1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * RTC driver for Maxim MAX8925
4 *
5 * Copyright (C) 2009-2010 Marvell International Ltd.
6 *	Haojian Zhuang <haojian.zhuang@marvell.com>
7 */
8
9#include <linux/module.h>
10#include <linux/i2c.h>
11#include <linux/slab.h>
12#include <linux/rtc.h>
13#include <linux/platform_device.h>
14#include <linux/mfd/max8925.h>
15
16enum {
17	RTC_SEC = 0,
18	RTC_MIN,
19	RTC_HOUR,
20	RTC_WEEKDAY,
21	RTC_DATE,
22	RTC_MONTH,
23	RTC_YEAR1,
24	RTC_YEAR2,
25};
26
27#define MAX8925_RTC_SEC			0x00
28#define MAX8925_RTC_MIN			0x01
29#define MAX8925_RTC_HOUR		0x02
30#define MAX8925_RTC_WEEKDAY		0x03
31#define MAX8925_RTC_DATE		0x04
32#define MAX8925_RTC_MONTH		0x05
33#define MAX8925_RTC_YEAR1		0x06
34#define MAX8925_RTC_YEAR2		0x07
35#define MAX8925_ALARM0_SEC		0x08
36#define MAX8925_ALARM0_MIN		0x09
37#define MAX8925_ALARM0_HOUR		0x0a
38#define MAX8925_ALARM0_WEEKDAY		0x0b
39#define MAX8925_ALARM0_DATE		0x0c
40#define MAX8925_ALARM0_MON		0x0d
41#define MAX8925_ALARM0_YEAR1		0x0e
42#define MAX8925_ALARM0_YEAR2		0x0f
43#define MAX8925_ALARM1_SEC		0x10
44#define MAX8925_ALARM1_MIN		0x11
45#define MAX8925_ALARM1_HOUR		0x12
46#define MAX8925_ALARM1_WEEKDAY		0x13
47#define MAX8925_ALARM1_DATE		0x14
48#define MAX8925_ALARM1_MON		0x15
49#define MAX8925_ALARM1_YEAR1		0x16
50#define MAX8925_ALARM1_YEAR2		0x17
51#define MAX8925_RTC_CNTL		0x1b
52#define MAX8925_RTC_STATUS		0x20
53
54#define TIME_NUM			8
55#define ALARM_1SEC			(1 << 7)
56#define HOUR_12				(1 << 7)
57#define HOUR_AM_PM			(1 << 5)
58#define ALARM0_IRQ			(1 << 3)
59#define ALARM1_IRQ			(1 << 2)
60#define ALARM0_STATUS			(1 << 2)
61#define ALARM1_STATUS			(1 << 1)
62
63
64struct max8925_rtc_info {
65	struct rtc_device	*rtc_dev;
66	struct max8925_chip	*chip;
67	struct i2c_client	*rtc;
68	struct device		*dev;
69	int			irq;
70};
71
72static irqreturn_t rtc_update_handler(int irq, void *data)
73{
74	struct max8925_rtc_info *info = (struct max8925_rtc_info *)data;
75
76	/* disable ALARM0 except for 1SEC alarm */
77	max8925_set_bits(info->rtc, MAX8925_ALARM0_CNTL, 0x7f, 0);
78	rtc_update_irq(info->rtc_dev, 1, RTC_IRQF | RTC_AF);
79	return IRQ_HANDLED;
80}
81
82static int tm_calc(struct rtc_time *tm, unsigned char *buf, int len)
83{
84	if (len < TIME_NUM)
85		return -EINVAL;
86	tm->tm_year = (buf[RTC_YEAR2] >> 4) * 1000
87			+ (buf[RTC_YEAR2] & 0xf) * 100
88			+ (buf[RTC_YEAR1] >> 4) * 10
89			+ (buf[RTC_YEAR1] & 0xf);
90	tm->tm_year -= 1900;
91	tm->tm_mon = ((buf[RTC_MONTH] >> 4) & 0x01) * 10
92			+ (buf[RTC_MONTH] & 0x0f);
93	tm->tm_mday = ((buf[RTC_DATE] >> 4) & 0x03) * 10
94			+ (buf[RTC_DATE] & 0x0f);
95	tm->tm_wday = buf[RTC_WEEKDAY] & 0x07;
96	if (buf[RTC_HOUR] & HOUR_12) {
97		tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x1) * 10
98				+ (buf[RTC_HOUR] & 0x0f);
99		if (buf[RTC_HOUR] & HOUR_AM_PM)
100			tm->tm_hour += 12;
101	} else
102		tm->tm_hour = ((buf[RTC_HOUR] >> 4) & 0x03) * 10
103				+ (buf[RTC_HOUR] & 0x0f);
104	tm->tm_min = ((buf[RTC_MIN] >> 4) & 0x7) * 10
