xref: /openbmc/linux/drivers/rtc/rtc-mpc5121.c (revision 48144c28)
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(&regs->second_set, tm->tm_sec);
91 	out_8(&regs->minute_set, tm->tm_min);
92 	out_8(&regs->hour_set, tm->tm_hour);
93 
94 	/* set time sequence */
95 	out_8(&regs->set_time, 0x1);
96 	out_8(&regs->set_time, 0x3);
97 	out_8(&regs->set_time, 0x1);
98 	out_8(&regs->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(&regs->actual_time) + in_be32(&regs->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(&regs->target_time, now - in_be32(&regs->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(&regs->second);
152 	tm->tm_min = in_8(&regs->minute);
153 
154 	/* 12 hour format? */
155 	if (in_8(&regs->hour) & 0x20)
156 		tm->tm_hour = (in_8(&regs->hour) >> 1) +
157 			(in_8(&regs->hour) & 1 ? 12 : 0);
158 	else
159 		tm->tm_hour = in_8(&regs->hour);
160 
161 	tmp = in_8(&regs->wday_mday);
162 	tm->tm_mday = tmp & 0x1f;
163 	tm->tm_mon = in_8(&regs->month) - 1;
164 	tm->tm_year = in_be16(&regs->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(&regs->month_set, tm->tm_mon + 1);
181 	out_8(&regs->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
182 	out_8(&regs->date_set, tm->tm_mday);
183 	out_be16(&regs->year_set, tm->tm_year + 1900);
184 
185 	/* set date sequence */
186 	out_8(&regs->set_date, 0x1);
187 	out_8(&regs->set_date, 0x3);
188 	out_8(&regs->set_date, 0x1);
189 	out_8(&regs->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(&regs->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(&regs->alm_min_set, alarm->time.tm_min);
216 	out_8(&regs->alm_hour_set, alarm->time.tm_hour);
217 
218 	out_8(&regs->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(&regs->int_alm)) {
230 		/* acknowledge and clear status */
231 		out_8(&regs->int_alm, 1);
232 		out_8(&regs->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(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
247 		/* acknowledge */
248 		out_8(&regs->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(&regs->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(&regs->alm_enable, 0);
380 	out_8(&regs->int_enable, in_8(&regs->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_new = mpc5121_rtc_remove,
402 };
403 
404 module_platform_driver(mpc5121_rtc_driver);
405 
406 MODULE_LICENSE("GPL");
407 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");
408