aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-tps6586x.c
blob: 459c2ffc95a6b3a9b59d6baf997949a0ac13ac0f (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
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
/*
 * rtc-tps6586x.c: RTC driver for TI PMIC TPS6586X
 *
 * Copyright (c) 2012, NVIDIA Corporation.
 *
 * Author: Laxman Dewangan <ldewangan@nvidia.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 version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
 * whether express or implied; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 * 02111-1307, USA
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/mfd/tps6586x.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/rtc.h>
#include <linux/slab.h>

#define RTC_CTRL			0xc0
#define POR_RESET_N			BIT(7)
#define OSC_SRC_SEL			BIT(6)
#define RTC_ENABLE			BIT(5)	/* enables alarm */
#define RTC_BUF_ENABLE			BIT(4)	/* 32 KHz buffer enable */
#define PRE_BYPASS			BIT(3)	/* 0=1KHz or 1=32KHz updates */
#define CL_SEL_MASK			(BIT(2)|BIT(1))
#define CL_SEL_POS			1
#define RTC_ALARM1_HI			0xc1
#define RTC_COUNT4			0xc6

/* start a PMU RTC access by reading the register prior to the RTC_COUNT4 */
#define RTC_COUNT4_DUMMYREAD		0xc5

/*only 14-bits width in second*/
#define ALM1_VALID_RANGE_IN_SEC		0x3FFF

#define TPS6586X_RTC_CL_SEL_1_5PF	0x0
#define TPS6586X_RTC_CL_SEL_6_5PF	0x1
#define TPS6586X_RTC_CL_SEL_7_5PF	0x2
#define TPS6586X_RTC_CL_SEL_12_5PF	0x3

struct tps6586x_rtc {
	struct device		*dev;
	struct rtc_device	*rtc;
	int			irq;
	bool			irq_en;
	unsigned long long	epoch_start;
};

static inline struct device *to_tps6586x_dev(struct device *dev)
{
	return dev->parent;
}

static int tps6586x_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
	struct device *tps_dev = to_tps6586x_dev(dev);
	unsigned long long ticks = 0;
	unsigned long seconds;
	u8 buff[6];
	int ret;
	int i;

	ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD, sizeof(buff), buff);
	if (ret < 0) {
		dev_err(dev, "read counter failed with err %d\n", ret);
		return ret;
	}

	for (i = 1; i < sizeof(buff); i++) {
		ticks <<= 8;
		ticks |= buff[i];
	}

	seconds = ticks >> 10;
	seconds += rtc->epoch_start;
	rtc_time_to_tm(seconds, tm);
	return rtc_valid_tm(tm);
}

static int tps6586x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
	struct device *tps_dev = to_tps6586x_dev(dev);
	unsigned long long ticks;
	unsigned long seconds;
	u8 buff[5];
	int ret;

	rtc_tm_to_time(tm, &seconds);
	if (seconds < rtc->epoch_start) {
		dev_err(dev, "requested time unsupported\n");
		return -EINVAL;
	}
	seconds -= rtc->epoch_start;

	ticks = (unsigned long long)seconds << 10;
	buff[0] = (ticks >> 32) & 0xff;
	buff[1] = (ticks >> 24) & 0xff;
	buff[2] = (ticks >> 16) & 0xff;
	buff[3] = (ticks >> 8) & 0xff;
	buff[4] = ticks & 0xff;

	/* Disable RTC before changing time */
	ret = tps6586x_clr_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
	if (ret < 0) {
		dev_err(dev, "failed to clear RTC_ENABLE\n");
		return ret;
	}

	ret = tps6586x_writes(tps_dev, RTC_COUNT4, sizeof(buff), buff);
	if (ret < 0) {
		dev_err(dev, "failed to program new time\n");
		return ret;
	}

	/* Enable RTC */
	ret = tps6586x_set_bits(tps_dev, RTC_CTRL, RTC_ENABLE);
	if (ret < 0) {
		dev_err(dev, "failed to set RTC_ENABLE\n");
		return ret;
	}
	return 0;
}

static int tps6586x_rtc_alarm_irq_enable(struct device *dev,
			 unsigned int enabled)
{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);

	if (enabled && !rtc->irq_en) {
		enable_irq(rtc->irq);
		rtc->irq_en = true;
	} else if (!enabled && rtc->irq_en)  {
		disable_irq(rtc->irq);
		rtc->irq_en = false;
	}
	return 0;
}

static int tps6586x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
	struct device *tps_dev = to_tps6586x_dev(dev);
	unsigned long seconds;
	unsigned long ticks;
	unsigned long rtc_current_time;
	unsigned long long rticks = 0;
	u8 buff[3];
	u8 rbuff[6];
	int ret;
	int i;

	rtc_tm_to_time(&alrm->time, &seconds);

	if (alrm->enabled && (seconds < rtc->epoch_start)) {
		dev_err(dev, "can't set alarm to requested time\n");
		return -EINVAL;
	}

	ret = tps6586x_rtc_alarm_irq_enable(dev, alrm->enabled);
	if (ret < 0) {
		dev_err(dev, "can't set alarm irq, err %d\n", ret);
		return ret;
	}

	seconds -= rtc->epoch_start;
	ret = tps6586x_reads(tps_dev, RTC_COUNT4_DUMMYREAD,
			sizeof(rbuff), rbuff);
	if (ret < 0) {
		dev_err(dev, "read counter failed with err %d\n", ret);
		return ret;
	}

