00c930f4b6f322fcfd42b37c8f2e6926f0bdbbfd
[~shefty/rdma-dev.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 #include <linux/of.h>
27
28 /*
29  * Register definitions
30  */
31 #define VT8500_RTC_TS           0x00    /* Time set */
32 #define VT8500_RTC_DS           0x04    /* Date set */
33 #define VT8500_RTC_AS           0x08    /* Alarm set */
34 #define VT8500_RTC_CR           0x0c    /* Control */
35 #define VT8500_RTC_TR           0x10    /* Time read */
36 #define VT8500_RTC_DR           0x14    /* Date read */
37 #define VT8500_RTC_WS           0x18    /* Write status */
38 #define VT8500_RTC_CL           0x20    /* Calibration */
39 #define VT8500_RTC_IS           0x24    /* Interrupt status */
40 #define VT8500_RTC_ST           0x28    /* Status */
41
42 #define INVALID_TIME_BIT        (1 << 31)
43
44 #define DATE_CENTURY_S          19
45 #define DATE_YEAR_S             11
46 #define DATE_YEAR_MASK          (0xff << DATE_YEAR_S)
47 #define DATE_MONTH_S            6
48 #define DATE_MONTH_MASK         (0x1f << DATE_MONTH_S)
49 #define DATE_DAY_MASK           0x3f
50
51 #define TIME_DOW_S              20
52 #define TIME_DOW_MASK           (0x07 << TIME_DOW_S)
53 #define TIME_HOUR_S             14
54 #define TIME_HOUR_MASK          (0x3f << TIME_HOUR_S)
55 #define TIME_MIN_S              7
56 #define TIME_MIN_MASK           (0x7f << TIME_MIN_S)
57 #define TIME_SEC_MASK           0x7f
58
59 #define ALARM_DAY_S             20
60 #define ALARM_DAY_MASK          (0x3f << ALARM_DAY_S)
61
62 #define ALARM_DAY_BIT           (1 << 29)
63 #define ALARM_HOUR_BIT          (1 << 28)
64 #define ALARM_MIN_BIT           (1 << 27)
65 #define ALARM_SEC_BIT           (1 << 26)
66
67 #define ALARM_ENABLE_MASK       (ALARM_DAY_BIT \
68                                 | ALARM_HOUR_BIT \
69                                 | ALARM_MIN_BIT \
70                                 | ALARM_SEC_BIT)
71
72 #define VT8500_RTC_CR_ENABLE    (1 << 0)        /* Enable RTC */
73 #define VT8500_RTC_CR_12H       (1 << 1)        /* 12h time format */
74 #define VT8500_RTC_CR_SM_ENABLE (1 << 2)        /* Enable periodic irqs */
75 #define VT8500_RTC_CR_SM_SEC    (1 << 3)        /* 0: 1Hz/60, 1: 1Hz */
76 #define VT8500_RTC_CR_CALIB     (1 << 4)        /* Enable calibration */
77
78 #define VT8500_RTC_IS_ALARM     (1 << 0)        /* Alarm interrupt status */
79
80 struct vt8500_rtc {
81         void __iomem            *regbase;
82         struct resource         *res;
83         int                     irq_alarm;
84         struct rtc_device       *rtc;
85         spinlock_t              lock;           /* Protects this structure */
86 };
87
88 static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
89 {
90         struct vt8500_rtc *vt8500_rtc = dev_id;
91         u32 isr;
92         unsigned long events = 0;
93
94         spin_lock(&vt8500_rtc->lock);
95
96         /* clear interrupt sources */
97         isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
98         writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);
99
100         spin_unlock(&vt8500_rtc->lock);
101
102         if (isr & VT8500_RTC_IS_ALARM)
103                 events |= RTC_AF | RTC_IRQF;
104
105         rtc_update_irq(vt8500_rtc->rtc, 1, events);
106
107         return IRQ_HANDLED;
108 }
109
110 static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
111 {
112         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
113         u32 date, time;
114
115         date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
116         time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);
117
118         tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
119         tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
120         tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
121         tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
122         tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S) - 1;
123         tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
124                         + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
125         tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
126
127         return 0;
128 }
129
130 static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
131 {
132         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
133
134         if (tm->tm_year < 100) {
135                 dev_warn(dev, "Only years 2000-2199 are supported by the "
136                               "hardware!\n");
137                 return -EINVAL;
138         }
139
140         writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S)
141                 | (bin2bcd(tm->tm_mon + 1) << DATE_MONTH_S)
142                 | (bin2bcd(tm->tm_mday))
143                 | ((tm->tm_year >= 200) << DATE_CENTURY_S),
144                 vt8500_rtc->regbase + VT8500_RTC_DS);
145         writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
146                 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
147                 | (bin2bcd(tm->tm_min) << TIME_MIN_S)
