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7#include <linux/compat.h>
8#include <linux/err.h>
9#include <linux/fs.h>
10#include <linux/init.h>
11#include <linux/io.h>
12#include <linux/ioport.h>
13#include <linux/interrupt.h>
14#include <linux/module.h>
15#include <linux/platform_device.h>
16#include <linux/rtc.h>
17#include <linux/spinlock.h>
18#include <linux/types.h>
19#include <linux/uaccess.h>
20#include <linux/log2.h>
21
22#include <asm/div64.h>
23
24MODULE_AUTHOR("Yoichi Yuasa <yuasa@linux-mips.org>");
25MODULE_DESCRIPTION("NEC VR4100 series RTC driver");
26MODULE_LICENSE("GPL v2");
27
28
29#define ETIMELREG 0x00
30#define ETIMEMREG 0x02
31#define ETIMEHREG 0x04
32
33#define ECMPLREG 0x08
34#define ECMPMREG 0x0a
35#define ECMPHREG 0x0c
36
37#define RTCL1LREG 0x10
38#define RTCL1HREG 0x12
39#define RTCL1CNTLREG 0x14
40#define RTCL1CNTHREG 0x16
41#define RTCL2LREG 0x18
42#define RTCL2HREG 0x1a
43#define RTCL2CNTLREG 0x1c
44#define RTCL2CNTHREG 0x1e
45
46
47#define TCLKLREG 0x00
48#define TCLKHREG 0x02
49#define TCLKCNTLREG 0x04
50#define TCLKCNTHREG 0x06
51
52#define RTCINTREG 0x1e
53 #define TCLOCK_INT 0x08
54 #define RTCLONG2_INT 0x04
55 #define RTCLONG1_INT 0x02
56 #define ELAPSEDTIME_INT 0x01
57
58#define RTC_FREQUENCY 32768
59#define MAX_PERIODIC_RATE 6553
60
61static void __iomem *rtc1_base;
62static void __iomem *rtc2_base;
63
64#define rtc1_read(offset) readw(rtc1_base + (offset))
65#define rtc1_write(offset, value) writew((value), rtc1_base + (offset))
66
67#define rtc2_read(offset) readw(rtc2_base + (offset))
68#define rtc2_write(offset, value) writew((value), rtc2_base + (offset))
69
70
71#define RTC_EPOCH_READ32 _IOR('p', 0x0d, __u32)
72
73static unsigned long epoch = 1970;
74
75static DEFINE_SPINLOCK(rtc_lock);
76static char rtc_name[] = "RTC";
77static unsigned long periodic_count;
78static unsigned int alarm_enabled;
79static int aie_irq;
80static int pie_irq;
81
82static inline time64_t read_elapsed_second(void)
83{
84
85 unsigned long first_low, first_mid, first_high;
86
87 unsigned long second_low, second_mid, second_high;
88
89 do {
90 first_low = rtc1_read(ETIMELREG);
91 first_mid = rtc1_read(ETIMEMREG);
92 first_high = rtc1_read(ETIMEHREG);
93 second_low = rtc1_read(ETIMELREG);
94 second_mid = rtc1_read(ETIMEMREG);
95 second_high = rtc1_read(ETIMEHREG);
96 } while (first_low != second_low || first_mid != second_mid ||
97 first_high != second_high);
98
99 return ((u64)first_high << 17) | (first_mid << 1) | (first_low >> 15);
100}
101
102static inline void write_elapsed_second(time64_t sec)
103{
104 spin_lock_irq(&rtc_lock);
105
106 rtc1_write(ETIMELREG, (uint16_t)(sec << 15));
107 rtc1_write(ETIMEMREG, (uint16_t)(sec >> 1));
108 rtc1_write(ETIMEHREG, (uint16_t)(sec >> 17));
109
110 spin_unlock_irq(&rtc_lock);
111}
112
113static int vr41xx_rtc_read_time(struct device *dev, struct rtc_time *time)
