summaryrefslogtreecommitdiff
path: root/drivers/rtc/rtc-nuc900.c
blob: 4ed81117cf5f346d663d11f0a799df4bd3801926 (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
/*
 * Copyright (c) 2008-2009 Nuvoton technology corporation.
 *
 * Wan ZongShun <mcuos.com@gmail.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 of the License.
 *
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/rtc.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/bcd.h>

/* RTC Control Registers */
#define REG_RTC_INIR		0x00
#define REG_RTC_AER		0x04
#define REG_RTC_FCR		0x08
#define REG_RTC_TLR		0x0C
#define REG_RTC_CLR		0x10
#define REG_RTC_TSSR		0x14
#define REG_RTC_DWR		0x18
#define REG_RTC_TAR		0x1C
#define REG_RTC_CAR		0x20
#define REG_RTC_LIR		0x24
#define REG_RTC_RIER		0x28
#define REG_RTC_RIIR		0x2C
#define REG_RTC_TTR		0x30

#define RTCSET			0x01
#define AERRWENB		0x10000
#define INIRRESET		0xa5eb1357
#define AERPOWERON		0xA965
#define AERPOWEROFF		0x0000
#define LEAPYEAR		0x0001
#define TICKENB			0x80
#define TICKINTENB		0x0002
#define ALARMINTENB		0x0001
#define MODE24			0x0001

struct nuc900_rtc {
	int			irq_num;
	void __iomem		*rtc_reg;
	struct rtc_device	*rtcdev;
};

struct nuc900_bcd_time {
	int bcd_sec;
	int bcd_min;
	int bcd_hour;
	int bcd_mday;
	int bcd_mon;
	int bcd_year;
};

static irqreturn_t nuc900_rtc_interrupt(int irq, void *_rtc)
{
	struct nuc900_rtc *rtc = _rtc;
	unsigned long events = 0, rtc_irq;

	rtc_irq = __raw_readl(rtc->rtc_reg + REG_RTC_RIIR);

	if (rtc_irq & ALARMINTENB) {
		rtc_irq &= ~ALARMINTENB;
		__raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
		events |= RTC_AF | RTC_IRQF;
	}

	if (rtc_irq & TICKINTENB) {
		rtc_irq &= ~TICKINTENB;
		__raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
		events |= RTC_UF | RTC_IRQF;
	}

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

	return IRQ_HANDLED;
}

static int *check_rtc_access_enable(struct nuc900_rtc *nuc900_rtc)
{
	unsigned int timeout = 0x1000;
	__raw_writel(INIRRESET, nuc900_rtc->rtc_reg + REG_RTC_INIR);

	mdelay(10);

	__raw_writel(AERPOWERON, nuc900_rtc->rtc_reg + REG_RTC_AER);

	while (!(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB)
								&& --timeout)
		mdelay(1);

	if (!timeout)
		return ERR_PTR(-EPERM);

	return NULL;
}

static int nuc900_rtc_bcd2bin(unsigned int timereg,
				unsigned int calreg, struct rtc_time *tm)
{
	tm->tm_mday	= bcd2bin(calreg >> 0);
	tm->tm_mon	= bcd2bin(calreg >> 8);
	tm->tm_year	= bcd2bin(calreg >> 16) + 100;

	tm->tm_sec	= bcd2bin(timereg >> 0);
	tm->tm_min	= bcd2bin(timereg >> 8);
	tm->tm_hour	= bcd2bin(timereg >> 16);

	return rtc_valid_tm(tm);
}

static void nuc900_rtc_bin2bcd(struct device *dev, struct rtc_time *settm,
						struct nuc900_bcd_time *gettm)
{
	gettm->bcd_mday = bin2bcd(settm->tm_mday) << 0;
	gettm->bcd_mon  = bin2bcd(settm->tm_mon) << 8;

	if (settm->tm_year < 100) {
		dev_warn(dev, "The year will be between 1970-1999, right?\n");
		gettm->bcd_year = bin2bcd(settm->tm_year) << 16;
	} else {
		gettm->bcd_year = bin2bcd(settm->tm_year - 100) << 16;
	}

	gettm->bcd_sec  = bin2bcd(settm->tm_sec) << 0;
	gettm->bcd_min  = bin2bcd(settm->tm_min) << 8;
	gettm->bcd_hour = bin2bcd(settm->tm_hour) << 16;
}

