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 | |
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 | |
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(mc13xxx: priv->mc13xxx); |
52 | |
53 | ret = mc13xxx_rtc_irq_enable_unlocked(dev, enabled, MC13XXX_IRQ_TODA); |
54 | |
55 | mc13xxx_unlock(mc13xxx: priv->mc13xxx); |
56 | |
57 | return ret; |
58 | } |
59 | |
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(mc13xxx: priv->mc13xxx, MC13XXX_RTCDAY, val: &days1); |
72 | if (ret) |
73 | return ret; |
74 | |
75 | ret = mc13xxx_reg_read(mc13xxx: priv->mc13xxx, MC13XXX_RTCTOD, val: &seconds); |
76 | if (ret) |
77 | return ret; |
78 | |
79 | ret = mc13xxx_reg_read(mc13xxx: priv->mc13xxx, MC13XXX_RTCDAY, val: &days2); |
80 | if (ret) |
81 | return ret; |
82 | } while (days1 != days2); |
83 | |
84 | rtc_time64_to_tm(time: (time64_t)days1 * SEC_PER_DAY + seconds, tm); |
85 | |
86 | return 0; |
87 | } |
88 | |
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(dividend: rtc_tm_to_time64(tm), SEC_PER_DAY, remainder: &seconds); |
97 | |
98 | mc13xxx_lock(mc13xxx: 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(mc13xxx: priv->mc13xxx, MC13XXX_RTCTODA, val: &alarmseconds); |
105 | if (unlikely(ret)) |
106 | goto out; |
107 | |
108 | if (alarmseconds < SEC_PER_DAY) { |
109 | ret = mc13xxx_reg_write(mc13xxx: priv->mc13xxx, |
110 | MC13XXX_RTCTODA, val: 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(mc13xxx: priv->mc13xxx, MC13XXX_RTCTOD, val: 0); |
120 | if (unlikely(ret)) |
121 | goto out; |
122 | |
123 | ret = mc13xxx_reg_write(mc13xxx: priv->mc13xxx, MC13XXX_RTCDAY, val: days); |
124 | if (unlikely(ret)) |
125 | goto out; |
126 | |
127 | ret = mc13xxx_reg_write(mc13xxx: priv->mc13xxx, MC13XXX_RTCTOD, val: seconds); |
128 | if (unlikely(ret)) |
129 | goto out; |
130 | |
131 | /* restore alarm */ |
132 | if (alarmseconds < SEC_PER_DAY) { |
133 | ret = mc13xxx_reg_write(mc13xxx: priv->mc13xxx, |
134 | MC13XXX_RTCTODA, val: alarmseconds); |
135 | if (unlikely(ret)) |
136 | goto out; |
137 | } |
138 | |
139 | if (!priv->valid) { |
140 | ret = mc13xxx_irq_ack(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_RTCRST); |
141 | if (unlikely(ret)) |
142 | goto out; |
143 | |
144 | ret = mc13xxx_irq_unmask(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_RTCRST); |
145 | } |
146 | |
147 | out: |
148 | priv->valid = !ret; |
149 | |
150 | mc13xxx_unlock(mc13xxx: priv->mc13xxx); |
151 | |
152 | return ret; |
153 | } |
154 | |
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(mc13xxx: priv->mc13xxx); |
164 | |
165 | ret = mc13xxx_reg_read(mc13xxx: priv->mc13xxx, MC13XXX_RTCTODA, val: &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(mc13xxx: priv->mc13xxx, MC13XXX_RTCDAY, val: &days); |
174 | if (unlikely(ret)) |
175 | goto out; |
176 | |
177 | ret = mc13xxx_irq_status(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_TODA, |
178 | enabled: &enabled, pending: &pending); |
179 | |
180 | out: |
181 | mc13xxx_unlock(mc13xxx: 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(time: s1970, tm: &alarm->time); |
192 | dev_dbg(dev, "%s: %lld\n" , __func__, (long long)s1970); |
193 | |
194 | return 0; |
195 | } |
196 | |
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(mc13xxx: priv->mc13xxx); |
205 | |
206 | /* disable alarm to prevent false triggering */ |
207 | ret = mc13xxx_reg_write(mc13xxx: priv->mc13xxx, MC13XXX_RTCTODA, val: 0x1ffff); |
208 | if (unlikely(ret)) |
209 | goto out; |
210 | |
211 | ret = mc13xxx_irq_ack(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_TODA); |
212 | if (unlikely(ret)) |
213 | goto out; |
214 | |
215 | s1970 = rtc_tm_to_time64(tm: &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, enabled: alarm->enabled, |
221 | MC13XXX_IRQ_TODA); |
222 | if (unlikely(ret)) |
223 | goto out; |
224 | |
225 | days = div_s64_rem(dividend: s1970, SEC_PER_DAY, remainder: &seconds); |
226 | |
227 | ret = mc13xxx_reg_write(mc13xxx: priv->mc13xxx, MC13XXX_RTCDAYA, val: days); |
228 | if (unlikely(ret)) |
229 | goto out; |
230 | |
231 | ret = mc13xxx_reg_write(mc13xxx: priv->mc13xxx, MC13XXX_RTCTODA, val: seconds); |
232 | |
233 | out: |
234 | mc13xxx_unlock(mc13xxx: priv->mc13xxx); |
235 | |
236 | return ret; |
237 | } |
238 | |
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(rtc: priv->rtc, num: 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 | |
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 | |
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(dev: &pdev->dev, size: sizeof(*priv), GFP_KERNEL); |
278 | if (!priv) |
279 | return -ENOMEM; |
280 | |
281 | mc13xxx = dev_get_drvdata(dev: pdev->dev.parent); |
282 | priv->mc13xxx = mc13xxx; |
283 | priv->valid = 1; |
284 | |
285 | priv->rtc = devm_rtc_allocate_device(dev: &pdev->dev); |
286 | if (IS_ERR(ptr: priv->rtc)) |
287 | return PTR_ERR(ptr: priv->rtc); |
288 | platform_set_drvdata(pdev, data: 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 | handler: mc13xxx_rtc_reset_handler, DRIVER_NAME, dev: priv); |
300 | if (ret) |
301 | goto err_irq_request; |
302 | |
303 | ret = mc13xxx_irq_request_nounmask(mc13xxx, MC13XXX_IRQ_TODA, |
304 | handler: mc13xxx_rtc_alarm_handler, DRIVER_NAME, dev: 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, dev: priv); |
320 | mc13xxx_irq_free(mc13xxx, MC13XXX_IRQ_RTCRST, dev: priv); |
321 | |
322 | mc13xxx_unlock(mc13xxx); |
323 | |
324 | return ret; |
325 | } |
326 | |
327 | static void mc13xxx_rtc_remove(struct platform_device *pdev) |
328 | { |
329 | struct mc13xxx_rtc *priv = platform_get_drvdata(pdev); |
330 | |
331 | mc13xxx_lock(mc13xxx: priv->mc13xxx); |
332 | |
333 | mc13xxx_irq_free(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_TODA, dev: priv); |
334 | mc13xxx_irq_free(mc13xxx: priv->mc13xxx, MC13XXX_IRQ_RTCRST, dev: priv); |
335 | |
336 | mc13xxx_unlock(mc13xxx: 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 | |