]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blame - drivers/rtc/rtc-vt8500.c
rtc: add support for the RTC in VIA VT8500 and compatibles
[mirror_ubuntu-artful-kernel.git] / drivers / rtc / rtc-vt8500.c
CommitLineData
f77fbdf9
AC
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
77struct vt8500_rtc {
78 void __iomem *regbase;
79 struct resource *res;
80 int irq_alarm;
81 int irq_hz;
82 struct rtc_device *rtc;
83 spinlock_t lock; /* Protects this structure */
84};
85
86static irqreturn_t vt8500_rtc_irq(int irq, void *dev_id)
87{
88 struct vt8500_rtc *vt8500_rtc = dev_id;
89 u32 isr;
90 unsigned long events = 0;
91
92 spin_lock(&vt8500_rtc->lock);
93
94 /* clear interrupt sources */
95 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
96 writel(isr, vt8500_rtc->regbase + VT8500_RTC_IS);
97
98 spin_unlock(&vt8500_rtc->lock);
99
100 if (isr & 1)
101 events |= RTC_AF | RTC_IRQF;
102
103 /* Only second/minute interrupts are supported */
104 if (isr & 2)
105 events |= RTC_UF | RTC_IRQF;
106
107 rtc_update_irq(vt8500_rtc->rtc, 1, events);
108
109 return IRQ_HANDLED;
110}
111
112static int vt8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
113{
114 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
115 u32 date, time;
116
117 date = readl(vt8500_rtc->regbase + VT8500_RTC_DR);
118 time = readl(vt8500_rtc->regbase + VT8500_RTC_TR);
119
120 tm->tm_sec = bcd2bin(time & TIME_SEC_MASK);
121 tm->tm_min = bcd2bin((time & TIME_MIN_MASK) >> TIME_MIN_S);
122 tm->tm_hour = bcd2bin((time & TIME_HOUR_MASK) >> TIME_HOUR_S);
123 tm->tm_mday = bcd2bin(date & DATE_DAY_MASK);
124 tm->tm_mon = bcd2bin((date & DATE_MONTH_MASK) >> DATE_MONTH_S);
125 tm->tm_year = bcd2bin((date & DATE_YEAR_MASK) >> DATE_YEAR_S)
126 + ((date >> DATE_CENTURY_S) & 1 ? 200 : 100);
127 tm->tm_wday = (time & TIME_DOW_MASK) >> TIME_DOW_S;
128
129 return 0;
130}
131
132static int vt8500_rtc_set_time(struct device *dev, struct rtc_time *tm)
133{
134 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
135
136 if (tm->tm_year < 100) {
137 dev_warn(dev, "Only years 2000-2199 are supported by the "
138 "hardware!\n");
139 return -EINVAL;
140 }
141
142 writel((bin2bcd(tm->tm_year - 100) << DATE_YEAR_S)
143 | (bin2bcd(tm->tm_mon) << DATE_MONTH_S)
144 | (bin2bcd(tm->tm_mday)),
145 vt8500_rtc->regbase + VT8500_RTC_DS);
146 writel((bin2bcd(tm->tm_wday) << TIME_DOW_S)
147 | (bin2bcd(tm->tm_hour) << TIME_HOUR_S)
148 | (bin2bcd(tm->tm_min) << TIME_MIN_S)
149 | (bin2bcd(tm->tm_sec)),
150 vt8500_rtc->regbase + VT8500_RTC_TS);
151
152 return 0;
153}
154
155static int vt8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
156{
157 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
158 u32 isr, alarm;
159
160 alarm = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
161 isr = readl(vt8500_rtc->regbase + VT8500_RTC_IS);
162
163 alrm->time.tm_mday = bcd2bin((alarm & ALARM_DAY_MASK) >> ALARM_DAY_S);
164 alrm->time.tm_hour = bcd2bin((alarm & TIME_HOUR_MASK) >> TIME_HOUR_S);
