summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-tps65910.c
blob: 8bd8115329b51b1e014baf9a2ec064ec01af4865 (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
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
/*
 * rtc-tps65910.c -- TPS65910 Real Time Clock interface
 *
 * Copyright (c) 2012, NVIDIA CORPORATION.  All rights reserved.
 * Author: Venu Byravarasu <vbyravarasu@nvidia.com>
 *
 * Based on original TI driver rtc-twl.c
 *   Copyright (C) 2007 MontaVista Software, Inc
 *   Author: Alexandre Rusev <source@mvista.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/kernel.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/interrupt.h>
#include <linux/mfd/tps65910.h>

struct tps65910_rtc {
	struct rtc_device	*rtc;
	int irq;
};

/* Total number of RTC registers needed to set time*/
#define NUM_TIME_REGS	(TPS65910_YEARS - TPS65910_SECONDS + 1)

static int tps65910_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
{
	struct tps65910 *tps = dev_get_drvdata(dev->parent);
	u8 val = 0;

	if (enabled)
		val = TPS65910_RTC_INTERRUPTS_IT_ALARM;

	return regmap_write(tps->regmap, TPS65910_RTC_INTERRUPTS, val);
}

/*
 * Gets current tps65910 RTC time and date parameters.
 *
 * The RTC's time/alarm representation is not what gmtime(3) requires
 * Linux to use:
 *
 *  - Months are 1..12 vs Linux 0-11
 *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
 */
static int tps65910_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char rtc_data[NUM_TIME_REGS];
	struct tps65910 *tps = dev_get_drvdata(dev->parent);
	int ret;

	/* Copy RTC counting registers to static registers or latches */
	ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
		TPS65910_RTC_CTRL_GET_TIME, TPS65910_RTC_CTRL_GET_TIME);
	if (ret < 0) {
		dev_err(dev, "RTC CTRL reg update failed with err:%d\n", ret);
		return ret;
	}

	ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, rtc_data,
		NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "reading from RTC failed with err:%d\n", ret);
		return ret;
	}

	tm->tm_sec = bcd2bin(rtc_data[0]);
	tm->tm_min = bcd2bin(rtc_data[1]);
	tm->tm_hour = bcd2bin(rtc_data[2]);
	tm->tm_mday = bcd2bin(rtc_data[3]);
	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
	tm->tm_year = bcd2bin(rtc_data[5]) + 100;

	return ret;
}

static int tps65910_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char rtc_data[NUM_TIME_REGS];
	struct tps65910 *tps = dev_get_drvdata(dev->parent);
	int ret;

	rtc_data[0] = bin2bcd(tm->tm_sec);
	rtc_data[1] = bin2bcd(tm->tm_min);
	rtc_data[2] = bin2bcd(tm->tm_hour);
	rtc_data[3] = bin2bcd(tm->tm_mday);
	rtc_data[4] = bin2bcd(tm->tm_mon + 1);
	rtc_data[5] = bin2bcd(tm->tm_year - 100);

	/* Stop RTC while updating the RTC time registers */
	ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
		TPS65910_RTC_CTRL_STOP_RTC, 0);
	if (ret < 0) {
		dev_err(dev, "RTC stop failed with err:%d\n", ret);
		return ret;
	}

	/* update all the time registers in one shot */
	ret = regmap_bulk_write(tps->regmap, TPS65910_SECONDS, rtc_data,
		NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "rtc_set_time error %d\n", ret);
		return ret;
	}

	/* Start back RTC */
	ret = regmap_update_bits(tps->regmap, TPS65910_RTC_CTRL,
		TPS65910_RTC_CTRL_STOP_RTC, 1);
	if (ret < 0)
		dev_err(dev, "RTC start failed with err:%d\n", ret);

	return ret;
}

/*
 * Gets current tps65910 RTC alarm time.
 */
static int tps65910_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	unsigned char alarm_data[NUM_TIME_REGS];
	u32 int_val;
	struct tps65910 *tps = dev_get_drvdata(dev->parent);
	int ret;

	ret = regmap_bulk_read(tps->regmap, TPS65910_SECONDS, alarm_data,
		NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "rtc_read_alarm error %d\n", ret);
		return ret;
	}

	alm->time.tm_sec = bcd2bin(alarm_data[0]);
	alm->time.tm_min = bcd2bin(alarm_data[1]);
	alm->time.tm_hour = bcd2bin(alarm_data[2]);
	alm->time.tm_mday = bcd2bin(alarm_data[3]);
	alm->time.tm_mon = bcd2bin(alarm_data[4]) - 1;
	alm->time.tm_year = bcd2bin(alarm_data[5]) + 100;

	ret = regmap_read(tps->regmap, TPS65910_RTC_INTERRUPTS, &int_val);
	if (ret < 0)
		return ret;

	if (int_val & TPS65910_RTC_INTERRUPTS_IT_ALARM)
		alm->enabled = 1;

	return ret;
}

static int tps65910_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	unsigned char alarm_data[NUM_TIME_REGS];
	struct tps65910 *tps = dev_get_drvdata(dev->parent);
	int ret;

	ret = tps65910_rtc_alarm_irq_enable(dev, 0);
	if (ret)
		return ret;

	alarm_data[0] = bin2bcd(alm->time.tm_sec);
	alarm_data[1] = bin2bcd(alm->time.tm_min);
	alarm_data[2] = bin2bcd(alm->time.tm_hour);
	alarm_data[3] = bin2bcd(alm->time.tm_mday);
	alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
	alarm_data[5] = bin2bcd(alm->time.tm_year - 100);

