summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-max8907.c
blob: 86afb797125dc4de28c643afaab1785375d47ca6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
/*
 * RTC driver for Maxim MAX8907
 *
 * Copyright (c) 2011-2012, NVIDIA Corporation.
 *
 * Based on drivers/rtc/rtc-max8925.c,
 * Copyright (C) 2009-2010 Marvell International Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/bcd.h>
#include <linux/i2c.h>
#include <linux/mfd/max8907.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/rtc.h>
#include <linux/slab.h>

enum {
	RTC_SEC = 0,
	RTC_MIN,
	RTC_HOUR,
	RTC_WEEKDAY,
	RTC_DATE,
	RTC_MONTH,
	RTC_YEAR1,
	RTC_YEAR2,
};

#define TIME_NUM			8
#define ALARM_1SEC			(1 << 7)
#define HOUR_12				(1 << 7)
#define HOUR_AM_PM			(1 << 5)
#define ALARM0_IRQ			(1 << 3)
#define ALARM1_IRQ			(1 << 2)
#define ALARM0_STATUS			(1 << 2)
#define ALARM1_STATUS			(1 << 1)

struct max8907_rtc {
	struct max8907		*max8907;
	struct regmap		*regmap;
	struct rtc_device	*rtc_dev;
	int			irq;
};

static irqreturn_t max8907_irq_handler(int irq, void *data)
{
	struct max8907_rtc *rtc = data;

	regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x7f, 0);

	rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);

	return IRQ_HANDLED;
}

static void regs_to_tm(u8 *regs, struct rtc_time *tm)
{
	tm->tm_year = bcd2bin(regs[RTC_YEAR2]) * 100 +
		bcd2bin(regs[RTC_YEAR1]) - 1900;
	tm->tm_mon = bcd2bin(regs[RTC_MONTH] & 0x1f) - 1;
	tm->tm_mday = bcd2bin(regs[RTC_DATE] & 0x3f);
	tm->tm_wday = (regs[RTC_WEEKDAY] & 0x07) - 1;
	if (regs[RTC_HOUR] & HOUR_12) {
		tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x01f);
		if (tm->tm_hour == 12)
			tm->tm_hour = 0;
		if (regs[RTC_HOUR] & HOUR_AM_PM)
			tm->tm_hour += 12;
	} else {
		tm->tm_hour = bcd2bin(regs[RTC_HOUR] & 0x03f);
	}
	tm->tm_min = bcd2bin(regs[RTC_MIN] & 0x7f);
	tm->tm_sec = bcd2bin(regs[RTC_SEC] & 0x7f);
}

static void tm_to_regs(struct rtc_time *tm, u8 *regs)
{
	u8 high, low;

	high = (tm->tm_year + 1900) / 100;
	low = tm->tm_year % 100;
	regs[RTC_YEAR2] = bin2bcd(high);
	regs[RTC_YEAR1] = bin2bcd(low);
	regs[RTC_MONTH] = bin2bcd(tm->tm_mon + 1);
	regs[RTC_DATE] = bin2bcd(tm->tm_mday);
	regs[RTC_WEEKDAY] = tm->tm_wday + 1;
	regs[RTC_HOUR] = bin2bcd(tm->tm_hour);
	regs[RTC_MIN] = bin2bcd(tm->tm_min);
	regs[RTC_SEC] = bin2bcd(tm->tm_sec);
}

static int max8907_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct max8907_rtc *rtc = dev_get_drvdata(dev);
	u8 regs[TIME_NUM];
	int ret;

	ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
			       TIME_NUM);
	if (ret < 0)
		return ret;

	regs_to_tm(regs, tm);

	return 0;
}

static int max8907_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct max8907_rtc *rtc = dev_get_drvdata(dev);
	u8 regs[TIME_NUM];

	tm_to_regs(tm, regs);

	return regmap_bulk_write(rtc->regmap, MAX8907_REG_RTC_SEC, regs,
				 TIME_NUM);
}

static int max8907_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct max8907_rtc *rtc = dev_get_drvdata(dev);
	u8 regs[TIME_NUM];
	unsigned int val;
	int ret;

	ret = regmap_bulk_read(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
			       TIME_NUM);
	if (ret < 0)
		return ret;

	regs_to_tm(regs, &alrm->time);

	ret = regmap_read(rtc->regmap, MAX8907_REG_ALARM0_CNTL, &val);
	if (ret < 0)
		return ret;

	alrm->enabled = !!(val & 0x7f);

	return 0;
}

static int max8907_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct max8907_rtc *rtc = dev_get_drvdata(dev);
	u8 regs[TIME_NUM];
	int ret;

	tm_to_regs(&alrm->time, regs);

	/* Disable alarm while we update the target time */
	ret = regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL, 0x7f, 0);
	if (ret < 0)
		return ret;

	ret = regmap_bulk_write(rtc->regmap, MAX8907_REG_ALARM0_SEC, regs,
				TIME_NUM);
	if (ret < 0)
		return ret;

	if (alrm->enabled)
		ret = regmap_update_bits(rtc->regmap, MAX8907_REG_ALARM0_CNTL,
					 0x7f, 0x7f);

	return ret;
}

static const struct rtc_class_ops max8907_rtc_ops = {
	.read_time	= max8907_rtc_read_time,
	.set_time	= max8907_rtc_set_time,
	.read_alarm	= max8907_rtc_read_alarm,
	.set_alarm	= max8907_rtc_set_alarm,
};

static int max8907_rtc_probe(struct platform_device *pdev)
{
	struct max8907 *max8907 = dev_get_drvdata(pdev->dev.parent);
	struct max8907_rtc *rtc;
	int ret;

	rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL);
	if (!rtc)
		return -ENOMEM;
	platform_set_drvdata(pdev, rtc);

	rtc->max8907 = max8907;
	rtc->regmap = max8907->regmap_rtc;

	rtc->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8907-rtc",
					&max8907_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc->rtc_dev)) {
		ret = PTR_ERR(rtc->rtc_dev);
		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
		return ret;
	}

	rtc->irq = regmap_irq_get_virq(max8907->irqc_rtc,
				       MAX8907_IRQ_RTC_ALARM0);
	if (rtc->irq < 0)
		return rtc->irq;

	ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
				max8907_irq_handler,
				IRQF_ONESHOT, "max8907-alarm0", rtc);
	if (ret < 0)
		dev_err(&pdev->dev, "Failed to request IRQ%d: %d\n",
			rtc->irq, ret);

	return ret;
}

static int max8907_rtc_remove(struct platform_device *pdev)
{
	return 0;
}

static struct platform_driver max8907_rtc_driver = {
	.driver = {
		.name = "max8907-rtc",
		.owner = THIS_MODULE,
	},
	.probe = max8907_rtc_probe,
	.remove = max8907_rtc_remove,
};
module_platform_driver(max8907_rtc_driver);

MODULE_DESCRIPTION("Maxim MAX8907 RTC driver");
MODULE_LICENSE("GPL v2");