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