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_time64_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 unsigned long now;
130
131 /*
132 * The actual_time register is read only so we write the offset
133 * between it and linux time to the target_time register.
134 */
135 now = rtc_tm_to_time64(tm);
136 out_be32(®s->target_time, now - in_be32(®s->actual_time));
137
138 /*
139 * update second minute hour registers
140 * so alarms will work
141 */
142 mpc5121_rtc_update_smh(regs, tm);
143
144 return 0;
145 }
146
mpc5200_rtc_read_time(struct device * dev,struct rtc_time * tm)147 static int mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm)
148 {
149 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
150 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
151 int tmp;
152
153 tm->tm_sec = in_8(®s->second);
154 tm->tm_min = in_8(®s->minute);
155
156 /* 12 hour format? */
157 if (in_8(®s->hour) & 0x20)
158 tm->tm_hour = (in_8(®s->hour) >> 1) +
159 (in_8(®s->hour) & 1 ? 12 : 0);
160 else
161 tm->tm_hour = in_8(®s->hour);
162
163 tmp = in_8(®s->wday_mday);
164 tm->tm_mday = tmp & 0x1f;
165 tm->tm_mon = in_8(®s->month) - 1;
166 tm->tm_year = in_be16(®s->year) - 1900;
167 tm->tm_wday = (tmp >> 5) % 7;
168 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
169 tm->tm_isdst = 0;
170
171 return 0;
172 }
173
mpc5200_rtc_set_time(struct device * dev,struct rtc_time * tm)174 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm)
175 {
176 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
177 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
178
179 mpc5121_rtc_update_smh(regs, tm);
180
181 /* date */
182 out_8(®s->month_set, tm->tm_mon + 1);
183 out_8(®s->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
184 out_8(®s->date_set, tm->tm_mday);
185 out_be16(®s->year_set, tm->tm_year + 1900);
186
187 /* set date sequence */
188 out_8(®s->set_date, 0x1);
189 out_8(®s->set_date, 0x3);
190 out_8(®s->set_date, 0x1);
191 out_8(®s->set_date, 0x0);
192
193 return 0;
194 }
195
mpc5121_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)196 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
197 {
198 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
199 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
200
201 *alarm = rtc->wkalarm;
202
203 alarm->pending = in_8(®s->alm_status);
204
205 return 0;
206 }
207
mpc5121_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)208 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
209 {
210 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
211 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
212
213 alarm->time.tm_mday = -1;
214 alarm->time.tm_mon = -1;
215 alarm->time.tm_year = -1;
216
217 out_8(®s->alm_min_set, alarm->time.tm_min);
218 out_8(®s->alm_hour_set, alarm->time.tm_hour);
219
220 out_8(®s->alm_enable, alarm->enabled);
221
222 rtc->wkalarm = *alarm;
223 return 0;
224 }
225
mpc5121_rtc_handler(int irq,void * dev)226 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
227 {
228 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
229 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
230
231 if (in_8(®s->int_alm)) {
232 /* acknowledge and clear status */
233 out_8(®s->int_alm, 1);
234 out_8(®s->alm_status, 1);
235
236 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
237 return IRQ_HANDLED;
238 }
239
240 return IRQ_NONE;
241 }
242
mpc5121_rtc_handler_upd(int irq,void * dev)243 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
244 {
245 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
246 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
247
248 if (in_8(®s->int_sec) && (in_8(®s->int_enable) & 0x1)) {
249 /* acknowledge */
250 out_8(®s->int_sec, 1);
251
252 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
253 return IRQ_HANDLED;
254 }
255
256 return IRQ_NONE;
257 }
258
mpc5121_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)259 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
260 unsigned int enabled)
261 {
262 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
263 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
264 int val;
265
266 if (enabled)
267 val = 1;
268 else
