summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-r7301.c
blob: 1943c815115266ff336690abdb0ac6331cb690fd (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
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
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
/*
 * EPSON TOYOCOM RTC-7301SF/DG Driver
 *
 * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
 *
 * Based on rtc-rp5c01.c
 *
 * Datasheet: http://www5.epsondevice.com/en/products/parallel/rtc7301sf.html
 */

#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/delay.h>
#include <linux/regmap.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>

#define DRV_NAME "rtc-r7301"

#define RTC7301_1_SEC		0x0	/* Bank 0 and Band 1 */
#define RTC7301_10_SEC		0x1	/* Bank 0 and Band 1 */
#define RTC7301_AE		BIT(3)
#define RTC7301_1_MIN		0x2	/* Bank 0 and Band 1 */
#define RTC7301_10_MIN		0x3	/* Bank 0 and Band 1 */
#define RTC7301_1_HOUR		0x4	/* Bank 0 and Band 1 */
#define RTC7301_10_HOUR		0x5	/* Bank 0 and Band 1 */
#define RTC7301_DAY_OF_WEEK	0x6	/* Bank 0 and Band 1 */
#define RTC7301_1_DAY		0x7	/* Bank 0 and Band 1 */
#define RTC7301_10_DAY		0x8	/* Bank 0 and Band 1 */
#define RTC7301_1_MONTH		0x9	/* Bank 0 */
#define RTC7301_10_MONTH	0xa	/* Bank 0 */
#define RTC7301_1_YEAR		0xb	/* Bank 0 */
#define RTC7301_10_YEAR		0xc	/* Bank 0 */
#define RTC7301_100_YEAR	0xd	/* Bank 0 */
#define RTC7301_1000_YEAR	0xe	/* Bank 0 */
#define RTC7301_ALARM_CONTROL	0xe	/* Bank 1 */
#define RTC7301_ALARM_CONTROL_AIE	BIT(0)
#define RTC7301_ALARM_CONTROL_AF	BIT(1)
#define RTC7301_TIMER_CONTROL	0xe	/* Bank 2 */
#define RTC7301_TIMER_CONTROL_TIE	BIT(0)
#define RTC7301_TIMER_CONTROL_TF	BIT(1)
#define RTC7301_CONTROL		0xf	/* All banks */
#define RTC7301_CONTROL_BUSY		BIT(0)
#define RTC7301_CONTROL_STOP		BIT(1)
#define RTC7301_CONTROL_BANK_SEL_0	BIT(2)
#define RTC7301_CONTROL_BANK_SEL_1	BIT(3)

struct rtc7301_priv {
	struct regmap *regmap;
	int irq;
	spinlock_t lock;
	u8 bank;
};

static const struct regmap_config rtc7301_regmap_config = {
	.reg_bits = 32,
	.val_bits = 8,
	.reg_stride = 4,
};

static u8 rtc7301_read(struct rtc7301_priv *priv, unsigned int reg)
{
	int reg_stride = regmap_get_reg_stride(priv->regmap);
	unsigned int val;

	regmap_read(priv->regmap, reg_stride * reg, &val);

	return val & 0xf;
}

static void rtc7301_write(struct rtc7301_priv *priv, u8 val, unsigned int reg)
{
	int reg_stride = regmap_get_reg_stride(priv->regmap);

	regmap_write(priv->regmap, reg_stride * reg, val);
}

static void rtc7301_update_bits(struct rtc7301_priv *priv, unsigned int reg,
				u8 mask, u8 val)
{
	int reg_stride = regmap_get_reg_stride(priv->regmap);

	regmap_update_bits(priv->regmap, reg_stride * reg, mask, val);
}

static int rtc7301_wait_while_busy(struct rtc7301_priv *priv)
{
	int retries = 100;

	while (retries-- > 0) {
		u8 val;

		val = rtc7301_read(priv, RTC7301_CONTROL);
		if (!(val & RTC7301_CONTROL_BUSY))
			return 0;

		udelay(300);
	}

	return -ETIMEDOUT;
}

static void rtc7301_stop(struct rtc7301_priv *priv)
{
	rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP,
			    RTC7301_CONTROL_STOP);
}

static void rtc7301_start(struct rtc7301_priv *priv)
{
	rtc7301_update_bits(priv, RTC7301_CONTROL, RTC7301_CONTROL_STOP, 0);
}

static void rtc7301_select_bank(struct rtc7301_priv *priv, u8 bank)
{
	u8 val = 0;

	if (bank == priv->bank)
		return;

	if (bank & BIT(0))
		val |= RTC7301_CONTROL_BANK_SEL_0;
	if (bank & BIT(1))
		val |= RTC7301_CONTROL_BANK_SEL_1;

	rtc7301_update_bits(priv, RTC7301_CONTROL,
			    RTC7301_CONTROL_BANK_SEL_0 |
			    RTC7301_CONTROL_BANK_SEL_1, val);

	priv->bank = bank;
}

static void rtc7301_get_time(struct rtc7301_priv *priv, struct rtc_time *tm,
			     bool alarm)
{
	int year;

