aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-max8998.c
blob: d5af7baa48b56c893e449b418d158f7b25448628 (plain) (blame)
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
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
/*
 * RTC driver for Maxim MAX8998
 *
 * Copyright (C) 2010 Samsung Electronics Co.Ltd
 * Author: Minkyu Kang <mk7.kang@samsung.com>
 * Author: Joonyoung Shim <jy0922.shim@samsung.com>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/mfd/max8998.h>
#include <linux/mfd/max8998-private.h>
#include <linux/delay.h>

#define MAX8998_RTC_SEC			0x00
#define MAX8998_RTC_MIN			0x01
#define MAX8998_RTC_HOUR		0x02
#define MAX8998_RTC_WEEKDAY		0x03
#define MAX8998_RTC_DATE		0x04
#define MAX8998_RTC_MONTH		0x05
#define MAX8998_RTC_YEAR1		0x06
#define MAX8998_RTC_YEAR2		0x07
#define MAX8998_ALARM0_SEC		0x08
#define MAX8998_ALARM0_MIN		0x09
#define MAX8998_ALARM0_HOUR		0x0a
#define MAX8998_ALARM0_WEEKDAY		0x0b
#define MAX8998_ALARM0_DATE		0x0c
#define MAX8998_ALARM0_MONTH		0x0d
#define MAX8998_ALARM0_YEAR1		0x0e
#define MAX8998_ALARM0_YEAR2		0x0f
#define MAX8998_ALARM1_SEC		0x10
#define MAX8998_ALARM1_MIN		0x11
#define MAX8998_ALARM1_HOUR		0x12
#define MAX8998_ALARM1_WEEKDAY		0x13
#define MAX8998_ALARM1_DATE		0x14
#define MAX8998_ALARM1_MONTH		0x15
#define MAX8998_ALARM1_YEAR1		0x16
#define MAX8998_ALARM1_YEAR2		0x17
#define MAX8998_ALARM0_CONF		0x18
#define MAX8998_ALARM1_CONF		0x19
#define MAX8998_RTC_STATUS		0x1a
#define MAX8998_WTSR_SMPL_CNTL		0x1b
#define MAX8998_TEST			0x1f

#define HOUR_12				(1 << 7)
#define HOUR_PM				(1 << 5)
#define ALARM0_STATUS			(1 << 1)
#define ALARM1_STATUS			(1 << 2)

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

struct max8998_rtc_info {
	struct device		*dev;
	struct max8998_dev	*max8998;
	struct i2c_client	*rtc;
	struct rtc_device	*rtc_dev;
	int irq;
	bool lp3974_bug_workaround;
};

static void max8998_data_to_tm(u8 *data, struct rtc_time *tm)
{
	tm->tm_sec = bcd2bin(data[RTC_SEC]);
	tm->tm_min = bcd2bin(data[RTC_MIN]);
	if (data[RTC_HOUR] & HOUR_12) {
		tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x1f);
		if (data[RTC_HOUR] & HOUR_PM)
			tm->tm_hour += 12;
	} else
		tm->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3f);

	tm->tm_wday = data[RTC_WEEKDAY] & 0x07;
	tm->tm_mday = bcd2bin(data[RTC_DATE]);
	tm->tm_mon = bcd2bin(data[RTC_MONTH]);
	tm->tm_year = bcd2bin(data[RTC_YEAR1]) + bcd2bin(data[RTC_YEAR2]) * 100;
	tm->tm_year -= 1900;
}

static void max8998_tm_to_data(struct rtc_time *tm, u8 *data)
{
	data[RTC_SEC] = bin2bcd(tm->tm_sec);
	data[RTC_MIN] = bin2bcd(tm->tm_min);
	data[RTC_HOUR] = bin2bcd(tm->tm_hour);
	data[RTC_WEEKDAY] = tm->tm_wday;
	data[RTC_DATE] = bin2bcd(tm->tm_mday);
	data[RTC_MONTH] = bin2bcd(tm->tm_mon);
	data[RTC_YEAR1] = bin2bcd(tm->tm_year % 100);
	data[RTC_YEAR2] = bin2bcd((tm->tm_year + 1900) / 100);
}

static int max8998_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct max8998_rtc_info *info = dev_get_drvdata(dev);
	u8 data[8];
	int ret;

	ret = max8998_bulk_read(info->rtc, MAX8998_RTC_SEC, 8, data);
	if (ret < 0)
		return ret;

	max8998_data_to_tm(data, tm);

	return rtc_valid_tm(tm);
}

static int max8998_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct max8998_rtc_info *info = dev_get_drvdata(dev);
	u8 data[8];
	int ret;

	max8998_tm_to_data(tm, data);

	ret = max8998_bulk_write(info->rtc, MAX8998_RTC_SEC, 8, data);

	if (info->lp3974_bug_workaround)
		msleep(2000);

	return ret;
}

static int max8998_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct max8998_rtc_info *info = dev_get_drvdata(dev);
	u8 data[8];
	u8 val;
	int ret;

