1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Real Time Clock driver for Freescale MC13XXX PMIC
4 *
5 * (C) 2009 Sascha Hauer, Pengutronix
6 * (C) 2009 Uwe Kleine-Koenig, Pengutronix
7 */
8
9 #include <linux/mfd/mc13xxx.h>
10 #include <linux/platform_device.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/mod_devicetable.h>
14 #include <linux/slab.h>
15 #include <linux/rtc.h>
16
17 #define DRIVER_NAME "mc13xxx-rtc"
18
19 #define MC13XXX_RTCTOD 20
20 #define MC13XXX_RTCTODA 21
21 #define MC13XXX_RTCDAY 22
22 #define MC13XXX_RTCDAYA 23
23
24 #define SEC_PER_DAY (24 * 60 * 60)
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_alarm_irq_enable(struct device * dev,unsigned int enabled)45 static int mc13xxx_rtc_alarm_irq_enable(struct device *dev,
46 unsigned int enabled)
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, MC13XXX_IRQ_TODA);
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
65 if (!priv->valid)
66 return -ENODATA;
67
68 do {
69 int ret;
70
71 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days1);
72 if (ret)
73 return ret;
74
75 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTOD, &seconds);
76 if (ret)
77 return ret;
78
79 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days2);
80 if (ret)
81 return ret;
82 } while (days1 != days2);
83
84 rtc_time64_to_tm((time64_t)days1 * SEC_PER_DAY + seconds, tm);
85
86 return 0;
87 }
88
mc13xxx_rtc_set_time(struct device * dev,struct rtc_time * tm)89 static int mc13xxx_rtc_set_time(struct device *dev, struct rtc_time *tm)
90 {
91 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
92 unsigned int seconds, days;
93 unsigned int alarmseconds;
94 int ret;
95
96 days = div_s64_rem(rtc_tm_to_time64(tm), SEC_PER_DAY, &seconds);
97
98 mc13xxx_lock(priv->mc13xxx);
99
100 /*
101 * temporarily invalidate alarm to prevent triggering it when the day is
102 * already updated while the time isn't yet.
103 */
104 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &alarmseconds);
105 if (unlikely(ret))
106 goto out;
107
108 if (alarmseconds < SEC_PER_DAY) {
109 ret = mc13xxx_reg_write(priv->mc13xxx,
110 MC13XXX_RTCTODA, 0x1ffff);
111 if (unlikely(ret))
112 goto out;
113 }
114
115 /*
116 * write seconds=0 to prevent a day switch between writing days
117 * and seconds below
118 */
119 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, 0);
120 if (unlikely(ret))
121 goto out;
122
123 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAY, days);
124 if (unlikely(ret))
125 goto out;
126
127 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTOD, seconds);
128 if (unlikely(ret))
129 goto out;
130
131 /* restore alarm */
132 if (alarmseconds < SEC_PER_DAY) {
133 ret = mc13xxx_reg_write(priv->mc13xxx,
134 MC13XXX_RTCTODA, alarmseconds);
135 if (unlikely(ret))
136 goto out;
137 }
138
139 if (!priv->valid) {
140 ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
141 if (unlikely(ret))
142 goto out;
143
144 ret = mc13xxx_irq_unmask(priv->mc13xxx, MC13XXX_IRQ_RTCRST);
145 }
146
147 out:
148 priv->valid = !ret;
149
150 mc13xxx_unlock(priv->mc13xxx);
151
152 return ret;
153 }
154
mc13xxx_rtc_read_alarm(struct device * dev,struct rtc_wkalrm * alarm)155 static int mc13xxx_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
156 {
157 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
158 unsigned int seconds, days;
159 time64_t s1970;
160 int enabled, pending;
161 int ret;
162
163 mc13xxx_lock(priv->mc13xxx);
164
165 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCTODA, &seconds);
166 if (unlikely(ret))
167 goto out;
168 if (seconds >= SEC_PER_DAY) {
169 ret = -ENODATA;
170 goto out;
171 }
172
173 ret = mc13xxx_reg_read(priv->mc13xxx, MC13XXX_RTCDAY, &days);
174 if (unlikely(ret))
175 goto out;
176
177 ret = mc13xxx_irq_status(priv->mc13xxx, MC13XXX_IRQ_TODA,
178 &enabled, &pending);
179
180 out:
181 mc13xxx_unlock(priv->mc13xxx);
182
183 if (ret)
184 return ret;
185
186 alarm->enabled = enabled;
187 alarm->pending = pending;
188
189 s1970 = (time64_t)days * SEC_PER_DAY + seconds;
190
191 rtc_time64_to_tm(s1970, &alarm->time);
192 dev_dbg(dev, "%s: %lld\n", __func__, (long long)s1970);
193
194 return 0;
195 }
196
mc13xxx_rtc_set_alarm(struct device * dev,struct rtc_wkalrm * alarm)197 static int mc13xxx_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
198 {
199 struct mc13xxx_rtc *priv = dev_get_drvdata(dev);
200 time64_t s1970;
201 u32 seconds, days;
202 int ret;
203