	for (i = 1; i < sizeof(rbuff); i++) {
		rticks <<= 8;
		rticks |= rbuff[i];
	}

	rtc_current_time = rticks >> 10;
	if ((seconds - rtc_current_time) > ALM1_VALID_RANGE_IN_SEC)
		seconds = rtc_current_time - 1;

	ticks = (unsigned long long)seconds << 10;
	buff[0] = (ticks >> 16) & 0xff;
	buff[1] = (ticks >> 8) & 0xff;
	buff[2] = ticks & 0xff;

	ret = tps6586x_writes(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
	if (ret)
		dev_err(dev, "programming alarm failed with err %d\n", ret);

	return ret;
}

static int tps6586x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);
	struct device *tps_dev = to_tps6586x_dev(dev);
	unsigned long ticks;
	unsigned long seconds;
	u8 buff[3];
	int ret;

	ret = tps6586x_reads(tps_dev, RTC_ALARM1_HI, sizeof(buff), buff);
	if (ret) {
		dev_err(dev, "read RTC_ALARM1_HI failed with err %d\n", ret);
		return ret;
	}

	ticks = (buff[0] << 16) | (buff[1] << 8) | buff[2];
	seconds = ticks >> 10;
	seconds += rtc->epoch_start;

	rtc_time_to_tm(seconds, &alrm->time);
	return 0;
}

static const struct rtc_class_ops tps6586x_rtc_ops = {
	.read_time	= tps6586x_rtc_read_time,
	.set_time	= tps6586x_rtc_set_time,
	.set_alarm	= tps6586x_rtc_set_alarm,
	.read_alarm	= tps6586x_rtc_read_alarm,
	.alarm_irq_enable = tps6586x_rtc_alarm_irq_enable,
};

static irqreturn_t tps6586x_rtc_irq(int irq, void *data)
{
	struct tps6586x_rtc *rtc = data;

	rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
	return IRQ_HANDLED;
}

static int tps6586x_rtc_probe(struct platform_device *pdev)
{
	struct device *tps_dev = to_tps6586x_dev(&pdev->dev);
	struct tps6586x_rtc *rtc;
	int ret;

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

	rtc->dev = &pdev->dev;
	rtc->irq = platform_get_irq(pdev, 0);

	/* Set epoch start as 00:00:00:01:01:2009 */
	rtc->epoch_start = mktime(2009, 1, 1, 0, 0, 0);

	/* 1 kHz tick mode, enable tick counting */
	ret = tps6586x_update(tps_dev, RTC_CTRL,
		RTC_ENABLE | OSC_SRC_SEL |
		((TPS6586X_RTC_CL_SEL_1_5PF << CL_SEL_POS) & CL_SEL_MASK),
		RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
	if (ret < 0) {
		dev_err(&pdev->dev, "unable to start counter\n");
		return ret;
	}

	platform_set_drvdata(pdev, rtc);
	rtc->rtc = devm_rtc_device_register(&pdev->dev, dev_name(&pdev->dev),
				       &tps6586x_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc->rtc)) {
		ret = PTR_ERR(rtc->rtc);
		dev_err(&pdev->dev, "RTC device register: ret %d\n", ret);
		goto fail_rtc_register;
	}

	ret = devm_request_threaded_irq(&pdev->dev, rtc->irq, NULL,
				tps6586x_rtc_irq,
				IRQF_ONESHOT | IRQF_EARLY_RESUME,
				dev_name(&pdev->dev), rtc);
	if (ret < 0) {
		dev_err(&pdev->dev, "request IRQ(%d) failed with ret %d\n",
				rtc->irq, ret);
		goto fail_rtc_register;
	}
	disable_irq(rtc->irq);
	device_set_wakeup_capable(&pdev->dev, 1);
	return 0;

fail_rtc_register:
	tps6586x_update(tps_dev, RTC_CTRL, 0,
		RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
	return ret;
};

static int tps6586x_rtc_remove(struct platform_device *pdev)
{
	struct device *tps_dev = to_tps6586x_dev(&pdev->dev);

	tps6586x_update(tps_dev, RTC_CTRL, 0,
		RTC_ENABLE | OSC_SRC_SEL | PRE_BYPASS | CL_SEL_MASK);
	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int tps6586x_rtc_suspend(struct device *dev)
{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		enable_irq_wake(rtc->irq);
	return 0;
}

static int tps6586x_rtc_resume(struct device *dev)
{
	struct tps6586x_rtc *rtc = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		disable_irq_wake(rtc->irq);
	return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(tps6586x_pm_ops, tps6586x_rtc_suspend,
			tps6586x_rtc_resume);

static struct platform_driver tps6586x_rtc_driver = {
	.driver	= {
		.name	= "tps6586x-rtc",
		.owner	= THIS_MODULE,
		.pm	= &tps6586x_pm_ops,
	},
	.probe	= tps6586x_rtc_probe,
	.remove	= tps6586x_rtc_remove,
};
module_platform_driver(tps6586x_rtc_driver);

MODULE_ALIAS("platform:rtc-tps6586x");
MODULE_DESCRIPTION("TI TPS6586x RTC driver");
MODULE_AUTHOR("Laxman dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");