148                 | (bin2bcd(tm->tm_sec)),
149                 vt8500_rtc->regbase + VT8500_RTC_TS);
150
151         return 0;
152 }
153
154 static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
155 {
156         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
157         u32 isr, alarm;
158
159         alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
160         isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
161
162         alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
163         alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
164         alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
165         alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));
166
167         alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;
168         alrm->pending = (isr & VT8500_RTC_IS_ALARM) ? 1 : 0;
169
170         return rtc_valid_tm(&alrm->time);
171 }
172
173 static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
174 {
175         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
176
177         writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
178                 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
179                 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
180                 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
181                 | (bin2bcd(alrm->time.tm_sec)),
182                 vt8500_rtc->regbase + VT8500_RTC_AS);
183
184         return 0;
185 }
186
187 static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
188 {
189         struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
190         unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
191
192         if (enabled)
193                 tmp |= ALARM_ENABLE_MASK;
194         else
195                 tmp &= ~ALARM_ENABLE_MASK;
196
197         writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
198         return 0;
199 }
200
201 static const struct rtc_class_ops vt8500_rtc_ops = {
202         .read_time = vt8500_rtc_read_time,
203         .set_time = vt8500_rtc_set_time,
204         .read_alarm = vt8500_rtc_read_alarm,
205         .set_alarm = vt8500_rtc_set_alarm,
206         .alarm_irq_enable = vt8500_alarm_irq_enable,
207 };
208
209 static int vt8500_rtc_probe(struct platform_device *pdev)
210 {
211         struct vt8500_rtc *vt8500_rtc;
212         int ret;
213
214         vt8500_rtc = devm_kzalloc(&pdev->dev,
215                            sizeof(struct vt8500_rtc), GFP_KERNEL);
216         if (!vt8500_rtc)
217                 return -ENOMEM;
218
219         spin_lock_init(&vt8500_rtc->lock);
220         platform_set_drvdata(pdev, vt8500_rtc);
221
222         vt8500_rtc->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
223         if (!vt8500_rtc->res) {
224                 dev_err(&pdev->dev, "No I/O memory resource defined\n");
225                 return -ENXIO;
226         }
227
228         vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
229         if (vt8500_rtc->irq_alarm < 0) {
230                 dev_err(&pdev->dev, "No alarm IRQ resource defined\n");
231                 return -ENXIO;
232         }
233
234         vt8500_rtc->res = request_mem_region(vt8500_rtc->res->start,
235                                              resource_size(vt8500_rtc->res),
236                                              "vt8500-rtc");
237         if (vt8500_rtc->res == NULL) {
238                 dev_err(&pdev->dev, "failed to request I/O memory\n");
239                 return -EBUSY;
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,
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         return ret;
281 }
282
283 static int vt8500_rtc_remove(struct platform_device *pdev)
284 {
285         struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);
286
287         free_irq(vt8500_rtc->irq_alarm, vt8500_rtc);
288
289         rtc_device_unregister(vt8500_rtc->rtc);
290
291         /* Disable alarm matching */
292         writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
293         iounmap(vt8500_rtc->regbase);
294         release_mem_region(vt8500_rtc->res->start,
295                            resource_size(vt8500_rtc->res));
296
297         platform_set_drvdata(pdev, NULL);
298
299         return 0;
300 }
301
302 static const struct of_device_id wmt_dt_ids[] = {
303         { .compatible = "via,vt8500-rtc", },
304         {}
305 };
306
307 static struct platform_driver vt8500_rtc_driver = {
308         .probe          = vt8500_rtc_probe,
309         .remove         = vt8500_rtc_remove,
310         .driver         = {
311                 .name   = "vt8500-rtc",
312                 .owner  = THIS_MODULE,
313                 .of_match_table = of_match_ptr(wmt_dt_ids),
314         },
315 };
316
317 module_platform_driver(vt8500_rtc_driver);
318
319 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
320 MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
321 MODULE_LICENSE("GPL v2");
322 MODULE_ALIAS("platform:vt8500-rtc");