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/mod_devicetable.h>
17 #include <linux/slab.h>
18 #include <linux/rtc.h>
19
20 #define DRIVER_NAME "mc13xxx-rtc"
21
22 #define MC13XXX_RTCTOD 20
23 #define MC13XXX_RTCTODA 21
24 #define MC13XXX_RTCDAY 22
25 #define MC13XXX_RTCDAYA 23
26
27 #define SEC_PER_DAY (24 * 60 * 60)
28
29 struct mc13xxx_rtc {
30 struct rtc_device *rtc;
31 struct mc13xxx *mc13xxx;
32 int valid;
33 };
34
mc13xxx_rtc_irq_enable_unlocked(struct device * dev,unsigned int enabled,int irq)35 static int mc13xxx_rtc_irq_enable_unlocked(struct device *dev,
36 unsigned int enabled, int irq)
37 {
38 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
39 int (*func)(struct mc13xxx *mc13xxx, int irq);
40
41 if (!priv->valid)
42 return -ENODATA;
43
44 func = enabled ? mc13xxx_irq_unmask : mc13xxx_irq_mask;
45 return func(priv->mc13xxx, irq);
46 }
47
mc13xxx_rtc_alarm_irq_enable(struct device * dev,unsigned int enabled)48 static int mc13xxx_rtc_alarm_irq_enable(struct device *dev,
49 unsigned int enabled)
50 {
51 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
52 int ret;
53
54 mc13xxx_lock(priv->mc13xxx);
55
56 ret = mc13xxx_rtc_irq_enable_unlocked(dev, enabled, MC13XXX_IRQ_TODA);
57
58 mc13xxx_unlock(priv->mc13xxx);
59
60 return ret;
61 }
62
mc13xxx_rtc_read_time(struct device * dev,struct rtc_time * tm)63 static int mc13xxx_rtc_read_time(struct device *dev, struct rtc_time *tm)
64 {
65 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
66 unsigned int seconds, days1, days2;
67
68 if (!priv->valid)
69 return -ENODATA;
70
71 do {
72 int ret;
73
74 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
75 if (ret)
76 return ret;
77
78 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
79 if (ret)
80 return ret;
81
82 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
83 if (ret)
84 return ret;
85 } while (days1 != days2);
86
87 rtc_time64_to_tm((time64_t)days1 * SEC_PER_DAY + seconds, tm);
88
89 return 0;
90 }
91
mc13xxx_rtc_set_mmss(struct device * dev,time64_t secs)92 static int mc13xxx_rtc_set_mmss(struct device *dev, time64_t secs)
93 {
94 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
95 unsigned int seconds, days;
96 unsigned int alarmseconds;
97 int ret;
98
99 days = div_s64_rem(secs, SEC_PER_DAY, &seconds);
100
101 mc13xxx_lock(priv->mc13xxx);
102
103 /*
104 * temporarily invalidate alarm to prevent triggering it when the day is
105 * already updated while the time isn't yet.
106 */
107 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &alarmseconds);
108 if (unlikely(ret))
109 goto out;
110
111 if (alarmseconds < SEC_PER_DAY) {
112 ret = mc13xxx_reg_write(priv->mc13xxx,
113 MC13XXX_RTCTODA, 0x1ffff);
114 if (unlikely(ret))
115 goto out;
116 }
117
118 /*
119 * write seconds=0 to prevent a day switch between writing days
120 * and seconds below
121 */
122 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, 0);
123 if (unlikely(ret))
124 goto out;
125
126 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAY, days);
127 if (unlikely(ret))
128 goto out;
129
130 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, seconds);
131 if (unlikely(ret))
132 goto out;
133
134 /* restore alarm */
135 if (alarmseconds < SEC_PER_DAY) {
136 ret = mc13xxx_reg_write(priv->mc13xxx,
137 MC13XXX_RTCTODA, alarmseconds);
138 if (unlikely(ret))
139 goto out;
140 }
141
142 if (!priv->valid) {
143 ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
144 if (unlikely(ret))
145 goto out;
146
147 ret = mc13xxx_irq_unmask(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
148 }
149
150 out:
151 priv->valid = !ret;
152
153 mc13xxx_unlock(priv->mc13xxx);
154
155 return ret;
156 }
157
mc13xxx_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)158 static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
159 {
160 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
161 unsigned seconds, days;
162 time64_t s1970;
163 int enabled, pending;
164 int ret;
165
166 mc13xxx_lock(priv->mc13xxx);
167
168 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds);
169 if (unlikely(ret))
170 goto out;
171 if (seconds >= SEC_PER_DAY) {
172 ret = -ENODATA;
173 goto out;
174 }
175
176 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days);
177 if (unlikely(ret))
178 goto out;
179
180 ret = mc13xxx_irq_status(priv->mc13xxx, MC13XXX_IRQ_TODA,
181 &enabled, &pending);
182
183 out:
184 mc13xxx_unlock(priv->mc13xxx);
185
186 if (ret)
187 return ret;
188
189 alarm->enabled = enabled;
190 alarm->pending = pending;
191
192 s1970 = (time64_t)days * SEC_PER_DAY + seconds;
