1 /*
2 * Copyright (c) 2008-2009 Nuvoton technology corporation.
3 *
4 * Wan ZongShun <mcuos.com@gmail.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation;version 2 of the License.
9 *
10 */
11
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/rtc.h>
17 #include <linux/delay.h>
18 #include <linux/io.h>
19 #include <linux/bcd.h>
20
21 /* RTC Control Registers */
22 #define REG_RTC_INIR 0x00
23 #define REG_RTC_AER 0x04
24 #define REG_RTC_FCR 0x08
25 #define REG_RTC_TLR 0x0C
26 #define REG_RTC_CLR 0x10
27 #define REG_RTC_TSSR 0x14
28 #define REG_RTC_DWR 0x18
29 #define REG_RTC_TAR 0x1C
30 #define REG_RTC_CAR 0x20
31 #define REG_RTC_LIR 0x24
32 #define REG_RTC_RIER 0x28
33 #define REG_RTC_RIIR 0x2C
34 #define REG_RTC_TTR 0x30
35
36 #define RTCSET 0x01
37 #define AERRWENB 0x10000
38 #define INIRRESET 0xa5eb1357
39 #define AERPOWERON 0xA965
40 #define AERPOWEROFF 0x0000
41 #define LEAPYEAR 0x0001
42 #define TICKENB 0x80
43 #define TICKINTENB 0x0002
44 #define ALARMINTENB 0x0001
45 #define MODE24 0x0001
46
47 struct nuc900_rtc {
48 int irq_num;
49 void __iomem *rtc_reg;
50 struct rtc_device *rtcdev;
51 };
52
53 struct nuc900_bcd_time {
54 int bcd_sec;
55 int bcd_min;
56 int bcd_hour;
57 int bcd_mday;
58 int bcd_mon;
59 int bcd_year;
60 };
61
nuc900_rtc_interrupt(int irq,void * _rtc)62 static irqreturn_t nuc900_rtc_interrupt(int irq, void *_rtc)
63 {
64 struct nuc900_rtc *rtc = _rtc;
65 unsigned long events = 0, rtc_irq;
66
67 rtc_irq = __raw_readl(rtc->rtc_reg + REG_RTC_RIIR);
68
69 if (rtc_irq & ALARMINTENB) {
70 rtc_irq &= ~ALARMINTENB;
71 __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
72 events |= RTC_AF | RTC_IRQF;
73 }
74
75 if (rtc_irq & TICKINTENB) {
76 rtc_irq &= ~TICKINTENB;
77 __raw_writel(rtc_irq, rtc->rtc_reg + REG_RTC_RIIR);
78 events |= RTC_UF | RTC_IRQF;
79 }
80
81 rtc_update_irq(rtc->rtcdev, 1, events);
82
83 return IRQ_HANDLED;
84 }
85
check_rtc_access_enable(struct nuc900_rtc * nuc900_rtc)86 static int *check_rtc_access_enable(struct nuc900_rtc *nuc900_rtc)
87 {
88 unsigned int timeout = 0x1000;
89 __raw_writel(INIRRESET, nuc900_rtc->rtc_reg + REG_RTC_INIR);
90
91 mdelay(10);
92
93 __raw_writel(AERPOWERON, nuc900_rtc->rtc_reg + REG_RTC_AER);
94
95 while (!(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_AER) & AERRWENB)
96 && --timeout)
97 mdelay(1);
98
99 if (!timeout)
100 return ERR_PTR(-EPERM);
101
102 return NULL;
103 }
104
nuc900_rtc_bcd2bin(unsigned int timereg,unsigned int calreg,struct rtc_time * tm)105 static void nuc900_rtc_bcd2bin(unsigned int timereg,
106 unsigned int calreg, struct rtc_time *tm)
107 {
108 tm->tm_mday = bcd2bin(calreg >> 0);
109 tm->tm_mon = bcd2bin(calreg >> 8);
110 tm->tm_year = bcd2bin(calreg >> 16) + 100;
111
112 tm->tm_sec = bcd2bin(timereg >> 0);
113 tm->tm_min = bcd2bin(timereg >> 8);
114 tm->tm_hour = bcd2bin(timereg >> 16);
115 }
116
nuc900_rtc_bin2bcd(struct device * dev,struct rtc_time * settm,struct nuc900_bcd_time * gettm)117 static void nuc900_rtc_bin2bcd(struct device *dev, struct rtc_time *settm,
118 struct nuc900_bcd_time *gettm)
119 {
120 gettm->bcd_mday = bin2bcd(settm->tm_mday) << 0;
121 gettm->bcd_mon = bin2bcd(settm->tm_mon) << 8;
122
123 if (settm->tm_year < 100) {
124 dev_warn(dev, "The year will be between 1970-1999, right?\n");
125 gettm->bcd_year = bin2bcd(settm->tm_year) << 16;
126 } else {
127 gettm->bcd_year = bin2bcd(settm->tm_year - 100) << 16;
128 }
129
130 gettm->bcd_sec = bin2bcd(settm->tm_sec) << 0;
131 gettm->bcd_min = bin2bcd(settm->tm_min) << 8;
132 gettm->bcd_hour = bin2bcd(settm->tm_hour) << 16;
133 }
134
nuc900_alarm_irq_enable(struct device * dev,unsigned int enabled)135 static int nuc900_alarm_irq_enable(struct device *dev, unsigned int enabled)
136 {
137 struct nuc900_rtc *rtc = dev_get_drvdata(dev);
138
139 if (enabled)
140 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
141 (ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
142 else
143 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
144 (~ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
145
146 return 0;
147 }