static int nuc900_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct nuc900_rtc *rtc = dev_get_drvdata(dev);

	if (enabled)
		__raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
				(ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
	else
		__raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
				(~ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);

	return 0;
}

static int nuc900_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct nuc900_rtc *rtc = dev_get_drvdata(dev);
	unsigned int timeval, clrval;

	timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TLR);
	clrval	= __raw_readl(rtc->rtc_reg + REG_RTC_CLR);

	return nuc900_rtc_bcd2bin(timeval, clrval, tm);
}

static int nuc900_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct nuc900_rtc *rtc = dev_get_drvdata(dev);
	struct nuc900_bcd_time gettm;
	unsigned long val;
	int *err;

	nuc900_rtc_bin2bcd(dev, tm, &gettm);

	err = check_rtc_access_enable(rtc);
	if (IS_ERR(err))
		return PTR_ERR(err);

	val = gettm.bcd_mday | gettm.bcd_mon | gettm.bcd_year;
	__raw_writel(val, rtc->rtc_reg + REG_RTC_CLR);

	val = gettm.bcd_sec | gettm.bcd_min | gettm.bcd_hour;
	__raw_writel(val, rtc->rtc_reg + REG_RTC_TLR);

	return 0;
}

static int nuc900_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct nuc900_rtc *rtc = dev_get_drvdata(dev);
	unsigned int timeval, carval;

	timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TAR);
	carval	= __raw_readl(rtc->rtc_reg + REG_RTC_CAR);

	return nuc900_rtc_bcd2bin(timeval, carval, &alrm->time);
}

static int nuc900_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct nuc900_rtc *rtc = dev_get_drvdata(dev);
	struct nuc900_bcd_time tm;
	unsigned long val;
	int *err;

	nuc900_rtc_bin2bcd(dev, &alrm->time, &tm);

	err = check_rtc_access_enable(rtc);
	if (IS_ERR(err))
		return PTR_ERR(err);

	val = tm.bcd_mday | tm.bcd_mon | tm.bcd_year;
	__raw_writel(val, rtc->rtc_reg + REG_RTC_CAR);

	val = tm.bcd_sec | tm.bcd_min | tm.bcd_hour;
	__raw_writel(val, rtc->rtc_reg + REG_RTC_TAR);

	return 0;
}

static const struct rtc_class_ops nuc900_rtc_ops = {
	.read_time = nuc900_rtc_read_time,
	.set_time = nuc900_rtc_set_time,
	.read_alarm = nuc900_rtc_read_alarm,
	.set_alarm = nuc900_rtc_set_alarm,
	.alarm_irq_enable = nuc900_alarm_irq_enable,
};

static int __init nuc900_rtc_probe(struct platform_device *pdev)
{
	struct resource *res;
	struct nuc900_rtc *nuc900_rtc;

	nuc900_rtc = devm_kzalloc(&pdev->dev, sizeof(struct nuc900_rtc),
				GFP_KERNEL);
	if (!nuc900_rtc)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	nuc900_rtc->rtc_reg = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(nuc900_rtc->rtc_reg))
		return PTR_ERR(nuc900_rtc->rtc_reg);

	platform_set_drvdata(pdev, nuc900_rtc);

	nuc900_rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name,
						&nuc900_rtc_ops, THIS_MODULE);
	if (IS_ERR(nuc900_rtc->rtcdev)) {
		dev_err(&pdev->dev, "rtc device register failed\n");
		return PTR_ERR(nuc900_rtc->rtcdev);
	}

	__raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24,
					nuc900_rtc->rtc_reg + REG_RTC_TSSR);

	nuc900_rtc->irq_num = platform_get_irq(pdev, 0);
	if (devm_request_irq(&pdev->dev, nuc900_rtc->irq_num,
			nuc900_rtc_interrupt, 0, "nuc900rtc", nuc900_rtc)) {
		dev_err(&pdev->dev, "NUC900 RTC request irq failed\n");
		return -EBUSY;
	}

	return 0;
}

static struct platform_driver nuc900_rtc_driver = {
	.driver		= {
		.name	= "nuc900-rtc",
	},
};

module_platform_driver_probe(nuc900_rtc_driver, nuc900_rtc_probe);

MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:nuc900-rtc");