	ret = max8998_bulk_read(info->rtc, MAX8998_ALARM0_SEC, 8, data);
	if (ret < 0)
		return ret;

	max8998_data_to_tm(data, &alrm->time);

	ret = max8998_read_reg(info->rtc, MAX8998_ALARM0_CONF, &val);
	if (ret < 0)
		return ret;

	alrm->enabled = !!val;

	ret = max8998_read_reg(info->rtc, MAX8998_RTC_STATUS, &val);
	if (ret < 0)
		return ret;

	if (val & ALARM0_STATUS)
		alrm->pending = 1;
	else
		alrm->pending = 0;

	return 0;
}

static int max8998_rtc_stop_alarm(struct max8998_rtc_info *info)
{
	int ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, 0);

	if (info->lp3974_bug_workaround)
		msleep(2000);

	return ret;
}

static int max8998_rtc_start_alarm(struct max8998_rtc_info *info)
{
	int ret;
	u8 alarm0_conf = 0x77;

	/* LP3974 with delay bug chips has rtc alarm bugs with "MONTH" field */
	if (info->lp3974_bug_workaround)
		alarm0_conf = 0x57;

	ret = max8998_write_reg(info->rtc, MAX8998_ALARM0_CONF, alarm0_conf);

	if (info->lp3974_bug_workaround)
		msleep(2000);

	return ret;
}

static int max8998_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct max8998_rtc_info *info = dev_get_drvdata(dev);
	u8 data[8];
	int ret;

	max8998_tm_to_data(&alrm->time, data);

	ret = max8998_rtc_stop_alarm(info);
	if (ret < 0)
		return ret;

	ret = max8998_bulk_write(info->rtc, MAX8998_ALARM0_SEC, 8, data);
	if (ret < 0)
		return ret;

	if (info->lp3974_bug_workaround)
		msleep(2000);

	if (alrm->enabled)
		ret = max8998_rtc_start_alarm(info);

	return ret;
}

static int max8998_rtc_alarm_irq_enable(struct device *dev,
					unsigned int enabled)
{
	struct max8998_rtc_info *info = dev_get_drvdata(dev);

	if (enabled)
		return max8998_rtc_start_alarm(info);
	else
		return max8998_rtc_stop_alarm(info);
}

static irqreturn_t max8998_rtc_alarm_irq(int irq, void *data)
{
	struct max8998_rtc_info *info = data;

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

	return IRQ_HANDLED;
}

static const struct rtc_class_ops max8998_rtc_ops = {
	.read_time = max8998_rtc_read_time,
	.set_time = max8998_rtc_set_time,
	.read_alarm = max8998_rtc_read_alarm,
	.set_alarm = max8998_rtc_set_alarm,
	.alarm_irq_enable = max8998_rtc_alarm_irq_enable,
};

static int max8998_rtc_probe(struct platform_device *pdev)
{
	struct max8998_dev *max8998 = dev_get_drvdata(pdev->dev.parent);
	struct max8998_platform_data *pdata = dev_get_platdata(max8998->dev);
	struct max8998_rtc_info *info;
	int ret;

	info = devm_kzalloc(&pdev->dev, sizeof(struct max8998_rtc_info),
			GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	info->dev = &pdev->dev;
	info->max8998 = max8998;
	info->rtc = max8998->rtc;
	info->irq = max8998->irq_base + MAX8998_IRQ_ALARM0;

	platform_set_drvdata(pdev, info);

	info->rtc_dev = devm_rtc_device_register(&pdev->dev, "max8998-rtc",
			&max8998_rtc_ops, THIS_MODULE);

	if (IS_ERR(info->rtc_dev)) {
		ret = PTR_ERR(info->rtc_dev);
		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
		goto out_rtc;
	}

	ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
				max8998_rtc_alarm_irq, 0, "rtc-alarm0", info);

	if (ret < 0)
		dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
			info->irq, ret);

	dev_info(&pdev->dev, "RTC CHIP NAME: %s\n", pdev->id_entry->name);
	if (pdata && pdata->rtc_delay) {
		info->lp3974_bug_workaround = true;
		dev_warn(&pdev->dev, "LP3974 with RTC REGERR option."
				" RTC updates will be extremely slow.\n");
	}

	return 0;

out_rtc:
	platform_set_drvdata(pdev, NULL);
	return ret;
}

static int max8998_rtc_remove(struct platform_device *pdev)
{
	return 0;
}

static const struct platform_device_id max8998_rtc_id[] = {
	{ "max8998-rtc", TYPE_MAX8998 },
	{ "lp3974-rtc", TYPE_LP3974 },
	{ }
};

static struct platform_driver max8998_rtc_driver = {
	.driver		= {
		.name	= "max8998-rtc",
		.owner	= THIS_MODULE,
	},
	.probe		= max8998_rtc_probe,
	.remove		= max8998_rtc_remove,
	.id_table	= max8998_rtc_id,
};

module_platform_driver(max8998_rtc_driver);

MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
MODULE_DESCRIPTION("Maxim MAX8998 RTC driver");
MODULE_LICENSE("GPL");