193
194 rtc_time64_to_tm(s1970, &alarm->time);
195 dev_dbg(dev, "%s: %lld\n", __func__, (long long)s1970);
196
197 return 0;
198 }
199
mc13xxx_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)200 static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
201 {
202 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
203 time64_t s1970;
204 u32 seconds, days;
205 int ret;
206
207 mc13xxx_lock(priv->mc13xxx);
208
209 /* disable alarm to prevent false triggering */
210 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, 0x1ffff);
211 if (unlikely(ret))
212 goto out;
213
214 ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TODA);
215 if (unlikely(ret))
216 goto out;
217
218 s1970 = rtc_tm_to_time64(&alarm->time);
219
220 dev_dbg(dev, "%s: %s %lld\n", __func__, alarm->enabled ? "on" : "off",
221 (long long)s1970);
222
223 ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
224 MC13XXX_IRQ_TODA);
225 if (unlikely(ret))
226 goto out;
227
228 days = div_s64_rem(s1970, SEC_PER_DAY, &seconds);
229
230 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
231 if (unlikely(ret))
232 goto out;
233
234 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, seconds);
235
236 out:
237 mc13xxx_unlock(priv->mc13xxx);
238
239 return ret;
240 }
241
mc13xxx_rtc_alarm_handler(int irq,void * dev)242 static irqreturn_t mc13xxx_rtc_alarm_handler(int irq, void *dev)
243 {
244 struct mc13xxx_rtc *priv = dev;
245 struct mc13xxx *mc13xxx = priv->mc13xxx;
246
247 rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);
248
249 mc13xxx_irq_ack(mc13xxx, irq);
250
251 return IRQ_HANDLED;
252 }
253
254 static const struct rtc_class_ops mc13xxx_rtc_ops = {
255 .read_time = mc13xxx_rtc_read_time,
256 .set_mmss64 = mc13xxx_rtc_set_mmss,
257 .read_alarm = mc13xxx_rtc_read_alarm,
258 .set_alarm = mc13xxx_rtc_set_alarm,
259 .alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable,
260 };
261
mc13xxx_rtc_reset_handler(int irq,void * dev)262 static irqreturn_t mc13xxx_rtc_reset_handler(int irq, void *dev)
263 {
264 struct mc13xxx_rtc *priv = dev;
265 struct mc13xxx *mc13xxx = priv->mc13xxx;
266
267 priv->valid = 0;
268
269 mc13xxx_irq_mask(mc13xxx, irq);
270
271 return IRQ_HANDLED;
272 }
273
mc13xxx_rtc_probe(struct platform_device * pdev)274 static int __init mc13xxx_rtc_probe(struct platform_device *pdev)
275 {
276 int ret;
277 struct mc13xxx_rtc *priv;
278 struct mc13xxx *mc13xxx;
279
280 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
281 if (!priv)
282 return -ENOMEM;
283
284 mc13xxx = dev_get_drvdata(pdev->dev.parent);
285 priv->mc13xxx = mc13xxx;
286 priv->valid = 1;
287
288 platform_set_drvdata(pdev, priv);
289
290 mc13xxx_lock(mc13xxx);
291
292 mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_RTCRST);
293
294 ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST,
295 mc13xxx_rtc_reset_handler, DRIVER_NAME, priv);
296 if (ret)
297 goto err_irq_request;
298
299 ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA,
300 mc13xxx_rtc_alarm_handler, DRIVER_NAME, priv);
301 if (ret)
302 goto err_irq_request;
303
304 mc13xxx_unlock(mc13xxx);
305
306 priv->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
307 &mc13xxx_rtc_ops, THIS_MODULE);
308
309 return 0;
310
311 err_irq_request:
312 mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv);
313 mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv);
314
315 mc13xxx_unlock(mc13xxx);
316
317 return ret;
318 }
319
mc13xxx_rtc_remove(struct platform_device * pdev)320 static int mc13xxx_rtc_remove(struct platform_device *pdev)
321 {
322 struct mc13xxx_rtc *priv = platform_get_drvdata(pdev);
323
324 mc13xxx_lock(priv->mc13xxx);
325
326 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TODA, priv);
327 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_RTCRST, priv);
328
329 mc13xxx_unlock(priv->mc13xxx);
330
331 return 0;
332 }
333
334 static const struct platform_device_id mc13xxx_rtc_idtable[] = {
335 {
336 .name = "mc13783-rtc",
337 }, {
338 .name = "mc13892-rtc",
339 }, {
340 .name = "mc34708-rtc",
341 },
342 { /* sentinel */ }
343 };
344 MODULE_DEVICE_TABLE(platform, mc13xxx_rtc_idtable);
345
346 static struct platform_driver mc13xxx_rtc_driver = {
347 .id_table = mc13xxx_rtc_idtable,
348 .remove = mc13xxx_rtc_remove,
349 .driver = {
350 .name = DRIVER_NAME,
351 },
352 };
353
354 module_platform_driver_probe(mc13xxx_rtc_driver, &mc13xxx_rtc_probe);
355
356 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
357 MODULE_DESCRIPTION("RTC driver for Freescale MC13XXX PMIC");
358 MODULE_LICENSE("GPL v2");
359