GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / rtc / rtc-nuc900.c
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
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
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
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
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
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
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
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
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
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
225 static int __init nuc900_rtc_probe(struct platform_device *pdev)
226 {
227         struct resource *res;
228         struct nuc900_rtc *nuc900_rtc;
229
230         nuc900_rtc = devm_kzalloc(&pdev->dev, sizeof(struct nuc900_rtc),
231                                 GFP_KERNEL);
232         if (!nuc900_rtc)
233                 return -ENOMEM;
234
235         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
236         nuc900_rtc->rtc_reg = devm_ioremap_resource(&pdev->dev, res);
237         if (IS_ERR(nuc900_rtc->rtc_reg))
238                 return PTR_ERR(nuc900_rtc->rtc_reg);
239
240         platform_set_drvdata(pdev, nuc900_rtc);
241
242         nuc900_rtc->rtcdev = devm_rtc_device_register(&pdev->dev, pdev->name,
243                                                 &nuc900_rtc_ops, THIS_MODULE);
244         if (IS_ERR(nuc900_rtc->rtcdev)) {
245                 dev_err(&pdev->dev, "rtc device register failed\n");
246                 return PTR_ERR(nuc900_rtc->rtcdev);
247         }
248
249         __raw_writel(__raw_readl(nuc900_rtc->rtc_reg + REG_RTC_TSSR) | MODE24,
250                                         nuc900_rtc->rtc_reg + REG_RTC_TSSR);
251
252         nuc900_rtc->irq_num = platform_get_irq(pdev, 0);
253         if (devm_request_irq(&pdev->dev, nuc900_rtc->irq_num,
254                         nuc900_rtc_interrupt, 0, "nuc900rtc", nuc900_rtc)) {
255                 dev_err(&pdev->dev, "NUC900 RTC request irq failed\n");
256                 return -EBUSY;
257         }
258
259         return 0;
260 }
261
262 static struct platform_driver nuc900_rtc_driver = {
263         .driver         = {
264                 .name   = "nuc900-rtc",
265         },
266 };
267
268 module_platform_driver_probe(nuc900_rtc_driver, nuc900_rtc_probe);
269
270 MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
271 MODULE_DESCRIPTION("nuc910/nuc920 RTC driver");
272 MODULE_LICENSE("GPL");
273 MODULE_ALIAS("platform:nuc900-rtc");