165 alrm->time.tm_min = bcd2bin((alarm & TIME_MIN_MASK) >> TIME_MIN_S);
166 alrm->time.tm_sec = bcd2bin((alarm & TIME_SEC_MASK));
167
168 alrm->enabled = (alarm & ALARM_ENABLE_MASK) ? 1 : 0;
169
170 alrm->pending = (isr & 1) ? 1 : 0;
171 return rtc_valid_tm(&alrm->time);
172}
173
174static int vt8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
175{
176 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
177
178 writel((alrm->enabled ? ALARM_ENABLE_MASK : 0)
179 | (bin2bcd(alrm->time.tm_mday) << ALARM_DAY_S)
180 | (bin2bcd(alrm->time.tm_hour) << TIME_HOUR_S)
181 | (bin2bcd(alrm->time.tm_min) << TIME_MIN_S)
182 | (bin2bcd(alrm->time.tm_sec)),
183 vt8500_rtc->regbase + VT8500_RTC_AS);
184
185 return 0;
186}
187
188static int vt8500_alarm_irq_enable(struct device *dev, unsigned int enabled)
189{
190 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
191 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_AS);
192
193 if (enabled)
194 tmp |= ALARM_ENABLE_MASK;
195 else
196 tmp &= ~ALARM_ENABLE_MASK;
197
198 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_AS);
199 return 0;
200}
201
202static int vt8500_update_irq_enable(struct device *dev, unsigned int enabled)
203{
204 struct vt8500_rtc *vt8500_rtc = dev_get_drvdata(dev);
205 unsigned long tmp = readl(vt8500_rtc->regbase + VT8500_RTC_CR);
206
207 if (enabled)
208 tmp |= VT8500_RTC_CR_SM_SEC | VT8500_RTC_CR_SM_ENABLE;
209 else
210 tmp &= ~VT8500_RTC_CR_SM_ENABLE;
211
212 writel(tmp, vt8500_rtc->regbase + VT8500_RTC_CR);
213 return 0;
214}
215
216static const struct rtc_class_ops vt8500_rtc_ops = {
217 .read_time = vt8500_rtc_read_time,
218 .set_time = vt8500_rtc_set_time,
219 .read_alarm = vt8500_rtc_read_alarm,
220 .set_alarm = vt8500_rtc_set_alarm,
221 .alarm_irq_enable = vt8500_alarm_irq_enable,
222 .update_irq_enable = vt8500_update_irq_enable,
223};
224
225static int __devinit vt8500_rtc_probe(struct platform_device *pdev)
226{
227 struct vt8500_rtc *vt8500_rtc;
228 int ret;
229
230 vt8500_rtc = kzalloc(sizeof(struct vt8500_rtc), GFP_KERNEL);
231 if (!vt8500_rtc)
232 return -ENOMEM;
233
234 spin_lock_init(&vt8500_rtc->lock);
235 platform_set_drvdata(pdev, vt8500_rtc);
236
237 vt8500_rtc->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
238 if (!vt8500_rtc->res) {
239 dev_err(&pdev->dev, "No I/O memory resource defined\n");
240 ret = -ENXIO;
241 goto err_free;
242 }
243
244 vt8500_rtc->irq_alarm = platform_get_irq(pdev, 0);
245 if (vt8500_rtc->irq_alarm < 0) {
246 dev_err(&pdev->dev, "No alarm IRQ resource defined\n");
247 ret = -ENXIO;
248 goto err_free;
249 }
250
251 vt8500_rtc->irq_hz = platform_get_irq(pdev, 1);
252 if (vt8500_rtc->irq_hz < 0) {
253 dev_err(&pdev->dev, "No 1Hz IRQ resource defined\n");
254 ret = -ENXIO;
255 goto err_free;
256 }
257
258 vt8500_rtc->res = request_mem_region(vt8500_rtc->res->start,
259 resource_size(vt8500_rtc->res),
260 "vt8500-rtc");
