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x86/PCI: use host bridge _CRS info on ASUS M2V-MX SE
[linux-btrfs-devel.git] / drivers / rtc / rtc-vt8500.c
blobf93f412423c6d4eaadcdfbe5412d4a65c80cc09e
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 static int __init vt8500_rtc_init(void)
315 {
316 return platform_driver_register(&vt8500_rtc_driver);
317 }
318 module_init(vt8500_rtc_init);
319
320 static void __exit vt8500_rtc_exit(void)
321 {
322 platform_driver_unregister(&vt8500_rtc_driver);
323 }
324 module_exit(vt8500_rtc_exit);
325
326 MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
327 MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
328 MODULE_LICENSE("GPL");
329 MODULE_ALIAS("platform:vt8500-rtc");
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