summaryrefslogtreecommitdiffstats
path: root/drivers/rtc/rtc-asm9260.c
blob: 5219916ce11d2b609bde574a4b99f72d279eb8e9 (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
/*
 * Copyright (C) 2016 Oleksij Rempel <linux@rempel-privat.de>
 *
 * 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/clk.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/rtc.h>

/* Miscellaneous registers */
/* Interrupt Location Register */
#define HW_ILR			0x00
#define BM_RTCALF		BIT(1)
#define BM_RTCCIF		BIT(0)

/* Clock Control Register */
#define HW_CCR			0x08
/* Calibration counter disable */
#define BM_CCALOFF		BIT(4)
/* Reset internal oscillator divider */
#define BM_CTCRST		BIT(1)
/* Clock Enable */
#define BM_CLKEN		BIT(0)

/* Counter Increment Interrupt Register */
#define HW_CIIR			0x0C
#define BM_CIIR_IMYEAR		BIT(7)
#define BM_CIIR_IMMON		BIT(6)
#define BM_CIIR_IMDOY		BIT(5)
#define BM_CIIR_IMDOW		BIT(4)
#define BM_CIIR_IMDOM		BIT(3)
#define BM_CIIR_IMHOUR		BIT(2)
#define BM_CIIR_IMMIN		BIT(1)
#define BM_CIIR_IMSEC		BIT(0)

/* Alarm Mask Register */
#define HW_AMR			0x10
#define BM_AMR_IMYEAR		BIT(7)
#define BM_AMR_IMMON		BIT(6)
#define BM_AMR_IMDOY		BIT(5)
#define BM_AMR_IMDOW		BIT(4)
#define BM_AMR_IMDOM		BIT(3)
#define BM_AMR_IMHOUR		BIT(2)
#define BM_AMR_IMMIN		BIT(1)
#define BM_AMR_IMSEC		BIT(0)
#define BM_AMR_OFF		0xff

/* Consolidated time registers */
#define HW_CTIME0		0x14
#define BM_CTIME0_DOW_S		24
#define BM_CTIME0_DOW_M		0x7
#define BM_CTIME0_HOUR_S	16
#define BM_CTIME0_HOUR_M	0x1f
#define BM_CTIME0_MIN_S		8
#define BM_CTIME0_MIN_M		0x3f
#define BM_CTIME0_SEC_S		0
#define BM_CTIME0_SEC_M		0x3f

#define HW_CTIME1		0x18
#define BM_CTIME1_YEAR_S	16
#define BM_CTIME1_YEAR_M	0xfff
#define BM_CTIME1_MON_S		8
#define BM_CTIME1_MON_M		0xf
#define BM_CTIME1_DOM_S		0
#define BM_CTIME1_DOM_M		0x1f

#define HW_CTIME2		0x1C
#define BM_CTIME2_DOY_S		0
#define BM_CTIME2_DOY_M		0xfff

/* Time counter registers */
#define HW_SEC			0x20
#define HW_MIN			0x24
#define HW_HOUR			0x28
#define HW_DOM			0x2C
#define HW_DOW			0x30
#define HW_DOY			0x34
#define HW_MONTH		0x38
#define HW_YEAR			0x3C

#define HW_CALIBRATION		0x40
#define BM_CALDIR_BACK		BIT(17)
#define BM_CALVAL_M		0x1ffff

/* General purpose registers */
#define HW_GPREG0		0x44
#define HW_GPREG1		0x48
#define HW_GPREG2		0x4C
#define HW_GPREG3		0x50
#define HW_GPREG4		0x54

/* Alarm register group */
#define HW_ALSEC		0x60
#define HW_ALMIN		0x64
#define HW_ALHOUR		0x68
#define HW_ALDOM		0x6C
#define HW_ALDOW		0x70
#define HW_ALDOY		0x74
#define HW_ALMON		0x78
#define HW_ALYEAR		0x7C

struct asm9260_rtc_priv {
	struct device		*dev;
	void __iomem		*iobase;
	struct rtc_device	*rtc;
	struct clk		*clk;
	/* io lock */
	spinlock_t		lock;
};

static irqreturn_t asm9260_rtc_irq(int irq, void *dev_id)
{
	struct asm9260_rtc_priv *priv = dev_id;
	u32 isr;
	unsigned long events = 0;

	isr = ioread32(priv->iobase + HW_CIIR);
	if (!isr)
		return IRQ_NONE;

	iowrite32(0, priv->iobase + HW_CIIR);

