1 /*
2 * Real Time Clock driver for Freescale MC13XXX PMIC
3 *
4 * (C) 2009 Sascha Hauer, Pengutronix
5 * (C) 2009 Uwe Kleine-Koenig, Pengutronix
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/mfd/mc13xxx.h>
13 #include <linux/platform_device.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/slab.h>
17 #include <linux/rtc.h>
18
19 #define DRIVER_NAME "mc13xxx-rtc"
20
21 #define MC13XXX_RTCTOD 20
22 #define MC13XXX_RTCTODA 21
23 #define MC13XXX_RTCDAY 22
24 #define MC13XXX_RTCDAYA 23
25
26 struct mc13xxx_rtc {
27 struct rtc_device *rtc;
28 struct mc13xxx *mc13xxx;
29 int valid;
30 };
31
mc13xxx_rtc_irq_enable_unlocked(struct device * dev,unsigned int enabled,int irq)32 static int mc13xxx_rtc_irq_enable_unlocked(struct device *dev,
33 unsigned int enabled, int irq)
34 {
35 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
36 int (*func)(struct mc13xxx *mc13xxx, int irq);
37
38 if (!priv->valid)
39 return -ENODATA;
40
41 func = enabled ? mc13xxx_irq_unmask : mc13xxx_irq_mask;
42 return func(priv->mc13xxx, irq);
43 }
44
mc13xxx_rtc_irq_enable(struct device * dev,unsigned int enabled,int irq)45 static int mc13xxx_rtc_irq_enable(struct device *dev,
46 unsigned int enabled, int irq)
47 {
48 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
49 int ret;
50
51 mc13xxx_lock(priv->mc13xxx);
52
53 ret = mc13xxx_rtc_irq_enable_unlocked(dev, enabled, irq);
54
55 mc13xxx_unlock(priv->mc13xxx);
56
57 return ret;
58 }
59
mc13xxx_rtc_read_time(struct device * dev,struct rtc_time * tm)60 static int mc13xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
61 {
62 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
63 unsigned int seconds, days1, days2;
64 unsigned long s1970;
65 int ret;
66
67 mc13xxx_lock(priv->mc13xxx);
68
69 if (!priv->valid) {
70 ret = -ENODATA;
71 goto out;
72 }
73
74 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
75 if (unlikely(ret))
76 goto out;
77
78 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
79 if (unlikely(ret))
80 goto out;
81
82 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
83 out:
84 mc13xxx_unlock(priv->mc13xxx);
85
86 if (ret)
87 return ret;
88
89 if (days2 == days1 + 1) {
90 if (seconds >= 86400 / 2)
91 days2 = days1;
92 else
93 days1 = days2;
94 }
95
96 if (days1 != days2)
97 return -EIO;
98
99 s1970 = days1 * 86400 + seconds;
100
101 rtc_time_to_tm(s1970, tm);
102
103 return rtc_valid_tm(tm);
104 }
105
mc13xxx_rtc_set_mmss(struct device * dev,unsigned long secs)106 static int mc13xxx_rtc_set_mmss(struct device *dev, unsigned long secs)
107 {
108 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
109 unsigned int seconds, days;
110 unsigned int alarmseconds;
111 int ret;
112
113 seconds = secs % 86400;
114 days = secs / 86400;
115
116 mc13xxx_lock(priv->mc13xxx);
117
118 /*
119 * temporarily invalidate alarm to prevent triggering it when the day is
120 * already updated while the time isn't yet.