	tm->tm_sec = rtc7301_read(priv, RTC7301_1_SEC);
	tm->tm_sec += (rtc7301_read(priv, RTC7301_10_SEC) & ~RTC7301_AE) * 10;
	tm->tm_min = rtc7301_read(priv, RTC7301_1_MIN);
	tm->tm_min += (rtc7301_read(priv, RTC7301_10_MIN) & ~RTC7301_AE) * 10;
	tm->tm_hour = rtc7301_read(priv, RTC7301_1_HOUR);
	tm->tm_hour += (rtc7301_read(priv, RTC7301_10_HOUR) & ~RTC7301_AE) * 10;
	tm->tm_mday = rtc7301_read(priv, RTC7301_1_DAY);
	tm->tm_mday += (rtc7301_read(priv, RTC7301_10_DAY) & ~RTC7301_AE) * 10;

	if (alarm) {
		tm->tm_wday = -1;
		tm->tm_mon = -1;
		tm->tm_year = -1;
		tm->tm_yday = -1;
		tm->tm_isdst = -1;
		return;
	}

	tm->tm_wday = (rtc7301_read(priv, RTC7301_DAY_OF_WEEK) & ~RTC7301_AE);
	tm->tm_mon = rtc7301_read(priv, RTC7301_10_MONTH) * 10 +
		     rtc7301_read(priv, RTC7301_1_MONTH) - 1;
	year = rtc7301_read(priv, RTC7301_1000_YEAR) * 1000 +
	       rtc7301_read(priv, RTC7301_100_YEAR) * 100 +
	       rtc7301_read(priv, RTC7301_10_YEAR) * 10 +
	       rtc7301_read(priv, RTC7301_1_YEAR);

	tm->tm_year = year - 1900;
}

static void rtc7301_write_time(struct rtc7301_priv *priv, struct rtc_time *tm,
			       bool alarm)
{
	int year;

	rtc7301_write(priv, tm->tm_sec % 10, RTC7301_1_SEC);
	rtc7301_write(priv, tm->tm_sec / 10, RTC7301_10_SEC);

	rtc7301_write(priv, tm->tm_min % 10, RTC7301_1_MIN);
	rtc7301_write(priv, tm->tm_min / 10, RTC7301_10_MIN);

	rtc7301_write(priv, tm->tm_hour % 10, RTC7301_1_HOUR);
	rtc7301_write(priv, tm->tm_hour / 10, RTC7301_10_HOUR);

	rtc7301_write(priv, tm->tm_mday % 10, RTC7301_1_DAY);
	rtc7301_write(priv, tm->tm_mday / 10, RTC7301_10_DAY);

	/* Don't care for alarm register */
	rtc7301_write(priv, alarm ? RTC7301_AE : tm->tm_wday,
		      RTC7301_DAY_OF_WEEK);

	if (alarm)
		return;

	rtc7301_write(priv, (tm->tm_mon + 1) % 10, RTC7301_1_MONTH);
	rtc7301_write(priv, (tm->tm_mon + 1) / 10, RTC7301_10_MONTH);

	year = tm->tm_year + 1900;

	rtc7301_write(priv, year % 10, RTC7301_1_YEAR);
	rtc7301_write(priv, (year / 10) % 10, RTC7301_10_YEAR);
	rtc7301_write(priv, (year / 100) % 10, RTC7301_100_YEAR);
	rtc7301_write(priv, year / 1000, RTC7301_1000_YEAR);
}

static void rtc7301_alarm_irq(struct rtc7301_priv *priv, unsigned int enabled)
{
	rtc7301_update_bits(priv, RTC7301_ALARM_CONTROL,
			    RTC7301_ALARM_CONTROL_AF |
			    RTC7301_ALARM_CONTROL_AIE,
			    enabled ? RTC7301_ALARM_CONTROL_AIE : 0);
}

static int rtc7301_read_time(struct device *dev, struct rtc_time *tm)
{
	struct rtc7301_priv *priv = dev_get_drvdata(dev);
	unsigned long flags;
	int err;

	spin_lock_irqsave(&priv->lock, flags);

	rtc7301_select_bank(priv, 0);

	err = rtc7301_wait_while_busy(priv);
	if (!err)
		rtc7301_get_time(priv, tm, false);

	spin_unlock_irqrestore(&priv->lock, flags);

	return err;
}

static int rtc7301_set_time(struct device *dev, struct rtc_time *tm)
{
	struct rtc7301_priv *priv = dev_get_drvdata(dev);
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);

	rtc7301_stop(priv);
	udelay(300);
	rtc7301_select_bank(priv, 0);
	rtc7301_write_time(priv, tm, false);
	rtc7301_start(priv);

	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int rtc7301_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct rtc7301_priv *priv = dev_get_drvdata(dev);
	unsigned long flags;
	u8 alrm_ctrl;

	if (priv->irq <= 0)
		return -EINVAL;

	spin_lock_irqsave(&priv->lock, flags);

	rtc7301_select_bank(priv, 1);
	rtc7301_get_time(priv, &alarm->time, true);

	alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL);

	alarm->enabled = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AIE);
	alarm->pending = !!(alrm_ctrl & RTC7301_ALARM_CONTROL_AF);