	events |= RTC_AF | RTC_IRQF;

	rtc_update_irq(priv->rtc, 1, events);

	return IRQ_HANDLED;
}

static int asm9260_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
	u32 ctime0, ctime1, ctime2;
	unsigned long irq_flags;

	spin_lock_irqsave(&priv->lock, irq_flags);
	ctime0 = ioread32(priv->iobase + HW_CTIME0);
	ctime1 = ioread32(priv->iobase + HW_CTIME1);
	ctime2 = ioread32(priv->iobase + HW_CTIME2);

	if (ctime1 != ioread32(priv->iobase + HW_CTIME1)) {
		/*
		 * woops, counter flipped right now. Now we are safe
		 * to reread.
		 */
		ctime0 = ioread32(priv->iobase + HW_CTIME0);
		ctime1 = ioread32(priv->iobase + HW_CTIME1);
		ctime2 = ioread32(priv->iobase + HW_CTIME2);
	}
	spin_unlock_irqrestore(&priv->lock, irq_flags);

	tm->tm_sec  = (ctime0 >> BM_CTIME0_SEC_S)  & BM_CTIME0_SEC_M;
	tm->tm_min  = (ctime0 >> BM_CTIME0_MIN_S)  & BM_CTIME0_MIN_M;
	tm->tm_hour = (ctime0 >> BM_CTIME0_HOUR_S) & BM_CTIME0_HOUR_M;
	tm->tm_wday = (ctime0 >> BM_CTIME0_DOW_S)  & BM_CTIME0_DOW_M;

	tm->tm_mday = (ctime1 >> BM_CTIME1_DOM_S)  & BM_CTIME1_DOM_M;
	tm->tm_mon  = (ctime1 >> BM_CTIME1_MON_S)  & BM_CTIME1_MON_M;
	tm->tm_year = (ctime1 >> BM_CTIME1_YEAR_S) & BM_CTIME1_YEAR_M;

	tm->tm_yday = (ctime2 >> BM_CTIME2_DOY_S)  & BM_CTIME2_DOY_M;

	return 0;
}

static int asm9260_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
	unsigned long irq_flags;

	spin_lock_irqsave(&priv->lock, irq_flags);
	/*
	 * make sure SEC counter will not flip other counter on write time,
	 * real value will be written at the enf of sequence.
	 */
	iowrite32(0, priv->iobase + HW_SEC);

	iowrite32(tm->tm_year, priv->iobase + HW_YEAR);
	iowrite32(tm->tm_mon,  priv->iobase + HW_MONTH);
	iowrite32(tm->tm_mday, priv->iobase + HW_DOM);
	iowrite32(tm->tm_wday, priv->iobase + HW_DOW);
	iowrite32(tm->tm_yday, priv->iobase + HW_DOY);
	iowrite32(tm->tm_hour, priv->iobase + HW_HOUR);
	iowrite32(tm->tm_min,  priv->iobase + HW_MIN);
	iowrite32(tm->tm_sec,  priv->iobase + HW_SEC);
	spin_unlock_irqrestore(&priv->lock, irq_flags);

	return 0;
}

static int asm9260_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
	unsigned long irq_flags;

	spin_lock_irqsave(&priv->lock, irq_flags);
	alrm->time.tm_year = ioread32(priv->iobase + HW_ALYEAR);
	alrm->time.tm_mon  = ioread32(priv->iobase + HW_ALMON);
	alrm->time.tm_mday = ioread32(priv->iobase + HW_ALDOM);
	alrm->time.tm_wday = ioread32(priv->iobase + HW_ALDOW);
	alrm->time.tm_yday = ioread32(priv->iobase + HW_ALDOY);
	alrm->time.tm_hour = ioread32(priv->iobase + HW_ALHOUR);
	alrm->time.tm_min  = ioread32(priv->iobase + HW_ALMIN);
	alrm->time.tm_sec  = ioread32(priv->iobase + HW_ALSEC);

	alrm->enabled = ioread32(priv->iobase + HW_AMR) ? 1 : 0;
	alrm->pending = ioread32(priv->iobase + HW_CIIR) ? 1 : 0;
	spin_unlock_irqrestore(&priv->lock, irq_flags);

	return rtc_valid_tm(&alrm->time);
}

static int asm9260_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);
	unsigned long irq_flags;