121 */
122 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &alarmseconds);
123 if (unlikely(ret))
124 goto out;
125
126 if (alarmseconds < 86400) {
127 ret = mc13xxx_reg_write(priv->mc13xxx,
128 MC13XXX_RTCTODA, 0x1ffff);
129 if (unlikely(ret))
130 goto out;
131 }
132
133 /*
134 * write seconds=0 to prevent a day switch between writing days
135 * and seconds below
136 */
137 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, 0);
138 if (unlikely(ret))
139 goto out;
140
141 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAY, days);
142 if (unlikely(ret))
143 goto out;
144
145 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, seconds);
146 if (unlikely(ret))
147 goto out;
148
149 /* restore alarm */
150 if (alarmseconds < 86400) {
151 ret = mc13xxx_reg_write(priv->mc13xxx,
152 MC13XXX_RTCTODA, alarmseconds);
153 if (unlikely(ret))
154 goto out;
155 }
156
157 ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
158 if (unlikely(ret))
159 goto out;
160
161 ret = mc13xxx_irq_unmask(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
162 out:
163 priv->valid = !ret;
164
165 mc13xxx_unlock(priv->mc13xxx);
166
167 return ret;
168 }
169
mc13xxx_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)170 static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
171 {
172 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
173 unsigned seconds, days;
174 unsigned long s1970;
175 int enabled, pending;
176 int ret;
177
178 mc13xxx_lock(priv->mc13xxx);
179
180 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds);
181 if (unlikely(ret))
182 goto out;
183 if (seconds >= 86400) {
184 ret = -ENODATA;
185 goto out;
186 }
187
188 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days);
189 if (unlikely(ret))
190 goto out;
191
192 ret = mc13xxx_irq_status(priv->mc13xxx, MC13XXX_IRQ_TODA,
193 &enabled, &pending);
194
195 out:
196 mc13xxx_unlock(priv->mc13xxx);
197
198 if (ret)
199 return ret;
200
201 alarm->enabled = enabled;
202 alarm->pending = pending;
203
204 s1970 = days * 86400 + seconds;
205
206 rtc_time_to_tm(s1970, &alarm->time);
207 dev_dbg(dev, "%s: %lu\n", __func__, s1970);
208
209 return 0;
210 }
211
mc13xxx_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)212 static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
213 {
214 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
215 unsigned long s1970;
216 unsigned seconds, days;
217 int ret;
218
219 mc13xxx_lock(priv->mc13xxx);
220
221 /* disable alarm to prevent false triggering */
222 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, 0x1ffff);
223 if (unlikely(ret))
224 goto out;
225
226 ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TODA);
227 if (unlikely(ret))
228 goto out;
229
230 ret = rtc_tm_to_time(&alarm->time, &s1970);
231 if (unlikely(ret))
232 goto out;
233
234 dev_dbg(dev, "%s: o%2.s %lu\n", __func__, alarm->enabled ? "n" : "ff",
235 s1970);
236
237 ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
238 MC13XXX_IRQ_TODA);
239 if (unlikely(ret))
240 goto out;
241
242 seconds = s1970 % 86400;
243 days = s1970 / 86400;
244
245 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
246 if (unlikely(ret))
247 goto out;
248
249 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, seconds);
250
251 out:
252 mc13xxx_unlock(priv->mc13xxx);
253
254 return ret;
255 }
256
mc13xxx_rtc_alarm_handler(int irq,void * dev)257 static irqreturn_t mc13xxx_rtc_alarm_handler(int irq, void *dev)
258 {
259 struct mc13xxx_rtc *priv = dev;
260 struct mc13xxx *mc13xxx = priv->mc13xxx;
261
262 dev_dbg(&priv->rtc->dev, "Alarm\n");
263
264 rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);
265
266 mc13xxx_irq_ack(mc13xxx, irq);
267
268 return IRQ_HANDLED;
269 }
270
mc13xxx_rtc_update_handler(int irq,void * dev)271 static irqreturn_t mc13xxx_rtc_update_handler(int irq, void *dev)
272 {
273 struct mc13xxx_rtc *priv = dev;
274 struct mc13xxx *mc13xxx = priv->mc13xxx;
275
276 dev_dbg(&priv->rtc->dev, "1HZ\n");
277
278 rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_UF);
279
280 mc13xxx_irq_ack(mc13xxx, irq);
281
282 return IRQ_HANDLED;
283 }
284
