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 0;
103 }
104
nuc900_rtc_bcd2bin(unsigned int timereg,unsigned int calreg,struct rtc_time * tm)105 static int 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 return rtc_valid_tm(tm);
117 }
118
nuc900_rtc_bin2bcd(struct device * dev,struct rtc_time * settm,struct nuc900_bcd_time * gettm)119 static void nuc900_rtc_bin2bcd(struct device *dev, struct rtc_time *settm,
120 struct nuc900_bcd_time *gettm)
121 {
122 gettm->bcd_mday = bin2bcd(settm->tm_mday) << 0;
123 gettm->bcd_mon = bin2bcd(settm->tm_mon) << 8;
124
125 if (settm->tm_year < 100) {
126 dev_warn(dev, "The year will be between 1970-1999, right?\n");
127 gettm->bcd_year = bin2bcd(settm->tm_year) << 16;
128 } else {
129 gettm->bcd_year = bin2bcd(settm->tm_year - 100) << 16;
130 }
131
132 gettm->bcd_sec = bin2bcd(settm->tm_sec) << 0;
133 gettm->bcd_min = bin2bcd(settm->tm_min) << 8;
134 gettm->bcd_hour = bin2bcd(settm->tm_hour) << 16;
135 }
136
nuc900_alarm_irq_enable(struct device * dev,unsigned int enabled)137 static int nuc900_alarm_irq_enable(struct device *dev, unsigned int enabled)
138 {
139 struct nuc900_rtc *rtc = dev_get_drvdata(dev);
140
141 if (enabled)
142 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)|
143 (ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
144 else
145 __raw_writel(__raw_readl(rtc->rtc_reg + REG_RTC_RIER)&
146 (~ALARMINTENB), rtc->rtc_reg + REG_RTC_RIER);
147
148 return 0;
149 }
150
nuc900_rtc_read_time(struct device * dev,struct rtc_time * tm)151 static int nuc900_rtc_read_time(struct device *dev, struct rtc_time *tm)
152 {
153 struct nuc900_rtc *rtc = dev_get_drvdata(dev);
154 unsigned int timeval, clrval;
155
156 timeval = __raw_readl(rtc->rtc_reg + REG_RTC_TLR);
157 clrval = __raw_readl(rtc->rtc_reg + REG_RTC_CLR);
158
159 return nuc900_rtc_bcd2bin(timeval, clrval, tm);
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 return nuc900_rtc_bcd2bin(timeval, carval, &alrm->time);
193 }
194
nuc900_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alrm)195 static int nuc900_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
196 {
197 struct nuc900_rtc *rtc = dev_get_drvdata(dev);
198 struct nuc900_bcd_time tm;
199 unsigned long val;
200 int *err;
201
202 nuc900_rtc_bin2bcd(dev, &alrm->time, &tm);
203
204 err = check_rtc_access_enable(rtc);
205 if (IS_ERR(err))
206 return PTR_ERR(err);
207
208 val = tm.bcd_mday | tm.bcd_mon | tm.bcd_year;
209 __raw_writel(val, rtc->rtc_reg + REG_RTC_CAR);
210
211 val = tm.bcd_sec | tm.bcd_min | tm.bcd_hour;
212 __raw_writel(val, rtc->rtc_reg + REG_RTC_TAR);
213
214 return 0;
215 }
216
217 static struct rtc_class_ops nuc900_rtc_ops = {
218 .read_time = nuc900_rtc_read_time,
219 .set_time = nuc900_rtc_set_time,
220 .read_alarm = nuc900_rtc_read_alarm,
221 .set_alarm = nuc900_rtc_set_alarm,
222 .alarm_irq_enable = nuc900_alarm_irq_enable,
223 };
224
nuc900_rtc_probe(struct platform_device * pdev)225 static int __devinit nuc900_rtc_probe(struct platform_device *pdev)
226 {