	spin_lock_irqsave(&priv->lock, irq_flags);
	iowrite32(alrm->time.tm_year, priv->iobase + HW_ALYEAR);
	iowrite32(alrm->time.tm_mon,  priv->iobase + HW_ALMON);
	iowrite32(alrm->time.tm_mday, priv->iobase + HW_ALDOM);
	iowrite32(alrm->time.tm_wday, priv->iobase + HW_ALDOW);
	iowrite32(alrm->time.tm_yday, priv->iobase + HW_ALDOY);
	iowrite32(alrm->time.tm_hour, priv->iobase + HW_ALHOUR);
	iowrite32(alrm->time.tm_min,  priv->iobase + HW_ALMIN);
	iowrite32(alrm->time.tm_sec,  priv->iobase + HW_ALSEC);

	iowrite32(alrm->enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR);
	spin_unlock_irqrestore(&priv->lock, irq_flags);

	return 0;
}

static int asm9260_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct asm9260_rtc_priv *priv = dev_get_drvdata(dev);

	iowrite32(enabled ? 0 : BM_AMR_OFF, priv->iobase + HW_AMR);
	return 0;
}

static const struct rtc_class_ops asm9260_rtc_ops = {
	.read_time		= asm9260_rtc_read_time,
	.set_time		= asm9260_rtc_set_time,
	.read_alarm		= asm9260_rtc_read_alarm,
	.set_alarm		= asm9260_rtc_set_alarm,
	.alarm_irq_enable	= asm9260_alarm_irq_enable,
};

static int asm9260_rtc_probe(struct platform_device *pdev)
{
	struct asm9260_rtc_priv *priv;
	struct device *dev = &pdev->dev;
	struct resource	*res;
	int irq_alarm, ret;
	u32 ccr;

	priv = devm_kzalloc(dev, sizeof(struct asm9260_rtc_priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

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

	irq_alarm = platform_get_irq(pdev, 0);
	if (irq_alarm < 0) {
		dev_err(dev, "No alarm IRQ resource defined\n");
		return irq_alarm;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	priv->iobase = devm_ioremap_resource(dev, res);
	if (IS_ERR(priv->iobase))
		return PTR_ERR(priv->iobase);

	priv->clk = devm_clk_get(dev, "ahb");
	ret = clk_prepare_enable(priv->clk);
	if (ret) {
		dev_err(dev, "Failed to enable clk!\n");
		return ret;
	}

	ccr = ioread32(priv->iobase + HW_CCR);
	/* if dev is not enabled, reset it */
	if ((ccr & (BM_CLKEN | BM_CTCRST)) != BM_CLKEN) {
		iowrite32(BM_CTCRST, priv->iobase + HW_CCR);
		ccr = 0;
	}

	iowrite32(BM_CLKEN | ccr, priv->iobase + HW_CCR);
	iowrite32(0, priv->iobase + HW_CIIR);
	iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR);

	priv->rtc = devm_rtc_device_register(dev, dev_name(dev),
					     &asm9260_rtc_ops, THIS_MODULE);
	if (IS_ERR(priv->rtc)) {
		ret = PTR_ERR(priv->rtc);
		dev_err(dev, "Failed to register RTC device: %d\n", ret);
		goto err_return;
	}

	ret = devm_request_threaded_irq(dev, irq_alarm, NULL,
					asm9260_rtc_irq, IRQF_ONESHOT,
					dev_name(dev), priv);
	if (ret < 0) {
		dev_err(dev, "can't get irq %i, err %d\n",
			irq_alarm, ret);
		goto err_return;
	}

	return 0;

err_return:
	clk_disable_unprepare(priv->clk);
	return ret;
}

static int asm9260_rtc_remove(struct platform_device *pdev)
{
	struct asm9260_rtc_priv *priv = platform_get_drvdata(pdev);

	/* Disable alarm matching */
	iowrite32(BM_AMR_OFF, priv->iobase + HW_AMR);
	clk_disable_unprepare(priv->clk);
	return 0;
}

static const struct of_device_id asm9260_dt_ids[] = {
	{ .compatible = "alphascale,asm9260-rtc", },
	{}
};

static struct platform_driver asm9260_rtc_driver = {
	.probe		= asm9260_rtc_probe,
	.remove		= asm9260_rtc_remove,
	.driver		= {
		.name	= "asm9260-rtc",
		.of_match_table = asm9260_dt_ids,
	},
};

module_platform_driver(asm9260_rtc_driver);

MODULE_AUTHOR("Oleksij Rempel <linux@rempel-privat.de>");
MODULE_DESCRIPTION("Alphascale asm9260 SoC Realtime Clock Driver (RTC)");
MODULE_LICENSE("GPL");