aboutsummaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-palmas.c
blob: 4bcfb88674d38b5d3343149708ed188e7d2c707e (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
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
/*
 * rtc-palmas.c -- Palmas Real Time Clock driver.

 * RTC driver for TI Palma series devices like TPS65913,
 * TPS65914 power management IC.
 *
 * 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/bcd.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mfd/palmas.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/rtc.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/pm.h>

struct palmas_rtc {
	struct rtc_device	*rtc;
	struct device		*dev;
	unsigned int		irq;
};

/* Total number of RTC registers needed to set time*/
#define PALMAS_NUM_TIME_REGS	(PALMAS_YEARS_REG - PALMAS_SECONDS_REG + 1)

static int palmas_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
	struct palmas *palmas = dev_get_drvdata(dev->parent);
	int ret;

	/* Copy RTC counting registers to static registers or latches */
	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
		PALMAS_RTC_CTRL_REG_GET_TIME, PALMAS_RTC_CTRL_REG_GET_TIME);
	if (ret < 0) {
		dev_err(dev, "RTC CTRL reg update failed, err: %d\n", ret);
		return ret;
	}

	ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
			rtc_data, PALMAS_NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "RTC_SECONDS reg read failed, 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 palmas_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char rtc_data[PALMAS_NUM_TIME_REGS];
	struct palmas *palmas = 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 = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
		PALMAS_RTC_CTRL_REG_STOP_RTC, 0);
	if (ret < 0) {
		dev_err(dev, "RTC stop failed, err = %d\n", ret);
		return ret;
	}

	ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE, PALMAS_SECONDS_REG,
		rtc_data, PALMAS_NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "RTC_SECONDS reg write failed, err = %d\n", ret);
		return ret;
	}

	/* Start back RTC */
	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
		PALMAS_RTC_CTRL_REG_STOP_RTC, PALMAS_RTC_CTRL_REG_STOP_RTC);
	if (ret < 0)
		dev_err(dev, "RTC start failed, err = %d\n", ret);
	return ret;
}

static int palmas_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
{
	struct palmas *palmas = dev_get_drvdata(dev->parent);
	u8 val;

	val = enabled ? PALMAS_RTC_INTERRUPTS_REG_IT_ALARM : 0;
	return palmas_write(palmas, PALMAS_RTC_BASE,
		PALMAS_RTC_INTERRUPTS_REG, val);
}

static int palmas_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
	u32 int_val;
	struct palmas *palmas = dev_get_drvdata(dev->parent);
	int ret;

	ret = palmas_bulk_read(palmas, PALMAS_RTC_BASE,
			PALMAS_ALARM_SECONDS_REG,
			alarm_data, PALMAS_NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "RTC_ALARM_SECONDS read failed, err = %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 = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_INTERRUPTS_REG,
			&int_val);
	if (ret < 0) {
		dev_err(dev, "RTC_INTERRUPTS reg read failed, err = %d\n", ret);
		return ret;
	}

	if (int_val & PALMAS_RTC_INTERRUPTS_REG_IT_ALARM)
		alm->enabled = 1;
	return ret;
}

static int palmas_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	unsigned char alarm_data[PALMAS_NUM_TIME_REGS];
	struct palmas *palmas = dev_get_drvdata(dev->parent);
	int ret;

	ret = palmas_rtc_alarm_irq_enable(dev, 0);
	if (ret < 0) {
		dev_err(dev, "Disable RTC alarm failed\n");
		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);

	ret = palmas_bulk_write(palmas, PALMAS_RTC_BASE,
		PALMAS_ALARM_SECONDS_REG, alarm_data, PALMAS_NUM_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "ALARM_SECONDS_REG write failed, err = %d\n", ret);
		return ret;
	}

	if (alm->enabled)
		ret = palmas_rtc_alarm_irq_enable(dev, 1);
	return ret;
}

static int palmas_clear_interrupts(struct device *dev)
{
	struct palmas *palmas = dev_get_drvdata(dev->parent);
	unsigned int rtc_reg;
	int ret;

	ret = palmas_read(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
				&rtc_reg);
	if (ret < 0) {
		dev_err(dev, "RTC_STATUS read failed, err = %d\n", ret);
		return ret;
	}

	ret = palmas_write(palmas, PALMAS_RTC_BASE, PALMAS_RTC_STATUS_REG,
			rtc_reg);
	if (ret < 0) {
		dev_err(dev, "RTC_STATUS write failed, err = %d\n", ret);
		return ret;
	}
	return 0;
}

static irqreturn_t palmas_rtc_interrupt(int irq, void *context)
{
	struct palmas_rtc *palmas_rtc = context;
	struct device *dev = palmas_rtc->dev;
	int ret;

	ret = palmas_clear_interrupts(dev);
	if (ret < 0) {
		dev_err(dev, "RTC interrupt clear failed, err = %d\n", ret);
		return IRQ_NONE;
	}

