watchdog: nowayout is bool
[linux-2.6.git] / drivers / rtc / rtc-vt8500.c
1 /*
2  * drivers/rtc/rtc-vt8500.c
3  *
4  *  Copyright (C) 2010 Alexey Charkov <alchark@gmail.com>
5  *
6  * Based on rtc-pxa.c
7  *
8  * This software is licensed under the terms of the GNU General Public
9  * License version 2, as published by the Free Software Foundation, and
10  * may be copied, distributed, and modified under those terms.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  */
17
18 #include <linux/module.h>
19 #include <linux/rtc.h>
20 #include <linux/init.h>
21 #include <linux/interrupt.h>
22 #include <linux/io.h>
23 #include <linux/bcd.h>
24 #include <linux/platform_device.h>
25 #include <linux/slab.h>
26
27 /*
28  * Register definitions
29  */
30 #define VT8500_RTC_TS           0x00    /* Time set */
31 #define VT8500_RTC_DS           0x04    /* Date set */
32 #define VT8500_RTC_AS           0x08    /* Alarm set */
33 #define VT8500_RTC_CR           0x0c    /* Control */
34 #define VT8500_RTC_TR           0x10    /* Time read */
35 #define VT8500_RTC_DR           0x14    /* Date read */
36 #define VT8500_RTC_WS           0x18    /* Write status */
37 #define VT8500_RTC_CL           0x20    /* Calibration */
38 #define VT8500_RTC_IS           0x24    /* Interrupt status */
39 #define VT8500_RTC_ST           0x28    /* Status */
40
41 #define INVALID_TIME_BIT        (1 << 31)
42
43 #define DATE_CENTURY_S          19
44 #define DATE_YEAR_S             11
45 #define DATE_YEAR_MASK          (0xff << DATE_YEAR_S)
46 #define DATE_MONTH_S            6
47 #define DATE_MONTH_MASK         (0x1f << DATE_MONTH_S)
48 #define DATE_DAY_MASK           0x3f
49
50 #define TIME_DOW_S              20
51 #define TIME_DOW_MASK           (0x07 << TIME_DOW_S)
52 #define TIME_HOUR_S             14
53 #define TIME_HOUR_MASK          (0x3f << TIME_HOUR_S)
54 #define TIME_MIN_S              7
55 #define TIME_MIN_MASK           (0x7f << TIME_MIN_S)
56 #define TIME_SEC_MASK           0x7f
57
58 #define ALARM_DAY_S             20
59 #define ALARM_DAY_MASK          (0x3f << ALARM_DAY_S)
60
61 #define ALARM_DAY_BIT           (1 << 29)
62 #define ALARM_HOUR_BIT          (1 << 28)
63 #define ALARM_MIN_BIT           (1 << 27)
64 #define ALARM_SEC_BIT           (1 << 26)
65
66 #define ALARM_ENABLE_MASK       (ALARM_DAY_BIT \
67                                 | ALARM_HOUR_BIT \
68                                 | ALARM_MIN_BIT \
69                                 | ALARM_SEC_BIT)
70
71 #define VT8500_RTC_CR_ENABLE    (1 << 0)        /* Enable RTC */
72 #define VT8500_RTC_CR_24H       (1 << 1)        /* 24h time format */
73 #define VT8500_RTC_CR_SM_ENABLE (1 << 2)        /* Enable periodic irqs */
74 #define VT8500_RTC_CR_SM_SEC    (1 << 3)        /* 0: 1Hz/60, 1: 1Hz */
75 #define VT8500_RTC_CR_CALIB     (1 << 4)        /* Enable calibration */
76
77 #define VT8500_RTC_IS_ALARM     (1 << 0)        /* Alarm interrupt status */
78
79 struct vt8500_rtc {
80         void __iomem            *regbase;
81         struct resource         *res;
82         int                     irq_alarm;
83         struct rtc_device       *rtc;
84         spinlock_t              lock;           /* Protects this structure */
85 };
86
87 static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
88 {
89         struct vt8500_rtc *vt8500_rtc = dev_id;
90         u32 isr;
91         unsigned long events = 0;
92
93         spin_lock(&vt8500_rtc->lock);
94
95         /* clear interrupt sources */
96         isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
97         writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);
98
99         spin_unlock(&vt8500_rtc->lock);
100
101         if (isr & VT8500_RTC_IS_ALARM)
102                 events |= RTC_AF | RTC_IRQF;
103
104         rtc_update_irq(vt8500_rtc->rtc, 1, events);
105
106         return IRQ_HANDLED;
107 }
108
109 static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
110 {
111         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
112         u32 date, time;
113
114         date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
115         time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);
116
117         tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
118         tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
119         tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
120         tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
121         tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S);
122         tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
123                         + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
124         tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
125
126         return 0;
127 }
128
129 static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
130 {
131         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
132
133         if (tm->tm_year < 100) {
134                 dev_warn(dev, "Only years 2000-2199 are supported by the "
135                               "hardware!\n");
136                 return -EINVAL;
137         }
138
139         writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S)
140                 | (bin2bcd(tm->tm_mon) << DATE_MONTH_S)
141                 | (bin2bcd(tm->tm_mday)),
142                 vt8500_rtc->regbase + VT8500_RTC_DS);
143         writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
144                 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
145                 | (bin2bcd(tm->tm_min) << TIME_MIN_S)
146                 | (bin2bcd(tm->tm_sec)),
147                 vt8500_rtc->regbase + VT8500_RTC_TS);
148
149         return 0;
150 }
151
152 static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
153 {
154         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
155         u32 isr, alarm;
156
157         alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
158         isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
159
