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
24struct 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
79struct 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 */
92static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
93				   struct rtc_time *tm)
94{
95	out_8(&regs->second_set, tm->tm_sec);
96	out_8(&regs->minute_set, tm->tm_min);
97	out_8(&regs->hour_set, tm->tm_hour);
98
99	/* set time sequence */
100	out_8(&regs->set_time, 0x1);
101	out_8(&regs->set_time, 0x3);
102	out_8(&regs->set_time, 0x1);
103	out_8(&regs->set_time, 0x0);
104}
105
106static 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(&regs->actual_time) + in_be32(&regs->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
128static 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(&regs->target_time, now - in_be32(&regs->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
152static 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(&regs->second);
159	tm->tm_min = in_8(&regs->minute);
160
161	/* 12 hour format? */
162	if (in_8(&regs->hour) & 0x20)
163		tm->tm_hour = (in_8(&regs->hour) >> 1) +
164			(in_8(&regs->hour) & 1 ? 12 : 0);
165	else
166		tm->tm_hour = in_8(&regs->hour);
167
168	tmp = in_8(&regs->wday_mday);
169	tm->tm_mday = tmp & 0x1f;
170	tm->tm_mon = in_8(&regs->month) - 1;
171	tm->tm_year = in_be16(&regs->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
179static 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(&regs->month_set, tm->tm_mon + 1);
188	out_8(&regs->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
189	out_8(&regs->date_set, tm->tm_mday);
190	out_be16(&regs->year_set, tm->tm_year + 1900);
191
192	/* set date sequence */
193	out_8(&regs->set_date, 0x1);
194	out_8(&regs->set_date, 0x3);
195	out_8(&regs->set_date, 0x1);
196	out_8(&regs->set_date, 0x0);
197
198	return 0;
199}
200
201static 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(&regs->alm_status);
209
210	return 0;
211}
212
213static 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(&regs->alm_min_set, alarm->time.tm_min);
237	out_8(&regs->alm_hour_set, alarm->time.tm_hour);
238
239	out_8(&regs->alm_enable, alarm->enabled);
240
241	rtc->wkalarm = *alarm;
242	return 0;
243}
244
245static 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(&regs->int_alm)) {
251		/* acknowledge and clear status */
252		out_8(&regs->int_alm, 1);
253		out_8(&regs->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
262static 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(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
268		/* acknowledge */
269		out_8(&regs->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
278static 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(&regs->alm_enable, val);
291	rtc->wkalarm.enabled = val;
292
293	return 0;
294}
295
296static 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
304static 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
312static 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
373out_free_irq:
374	free_irq(rtc->irq_periodic, &op->dev);
375out_dispose2:
376	irq_dispose_mapping(rtc->irq_periodic);
377	free_irq(rtc->irq, &op->dev);
378out_dispose:
379	irq_dispose_mapping(rtc->irq);
380	iounmap(rtc->regs);
381
382	return err;
383}
384
385static 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(&regs->alm_enable, 0);
392	out_8(&regs->int_enable, in_8(&regs->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
404static const struct of_device_id mpc5121_rtc_match[] = {
405	{ .compatible = "fsl,mpc5121-rtc", },
406	{ .compatible = "fsl,mpc5200-rtc", },
407	{},
408};
409MODULE_DEVICE_TABLE(of, mpc5121_rtc_match);
410#endif
411
412static 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
421module_platform_driver(mpc5121_rtc_driver);
422
423MODULE_LICENSE("GPL");
424MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");
425