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Anatolij Gustschin50aae722010-02-16 10:47:35 -07001/*
2 * Real-time clock driver for MPC5121
3 *
4 * Copyright 2007, Domen Puncer <domen.puncer@telargo.com>
5 * Copyright 2008, Freescale Semiconductor, Inc. All rights reserved.
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/init.h>
13#include <linux/module.h>
14#include <linux/rtc.h>
15#include <linux/of_device.h>
16#include <linux/of_platform.h>
17#include <linux/io.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090018#include <linux/slab.h>
Anatolij Gustschin50aae722010-02-16 10:47:35 -070019
20struct mpc5121_rtc_regs {
21 u8 set_time; /* RTC + 0x00 */
22 u8 hour_set; /* RTC + 0x01 */
23 u8 minute_set; /* RTC + 0x02 */
24 u8 second_set; /* RTC + 0x03 */
25
26 u8 set_date; /* RTC + 0x04 */
27 u8 month_set; /* RTC + 0x05 */
28 u8 weekday_set; /* RTC + 0x06 */
29 u8 date_set; /* RTC + 0x07 */
30
31 u8 write_sw; /* RTC + 0x08 */
32 u8 sw_set; /* RTC + 0x09 */
33 u16 year_set; /* RTC + 0x0a */
34
35 u8 alm_enable; /* RTC + 0x0c */
36 u8 alm_hour_set; /* RTC + 0x0d */
37 u8 alm_min_set; /* RTC + 0x0e */
38 u8 int_enable; /* RTC + 0x0f */
39
40 u8 reserved1;
41 u8 hour; /* RTC + 0x11 */
42 u8 minute; /* RTC + 0x12 */
43 u8 second; /* RTC + 0x13 */
44
45 u8 month; /* RTC + 0x14 */
46 u8 wday_mday; /* RTC + 0x15 */
47 u16 year; /* RTC + 0x16 */
48
49 u8 int_alm; /* RTC + 0x18 */
50 u8 int_sw; /* RTC + 0x19 */
51 u8 alm_status; /* RTC + 0x1a */
52 u8 sw_minute; /* RTC + 0x1b */
53
54 u8 bus_error_1; /* RTC + 0x1c */
55 u8 int_day; /* RTC + 0x1d */
56 u8 int_min; /* RTC + 0x1e */
57 u8 int_sec; /* RTC + 0x1f */
58
59 /*
60 * target_time:
61 * intended to be used for hibernation but hibernation
62 * does not work on silicon rev 1.5 so use it for non-volatile
63 * storage of offset between the actual_time register and linux
64 * time
65 */
66 u32 target_time; /* RTC + 0x20 */
67 /*
68 * actual_time:
69 * readonly time since VBAT_RTC was last connected
70 */
71 u32 actual_time; /* RTC + 0x24 */
72 u32 keep_alive; /* RTC + 0x28 */
73};
74
75struct mpc5121_rtc_data {
76 unsigned irq;
77 unsigned irq_periodic;
78 struct mpc5121_rtc_regs __iomem *regs;
79 struct rtc_device *rtc;
80 struct rtc_wkalrm wkalarm;
81};
82
83/*
84 * Update second/minute/hour registers.
85 *
86 * This is just so alarm will work.
87 */
88static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
89 struct rtc_time *tm)
90{
91 out_8(&regs->second_set, tm->tm_sec);
92 out_8(&regs->minute_set, tm->tm_min);
93 out_8(&regs->hour_set, tm->tm_hour);
94
95 /* set time sequence */
96 out_8(&regs->set_time, 0x1);
97 out_8(&regs->set_time, 0x3);
98 out_8(&regs->set_time, 0x1);
99 out_8(&regs->set_time, 0x0);
100}
101
102static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
103{
104 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
105 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
106 unsigned long now;
107
108 /*
109 * linux time is actual_time plus the offset saved in target_time
110 */
111 now = in_be32(&regs->actual_time) + in_be32(&regs->target_time);
112
113 rtc_time_to_tm(now, tm);
114
115 /*
116 * update second minute hour registers
117 * so alarms will work
118 */
119 mpc5121_rtc_update_smh(regs, tm);
120
121 return rtc_valid_tm(tm);
122}
123
124static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
125{
126 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
127 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
128 int ret;
129 unsigned long now;
130
131 /*
132 * The actual_time register is read only so we write the offset
133 * between it and linux time to the target_time register.
