rtc->irq);
377 iounmap(rtc->regs);
378
379 return err;
380 }
381
mpc5121_rtc_remove(struct platform_device * op)382 static int mpc5121_rtc_remove(struct platform_device *op)
383 {
384 struct mpc5121_rtc_data *rtc = platform_get_drvdata(op);
385 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
386
387 /* disable interrupt, so there are no nasty surprises */
388 out_8(®s->alm_enable, 0);
389 out_8(®s->int_enable, in_8(®s->int_enable) & ~0x1);
390
391 iounmap(rtc->regs);
392 free_irq(rtc->irq, &op->dev);
393 free_irq(rtc->irq_periodic, &op->dev);
394 irq_dispose_mapping(rtc->irq);
395 irq_dispose_mapping(rtc->irq_periodic);
396
397 return 0;
398 }
399
400 #ifdef CONFIG_OF
401 static const struct of_device_id mpc5121_rtc_match[] = {
402 { .compatible = "fsl,mpc5121-rtc", },
403 { .compatible = "fsl,mpc5200-rtc", },
404 {},
405 };
406 MODULE_DEVICE_TABLE(of, mpc5121_rtc_match);
407 #endif
408
409 static struct platform_driver mpc5121_rtc_driver = {
410 .driver = {
411 .name = "mpc5121-rtc",
412 .of_match_table = of_match_ptr(mpc5121_rtc_match),
413 },
414 .probe = mpc5121_rtc_probe,
415 .remove = mpc5121_rtc_remove,
416 };
417
418 module_platform_driver(mpc5121_rtc_driver);
419
420 MODULE_LICENSE("GPL");
421 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");
422