mc13xxx_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)285 static int mc13xxx_rtc_alarm_irq_enable(struct device *dev,
286 unsigned int enabled)
287 {
288 return mc13xxx_rtc_irq_enable(dev, enabled, MC13XXX_IRQ_TODA);
289 }
290
291 static const struct rtc_class_ops mc13xxx_rtc_ops = {
292 .read_time = mc13xxx_rtc_read_time,
293 .set_mmss = mc13xxx_rtc_set_mmss,
294 .read_alarm = mc13xxx_rtc_read_alarm,
295 .set_alarm = mc13xxx_rtc_set_alarm,
296 .alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable,
297 };
298
mc13xxx_rtc_reset_handler(int irq,void * dev)299 static irqreturn_t mc13xxx_rtc_reset_handler(int irq, void *dev)
300 {
301 struct mc13xxx_rtc *priv = dev;
302 struct mc13xxx *mc13xxx = priv->mc13xxx;
303
304 dev_dbg(&priv->rtc->dev, "RTCRST\n");
305 priv->valid = 0;
306
307 mc13xxx_irq_mask(mc13xxx, irq);
308
309 return IRQ_HANDLED;
310 }
311
mc13xxx_rtc_probe(struct platform_device * pdev)312 static int __init mc13xxx_rtc_probe(struct platform_device *pdev)
313 {
314 int ret;
315 struct mc13xxx_rtc *priv;
316 struct mc13xxx *mc13xxx;
317 int rtcrst_pending;
318
319 priv = kzalloc(sizeof(*priv), GFP_KERNEL);
320 if (!priv)
321 return -ENOMEM;
322
323 mc13xxx = dev_get_drvdata(pdev->dev.parent);
324 priv->mc13xxx = mc13xxx;
325
326 platform_set_drvdata(pdev, priv);
327
328 mc13xxx_lock(mc13xxx);
329
330 ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST,
331 mc13xxx_rtc_reset_handler, DRIVER_NAME, priv);
332 if (ret)
333 goto err_reset_irq_request;
334
335 ret = mc13xxx_irq_status(mc13xxx, MC13XXX_IRQ_RTCRST,
336 NULL, &rtcrst_pending);
337 if (ret)
338 goto err_reset_irq_status;
339
340 priv->valid = !rtcrst_pending;
341
342 ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_1HZ,
343 mc13xxx_rtc_update_handler, DRIVER_NAME, priv);
344 if (ret)
345 goto err_update_irq_request;
346
347 ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA,
348 mc13xxx_rtc_alarm_handler, DRIVER_NAME, priv);
349 if (ret)
350 goto err_alarm_irq_request;
351
352 mc13xxx_unlock(mc13xxx);
353
354 priv->rtc = rtc_device_register(pdev->name,
355 &pdev->dev, &mc13xxx_rtc_ops, THIS_MODULE);
356 if (IS_ERR(priv->rtc)) {
357 ret = PTR_ERR(priv->rtc);
358
359 mc13xxx_lock(mc13xxx);
360
361 mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv);
362 err_alarm_irq_request:
363
364 mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_1HZ, priv);
365 err_update_irq_request:
366
367 err_reset_irq_status:
368
369 mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv);
370 err_reset_irq_request:
371
372 mc13xxx_unlock(mc13xxx);
373
374 platform_set_drvdata(pdev, NULL);
375 kfree(priv);
376 }
377
378 return ret;
379 }
380
mc13xxx_rtc_remove(struct platform_device * pdev)381 static int __exit mc13xxx_rtc_remove(struct platform_device *pdev)
382 {
383 struct mc13xxx_rtc *priv = platform_get_drvdata(pdev);
384
385 mc13xxx_lock(priv->mc13xxx);
386
387 rtc_device_unregister(priv->rtc);
388
389 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TODA, priv);
390 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_1HZ, priv);
391 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_RTCRST, priv);
392
393 mc13xxx_unlock(priv->mc13xxx);
394
395 platform_set_drvdata(pdev, NULL);
396
397 kfree(priv);
398
399 return 0;
400 }
401
402 static const struct platform_device_id mc13xxx_rtc_idtable[] = {
403 {
404 .name = "mc13783-rtc",
405 }, {
406 .name = "mc13892-rtc",
407 },
408 { }
409 };
410
411 static struct platform_driver mc13xxx_rtc_driver = {
412 .id_table = mc13xxx_rtc_idtable,
413 .remove = __exit_p(mc13xxx_rtc_remove),
414 .driver = {
415 .name = DRIVER_NAME,
416 .owner = THIS_MODULE,
417 },
418 };
419
mc13xxx_rtc_init(void)420 static int __init mc13xxx_rtc_init(void)
421 {
422 return platform_driver_probe(&mc13xxx_rtc_driver, &mc13xxx_rtc_probe);
423 }
424 module_init(mc13xxx_rtc_init);
425
mc13xxx_rtc_exit(void)426 static void __exit mc13xxx_rtc_exit(void)
427 {
428 platform_driver_unregister(&mc13xxx_rtc_driver);
429 }
430 module_exit(mc13xxx_rtc_exit);
431
432 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
433 MODULE_DESCRIPTION("RTC driver for Freescale MC13XXX PMIC");
434 MODULE_LICENSE("GPL v2");
435 MODULE_ALIAS("platform:" DRIVER_NAME);
436