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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
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
47struct nuc900_rtc {
48 int irq_num;
49 void __iomem *rtc_reg;
50 struct rtc_device *rtcdev;
51};
52
53struct 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
62static 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
86static 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
105static 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
117static 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
135static 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
149static 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
162static 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
184static 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
197static 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
219static 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
227static 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
264static struct platform_driver nuc900_rtc_driver = {
265 .driver = {
266 .name = "nuc900-rtc",
267 },
268};
269
270module_platform_driver_probe(nuc900_rtc_driver, nuc900_rtc_probe);
271
272MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
273MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
274MODULE_LICENSE("GPL");
275MODULE_ALIAS("platform:nuc900-rtc");
276