227 struct resource *res;
228 struct nuc900_rtc *nuc900_rtc;
229 int err = 0;
230
231 nuc900_rtc = kzalloc(sizeof(struct nuc900_rtc), GFP_KERNEL);
232 if (!nuc900_rtc) {
233 dev_err(&pdev->dev, "kzalloc nuc900_rtc failed\n");
234 return -ENOMEM;
235 }
236 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
237 if (!res) {
238 dev_err(&pdev->dev, "platform_get_resource failed\n");
239 err = -ENXIO;
240 goto fail1;
241 }
242
243 if (!request_mem_region(res->start, resource_size(res),
244 pdev->name)) {
245 dev_err(&pdev->dev, "request_mem_region failed\n");
246 err = -EBUSY;
247 goto fail1;
248 }
249
250 nuc900_rtc->rtc_reg = ioremap(res->start, resource_size(res));
251 if (!nuc900_rtc->rtc_reg) {
252 dev_err(&pdev->dev, "ioremap rtc_reg failed\n");
253 err = -ENOMEM;
254 goto fail2;
255 }
256
257 platform_set_drvdata(pdev, nuc900_rtc);
258
259 nuc900_rtc->rtcdev = rtc_device_register(pdev->name, &pdev->dev,
260 &nuc900_rtc_ops, THIS_MODULE);
261 if (IS_ERR(nuc900_rtc->rtcdev)) {
262 dev_err(&pdev->dev, "rtc device register failed\n");
263 err = PTR_ERR(nuc900_rtc->rtcdev);
264 goto fail3;
265 }
266
267 __raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24,
268 nuc900_rtc->rtc_reg + REG_RTC_TSSR);
269
270 nuc900_rtc->irq_num = platform_get_irq(pdev, 0);
271 if (request_irq(nuc900_rtc->irq_num, nuc900_rtc_interrupt,
272 0, "nuc900rtc", nuc900_rtc)) {
273 dev_err(&pdev->dev, "NUC900 RTC request irq failed\n");
274 err = -EBUSY;
275 goto fail4;
276 }
277
278 return 0;
279
280 fail4: rtc_device_unregister(nuc900_rtc->rtcdev);
281 fail3: iounmap(nuc900_rtc->rtc_reg);
282 fail2: release_mem_region(res->start, resource_size(res));
283 fail1: kfree(nuc900_rtc);
284 return err;
285 }
286
nuc900_rtc_remove(struct platform_device * pdev)287 static int __devexit nuc900_rtc_remove(struct platform_device *pdev)
288 {
289 struct nuc900_rtc *nuc900_rtc = platform_get_drvdata(pdev);
290 struct resource *res;
291
292 free_irq(nuc900_rtc->irq_num, nuc900_rtc);
293 rtc_device_unregister(nuc900_rtc->rtcdev);
294 iounmap(nuc900_rtc->rtc_reg);
295
296 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
297 release_mem_region(res->start, resource_size(res));
298
299 kfree(nuc900_rtc);
300
301 platform_set_drvdata(pdev, NULL);
302
303 return 0;
304 }
305
306 static struct platform_driver nuc900_rtc_driver = {
307 .remove = __devexit_p(nuc900_rtc_remove),
308 .driver = {
309 .name = "nuc900-rtc",
310 .owner = THIS_MODULE,
311 },
312 };
313
nuc900_rtc_init(void)314 static int __init nuc900_rtc_init(void)
315 {
316 return platform_driver_probe(&nuc900_rtc_driver, nuc900_rtc_probe);
317 }
318
nuc900_rtc_exit(void)319 static void __exit nuc900_rtc_exit(void)
320 {
321 platform_driver_unregister(&nuc900_rtc_driver);
322 }
323
324 module_init(nuc900_rtc_init);
325 module_exit(nuc900_rtc_exit);
326
327 MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
328 MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
329 MODULE_LICENSE("GPL");
330 MODULE_ALIAS("platform:nuc900-rtc");
331