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_irq.h>
15 #include <linux/platform_device.h>
16 #include <linux/io.h>
17 #include <linux/slab.h>
18
19 struct mpc5121_rtc_regs {
20 u8 set_time; /* RTC + 0x00 */
21 u8 hour_set; /* RTC + 0x01 */
22 u8 minute_set; /* RTC + 0x02 */
23 u8 second_set; /* RTC + 0x03 */
24
25 u8 set_date; /* RTC + 0x04 */
26 u8 month_set; /* RTC + 0x05 */
27 u8 weekday_set; /* RTC + 0x06 */
28 u8 date_set; /* RTC + 0x07 */
29
30 u8 write_sw; /* RTC + 0x08 */
31 u8 sw_set; /* RTC + 0x09 */
32 u16 year_set; /* RTC + 0x0a */
33
34 u8 alm_enable; /* RTC + 0x0c */
35 u8 alm_hour_set; /* RTC + 0x0d */
36 u8 alm_min_set; /* RTC + 0x0e */
37 u8 int_enable; /* RTC + 0x0f */
38
39 u8 reserved1;
40 u8 hour; /* RTC + 0x11 */
41 u8 minute; /* RTC + 0x12 */
42 u8 second; /* RTC + 0x13 */
43
44 u8 month; /* RTC + 0x14 */
45 u8 wday_mday; /* RTC + 0x15 */
46 u16 year; /* RTC + 0x16 */
47
48 u8 int_alm; /* RTC + 0x18 */
49 u8 int_sw; /* RTC + 0x19 */
50 u8 alm_status; /* RTC + 0x1a */
51 u8 sw_minute; /* RTC + 0x1b */
52
53 u8 bus_error_1; /* RTC + 0x1c */
54 u8 int_day; /* RTC + 0x1d */
55 u8 int_min; /* RTC + 0x1e */
56 u8 int_sec; /* RTC + 0x1f */
57
58 /*
59 * target_time:
60 * intended to be used for hibernation but hibernation
61 * does not work on silicon rev 1.5 so use it for non-volatile
62 * storage of offset between the actual_time register and linux
63 * time
64 */
65 u32 target_time; /* RTC + 0x20 */
66 /*
67 * actual_time:
68 * readonly time since VBAT_RTC was last connected
69 */
70 u32 actual_time; /* RTC + 0x24 */
71 u32 keep_alive; /* RTC + 0x28 */
72 };
73
74 struct mpc5121_rtc_data {
75 unsigned irq;
76 unsigned irq_periodic;
77 struct mpc5121_rtc_regs __iomem *regs;
78 struct rtc_device *rtc;
79 struct rtc_wkalrm wkalarm;
80 };
81
82 /*
83 * Update second/minute/hour registers.
84 *
85 * This is just so alarm will work.
86 */
mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem * regs,struct rtc_time * tm)87 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
88 struct rtc_time *tm)
89 {
90 out_8(®s->second_set, tm->tm_sec);
91 out_8(®s->minute_set, tm->tm_min);
92 out_8(®s->hour_set, tm->tm_hour);
93
94 /* set time sequence */
95 out_8(®s->set_time, 0x1);
96 out_8(®s->set_time, 0x3);
97 out_8(®s->set_time, 0x1);
98 out_8(®s->set_time, 0x0);
99 }
100
mpc5121_rtc_read_time(struct device * dev,struct rtc_time * tm)101 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
102 {
103 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
104 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
105 unsigned long now;
106
107 /*
108 * linux time is actual_time plus the offset saved in target_time
109 */
110 now = in_be32(®s->actual_time) + in_be32(®s->target_time);
111
112 rtc_time64_to_tm(now, tm);
113
114 /*
115 * update second minute hour registers
116 * so alarms will work
117 */
118 mpc5121_rtc_update_smh(regs, tm);
119
120 return 0;
121 }
122
mpc5121_rtc_set_time(struct device * dev,struct rtc_time * tm)123 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
124 {
125 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
126 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
127 unsigned long now;
128
129 /*
130 * The actual_time register is read only so we write the offset
131 * between it and linux time to the target_time register.