	/* update all the alarm registers in one shot */
	ret = regmap_bulk_write(tps->regmap, TPS65910_ALARM_SECONDS,
		alarm_data, NUM_TIME_REGS);
	if (ret) {
		dev_err(dev, "rtc_set_alarm error %d\n", ret);
		return ret;
	}

	if (alm->enabled)
		ret = tps65910_rtc_alarm_irq_enable(dev, 1);

	return ret;
}

static irqreturn_t tps65910_rtc_interrupt(int irq, void *rtc)
{
	struct device *dev = rtc;
	unsigned long events = 0;
	struct tps65910 *tps = dev_get_drvdata(dev->parent);
	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);
	int ret;
	u32 rtc_reg;

	ret = regmap_read(tps->regmap, TPS65910_RTC_STATUS, &rtc_reg);
	if (ret)
		return IRQ_NONE;

	if (rtc_reg & TPS65910_RTC_STATUS_ALARM)
		events = RTC_IRQF | RTC_AF;

	ret = regmap_write(tps->regmap, TPS65910_RTC_STATUS, rtc_reg);
	if (ret)
		return IRQ_NONE;

	/* Notify RTC core on event */
	rtc_update_irq(tps_rtc->rtc, 1, events);

	return IRQ_HANDLED;
}

static const struct rtc_class_ops tps65910_rtc_ops = {
	.read_time	= tps65910_rtc_read_time,
	.set_time	= tps65910_rtc_set_time,
	.read_alarm	= tps65910_rtc_read_alarm,
	.set_alarm	= tps65910_rtc_set_alarm,
	.alarm_irq_enable = tps65910_rtc_alarm_irq_enable,
};

static int tps65910_rtc_probe(struct platform_device *pdev)
{
	struct tps65910 *tps65910 = NULL;
	struct tps65910_rtc *tps_rtc = NULL;
	int ret;
	int irq;
	u32 rtc_reg;

	tps65910 = dev_get_drvdata(pdev->dev.parent);

	tps_rtc = devm_kzalloc(&pdev->dev, sizeof(struct tps65910_rtc),
			GFP_KERNEL);
	if (!tps_rtc)
		return -ENOMEM;

	/* Clear pending interrupts */
	ret = regmap_read(tps65910->regmap, TPS65910_RTC_STATUS, &rtc_reg);
	if (ret < 0)
		return ret;

	ret = regmap_write(tps65910->regmap, TPS65910_RTC_STATUS, rtc_reg);
	if (ret < 0)
		return ret;

	dev_dbg(&pdev->dev, "Enabling rtc-tps65910.\n");

	/* Enable RTC digital power domain */
	ret = regmap_update_bits(tps65910->regmap, TPS65910_DEVCTRL,
		DEVCTRL_RTC_PWDN_MASK, 0 << DEVCTRL_RTC_PWDN_SHIFT);
	if (ret < 0)
		return ret;

	rtc_reg = TPS65910_RTC_CTRL_STOP_RTC;
	ret = regmap_write(tps65910->regmap, TPS65910_RTC_CTRL, rtc_reg);
	if (ret < 0)
		return ret;

	irq  = platform_get_irq(pdev, 0);
	if (irq <= 0) {
		dev_warn(&pdev->dev, "Wake up is not possible as irq = %d\n",
			irq);
		return ret;
	}

	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
		tps65910_rtc_interrupt, IRQF_TRIGGER_LOW | IRQF_EARLY_RESUME,
		dev_name(&pdev->dev), &pdev->dev);
	if (ret < 0) {
		dev_err(&pdev->dev, "IRQ is not free.\n");
		return ret;
	}
	tps_rtc->irq = irq;
	device_set_wakeup_capable(&pdev->dev, 1);

	tps_rtc->rtc = rtc_device_register(pdev->name, &pdev->dev,
		&tps65910_rtc_ops, THIS_MODULE);
	if (IS_ERR(tps_rtc->rtc)) {
		ret = PTR_ERR(tps_rtc->rtc);
		dev_err(&pdev->dev, "RTC device register: err %d\n", ret);
		return ret;
	}

	platform_set_drvdata(pdev, tps_rtc);

	return 0;
}

/*
 * Disable tps65910 RTC interrupts.
 * Sets status flag to free.
 */
static int tps65910_rtc_remove(struct platform_device *pdev)
{
	/* leave rtc running, but disable irqs */
	struct tps65910_rtc *tps_rtc = platform_get_drvdata(pdev);

	tps65910_rtc_alarm_irq_enable(&pdev->dev, 0);

	rtc_device_unregister(tps_rtc->rtc);
	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int tps65910_rtc_suspend(struct device *dev)
{
	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);

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

static int tps65910_rtc_resume(struct device *dev)
{
	struct tps65910_rtc *tps_rtc = dev_get_drvdata(dev);

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

static const struct dev_pm_ops tps65910_rtc_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(tps65910_rtc_suspend, tps65910_rtc_resume)
};

static struct platform_driver tps65910_rtc_driver = {
	.probe		= tps65910_rtc_probe,
	.remove		= tps65910_rtc_remove,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "tps65910-rtc",
		.pm	= &tps65910_rtc_pm_ops,
	},
};

module_platform_driver(tps65910_rtc_driver);
MODULE_ALIAS("platform:rtc-tps65910");
MODULE_AUTHOR("Venu Byravarasu <vbyravarasu@nvidia.com>");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud