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Linux/drivers/rtc/rtc-mpc5121.c

  1 /*
  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  * Copyright 2011, Dmitry Eremin-Solenikov
  7  *
  8  * This program is free software; you can redistribute it and/or modify
  9  * it under the terms of the GNU General Public License version 2 as
 10  * published by the Free Software Foundation.
 11  */
 12 
 13 #include <linux/init.h>
 14 #include <linux/module.h>
 15 #include <linux/rtc.h>
 16 #include <linux/of.h>
 17 #include <linux/of_address.h>
 18 #include <linux/of_device.h>
 19 #include <linux/of_irq.h>
 20 #include <linux/of_platform.h>
 21 #include <linux/io.h>
 22 #include <linux/slab.h>
 23 
 24 struct mpc5121_rtc_regs {
 25         u8 set_time;            /* RTC + 0x00 */
 26         u8 hour_set;            /* RTC + 0x01 */
 27         u8 minute_set;          /* RTC + 0x02 */
 28         u8 second_set;          /* RTC + 0x03 */
 29 
 30         u8 set_date;            /* RTC + 0x04 */
 31         u8 month_set;           /* RTC + 0x05 */
 32         u8 weekday_set;         /* RTC + 0x06 */
 33         u8 date_set;            /* RTC + 0x07 */
 34 
 35         u8 write_sw;            /* RTC + 0x08 */
 36         u8 sw_set;              /* RTC + 0x09 */
 37         u16 year_set;           /* RTC + 0x0a */
 38 
 39         u8 alm_enable;          /* RTC + 0x0c */
 40         u8 alm_hour_set;        /* RTC + 0x0d */
 41         u8 alm_min_set;         /* RTC + 0x0e */
 42         u8 int_enable;          /* RTC + 0x0f */
 43 
 44         u8 reserved1;
 45         u8 hour;                /* RTC + 0x11 */
 46         u8 minute;              /* RTC + 0x12 */
 47         u8 second;              /* RTC + 0x13 */
 48 
 49         u8 month;               /* RTC + 0x14 */
 50         u8 wday_mday;           /* RTC + 0x15 */
 51         u16 year;               /* RTC + 0x16 */
 52 
 53         u8 int_alm;             /* RTC + 0x18 */
 54         u8 int_sw;              /* RTC + 0x19 */
 55         u8 alm_status;          /* RTC + 0x1a */
 56         u8 sw_minute;           /* RTC + 0x1b */
 57 
 58         u8 bus_error_1;         /* RTC + 0x1c */
 59         u8 int_day;             /* RTC + 0x1d */
 60         u8 int_min;             /* RTC + 0x1e */
 61         u8 int_sec;             /* RTC + 0x1f */
 62 
 63         /*
 64          * target_time:
 65          *      intended to be used for hibernation but hibernation
 66          *      does not work on silicon rev 1.5 so use it for non-volatile
 67          *      storage of offset between the actual_time register and linux
 68          *      time
 69          */
 70         u32 target_time;        /* RTC + 0x20 */
 71         /*
 72          * actual_time:
 73          *      readonly time since VBAT_RTC was last connected
 74          */
 75         u32 actual_time;        /* RTC + 0x24 */
 76         u32 keep_alive;         /* RTC + 0x28 */
 77 };
 78 
 79 struct mpc5121_rtc_data {
 80         unsigned irq;
 81         unsigned irq_periodic;
 82         struct mpc5121_rtc_regs __iomem *regs;
 83         struct rtc_device *rtc;
 84         struct rtc_wkalrm wkalarm;
 85 };
 86 
 87 /*
 88  * Update second/minute/hour registers.
 89  *
 90  * This is just so alarm will work.
 91  */
 92 static void mpc5121_rtc_update_smh(struct mpc5121_rtc_regs __iomem *regs,
 93                                    struct rtc_time *tm)
 94 {
 95         out_8(&regs->second_set, tm->tm_sec);
 96         out_8(&regs->minute_set, tm->tm_min);
 97         out_8(&regs->hour_set, tm->tm_hour);
 98 
 99         /* set time sequence */
100         out_8(&regs->set_time, 0x1);
101         out_8(&regs->set_time, 0x3);
102         out_8(&regs->set_time, 0x1);
103         out_8(&regs->set_time, 0x0);
104 }
105 
106 static int mpc5121_rtc_read_time(struct device *dev, struct rtc_time *tm)
107 {
108         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
109         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
110         unsigned long now;
111 
112         /*
113          * linux time is actual_time plus the offset saved in target_time
114          */
115         now = in_be32(&regs->actual_time) + in_be32(&regs->target_time);
116 
117         rtc_time_to_tm(now, tm);
118 
119         /*
120          * update second minute hour registers
121          * so alarms will work
122          */
123         mpc5121_rtc_update_smh(regs, tm);
124 
125         return rtc_valid_tm(tm);
126 }
127 
128 static int mpc5121_rtc_set_time(struct device *dev, struct rtc_time *tm)
129 {
130         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
131         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
132         int ret;
133         unsigned long now;
134 
135         /*
136          * The actual_time register is read only so we write the offset
137          * between it and linux time to the target_time register.
138          */
139         ret = rtc_tm_to_time(tm, &now);
140         if (ret == 0)
141                 out_be32(&regs->target_time, now - in_be32(&regs->actual_time));
142 
143         /*
144          * update second minute hour registers
145          * so alarms will work
146          */
147         mpc5121_rtc_update_smh(regs, tm);
148 
149         return 0;
150 }
151 
152 static int mpc5200_rtc_read_time(struct device *dev, struct rtc_time *tm)
153 {
154         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
155         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
156         int tmp;
157 
158         tm->tm_sec = in_8(&regs->second);
159         tm->tm_min = in_8(&regs->minute);
160 
161         /* 12 hour format? */
162         if (in_8(&regs->hour) & 0x20)
163                 tm->tm_hour = (in_8(&regs->hour) >> 1) +
164                         (in_8(&regs->hour) & 1 ? 12 : 0);
165         else
166                 tm->tm_hour = in_8(&regs->hour);
167 
168         tmp = in_8(&regs->wday_mday);
169         tm->tm_mday = tmp & 0x1f;
170         tm->tm_mon = in_8(&regs->month) - 1;
171         tm->tm_year = in_be16(&regs->year) - 1900;
172         tm->tm_wday = (tmp >> 5) % 7;
173         tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
174         tm->tm_isdst = 0;
175 
176         return 0;
177 }
178 
179 static int mpc5200_rtc_set_time(struct device *dev, struct rtc_time *tm)
180 {
181         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
182         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
183 
184         mpc5121_rtc_update_smh(regs, tm);
185 
186         /* date */
187         out_8(&regs->month_set, tm->tm_mon + 1);
188         out_8(&regs->weekday_set, tm->tm_wday ? tm->tm_wday : 7);
189         out_8(&regs->date_set, tm->tm_mday);
190         out_be16(&regs->year_set, tm->tm_year + 1900);
191 
192         /* set date sequence */
193         out_8(&regs->set_date, 0x1);
194         out_8(&regs->set_date, 0x3);
195         out_8(&regs->set_date, 0x1);
196         out_8(&regs->set_date, 0x0);
197 
198         return 0;
199 }
200 
201 static int mpc5121_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
202 {
203         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
204         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
205 
206         *alarm = rtc->wkalarm;
207 
208         alarm->pending = in_8(&regs->alm_status);
209 
210         return 0;
211 }
212 
213 static int mpc5121_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
214 {
215         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
216         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
217 
218         /*
219          * the alarm has no seconds so deal with it
220          */
221         if (alarm->time.tm_sec) {
222                 alarm->time.tm_sec = 0;
223                 alarm->time.tm_min++;
224                 if (alarm->time.tm_min >= 60) {
225                         alarm->time.tm_min = 0;
226                         alarm->time.tm_hour++;
227                         if (alarm->time.tm_hour >= 24)
228                                 alarm->time.tm_hour = 0;
229                 }
230         }
231 
232         alarm->time.tm_mday = -1;
233         alarm->time.tm_mon = -1;
234         alarm->time.tm_year = -1;
235 
236         out_8(&regs->alm_min_set, alarm->time.tm_min);
237         out_8(&regs->alm_hour_set, alarm->time.tm_hour);
238 
239         out_8(&regs->alm_enable, alarm->enabled);
240 
241         rtc->wkalarm = *alarm;
242         return 0;
243 }
244 
245 static irqreturn_t mpc5121_rtc_handler(int irq, void *dev)
246 {
247         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
248         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
249 
250         if (in_8(&regs->int_alm)) {
251                 /* acknowledge and clear status */
252                 out_8(&regs->int_alm, 1);
253                 out_8(&regs->alm_status, 1);
254 
255                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_AF);
256                 return IRQ_HANDLED;
257         }
258 
259         return IRQ_NONE;
260 }
261 
262 static irqreturn_t mpc5121_rtc_handler_upd(int irq, void *dev)
263 {
264         struct mpc5121_rtc_data *rtc = dev_get_drvdata((struct device *)dev);
265         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
266 
267         if (in_8(&regs->int_sec) && (in_8(&regs->int_enable) & 0x1)) {
268                 /* acknowledge */
269                 out_8(&regs->int_sec, 1);
270 
271                 rtc_update_irq(rtc->rtc, 1, RTC_IRQF | RTC_UF);
272                 return IRQ_HANDLED;
273         }
274 
275         return IRQ_NONE;
276 }
277 
278 static int mpc5121_rtc_alarm_irq_enable(struct device *dev,
279                                         unsigned int enabled)
280 {
281         struct mpc5121_rtc_data *rtc = dev_get_drvdata(dev);
282         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
283         int val;
284 
285         if (enabled)
286                 val = 1;
287         else
288                 val = 0;
289 
290         out_8(&regs->alm_enable, val);
291         rtc->wkalarm.enabled = val;
292 
293         return 0;
294 }
295 
296 static const struct rtc_class_ops mpc5121_rtc_ops = {
297         .read_time = mpc5121_rtc_read_time,
298         .set_time = mpc5121_rtc_set_time,
299         .read_alarm = mpc5121_rtc_read_alarm,
300         .set_alarm = mpc5121_rtc_set_alarm,
301         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
302 };
303 
304 static const struct rtc_class_ops mpc5200_rtc_ops = {
305         .read_time = mpc5200_rtc_read_time,
306         .set_time = mpc5200_rtc_set_time,
307         .read_alarm = mpc5121_rtc_read_alarm,
308         .set_alarm = mpc5121_rtc_set_alarm,
309         .alarm_irq_enable = mpc5121_rtc_alarm_irq_enable,
310 };
311 
312 static int mpc5121_rtc_probe(struct platform_device *op)
313 {
314         struct mpc5121_rtc_data *rtc;
315         int err = 0;
316 
317         rtc = devm_kzalloc(&op->dev, sizeof(*rtc), GFP_KERNEL);
318         if (!rtc)
319                 return -ENOMEM;
320 
321         rtc->regs = of_iomap(op->dev.of_node, 0);
322         if (!rtc->regs) {
323                 dev_err(&op->dev, "%s: couldn't map io space\n", __func__);
324                 return -ENOSYS;
325         }
326 
327         device_init_wakeup(&op->dev, 1);
328 
329         platform_set_drvdata(op, rtc);
330 
331         rtc->irq = irq_of_parse_and_map(op->dev.of_node, 1);
332         err = request_irq(rtc->irq, mpc5121_rtc_handler, 0,
333                                                 "mpc5121-rtc", &op->dev);
334         if (err) {
335                 dev_err(&op->dev, "%s: could not request irq: %i\n",
336                                                         __func__, rtc->irq);
337                 goto out_dispose;
338         }
339 
340         rtc->irq_periodic = irq_of_parse_and_map(op->dev.of_node, 0);
341         err = request_irq(rtc->irq_periodic, mpc5121_rtc_handler_upd,
342                                 0, "mpc5121-rtc_upd", &op->dev);
343         if (err) {
344                 dev_err(&op->dev, "%s: could not request irq: %i\n",
345                                                 __func__, rtc->irq_periodic);
346                 goto out_dispose2;
347         }
348 
349         if (of_device_is_compatible(op->dev.of_node, "fsl,mpc5121-rtc")) {
350                 u32 ka;
351                 ka = in_be32(&rtc->regs->keep_alive);
352                 if (ka & 0x02) {
353                         dev_warn(&op->dev,
354                                 "mpc5121-rtc: Battery or oscillator failure!\n");
355                         out_be32(&rtc->regs->keep_alive, ka);
356                 }
357 
358                 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5121-rtc",
359                                                 &mpc5121_rtc_ops, THIS_MODULE);
360         } else {
361                 rtc->rtc = devm_rtc_device_register(&op->dev, "mpc5200-rtc",
362                                                 &mpc5200_rtc_ops, THIS_MODULE);
363         }
364 
365         if (IS_ERR(rtc->rtc)) {
366                 err = PTR_ERR(rtc->rtc);
367                 goto out_free_irq;
368         }
369         rtc->rtc->uie_unsupported = 1;
370 
371         return 0;
372 
373 out_free_irq:
374         free_irq(rtc->irq_periodic, &op->dev);
375 out_dispose2:
376         irq_dispose_mapping(rtc->irq_periodic);
377         free_irq(rtc->irq, &op->dev);
378 out_dispose:
379         irq_dispose_mapping(rtc->irq);
380         iounmap(rtc->regs);
381 
382         return err;
383 }
384 
385 static int mpc5121_rtc_remove(struct platform_device *op)
386 {
387         struct mpc5121_rtc_data *rtc = platform_get_drvdata(op);
388         struct mpc5121_rtc_regs __iomem *regs = rtc->regs;
389 
390         /* disable interrupt, so there are no nasty surprises */
391         out_8(&regs->alm_enable, 0);
392         out_8(&regs->int_enable, in_8(&regs->int_enable) & ~0x1);
393 
394         iounmap(rtc->regs);
395         free_irq(rtc->irq, &op->dev);
396         free_irq(rtc->irq_periodic, &op->dev);
397         irq_dispose_mapping(rtc->irq);
398         irq_dispose_mapping(rtc->irq_periodic);
399 
400         return 0;
401 }
402 
403 #ifdef CONFIG_OF
404 static struct of_device_id mpc5121_rtc_match[] = {
405         { .compatible = "fsl,mpc5121-rtc", },
406         { .compatible = "fsl,mpc5200-rtc", },
407         {},
408 };
409 #endif
410 
411 static struct platform_driver mpc5121_rtc_driver = {
412         .driver = {
413                 .name = "mpc5121-rtc",
414                 .owner = THIS_MODULE,
415                 .of_match_table = of_match_ptr(mpc5121_rtc_match),
416         },
417         .probe = mpc5121_rtc_probe,
418         .remove = mpc5121_rtc_remove,
419 };
420 
421 module_platform_driver(mpc5121_rtc_driver);
422 
423 MODULE_LICENSE("GPL");
424 MODULE_AUTHOR("John Rigby <jcrigby@gmail.com>");
425 

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