aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/rtc/rtc-88pm860x.c
blob: 64b847b7f9705e55e7471ce301bff5a4a3a7bd62 (plain) (tree)
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
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427










































































































































































































































































































































































































































                                                                                
/*
 * Real Time Clock driver for Marvell 88PM860x PMIC
 *
 * Copyright (c) 2010 Marvell International Ltd.
 * Author:	Haojian Zhuang <haojian.zhuang@marvell.com>
 *
 * 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/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/mfd/core.h>
#include <linux/mfd/88pm860x.h>

#define VRTC_CALIBRATION

struct pm860x_rtc_info {
	struct pm860x_chip	*chip;
	struct i2c_client	*i2c;
	struct rtc_device	*rtc_dev;
	struct device		*dev;
	struct delayed_work	calib_work;

	int			irq;
	int			vrtc;
	int			(*sync)(unsigned int ticks);
};

#define REG_VRTC_MEAS1		0x7D

#define REG0_ADDR		0xB0
#define REG1_ADDR		0xB2
#define REG2_ADDR		0xB4
#define REG3_ADDR		0xB6

#define REG0_DATA		0xB1
#define REG1_DATA		0xB3
#define REG2_DATA		0xB5
#define REG3_DATA		0xB7

/* bit definitions of Measurement Enable Register 2 (0x51) */
#define MEAS2_VRTC		(1 << 0)

/* bit definitions of RTC Register 1 (0xA0) */
#define ALARM_EN		(1 << 3)
#define ALARM_WAKEUP		(1 << 4)
#define ALARM			(1 << 5)
#define RTC1_USE_XO		(1 << 7)

#define VRTC_CALIB_INTERVAL	(HZ * 60 * 10)		/* 10 minutes */

static irqreturn_t rtc_update_handler(int irq, void *data)
{
	struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
	int mask;

	mask = ALARM | ALARM_WAKEUP;
	pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
	rtc_update_irq(info->rtc_dev, 1, RTC_AF);
	return IRQ_HANDLED;
}

static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct pm860x_rtc_info *info = dev_get_drvdata(dev);

	if (enabled)
		pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM, ALARM);
	else
		pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM, 0);
	return 0;
}

/*
 * Calculate the next alarm time given the requested alarm time mask
 * and the current time.
 */
static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
				struct rtc_time *alrm)
{
	unsigned long next_time;
	unsigned long now_time;

	next->tm_year = now->tm_year;
	next->tm_mon = now->tm_mon;
	next->tm_mday = now->tm_mday;
	next->tm_hour = alrm->tm_hour;
	next->tm_min = alrm->tm_min;
	next->tm_sec = alrm->tm_sec;

	rtc_tm_to_time(now, &now_time);
	rtc_tm_to_time(next, &next_time);

	if (next_time < now_time) {
		/* Advance one day */
		next_time += 60 * 60 * 24;
		rtc_time_to_tm(next_time, next);
	}
}

static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
	unsigned char buf[8];
	unsigned long ticks, base, data;

	pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
	dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
		buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
	base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];

	/* load 32-bit read-only counter */
	pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
	data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
	ticks = base + data;
	dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
		base, data, ticks);

	rtc_time_to_tm(ticks, tm);

	return 0;
}

static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
	unsigned char buf[4];
	unsigned long ticks, base, data;

	if ((tm->tm_year < 70) || (tm->tm_year > 138)) {
		dev_dbg(info->dev, "Set time %d out of range. "
			"Please set time between 1970 to 2038.\n",
			1900 + tm->tm_year);
		return -EINVAL;
	}
	rtc_tm_to_time(tm, &ticks);

	/* load 32-bit read-only counter */
	pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
	data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
	base = ticks - data;
	dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
		base, data, ticks);

	pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
	pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
	pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
	pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);

	if (info->sync)
		info->sync(ticks);
	return 0;
}

static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
	unsigned char buf[8];
	unsigned long ticks, base, data;
	int ret;

	pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
	dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
		buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
	base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];

	pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
	data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
	ticks = base + data;
	dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
		base, data, ticks);

	rtc_time_to_tm(ticks, &alrm->time);
	ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
	alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
	alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
	return 0;
}

static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct pm860x_rtc_info *info = dev_get_drvdata(dev);
	struct rtc_time now_tm, alarm_tm;
	unsigned long ticks, base, data;
	unsigned char buf[8];
	int mask;

	pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);

	pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
	dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
		buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
	base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];

	/* load 32-bit read-only counter */
	pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
	data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
	ticks = base + data;
	dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
		base, data, ticks);

	rtc_time_to_tm(ticks, &now_tm);
	rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time);
	/* get new ticks for alarm in 24 hours */
	rtc_tm_to_time(&alarm_tm, &ticks);
	data = ticks - base;

	buf[0] = data & 0xff;
	buf[1] = (data >> 8) & 0xff;
	buf[2] = (data >> 16) & 0xff;
	buf[3] = (data >> 24) & 0xff;
	pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
	if (alrm->enabled) {
		mask = ALARM | ALARM_WAKEUP | ALARM_EN;
		pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
	} else {
		mask = ALARM | ALARM_WAKEUP | ALARM_EN;
		pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
				ALARM | ALARM_WAKEUP);
	}
	return 0;
}

static const struct rtc_class_ops pm860x_rtc_ops = {
	.read_time	= pm860x_rtc_read_time,
	.set_time	= pm860x_rtc_set_time,
	.read_alarm	= pm860x_rtc_read_alarm,
	.set_alarm	= pm860x_rtc_set_alarm,
	.alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
};