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

static const struct rtc_class_ops palmas_rtc_ops = {
	.read_time	= palmas_rtc_read_time,
	.set_time	= palmas_rtc_set_time,
	.read_alarm	= palmas_rtc_read_alarm,
	.set_alarm	= palmas_rtc_set_alarm,
	.alarm_irq_enable = palmas_rtc_alarm_irq_enable,
};

static int palmas_rtc_probe(struct platform_device *pdev)
{
	struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
	struct palmas_rtc *palmas_rtc = NULL;
	int ret;
	bool enable_bb_charging = false;
	bool high_bb_charging = false;

	if (pdev->dev.of_node) {
		enable_bb_charging = of_property_read_bool(pdev->dev.of_node,
					"ti,backup-battery-chargeable");
		high_bb_charging = of_property_read_bool(pdev->dev.of_node,
					"ti,backup-battery-charge-high-current");
	}

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

	/* Clear pending interrupts */
	ret = palmas_clear_interrupts(&pdev->dev);
	if (ret < 0) {
		dev_err(&pdev->dev, "clear RTC int failed, err = %d\n", ret);
		return ret;
	}

	palmas_rtc->dev = &pdev->dev;
	platform_set_drvdata(pdev, palmas_rtc);

	if (enable_bb_charging) {
		unsigned reg = PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG;

		if (high_bb_charging)
			reg = 0;

		ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
			PALMAS_BACKUP_BATTERY_CTRL,
			PALMAS_BACKUP_BATTERY_CTRL_BBS_BBC_LOW_ICHRG, reg);
		if (ret < 0) {
			dev_err(&pdev->dev,
				"BACKUP_BATTERY_CTRL update failed, %d\n", ret);
			return ret;
		}

		ret = palmas_update_bits(palmas, PALMAS_PMU_CONTROL_BASE,
			PALMAS_BACKUP_BATTERY_CTRL,
			PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN,
			PALMAS_BACKUP_BATTERY_CTRL_BB_CHG_EN);
		if (ret < 0) {
			dev_err(&pdev->dev,
				"BACKUP_BATTERY_CTRL update failed, %d\n", ret);
			return ret;
		}
	}

	/* Start RTC */
	ret = palmas_update_bits(palmas, PALMAS_RTC_BASE, PALMAS_RTC_CTRL_REG,
			PALMAS_RTC_CTRL_REG_STOP_RTC,
			PALMAS_RTC_CTRL_REG_STOP_RTC);
	if (ret < 0) {
		dev_err(&pdev->dev, "RTC_CTRL write failed, err = %d\n", ret);
		return ret;
	}

	palmas_rtc->irq = platform_get_irq(pdev, 0);

	device_init_wakeup(&pdev->dev, 1);
	palmas_rtc->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
				&palmas_rtc_ops, THIS_MODULE);
	if (IS_ERR(palmas_rtc->rtc)) {
		ret = PTR_ERR(palmas_rtc->rtc);
		dev_err(&pdev->dev, "RTC register failed, err = %d\n", ret);
		return ret;
	}

	ret = devm_request_threaded_irq(&pdev->dev, palmas_rtc->irq, NULL,
			palmas_rtc_interrupt,
			IRQF_TRIGGER_LOW | IRQF_ONESHOT,
			dev_name(&pdev->dev), palmas_rtc);
	if (ret < 0) {
		dev_err(&pdev->dev, "IRQ request failed, err = %d\n", ret);
		return ret;
	}

	return 0;
}

static int palmas_rtc_remove(struct platform_device *pdev)
{
	palmas_rtc_alarm_irq_enable(&pdev->dev, 0);
	return 0;
}

#ifdef CONFIG_PM_SLEEP
static int palmas_rtc_suspend(struct device *dev)
{
	struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);

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

static int palmas_rtc_resume(struct device *dev)
{
	struct palmas_rtc *palmas_rtc = dev_get_drvdata(dev);

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

static SIMPLE_DEV_PM_OPS(palmas_rtc_pm_ops, palmas_rtc_suspend,
			 palmas_rtc_resume);

#ifdef CONFIG_OF
static const struct of_device_id of_palmas_rtc_match[] = {
	{ .compatible = "ti,palmas-rtc"},
	{ },
};
MODULE_DEVICE_TABLE(of, of_palmas_rtc_match);
#endif

static struct platform_driver palmas_rtc_driver = {
	.probe		= palmas_rtc_probe,
	.remove		= palmas_rtc_remove,
	.driver		= {
		.name	= "palmas-rtc",
		.pm	= &palmas_rtc_pm_ops,
		.of_match_table = of_match_ptr(of_palmas_rtc_match),
	},
};

module_platform_driver(palmas_rtc_driver);

MODULE_ALIAS("platform:palmas_rtc");
MODULE_DESCRIPTION("TI PALMAS series RTC driver");
MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_LICENSE("GPL v2");