134 */
135 ret = rtc_tm_to_time(tm, &now);
136 if (ret == 0)
137 out_be32(&regs->target_time, now - in_be32(&regs->actual_time));
138
139 /*
140 * update second minute hour registers
141 * so alarms will work
142 */
143 mpc5121_rtc_update_smh(regs, tm);
144
145 return 0;
146}
147
148static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
149{
150 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
151 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
152
153 *alarm = rtc->wkalarm;
154
155 alarm->pending = in_8(&regs->alm_status);
156
157 return 0;
158}
159
160static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
161{
162 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
163 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
164
165 /*
166 * the alarm has no seconds so deal with it
167 */
168 if (alarm->time.tm_sec) {
169 alarm->time.tm_sec = 0;
170 alarm->time.tm_min++;
171 if (alarm->time.tm_min >= 60) {
172 alarm->time.tm_min = 0;
173 alarm->time.tm_hour++;
174 if (alarm->time.tm_hour >= 24)
175 alarm->time.tm_hour = 0;
176 }
177 }
178
179 alarm->time.tm_mday = -1;
180 alarm->time.tm_mon = -1;
181 alarm->time.tm_year = -1;
182
183 out_8(&regs->alm_min_set, alarm->time.tm_min);
184 out_8(&regs->alm_hour_set, alarm->time.tm_hour);
185
186 out_8(&regs->alm_enable, alarm->enabled);
187
188 rtc->wkalarm = *alarm;
189 return 0;
190}
191
192static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
193{
194 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
195 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
196
197 if (in_8(&regs->int_alm)) {
198 /* acknowledge and clear status */
199 out_8(&regs->int_alm, 1);
200 out_8(&regs->alm_status, 1);
201
202 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
203 return IRQ_HANDLED;
204 }
205
206 return IRQ_NONE;
207}
208
209static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
210{
211 struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
212 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
213
214 if (in_8(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
215 /* acknowledge */
216 out_8(&regs->int_sec, 1);
217
218 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
219 return IRQ_HANDLED;
220 }
221
222 return IRQ_NONE;
223}
224
225static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
226 unsigned int enabled)
227{
228 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
229 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
230 int val;
231
232 if (enabled)
233 val = 1;
234 else
235 val = 0;
236
237 out_8(&regs->alm_enable, val);
238 rtc->wkalarm.enabled = val;
239
240 return 0;
241}
242
243static int mpc5121_rtc_update_irq_enable(struct device *dev,
244 unsigned int enabled)
245{
246 struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
247 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
248 int val;
249
250 val = in_8(&regs->int_enable);
251
252 if (enabled)
253 val = (val & ~0x8) | 0x1;
254 else
255 val &= ~0x1;
256
257 out_8(&regs->int_enable, val);
258
259 return 0;
260}
261
262static const struct rtc_class_ops mpc5121_rtc_ops = {
263 .read_time = mpc5121_rtc_read_time,
264 .set_time = mpc5121_rtc_set_time,
265 .read_alarm = mpc5121_rtc_read_alarm,
266 .set_alarm = mpc5121_rtc_set_alarm,