114{
115 time64_t epoch_sec, elapsed_sec;
116
117 epoch_sec = mktime64(epoch, 1, 1, 0, 0, 0);
118 elapsed_sec = read_elapsed_second();
119
120 rtc_time64_to_tm(epoch_sec + elapsed_sec, time);
121
122 return 0;
123}
124
125static int vr41xx_rtc_set_time(struct device *dev, struct rtc_time *time)
126{
127 time64_t epoch_sec, current_sec;
128
129 epoch_sec = mktime64(epoch, 1, 1, 0, 0, 0);
130 current_sec = rtc_tm_to_time64(time);
131
132 write_elapsed_second(current_sec - epoch_sec);
133
134 return 0;
135}
136
137static int vr41xx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
138{
139 unsigned long low, mid, high;
140 struct rtc_time *time = &wkalrm->time;
141
142 spin_lock_irq(&rtc_lock);
143
144 low = rtc1_read(ECMPLREG);
145 mid = rtc1_read(ECMPMREG);
146 high = rtc1_read(ECMPHREG);
147 wkalrm->enabled = alarm_enabled;
148
149 spin_unlock_irq(&rtc_lock);
150
151 rtc_time64_to_tm((high << 17) | (mid << 1) | (low >> 15), time);
152
153 return 0;
154}
155
156static int vr41xx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
157{
158 time64_t alarm_sec;
159
160 alarm_sec = rtc_tm_to_time64(&wkalrm->time);
161
162 spin_lock_irq(&rtc_lock);
163
164 if (alarm_enabled)
165 disable_irq(aie_irq);
166
167 rtc1_write(ECMPLREG, (uint16_t)(alarm_sec << 15));
168 rtc1_write(ECMPMREG, (uint16_t)(alarm_sec >> 1));
169 rtc1_write(ECMPHREG, (uint16_t)(alarm_sec >> 17));
170
171 if (wkalrm->enabled)
172 enable_irq(aie_irq);
173
174 alarm_enabled = wkalrm->enabled;
175
176 spin_unlock_irq(&rtc_lock);
177
178 return 0;
179}
180
181static int vr41xx_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
182{
183 switch (cmd) {
184 case RTC_EPOCH_READ:
185 return put_user(epoch, (unsigned long __user *)arg);
186#ifdef CONFIG_64BIT
187 case RTC_EPOCH_READ32:
188 return put_user(epoch, (unsigned int __user *)arg);
189#endif
190 case RTC_EPOCH_SET:
191
192 if (arg < 1900)
193 return -EINVAL;
194 epoch = arg;
195 break;
196 default:
197 return -ENOIOCTLCMD;
198 }
199
200 return 0;
201}
202
203static int vr41xx_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
204{
205 spin_lock_irq(&rtc_lock);
206 if (enabled) {
207 if (!alarm_enabled) {
208 enable_irq(aie_irq);
209 alarm_enabled = 1;
210 }
211 } else {
212 if (alarm_enabled) {
213 disable_irq(aie_irq);
214 alarm_enabled = 0;
215 }
216 }
217 spin_unlock_irq(&rtc_lock);
218 return 0;
219}
220
221static irqreturn_t elapsedtime_interrupt(int irq, void *dev_id)
222{
223 struct platform_device *pdev = (struct platform_device *)dev_id;
224 struct rtc_device *rtc = platform_get_drvdata(pdev);
225
226 rtc2_write(RTCINTREG, ELAPSEDTIME_INT);
227
228 rtc_update_irq(rtc, 1, RTC_AF);
229
230 return IRQ_HANDLED;
231}
232
233static irqreturn_t rtclong1_interrupt(int irq, void *dev_id)
234{
235 struct platform_device *pdev = (struct platform_device *)dev_id;
236 struct rtc_device *rtc = platform_get_drvdata(pdev);