132 */
133 now = rtc_tm_to_time64(tm);
134 out_be32(®s->target_time, now - in_be32(®s->actual_time));
135
136 /*
137 * update second minute hour registers
138 * so alarms will work
139 */
140 mpc5121_rtc_update_smh(regs, tm);
141
142 return 0;
143 }
144
mpc5200_rtc_read_time(struct device * dev,struct rtc_time * tm)145 static int mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm)
146 {
147 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
148 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
149 int tmp;
150
151 tm->tm_sec = in_8(®s->second);
152 tm->tm_min = in_8(®s->minute);
153
154 /* 12 hour format? */
155 if (in_8(®s->hour) & 0x20)
156 tm->tm_hour = (in_8(®s->hour) >> 1) +
157 (in_8(®s->hour) & 1 ? 12 : 0);
158 else
159 tm->tm_hour = in_8(®s->hour);
160
161 tmp = in_8(®s->wday_mday);
162 tm->tm_mday = tmp & 0x1f;
163 tm->tm_mon = in_8(®s->month) - 1;
164 tm->tm_year = in_be16(®s->year) - 1900;
165 tm->tm_wday = (tmp >> 5) % 7;
166 tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
167 tm->tm_isdst = 0;
168
169 return 0;
170 }
171
mpc5200_rtc_set_time(struct device * dev,struct rtc_time * tm)172 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm)
173 {
174 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
175 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
176
177 mpc5121_rtc_update_smh(regs, tm);
178
179 /* date */
180 out_8(®s->month_set, tm->tm_mon + 1);
181 out_8(®s->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
182 out_8(®s->date_set, tm->tm_mday);
183 out_be16(®s->year_set, tm->tm_year + 1900);
184
185 /* set date sequence */
186 out_8(®s->set_date, 0x1);
187 out_8(®s->set_date, 0x3);
188 out_8(®s->set_date, 0x1);
189 out_8(®s->set_date, 0x0);
190
191 return 0;
192 }
193
mpc5121_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)194 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
195 {
196 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
197 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
198
199 *alarm = rtc->wkalarm;
200
201 alarm->pending = in_8(®s->alm_status);
202
203 return 0;
204 }
205
mpc5121_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)206 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
207 {
208 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
209 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
210
211 alarm->time.tm_mday = -1;
212 alarm->time.tm_mon = -1;
213 alarm->time.tm_year = -1;
214
215 out_8(®s->alm_min_set, alarm->time.tm_min);
216 out_8(®s->alm_hour_set, alarm->time.tm_hour);
217
218 out_8(®s->alm_enable, alarm->enabled);
219
220 rtc->wkalarm = *alarm;
221 return 0;
222 }
223
mpc5121_rtc_handler(int irq,void * dev)224 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
225 {
226 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
227 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
228
229 if (in_8(®s->int_alm)) {
230 /* acknowledge and clear status */
231 out_8(®s->int_alm, 1);
232 out_8(®s->alm_status, 1);
233
234 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
235 return IRQ_HANDLED;
236 }
237
238 return IRQ_NONE;
239 }
240
mpc5121_rtc_handler_upd(int irq,void * dev)241 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
242 {
243 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
244 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
245
246 if (in_8(®s->int_sec) && (in_8(®s->int_enable) & 0x1)) {
247 /* acknowledge */
248 out_8(®s->int_sec, 1);
249
250 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
251 return IRQ_HANDLED;
252 }
253
254 return IRQ_NONE;
255 }
256
mpc5121_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)257 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
258 unsigned int enabled)
259 {
260 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
261 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
262 int val;
263
264 if (enabled)
265 val = 1;
266 else
267 val = 0;
268
269 out_8(®s->alm_enable, val);
270 rtc->wkalarm.enabled = val;
271
272 return 0;
273 }
274
275 static const struct rtc_class_ops mpc5121_rtc_ops = {