267 .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
268 .update_irq_enable = mpc5121_rtc_update_irq_enable,
269};
270
271static int __devinit mpc5121_rtc_probe(struct of_device *op,
272 const struct of_device_id *match)
273{
274 struct mpc5121_rtc_data *rtc;
275 int err = 0;
276 u32 ka;
277
278 rtc = kzalloc(sizeof(*rtc), GFP_KERNEL);
279 if (!rtc)
280 return -ENOMEM;
281
282 rtc->regs = of_iomap(op->node, 0);
283 if (!rtc->regs) {
284 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
285 err = -ENOSYS;
286 goto out_free;
287 }
288
289 device_init_wakeup(&op->dev, 1);
290
291 dev_set_drvdata(&op->dev, rtc);
292
293 rtc->irq = irq_of_parse_and_map(op->node, 1);
294 err = request_irq(rtc->irq, mpc5121_rtc_handler, IRQF_DISABLED,
295 "mpc5121-rtc", &op->dev);
296 if (err) {
297 dev_err(&op->dev, "%s: could not request irq: %i\n",
298 __func__, rtc->irq);
299 goto out_dispose;
300 }
301
302 rtc->irq_periodic = irq_of_parse_and_map(op->node, 0);
303 err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
304 IRQF_DISABLED, "mpc5121-rtc_upd", &op->dev);
305 if (err) {
306 dev_err(&op->dev, "%s: could not request irq: %i\n",
307 __func__, rtc->irq_periodic);
308 goto out_dispose2;
309 }
310
311 ka = in_be32(&rtc->regs->keep_alive);
312 if (ka & 0x02) {
313 dev_warn(&op->dev,
314 "mpc5121-rtc: Battery or oscillator failure!\n");
315 out_be32(&rtc->regs->keep_alive, ka);
316 }
317
318 rtc->rtc = rtc_device_register("mpc5121-rtc", &op->dev,
319 &mpc5121_rtc_ops, THIS_MODULE);
320 if (IS_ERR(rtc->rtc)) {
321 err = PTR_ERR(rtc->rtc);
322 goto out_free_irq;
323 }
324
325 return 0;
326
327out_free_irq:
328 free_irq(rtc->irq_periodic, &op->dev);
329out_dispose2:
330 irq_dispose_mapping(rtc->irq_periodic);
331 free_irq(rtc->irq, &op->dev);
332out_dispose:
333 irq_dispose_mapping(rtc->irq);
334 iounmap(rtc->regs);
335out_free:
336 kfree(rtc);
337
338 return err;
339}
340
341static int __devexit mpc5121_rtc_remove(struct of_device *op)
342{
343 struct mpc5121_rtc_data *rtc = dev_get_drvdata(&op->dev);
344 struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
345
346 /* disable interrupt, so there are no nasty surprises */
347 out_8(&regs->alm_enable, 0);
348 out_8(&regs->int_enable, in_8(&regs->int_enable) & ~0x1);
349
350 rtc_device_unregister(rtc->rtc);
351 iounmap(rtc->regs);
352 free_irq(rtc->irq, &op->dev);
353 free_irq(rtc->irq_periodic, &op->dev);
354 irq_dispose_mapping(rtc->irq);
355 irq_dispose_mapping(rtc->irq_periodic);
356 dev_set_drvdata(&op->dev, NULL);
357 kfree(rtc);
358
359 return 0;
360}
361
362static struct of_device_id mpc5121_rtc_match[] __devinitdata = {
363 { .compatible = "fsl,mpc5121-rtc", },
364 {},
365};
366
367static struct of_platform_driver mpc5121_rtc_driver = {
368 .owner = THIS_MODULE,
369 .name = "mpc5121-rtc",
370 .match_table = mpc5121_rtc_match,
371 .probe = mpc5121_rtc_probe,
372 .remove = __devexit_p(mpc5121_rtc_remove),
373};
374
375static int __init mpc5121_rtc_init(void)
376{
377 return of_register_platform_driver(&mpc5121_rtc_driver);
378}
379module_init(mpc5121_rtc_init);
380
381static void __exit mpc5121_rtc_exit(void)
382{
383 of_unregister_platform_driver(&mpc5121_rtc_driver);
384}
385module_exit(mpc5121_rtc_exit);
386
387MODULE_LICENSE("GPL");
388MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");