160         alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
161         alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
162         alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
163         alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));
164
165         alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;
166         alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0;
167
168         return rtc_valid_tm(&alrm->time);
169 }
170
171 static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
172 {
173         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
174
175         writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
176                 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
177                 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
178                 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
179                 | (bin2bcd(alrm->time.tm_sec)),
180                 vt8500_rtc->regbase + VT8500_RTC_AS);
181
182         return 0;
183 }
184
185 static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
186 {
187         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
188         unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
189
190         if (enabled)
191                 tmp |= ALARM_ENABLE_MASK;
192         else
193                 tmp &= ~ALARM_ENABLE_MASK;
194
195         writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
196         return 0;
197 }
198
199 static const struct rtc_class_ops vt8500_rtc_ops = {
200         .read_time = vt8500_rtc_read_time,
201         .set_time = vt8500_rtc_set_time,
202         .read_alarm = vt8500_rtc_read_alarm,
203         .set_alarm = vt8500_rtc_set_alarm,
204         .alarm_irq_enable = vt8500_alarm_irq_enable,
205 };
206
207 static int __devinit vt8500_rtc_probe(struct platform_device *pdev)
208 {
209         struct vt8500_rtc *vt8500_rtc;
210         int ret;
211
212         vt8500_rtc = kzalloc(sizeof(struct vt8500_rtc), GFP_KERNEL);
213         if (!vt8500_rtc)
214                 return -ENOMEM;
215
216         spin_lock_init(&vt8500_rtc->lock);
217         platform_set_drvdata(pdev, vt8500_rtc);
218
219         vt8500_rtc->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
220         if (!vt8500_rtc->res) {
221                 dev_err(&pdev->dev, "No I/O memory resource defined\n");
222                 ret = -ENXIO;
223                 goto err_free;
224         }
225
226         vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
227         if (vt8500_rtc->irq_alarm < 0) {
228                 dev_err(&pdev->dev, "No alarm IRQ resource defined\n");
229                 ret = -ENXIO;
230                 goto err_free;
231         }
232
233         vt8500_rtc->res = request_mem_region(vt8500_rtc->res->start,
234                                              resource_size(vt8500_rtc->res),
235                                              "vt8500-rtc");
236         if (vt8500_rtc->res == NULL) {
237                 dev_err(&pdev->dev, "failed to request I/O memory\n");
238                 ret = -EBUSY;
239                 goto err_free;
240         }
241
242         vt8500_rtc->regbase = ioremap(vt8500_rtc->res->start,
243                                       resource_size(vt8500_rtc->res));
244         if (!vt8500_rtc->regbase) {
245                 dev_err(&pdev->dev, "Unable to map RTC I/O memory\n");
246                 ret = -EBUSY;
247                 goto err_release;
248         }
249
250         /* Enable RTC and set it to 24-hour mode */
251         writel(VT8500_RTC_CR_ENABLE | VT8500_RTC_CR_24H,
252                vt8500_rtc->regbase + VT8500_RTC_CR);
253
254         vt8500_rtc->rtc = rtc_device_register("vt8500-rtc", &pdev->dev,
255                                               &vt8500_rtc_ops, THIS_MODULE);
256         if (IS_ERR(vt8500_rtc->rtc)) {
257                 ret = PTR_ERR(vt8500_rtc->rtc);
258                 dev_err(&pdev->dev,
259                         "Failed to register RTC device -> %d\n", ret);
260                 goto err_unmap;
261         }
262
263         ret = request_irq(vt8500_rtc->irq_alarm, vt8500_rtc_irq, 0,
264                           "rtc alarm", vt8500_rtc);
265         if (ret < 0) {
266                 dev_err(&pdev->dev, "can't get irq %i, err %d\n",
267                         vt8500_rtc->irq_alarm, ret);
268                 goto err_unreg;
269         }
270
271         return 0;
272
273 err_unreg:
274         rtc_device_unregister(vt8500_rtc->rtc);
275 err_unmap:
276         iounmap(vt8500_rtc->regbase);
277 err_release:
278         release_mem_region(vt8500_rtc->res->start,
279                            resource_size(vt8500_rtc->res));
280 err_free:
281         kfree(vt8500_rtc);
282         return ret;
283 }
284
285 static int __devexit vt8500_rtc_remove(struct platform_device *pdev)
286 {
287         struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);
288
289         free_irq(vt8500_rtc->irq_alarm, vt8500_rtc);
290
291         rtc_device_unregister(vt8500_rtc->rtc);
292
293         /* Disable alarm matching */
294         writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
295         iounmap(vt8500_rtc->regbase);
296         release_mem_region(vt8500_rtc->res->start,
297                            resource_size(vt8500_rtc->res));
298
299         kfree(vt8500_rtc);
300         platform_set_drvdata(pdev, NULL);
301
302         return 0;
303 }
304
305 static struct platform_driver vt8500_rtc_driver = {
306         .probe          = vt8500_rtc_probe,
307         .remove         = __devexit_p(vt8500_rtc_remove),
308         .driver         = {
309                 .name   = "vt8500-rtc",
310                 .owner  = THIS_MODULE,
311         },
312 };
313
314 module_platform_driver(vt8500_rtc_driver);
315
316 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
317 MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
318 MODULE_LICENSE("GPL");
319 MODULE_ALIAS("platform:vt8500-rtc");