105			+ (buf[RTC_MIN] & 0x0f);
106	tm->tm_sec = ((buf[RTC_SEC] >> 4) & 0x7) * 10
107			+ (buf[RTC_SEC] & 0x0f);
108	return 0;
109}
110
111static int data_calc(unsigned char *buf, struct rtc_time *tm, int len)
112{
113	unsigned char high, low;
114
115	if (len < TIME_NUM)
116		return -EINVAL;
117
118	high = (tm->tm_year + 1900) / 1000;
119	low = (tm->tm_year + 1900) / 100;
120	low = low - high * 10;
121	buf[RTC_YEAR2] = (high << 4) + low;
122	high = (tm->tm_year + 1900) / 10;
123	low = tm->tm_year + 1900;
124	low = low - high * 10;
125	high = high - (high / 10) * 10;
126	buf[RTC_YEAR1] = (high << 4) + low;
127	high = tm->tm_mon / 10;
128	low = tm->tm_mon;
129	low = low - high * 10;
130	buf[RTC_MONTH] = (high << 4) + low;
131	high = tm->tm_mday / 10;
132	low = tm->tm_mday;
133	low = low - high * 10;
134	buf[RTC_DATE] = (high << 4) + low;
135	buf[RTC_WEEKDAY] = tm->tm_wday;
136	high = tm->tm_hour / 10;
137	low = tm->tm_hour;
138	low = low - high * 10;
139	buf[RTC_HOUR] = (high << 4) + low;
140	high = tm->tm_min / 10;
141	low = tm->tm_min;
142	low = low - high * 10;
143	buf[RTC_MIN] = (high << 4) + low;
144	high = tm->tm_sec / 10;
145	low = tm->tm_sec;
146	low = low - high * 10;
147	buf[RTC_SEC] = (high << 4) + low;
148	return 0;
149}
150
151static int max8925_rtc_read_time(struct device *dev, struct rtc_time *tm)
152{
153	struct max8925_rtc_info *info = dev_get_drvdata(dev);
154	unsigned char buf[TIME_NUM];
155	int ret;
156
157	ret = max8925_bulk_read(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
158	if (ret < 0)
159		goto out;
160	ret = tm_calc(tm, buf, TIME_NUM);
161out:
162	return ret;
163}
164
165static int max8925_rtc_set_time(struct device *dev, struct rtc_time *tm)
166{
167	struct max8925_rtc_info *info = dev_get_drvdata(dev);
168	unsigned char buf[TIME_NUM];
169	int ret;
170
171	ret = data_calc(buf, tm, TIME_NUM);
172	if (ret < 0)
173		goto out;
174	ret = max8925_bulk_write(info->rtc, MAX8925_RTC_SEC, TIME_NUM, buf);
175out:
176	return ret;
177}
178
179static int max8925_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
180{
181	struct max8925_rtc_info *info = dev_get_drvdata(dev);
182	unsigned char buf[TIME_NUM];
183	int ret;
184
185	ret = max8925_bulk_read(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
186	if (ret < 0)
187		goto out;
188	ret = tm_calc(&alrm->time, buf, TIME_NUM);
189	if (ret < 0)
190		goto out;
191	ret = max8925_reg_read(info->rtc, MAX8925_RTC_IRQ_MASK);
192	if (ret < 0)
193		goto out;
194	if (ret & ALARM0_IRQ) {
195		alrm->enabled = 0;
196	} else {
197		ret = max8925_reg_read(info->rtc, MAX8925_ALARM0_CNTL);
198		if (ret < 0)
199			goto out;
200		if (!ret)
201			alrm->enabled = 0;
202		else
203			alrm->enabled = 1;
204	}
205	ret = max8925_reg_read(info->rtc, MAX8925_RTC_STATUS);
206	if (ret < 0)
207		goto out;
208	if (ret & ALARM0_STATUS)
209		alrm->pending = 1;
210	else
211		alrm->pending = 0;
212	return 0;
213out:
214	return ret;
215}
216
217static int max8925_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
218{