148
nuc900_rtc_read_time(struct device * dev,struct rtc_time * tm)149 static int nuc900_rtc_read_time(struct device *dev, struct rtc_time *tm)
150 {
151 struct nuc900_rtc *rtc = dev_get_drvdata(dev);
152 unsigned int timeval, clrval;
153
154 timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TLR);
155 clrval = __raw_readl(rtc->rtc_reg + REG_RTC_CLR);
156
157 nuc900_rtc_bcd2bin(timeval, clrval, tm);
158
159 return 0;
160 }
161
nuc900_rtc_set_time(struct device * dev,struct rtc_time * tm)162 static int nuc900_rtc_set_time(struct device *dev, struct rtc_time *tm)
163 {
164 struct nuc900_rtc *rtc = dev_get_drvdata(dev);
165 struct nuc900_bcd_time gettm;
166 unsigned long val;
167 int *err;
168
169 nuc900_rtc_bin2bcd(dev, tm, &gettm);
170
171 err = check_rtc_access_enable(rtc);
172 if (IS_ERR(err))
173 return PTR_ERR(err);
174
175 val = gettm.bcd_mday | gettm.bcd_mon | gettm.bcd_year;
176 __raw_writel(val, rtc->rtc_reg + REG_RTC_CLR);
177
178 val = gettm.bcd_sec | gettm.bcd_min | gettm.bcd_hour;
179 __raw_writel(val, rtc->rtc_reg + REG_RTC_TLR);
180
181 return 0;
182 }
183
nuc900_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alrm)184 static int nuc900_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
185 {
186 struct nuc900_rtc *rtc = dev_get_drvdata(dev);
187 unsigned int timeval, carval;
188
189 timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TAR);
190 carval = __raw_readl(rtc->rtc_reg + REG_RTC_CAR);
191
192 nuc900_rtc_bcd2bin(timeval, carval, &alrm->time);
193
194 return rtc_valid_tm(&alrm->time);
195 }
196
nuc900_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)197 static int nuc900_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
198 {
199 struct nuc900_rtc *rtc = dev_get_drvdata(dev);
200 struct nuc900_bcd_time tm;
201 unsigned long val;
202 int *err;
203
204 nuc900_rtc_bin2bcd(dev, &alrm->time, &tm);
205
206 err = check_rtc_access_enable(rtc);
207 if (IS_ERR(err))
208 return PTR_ERR(err);
209
210 val = tm.bcd_mday | tm.bcd_mon | tm.bcd_year;
211 __raw_writel(val, rtc->rtc_reg + REG_RTC_CAR);
212
213 val = tm.bcd_sec | tm.bcd_min | tm.bcd_hour;
214 __raw_writel(val, rtc->rtc_reg + REG_RTC_TAR);
215
216 return 0;
217 }
218
219 static const struct rtc_class_ops nuc900_rtc_ops = {
220 .read_time = nuc900_rtc_read_time,
221 .set_time = nuc900_rtc_set_time,
222 .read_alarm = nuc900_rtc_read_alarm,
223 .set_alarm = nuc900_rtc_set_alarm,
224 .alarm_irq_enable = nuc900_alarm_irq_enable,
225 };
226
nuc900_rtc_probe(struct platform_device * pdev)227 static int __init nuc900_rtc_probe(struct platform_device *pdev)
228 {
229 struct resource *res;
230 struct nuc900_rtc *nuc900_rtc;
231
232 nuc900_rtc = devm_kzalloc(&pdev->dev, sizeof(struct nuc900_rtc),
233 GFP_KERNEL);
234 if (!nuc900_rtc)
235 return -ENOMEM;
236
237 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
238 nuc900_rtc->rtc_reg = devm_ioremap_resource(&pdev->dev, res);
239 if (IS_ERR(nuc900_rtc->rtc_reg))
240 return PTR_ERR(nuc900_rtc->rtc_reg);
241
242 platform_set_drvdata(pdev, nuc900_rtc);
243
244 nuc900_rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name,
245 &nuc900_rtc_ops, THIS_MODULE);
246 if (IS_ERR(nuc900_rtc->rtcdev)) {
247 dev_err(&pdev->dev, "rtc device register failed\n");
248 return PTR_ERR(nuc900_rtc->rtcdev);
249 }
250
251 __raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24,
252 nuc900_rtc->rtc_reg + REG_RTC_TSSR);
253
254 nuc900_rtc->irq_num = platform_get_irq(pdev, 0);
255 if (devm_request_irq(&pdev->dev, nuc900_rtc->irq_num,
256 nuc900_rtc_interrupt, 0, "nuc900rtc", nuc900_rtc)) {
257 dev_err(&pdev->dev, "NUC900 RTC request irq failed\n");
258 return -EBUSY;
259 }
260
261 return 0;
262 }
263
264 static struct platform_driver nuc900_rtc_driver = {
265 .driver = {
266 .name = "nuc900-rtc",
267 },
268 };
269
270 module_platform_driver_probe(nuc900_rtc_driver, nuc900_rtc_probe);
271
272 MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
273 MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
274 MODULE_LICENSE("GPL");
275 MODULE_ALIAS("platform:nuc900-rtc");
276