276 .read_time = mpc5121_rtc_read_time,
277 .set_time = mpc5121_rtc_set_time,
278 .read_alarm = mpc5121_rtc_read_alarm,
279 .set_alarm = mpc5121_rtc_set_alarm,
280 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
281 };
282
283 static const struct rtc_class_ops mpc5200_rtc_ops = {
284 .read_time = mpc5200_rtc_read_time,
285 .set_time = mpc5200_rtc_set_time,
286 .read_alarm = mpc5121_rtc_read_alarm,
287 .set_alarm = mpc5121_rtc_set_alarm,
288 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
289 };
290
mpc5121_rtc_probe(struct platform_device * op)291 static int mpc5121_rtc_probe(struct platform_device *op)
292 {
293 struct mpc5121_rtc_data *rtc;
294 int err = 0;
295
296 rtc = devm_kzalloc(&op->dev, sizeof(*rtc), GFP_KERNEL);
297 if (!rtc)
298 return -ENOMEM;
299
300 rtc->regs = devm_platform_ioremap_resource(op, 0);
301 if (IS_ERR(rtc->regs)) {
302 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
303 return PTR_ERR(rtc->regs);
304 }
305
306 device_init_wakeup(&op->dev, 1);
307
308 platform_set_drvdata(op, rtc);
309
310 rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
311 err = devm_request_irq(&op->dev, rtc->irq, mpc5121_rtc_handler, 0,
312 "mpc5121-rtc", &op->dev);
313 if (err) {
314 dev_err(&op->dev, "%s: could not request irq: %i\n",
315 __func__, rtc->irq);
316 goto out_dispose;
317 }
318
319 rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
320 err = devm_request_irq(&op->dev, rtc->irq_periodic,
321 mpc5121_rtc_handler_upd, 0, "mpc5121-rtc_upd",
322 &op->dev);
323 if (err) {
324 dev_err(&op->dev, "%s: could not request irq: %i\n",
325 __func__, rtc->irq_periodic);
326 goto out_dispose2;
327 }
328
329 rtc->rtc = devm_rtc_allocate_device(&op->dev);
330 if (IS_ERR(rtc->rtc)) {
331 err = PTR_ERR(rtc->rtc);
332 goto out_dispose2;
333 }
334
335 rtc->rtc->ops = &mpc5200_rtc_ops;
336 set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->rtc->features);
337 clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->rtc->features);
338 rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_0000;
339 rtc->rtc->range_max = 65733206399ULL; /* 4052-12-31 23:59:59 */
340
341 if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
342 u32 ka;
343 ka = in_be32(&rtc->regs->keep_alive);
344 if (ka & 0x02) {
345 dev_warn(&op->dev,
346 "mpc5121-rtc: Battery or oscillator failure!\n");
347 out_be32(&rtc->regs->keep_alive, ka);
348 }
349 rtc->rtc->ops = &mpc5121_rtc_ops;
350 /*
351 * This is a limitation of the driver that abuses the target
352 * time register, the actual maximum year for the mpc5121 is
353 * also 4052.
354 */
355 rtc->rtc->range_min = 0;
356 rtc->rtc->range_max = U32_MAX;
357 }
358
359 err = devm_rtc_register_device(rtc->rtc);
360 if (err)
361 goto out_dispose2;
362
363 return 0;
364
365 out_dispose2:
366 irq_dispose_mapping(rtc->irq_periodic);
367 out_dispose:
368 irq_dispose_mapping(rtc->irq);
369
370 return err;
371 }
372
mpc5121_rtc_remove(struct platform_device * op)373 static void mpc5121_rtc_remove(struct platform_device *op)
374 {
375 struct mpc5121_rtc_data *rtc = platform_get_drvdata(op);
376 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
377
378 /* disable interrupt, so there are no nasty surprises */
379 out_8(®s->alm_enable, 0);
380 out_8(®s->int_enable, in_8(®s->int_enable) & ~0x1);
381
382 irq_dispose_mapping(rtc->irq);
383 irq_dispose_mapping(rtc->irq_periodic);
384 }
385
386 #ifdef CONFIG_OF
387 static const struct of_device_id mpc5121_rtc_match[] = {
388 { .compatible = "fsl,mpc5121-rtc", },
389 { .compatible = "fsl,mpc5200-rtc", },
390 {},
391 };
392 MODULE_DEVICE_TABLE(of, mpc5121_rtc_match);
393 #endif
394
395 static struct platform_driver mpc5121_rtc_driver = {
396 .driver = {
397 .name = "mpc5121-rtc",
398 .of_match_table = of_match_ptr(mpc5121_rtc_match),
399 },
400 .probe = mpc5121_rtc_probe,
401 .remove = mpc5121_rtc_remove,
402 };
403
404 module_platform_driver(mpc5121_rtc_driver);
405
406 MODULE_DESCRIPTION("Freescale MPC5121 built-in RTC driver");
407 MODULE_LICENSE("GPL");
408 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");
409