261 if (vt8500_rtc->res == NULL) {
262 dev_err(&pdev->dev, "failed to request I/O memory\n");
263 ret = -EBUSY;
264 goto err_free;
265 }
266
267 vt8500_rtc->regbase = ioremap(vt8500_rtc->res->start,
268 resource_size(vt8500_rtc->res));
269 if (!vt8500_rtc->regbase) {
270 dev_err(&pdev->dev, "Unable to map RTC I/O memory\n");
271 ret = -EBUSY;
272 goto err_release;
273 }
274
275 /* Enable the second/minute interrupt generation and enable RTC */
276 writel(VT8500_RTC_CR_ENABLE | VT8500_RTC_CR_24H
277 | VT8500_RTC_CR_SM_ENABLE | VT8500_RTC_CR_SM_SEC,
278 vt8500_rtc->regbase + VT8500_RTC_CR);
279
280 vt8500_rtc->rtc = rtc_device_register("vt8500-rtc", &pdev->dev,
281 &vt8500_rtc_ops, THIS_MODULE);
282 if (IS_ERR(vt8500_rtc->rtc)) {
283 ret = PTR_ERR(vt8500_rtc->rtc);
284 dev_err(&pdev->dev,
285 "Failed to register RTC device -> %d\n", ret);
286 goto err_unmap;
287 }
288
289 ret = request_irq(vt8500_rtc->irq_hz, vt8500_rtc_irq, 0,
290 "rtc 1Hz", vt8500_rtc);
291 if (ret < 0) {
292 dev_err(&pdev->dev, "can't get irq %i, err %d\n",
293 vt8500_rtc->irq_hz, ret);
294 goto err_unreg;
295 }
296
297 ret = request_irq(vt8500_rtc->irq_alarm, vt8500_rtc_irq, 0,
298 "rtc alarm", vt8500_rtc);
299 if (ret < 0) {
300 dev_err(&pdev->dev, "can't get irq %i, err %d\n",
301 vt8500_rtc->irq_alarm, ret);
302 goto err_free_hz;
303 }
304
305 return 0;
306
307err_free_hz:
308 free_irq(vt8500_rtc->irq_hz, vt8500_rtc);
309err_unreg:
310 rtc_device_unregister(vt8500_rtc->rtc);
311err_unmap:
312 iounmap(vt8500_rtc->regbase);
313err_release:
314 release_mem_region(vt8500_rtc->res->start,
315 resource_size(vt8500_rtc->res));
316err_free:
317 kfree(vt8500_rtc);
318 return ret;
319}
320
321static int __devexit vt8500_rtc_remove(struct platform_device *pdev)
322{
323 struct vt8500_rtc *vt8500_rtc = platform_get_drvdata(pdev);
324
325 free_irq(vt8500_rtc->irq_alarm, vt8500_rtc);
326 free_irq(vt8500_rtc->irq_hz, vt8500_rtc);
327
328 rtc_device_unregister(vt8500_rtc->rtc);
329
330 /* Disable alarm matching */
331 writel(0, vt8500_rtc->regbase + VT8500_RTC_IS);
332 iounmap(vt8500_rtc->regbase);
333 release_mem_region(vt8500_rtc->res->start,
334 resource_size(vt8500_rtc->res));
335
336 kfree(vt8500_rtc);
337 platform_set_drvdata(pdev, NULL);
338
339 return 0;
340}
341
342static struct platform_driver vt8500_rtc_driver = {
343 .probe = vt8500_rtc_probe,
344 .remove = __devexit_p(vt8500_rtc_remove),
345 .driver = {
346 .name = "vt8500-rtc",
347 .owner = THIS_MODULE,
348 },
349};
350
351static int __init vt8500_rtc_init(void)
352{
353 return platform_driver_register(&vt8500_rtc_driver);
354}
355module_init(vt8500_rtc_init);
356
357static void __exit vt8500_rtc_exit(void)
358{
359 platform_driver_unregister(&vt8500_rtc_driver);
360}
361module_exit(vt8500_rtc_exit);
362
363MODULE_AUTHOR("Alexey Charkov <alchark@gmail.com>");
364MODULE_DESCRIPTION("VIA VT8500 SoC Realtime Clock Driver (RTC)");
365MODULE_LICENSE("GPL");
366MODULE_ALIAS("platform:vt8500-rtc");