#ifdef VRTC_CALIBRATION
static void calibrate_vrtc_work(struct work_struct *work)
{
	struct pm860x_rtc_info *info = container_of(work,
		struct pm860x_rtc_info, calib_work.work);
	unsigned char buf[2];
	unsigned int sum, data, mean, vrtc_set;
	int i;

	for (i = 0, sum = 0; i < 16; i++) {
		msleep(100);
		pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
		data = (buf[0] << 4) | buf[1];
		data = (data * 5400) >> 12;	/* convert to mv */
		sum += data;
	}
	mean = sum >> 4;
	vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
	dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);

	sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
	data = sum & 0x3;
	if ((mean + 200) < vrtc_set) {
		/* try higher voltage */
		if (++data == 4)
			goto out;
		data = (sum & 0xf8) | (data & 0x3);
		pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
	} else if ((mean - 200) > vrtc_set) {
		/* try lower voltage */
		if (data-- == 0)
			goto out;
		data = (sum & 0xf8) | (data & 0x3);
		pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
	} else
		goto out;
	dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
	/* trigger next calibration since VRTC is updated */
	schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
	return;
out:
	/* disable measurement */
	pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
	dev_dbg(info->dev, "finish VRTC calibration\n");
	return;
}
#endif

static int __devinit pm860x_rtc_probe(struct platform_device *pdev)
{
	struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
	struct pm860x_rtc_pdata *pdata = NULL;
	struct pm860x_rtc_info *info;
	struct rtc_time tm;
	unsigned long ticks = 0;
	int ret;

	pdata = pdev->dev.platform_data;
	if (pdata == NULL)
		dev_warn(&pdev->dev, "No platform data!\n");

	info = kzalloc(sizeof(struct pm860x_rtc_info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;
	info->irq = platform_get_irq(pdev, 0);
	if (info->irq < 0) {
		dev_err(&pdev->dev, "No IRQ resource!\n");
		ret = -EINVAL;
		goto out;
	}

	info->chip = chip;
	info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
	info->dev = &pdev->dev;
	dev_set_drvdata(&pdev->dev, info);

	ret = request_threaded_irq(info->irq, NULL, rtc_update_handler,
				   IRQF_ONESHOT, "rtc", info);
	if (ret < 0) {
		dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
			info->irq, ret);
		goto out;
	}

	/* set addresses of 32-bit base value for RTC time */
	pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
	pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
	pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
	pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);

	ret = pm860x_rtc_read_time(&pdev->dev, &tm);
	if (ret < 0) {
		dev_err(&pdev->dev, "Failed to read initial time.\n");
		goto out_rtc;
	}
	if ((tm.tm_year < 70) || (tm.tm_year > 138)) {
		tm.tm_year = 70;
		tm.tm_mon = 0;
		tm.tm_mday = 1;
		tm.tm_hour = 0;
		tm.tm_min = 0;
		tm.tm_sec = 0;
		ret = pm860x_rtc_set_time(&pdev->dev, &tm);
		if (ret < 0) {
			dev_err(&pdev->dev, "Failed to set initial time.\n");
			goto out_rtc;
		}
	}
	rtc_tm_to_time(&tm, &ticks);
	if (pdata && pdata->sync) {
		pdata->sync(ticks);
		info->sync = pdata->sync;
	}

	info->rtc_dev = rtc_device_register("88pm860x-rtc", &pdev->dev,
					    &pm860x_rtc_ops, THIS_MODULE);
	ret = PTR_ERR(info->rtc_dev);
	if (IS_ERR(info->rtc_dev)) {
		dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
		goto out_rtc;
	}

	/*
	 * enable internal XO instead of internal 3.25MHz clock since it can
	 * free running in PMIC power-down state.
	 */
	pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);

#ifdef VRTC_CALIBRATION
	/* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
	if (pdata && pdata->vrtc)
		info->vrtc = pdata->vrtc & 0x3;
	else
		info->vrtc = 1;
	pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);

	/* calibrate VRTC */
	INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
	schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
#endif	/* VRTC_CALIBRATION */
	return 0;
out_rtc:
	free_irq(info->irq, info);
out:
	kfree(info);
	return ret;
}

static int __devexit pm860x_rtc_remove(struct platform_device *pdev)
{
	struct pm860x_rtc_info *info = platform_get_drvdata(pdev);

#ifdef VRTC_CALIBRATION
	flush_scheduled_work();
	/* disable measurement */
	pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
#endif	/* VRTC_CALIBRATION */

	platform_set_drvdata(pdev, NULL);
	rtc_device_unregister(info->rtc_dev);
	free_irq(info->irq, info);
	kfree(info);
	return 0;
}

static struct platform_driver pm860x_rtc_driver = {
	.driver		= {
		.name	= "88pm860x-rtc",
		.owner	= THIS_MODULE,
	},
	.probe		= pm860x_rtc_probe,
	.remove		= __devexit_p(pm860x_rtc_remove),
};

static int __init pm860x_rtc_init(void)
{
	return platform_driver_register(&pm860x_rtc_driver);
}
module_init(pm860x_rtc_init);

static void __exit pm860x_rtc_exit(void)
{
	platform_driver_unregister(&pm860x_rtc_driver);
}
module_exit(pm860x_rtc_exit);

MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
MODULE_LICENSE("GPL");