219	struct max8925_rtc_info *info = dev_get_drvdata(dev);
220	unsigned char buf[TIME_NUM];
221	int ret;
222
223	ret = data_calc(buf, &alrm->time, TIME_NUM);
224	if (ret < 0)
225		goto out;
226	ret = max8925_bulk_write(info->rtc, MAX8925_ALARM0_SEC, TIME_NUM, buf);
227	if (ret < 0)
228		goto out;
229	if (alrm->enabled)
230		/* only enable alarm on year/month/day/hour/min/sec */
231		ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x77);
232	else
233		ret = max8925_reg_write(info->rtc, MAX8925_ALARM0_CNTL, 0x0);
234out:
235	return ret;
236}
237
238static const struct rtc_class_ops max8925_rtc_ops = {
239	.read_time	= max8925_rtc_read_time,
240	.set_time	= max8925_rtc_set_time,
241	.read_alarm	= max8925_rtc_read_alarm,
242	.set_alarm	= max8925_rtc_set_alarm,
243};
244
245static int max8925_rtc_probe(struct platform_device *pdev)
246{
247	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
248	struct max8925_rtc_info *info;
249	int ret;
250
251	info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_rtc_info),
252			    GFP_KERNEL);
253	if (!info)
254		return -ENOMEM;
255	info->chip = chip;
256	info->rtc = chip->rtc;
257	info->dev = &pdev->dev;
258	info->irq = platform_get_irq(pdev, 0);
259
260	ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
261					rtc_update_handler, IRQF_ONESHOT,
262					"rtc-alarm0", info);
263	if (ret < 0) {
264		dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
265			info->irq, ret);
266		return ret;
267	}
268
269	dev_set_drvdata(&pdev->dev, info);
270	/* XXX - isn't this redundant? */
271	platform_set_drvdata(pdev, info);
272
273	device_init_wakeup(&pdev->dev, 1);
274
275	info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8925-rtc",
276					&max8925_rtc_ops, THIS_MODULE);
277	ret = PTR_ERR(info->rtc_dev);
278	if (IS_ERR(info->rtc_dev)) {
279		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
280		return ret;
281	}
282
283	return 0;
284}
285
286#ifdef CONFIG_PM_SLEEP
287static int max8925_rtc_suspend(struct device *dev)
288{
289	struct platform_device *pdev = to_platform_device(dev);
290	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
291
292	if (device_may_wakeup(dev))
293		chip->wakeup_flag |= 1 << MAX8925_IRQ_RTC_ALARM0;
294	return 0;
295}
296static int max8925_rtc_resume(struct device *dev)
297{
298	struct platform_device *pdev = to_platform_device(dev);
299	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
300
301	if (device_may_wakeup(dev))
302		chip->wakeup_flag &= ~(1 << MAX8925_IRQ_RTC_ALARM0);
303	return 0;
304}
305#endif
306
307static SIMPLE_DEV_PM_OPS(max8925_rtc_pm_ops, max8925_rtc_suspend, max8925_rtc_resume);
308
309static struct platform_driver max8925_rtc_driver = {
310	.driver		= {
311		.name	= "max8925-rtc",
312		.pm     = &max8925_rtc_pm_ops,
313	},
314	.probe		= max8925_rtc_probe,
315};
316
317module_platform_driver(max8925_rtc_driver);
318
319MODULE_DESCRIPTION("Maxim MAX8925 RTC driver");
320MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
321MODULE_LICENSE("GPL");
322
323