237 unsigned long count = periodic_count;
238
239 rtc2_write(RTCINTREG, RTCLONG1_INT);
240
241 rtc1_write(RTCL1LREG, count);
242 rtc1_write(RTCL1HREG, count >> 16);
243
244 rtc_update_irq(rtc, 1, RTC_PF);
245
246 return IRQ_HANDLED;
247}
248
249static const struct rtc_class_ops vr41xx_rtc_ops = {
250 .ioctl = vr41xx_rtc_ioctl,
251 .read_time = vr41xx_rtc_read_time,
252 .set_time = vr41xx_rtc_set_time,
253 .read_alarm = vr41xx_rtc_read_alarm,
254 .set_alarm = vr41xx_rtc_set_alarm,
255 .alarm_irq_enable = vr41xx_rtc_alarm_irq_enable,
256};
257
258static int rtc_probe(struct platform_device *pdev)
259{
260 struct resource *res;
261 struct rtc_device *rtc;
262 int retval;
263
264 if (pdev->num_resources != 4)
265 return -EBUSY;
266
267 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
268 if (!res)
269 return -EBUSY;
270
271 rtc1_base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
272 if (!rtc1_base)
273 return -EBUSY;
274
275 res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
276 if (!res) {
277 retval = -EBUSY;
278 goto err_rtc1_iounmap;
279 }
280
281 rtc2_base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
282 if (!rtc2_base) {
283 retval = -EBUSY;
284 goto err_rtc1_iounmap;
285 }
286
287 rtc = devm_rtc_allocate_device(&pdev->dev);
288 if (IS_ERR(rtc)) {
289 retval = PTR_ERR(rtc);
290 goto err_iounmap_all;
291 }
292
293 rtc->ops = &vr41xx_rtc_ops;
294
295
296 rtc->range_max = (1ULL << 33) - 1;
297 rtc->max_user_freq = MAX_PERIODIC_RATE;
298
299 spin_lock_irq(&rtc_lock);
300
301 rtc1_write(ECMPLREG, 0);
302 rtc1_write(ECMPMREG, 0);
303 rtc1_write(ECMPHREG, 0);
304 rtc1_write(RTCL1LREG, 0);
305 rtc1_write(RTCL1HREG, 0);
306
307 spin_unlock_irq(&rtc_lock);
308
309 aie_irq = platform_get_irq(pdev, 0);
310 if (aie_irq <= 0) {
311 retval = -EBUSY;
312 goto err_iounmap_all;
313 }
314
315 retval = devm_request_irq(&pdev->dev, aie_irq, elapsedtime_interrupt, 0,
316 "elapsed_time", pdev);
317 if (retval < 0)
318 goto err_iounmap_all;
319
320 pie_irq = platform_get_irq(pdev, 1);
321 if (pie_irq <= 0) {
322 retval = -EBUSY;
323 goto err_iounmap_all;
324 }
325
326 retval = devm_request_irq(&pdev->dev, pie_irq, rtclong1_interrupt, 0,
327 "rtclong1", pdev);
328 if (retval < 0)
329 goto err_iounmap_all;
330
331 platform_set_drvdata(pdev, rtc);
332
333 disable_irq(aie_irq);
334 disable_irq(pie_irq);
335
336 dev_info(&pdev->dev, "Real Time Clock of NEC VR4100 series\n");
337
338 retval = devm_rtc_register_device(rtc);
339 if (retval)
340 goto err_iounmap_all;
341
342 return 0;
343
344err_iounmap_all:
345 rtc2_base = NULL;
346
347err_rtc1_iounmap:
348 rtc1_base = NULL;
349
350 return retval;
351}
352
353
354MODULE_ALIAS("platform:RTC");
355
356static struct platform_driver rtc_platform_driver = {
357 .probe = rtc_probe,
358 .driver = {
359 .name = rtc_name,
360 },
361};
362
363module_platform_driver(rtc_platform_driver);
364