204 mc13xxx_lock(priv->mc13xxx);
205
206 /* disable alarm to prevent false triggering */
207 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, 0x1ffff);
208 if (unlikely(ret))
209 goto out;
210
211 ret = mc13xxx_irq_ack(priv->mc13xxx, MC13XXX_IRQ_TODA);
212 if (unlikely(ret))
213 goto out;
214
215 s1970 = rtc_tm_to_time64(&alarm->time);
216
217 dev_dbg(dev, "%s: %s %lld\n", __func__, alarm->enabled ? "on" : "off",
218 (long long)s1970);
219
220 ret = mc13xxx_rtc_irq_enable_unlocked(dev, alarm->enabled,
221 MC13XXX_IRQ_TODA);
222 if (unlikely(ret))
223 goto out;
224
225 days = div_s64_rem(s1970, SEC_PER_DAY, &seconds);
226
227 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCDAYA, days);
228 if (unlikely(ret))
229 goto out;
230
231 ret = mc13xxx_reg_write(priv->mc13xxx, MC13XXX_RTCTODA, seconds);
232
233 out:
234 mc13xxx_unlock(priv->mc13xxx);
235
236 return ret;
237 }
238
mc13xxx_rtc_alarm_handler(int irq,void * dev)239 static irqreturn_t mc13xxx_rtc_alarm_handler(int irq, void *dev)
240 {
241 struct mc13xxx_rtc *priv = dev;
242 struct mc13xxx *mc13xxx = priv->mc13xxx;
243
244 rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);
245
246 mc13xxx_irq_ack(mc13xxx, irq);
247
248 return IRQ_HANDLED;
249 }
250
251 static const struct rtc_class_ops mc13xxx_rtc_ops = {
252 .read_time = mc13xxx_rtc_read_time,
253 .set_time = mc13xxx_rtc_set_time,
254 .read_alarm = mc13xxx_rtc_read_alarm,
255 .set_alarm = mc13xxx_rtc_set_alarm,
256 .alarm_irq_enable = mc13xxx_rtc_alarm_irq_enable,
257 };
258
mc13xxx_rtc_reset_handler(int irq,void * dev)259 static irqreturn_t mc13xxx_rtc_reset_handler(int irq, void *dev)
260 {
261 struct mc13xxx_rtc *priv = dev;
262 struct mc13xxx *mc13xxx = priv->mc13xxx;
263
264 priv->valid = 0;
265
266 mc13xxx_irq_mask(mc13xxx, irq);
267
268 return IRQ_HANDLED;
269 }
270
mc13xxx_rtc_probe(struct platform_device * pdev)271 static int __init mc13xxx_rtc_probe(struct platform_device *pdev)
272 {
273 int ret;
274 struct mc13xxx_rtc *priv;
275 struct mc13xxx *mc13xxx;
276
277 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
278 if (!priv)
279 return -ENOMEM;
280
281 mc13xxx = dev_get_drvdata(pdev->dev.parent);
282 priv->mc13xxx = mc13xxx;
283 priv->valid = 1;
284
285 priv->rtc = devm_rtc_allocate_device(&pdev->dev);
286 if (IS_ERR(priv->rtc))
287 return PTR_ERR(priv->rtc);
288 platform_set_drvdata(pdev, priv);
289
290 priv->rtc->ops = &mc13xxx_rtc_ops;
291 /* 15bit days + hours, minutes, seconds */
292 priv->rtc->range_max = (timeu64_t)(1 << 15) * SEC_PER_DAY - 1;
293
294 mc13xxx_lock(mc13xxx);
295
296 mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_RTCRST);
297
298 ret = mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_RTCRST,
299 mc13xxx_rtc_reset_handler, DRIVER_NAME, priv);
300 if (ret)
301 goto err_irq_request;
302
303 ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA,
304 mc13xxx_rtc_alarm_handler, DRIVER_NAME, priv);
305 if (ret)
306 goto err_irq_request;
307
308 mc13xxx_unlock(mc13xxx);
309
310 ret = devm_rtc_register_device(priv->rtc);
311 if (ret) {
312 mc13xxx_lock(mc13xxx);
313 goto err_irq_request;
314 }
315
316 return 0;
317
318 err_irq_request:
319 mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_TODA, priv);
320 mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, priv);
321
322 mc13xxx_unlock(mc13xxx);
323
324 return ret;
325 }
326
mc13xxx_rtc_remove(struct platform_device * pdev)327 static void mc13xxx_rtc_remove(struct platform_device *pdev)
328 {
329 struct mc13xxx_rtc *priv = platform_get_drvdata(pdev);
330
331 mc13xxx_lock(priv->mc13xxx);
332
333 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_TODA, priv);
334 mc13xxx_irq_free(priv->mc13xxx, MC13XXX_IRQ_RTCRST, priv);
335
336 mc13xxx_unlock(priv->mc13xxx);
337 }
338
339 static const struct platform_device_id mc13xxx_rtc_idtable[] = {
340 {
341 .name = "mc13783-rtc",
342 }, {
343 .name = "mc13892-rtc",
344 }, {
345 .name = "mc34708-rtc",
346 },
347 { /* sentinel */ }
348 };
349 MODULE_DEVICE_TABLE(platform, mc13xxx_rtc_idtable);
350
351 static struct platform_driver mc13xxx_rtc_driver = {
352 .id_table = mc13xxx_rtc_idtable,
353 .remove_new = mc13xxx_rtc_remove,
354 .driver = {
355 .name = DRIVER_NAME,
356 },
357 };
358
359 module_platform_driver_probe(mc13xxx_rtc_driver, &mc13xxx_rtc_probe);
360
361 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
362 MODULE_DESCRIPTION("RTC driver for Freescale MC13XXX PMIC");
363 MODULE_LICENSE("GPL v2");
364