	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int rtc7301_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
{
	struct rtc7301_priv *priv = dev_get_drvdata(dev);
	unsigned long flags;

	if (priv->irq <= 0)
		return -EINVAL;

	spin_lock_irqsave(&priv->lock, flags);

	rtc7301_select_bank(priv, 1);
	rtc7301_write_time(priv, &alarm->time, true);
	rtc7301_alarm_irq(priv, alarm->enabled);

	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static int rtc7301_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct rtc7301_priv *priv = dev_get_drvdata(dev);
	unsigned long flags;

	if (priv->irq <= 0)
		return -EINVAL;

	spin_lock_irqsave(&priv->lock, flags);

	rtc7301_select_bank(priv, 1);
	rtc7301_alarm_irq(priv, enabled);

	spin_unlock_irqrestore(&priv->lock, flags);

	return 0;
}

static const struct rtc_class_ops rtc7301_rtc_ops = {
	.read_time	= rtc7301_read_time,
	.set_time	= rtc7301_set_time,
	.read_alarm	= rtc7301_read_alarm,
	.set_alarm	= rtc7301_set_alarm,
	.alarm_irq_enable = rtc7301_alarm_irq_enable,
};

static irqreturn_t rtc7301_irq_handler(int irq, void *dev_id)
{
	struct rtc_device *rtc = dev_id;
	struct rtc7301_priv *priv = dev_get_drvdata(rtc->dev.parent);
	unsigned long flags;
	irqreturn_t ret = IRQ_NONE;
	u8 alrm_ctrl;

	spin_lock_irqsave(&priv->lock, flags);

	rtc7301_select_bank(priv, 1);

	alrm_ctrl = rtc7301_read(priv, RTC7301_ALARM_CONTROL);
	if (alrm_ctrl & RTC7301_ALARM_CONTROL_AF) {
		ret = IRQ_HANDLED;
		rtc7301_alarm_irq(priv, false);
		rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
	}

	spin_unlock_irqrestore(&priv->lock, flags);

	return ret;
}

static void rtc7301_init(struct rtc7301_priv *priv)
{
	unsigned long flags;

	spin_lock_irqsave(&priv->lock, flags);

	rtc7301_select_bank(priv, 2);
	rtc7301_write(priv, 0, RTC7301_TIMER_CONTROL);

	spin_unlock_irqrestore(&priv->lock, flags);
}

static int __init rtc7301_rtc_probe(struct platform_device *dev)
{
	struct resource *res;
	void __iomem *regs;
	struct rtc7301_priv *priv;
	struct rtc_device *rtc;
	int ret;

	res = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (!res)
		return -ENODEV;

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

	regs = devm_ioremap_resource(&dev->dev, res);
	if (IS_ERR(regs))
		return PTR_ERR(regs);

	priv->regmap = devm_regmap_init_mmio(&dev->dev, regs,
					     &rtc7301_regmap_config);
	if (IS_ERR(priv->regmap))
		return PTR_ERR(priv->regmap);

	priv->irq = platform_get_irq(dev, 0);

	spin_lock_init(&priv->lock);
	priv->bank = -1;

	rtc7301_init(priv);

	platform_set_drvdata(dev, priv);

	rtc = devm_rtc_device_register(&dev->dev, DRV_NAME, &rtc7301_rtc_ops,
				       THIS_MODULE);
	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	if (priv->irq > 0) {
		ret = devm_request_irq(&dev->dev, priv->irq,
				       rtc7301_irq_handler, IRQF_SHARED,
				       dev_name(&dev->dev), rtc);
		if (ret) {
			priv->irq = 0;
			dev_err(&dev->dev, "unable to request IRQ\n");
		} else {
			device_set_wakeup_capable(&dev->dev, true);
		}
	}

	return 0;
}

#ifdef CONFIG_PM_SLEEP

static int rtc7301_suspend(struct device *dev)
{
	struct rtc7301_priv *priv = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		enable_irq_wake(priv->irq);

	return 0;
}

static int rtc7301_resume(struct device *dev)
{
	struct rtc7301_priv *priv = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		disable_irq_wake(priv->irq);

	return 0;
}

#endif

static SIMPLE_DEV_PM_OPS(rtc7301_pm_ops, rtc7301_suspend, rtc7301_resume);

static const struct of_device_id rtc7301_dt_match[] = {
	{ .compatible = "epson,rtc7301sf" },
	{ .compatible = "epson,rtc7301dg" },
	{}
};
MODULE_DEVICE_TABLE(of, rtc7301_dt_match);

static struct platform_driver rtc7301_rtc_driver = {
	.driver	= {
		.name = DRV_NAME,
		.of_match_table = rtc7301_dt_match,
		.pm = &rtc7301_pm_ops,
	},
};

module_platform_driver_probe(rtc7301_rtc_driver, rtc7301_rtc_probe);

MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("EPSON TOYOCOM RTC-7301SF/DG Driver");
MODULE_ALIAS("platform:rtc-r7301");