269 val = 0;
270
271 out_8(®s->alm_enable, val);
272 rtc->wkalarm.enabled = val;
273
274 return 0;
275 }
276
277 static const struct rtc_class_ops mpc5121_rtc_ops = {
278 .read_time = mpc5121_rtc_read_time,
279 .set_time = mpc5121_rtc_set_time,
280 .read_alarm = mpc5121_rtc_read_alarm,
281 .set_alarm = mpc5121_rtc_set_alarm,
282 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
283 };
284
285 static const struct rtc_class_ops mpc5200_rtc_ops = {
286 .read_time = mpc5200_rtc_read_time,
287 .set_time = mpc5200_rtc_set_time,
288 .read_alarm = mpc5121_rtc_read_alarm,
289 .set_alarm = mpc5121_rtc_set_alarm,
290 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
291 };
292
mpc5121_rtc_probe(struct platform_device * op)293 static int mpc5121_rtc_probe(struct platform_device *op)
294 {
295 struct mpc5121_rtc_data *rtc;
296 int err = 0;
297
298 rtc = devm_kzalloc(&op->dev, sizeof(*rtc), GFP_KERNEL);
299 if (!rtc)
300 return -ENOMEM;
301
302 rtc->regs = devm_platform_ioremap_resource(op, 0);
303 if (IS_ERR(rtc->regs)) {
304 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
305 return PTR_ERR(rtc->regs);
306 }
307
308 device_init_wakeup(&op->dev, 1);
309
310 platform_set_drvdata(op, rtc);
311
312 rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
313 err = devm_request_irq(&op->dev, rtc->irq, mpc5121_rtc_handler, 0,
314 "mpc5121-rtc", &op->dev);
315 if (err) {
316 dev_err(&op->dev, "%s: could not request irq: %i\n",
317 __func__, rtc->irq);
318 goto out_dispose;
319 }
320
321 rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
322 err = devm_request_irq(&op->dev, rtc->irq_periodic,
323 mpc5121_rtc_handler_upd, 0, "mpc5121-rtc_upd",
324 &op->dev);
325 if (err) {
326 dev_err(&op->dev, "%s: could not request irq: %i\n",
327 __func__, rtc->irq_periodic);
328 goto out_dispose2;
329 }
330
331 rtc->rtc = devm_rtc_allocate_device(&op->dev);
332 if (IS_ERR(rtc->rtc)) {
333 err = PTR_ERR(rtc->rtc);
334 goto out_dispose2;
335 }
336
337 rtc->rtc->ops = &mpc5200_rtc_ops;
338 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtc->features);
339 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtc->features);
340 rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_0000;
341 rtc->rtc->range_max = 65733206399ULL; /* 4052-12-31 23:59:59 */
342
343 if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
344 u32 ka;
345 ka = in_be32(&rtc->regs->keep_alive);
346 if (ka & 0x02) {
347 dev_warn(&op->dev,
348 "mpc5121-rtc: Battery or oscillator failure!\n");
349 out_be32(&rtc->regs->keep_alive, ka);
350 }
351 rtc->rtc->ops = &mpc5121_rtc_ops;
352 /*
353 * This is a limitation of the driver that abuses the target
354 * time register, the actual maximum year for the mpc5121 is
355 * also 4052.
356 */
357 rtc->rtc->range_min = 0;
358 rtc->rtc->range_max = U32_MAX;
359 }
360
361 err = devm_rtc_register_device(rtc->rtc);
362 if (err)
363 goto out_dispose2;
364
365 return 0;
366
367 out_dispose2:
368 irq_dispose_mapping(rtc->irq_periodic);
369 out_dispose:
370 irq_dispose_mapping(rtc->irq);
371
372 return err;
373 }
374
mpc5121_rtc_remove(struct platform_device * op)375 static int mpc5121_rtc_remove(struct platform_device *op)
376 {
377 struct mpc5121_rtc_data *rtc = platform_get_drvdata(op);
378 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
379
380 /* disable interrupt, so there are no nasty surprises */
381 out_8(®s->alm_enable, 0);
382 out_8(®s->int_enable, in_8(®s->int_enable) & ~0x1);
383
384 irq_dispose_mapping(rtc->irq);
385 irq_dispose_mapping(rtc->irq_periodic);
386
387 return 0;
388 }
389
390 #ifdef CONFIG_OF
391 static const struct of_device_id mpc5121_rtc_match[] = {
392 { .compatible = "fsl,mpc5121-rtc", },
393 { .compatible = "fsl,mpc5200-rtc", },
394 {},
395 };
396 MODULE_DEVICE_TABLE(of, mpc5121_rtc_match);
397 #endif
398
399 static struct platform_driver mpc5121_rtc_driver = {
400 .driver = {
401 .name = "mpc5121-rtc",
402 .of_match_table = of_match_ptr(mpc5121_rtc_match),
403 },
404 .probe = mpc5121_rtc_probe,
405 .remove = mpc5121_rtc_remove,
406 };
407
408 module_platform_driver(mpc5121_rtc_driver);
409
410 MODULE_LICENSE("GPL");
411 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");
412