watchdog: nowayout is bool
[linux-2.6.git] / drivers / rtc / rtc-88pm860x.c
1 /*
2  * Real Time Clock driver for Marvell 88PM860x PMIC
3  *
4  * Copyright (c) 2010 Marvell International Ltd.
5  * Author:      Haojian Zhuang <haojian.zhuang@marvell.com>
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/kernel.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/mutex.h>
17 #include <linux/rtc.h>
18 #include <linux/delay.h>
19 #include <linux/mfd/core.h>
20 #include <linux/mfd/88pm860x.h>
21
22 #define VRTC_CALIBRATION
23
24 struct pm860x_rtc_info {
25         struct pm860x_chip      *chip;
26         struct i2c_client       *i2c;
27         struct rtc_device       *rtc_dev;
28         struct device           *dev;
29         struct delayed_work     calib_work;
30
31         int                     irq;
32         int                     vrtc;
33         int                     (*sync)(unsigned int ticks);
34 };
35
36 #define REG_VRTC_MEAS1          0x7D
37
38 #define REG0_ADDR               0xB0
39 #define REG1_ADDR               0xB2
40 #define REG2_ADDR               0xB4
41 #define REG3_ADDR               0xB6
42
43 #define REG0_DATA               0xB1
44 #define REG1_DATA               0xB3
45 #define REG2_DATA               0xB5
46 #define REG3_DATA               0xB7
47
48 /* bit definitions of Measurement Enable Register 2 (0x51) */
49 #define MEAS2_VRTC              (1 << 0)
50
51 /* bit definitions of RTC Register 1 (0xA0) */
52 #define ALARM_EN                (1 << 3)
53 #define ALARM_WAKEUP            (1 << 4)
54 #define ALARM                   (1 << 5)
55 #define RTC1_USE_XO             (1 << 7)
56
57 #define VRTC_CALIB_INTERVAL     (HZ * 60 * 10)          /* 10 minutes */
58
59 static irqreturn_t rtc_update_handler(int irq, void *data)
60 {
61         struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
62         int mask;
63
64         mask = ALARM | ALARM_WAKEUP;
65         pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
66         rtc_update_irq(info->rtc_dev, 1, RTC_AF);
67         return IRQ_HANDLED;
68 }
69
70 static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
71 {
72         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
73
74         if (enabled)
75                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM, ALARM);
76         else
77                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM, 0);
78         return 0;
79 }
80
81 /*
82  * Calculate the next alarm time given the requested alarm time mask
83  * and the current time.
84  */
85 static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
86                                 struct rtc_time *alrm)
87 {
88         unsigned long next_time;
89         unsigned long now_time;
90
91         next->tm_year = now->tm_year;
92         next->tm_mon = now->tm_mon;
93         next->tm_mday = now->tm_mday;
94         next->tm_hour = alrm->tm_hour;
95         next->tm_min = alrm->tm_min;
96         next->tm_sec = alrm->tm_sec;
97
98         rtc_tm_to_time(now, &now_time);
99         rtc_tm_to_time(next, &next_time);
100
101         if (next_time < now_time) {
102                 /* Advance one day */
103                 next_time += 60 * 60 * 24;
104                 rtc_time_to_tm(next_time, next);
105         }
106 }
107
108 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
109 {
110         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
111         unsigned char buf[8];
112         unsigned long ticks, base, data;
113
114         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
115         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
116                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
117         base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];
118
119         /* load 32-bit read-only counter */
120         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
121         data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
122         ticks = base + data;
123         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
124                 base, data, ticks);
125
126         rtc_time_to_tm(ticks, tm);
127
128         return 0;
129 }
130
131 static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
132 {
133         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
134         unsigned char buf[4];
135         unsigned long ticks, base, data;
136
137         if ((tm->tm_year < 70) || (tm->tm_year > 138)) {
138                 dev_dbg(info->dev, "Set time %d out of range. "
139                         "Please set time between 1970 to 2038.\n",
140                         1900 + tm->tm_year);
141                 return -EINVAL;
142         }
143         rtc_tm_to_time(tm, &ticks);
144
145         /* load 32-bit read-only counter */
146         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
147         data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
148         base = ticks - data;
149         dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
150                 base, data, ticks);
151
152         pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
153         pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
154         pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
155         pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
156
157         if (info->sync)
158                 info->sync(ticks);
159         return 0;
160 }
161
162 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
163 {
164         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
165         unsigned char buf[8];
166         unsigned long ticks, base, data;
167         int ret;
168
169         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
170         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
171                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
172         base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];
173
174         pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
175         data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
176         ticks = base + data;
177         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
178                 base, data, ticks);
179
180         rtc_time_to_tm(ticks, &alrm->time);
181         ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
182         alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
183         alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
184         return 0;
185 }
186
187 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
188 {
189         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
190         struct rtc_time now_tm, alarm_tm;
191         unsigned long ticks, base, data;
192         unsigned char buf[8];
193         int mask;
194
195         pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
196
197         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
198         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
199                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
200         base = (buf[1] << 24) | (buf[3] << 16) | (buf[5] << 8) | buf[7];
201
202         /* load 32-bit read-only counter */
203         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
204         data = (buf[3] << 24) | (buf[2] << 16) | (buf[1] << 8) | buf[0];
205         ticks = base + data;
206         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
207                 base, data, ticks);
208
209         rtc_time_to_tm(ticks, &now_tm);
210         rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time);
211         /* get new ticks for alarm in 24 hours */
212         rtc_tm_to_time(&alarm_tm, &ticks);
213         data = ticks - base;
214
215         buf[0] = data & 0xff;
216         buf[1] = (data >> 8) & 0xff;
217         buf[2] = (data >> 16) & 0xff;
218         buf[3] = (data >> 24) & 0xff;
219         pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
220         if (alrm->enabled) {
221                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
222                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
223         } else {
224                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
225                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
226                                 ALARM | ALARM_WAKEUP);
227         }
228         return 0;
229 }
230
231 static const struct rtc_class_ops pm860x_rtc_ops = {
232         .read_time      = pm860x_rtc_read_time,
233         .set_time       = pm860x_rtc_set_time,
234         .read_alarm     = pm860x_rtc_read_alarm,
235         .set_alarm      = pm860x_rtc_set_alarm,
236         .alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
237 };
238
239 #ifdef VRTC_CALIBRATION
240 static void calibrate_vrtc_work(struct work_struct *work)
241 {
242         struct pm860x_rtc_info *info = container_of(work,
243                 struct pm860x_rtc_info, calib_work.work);
244         unsigned char buf[2];
245         unsigned int sum, data, mean, vrtc_set;
246         int i;
247
248         for (i = 0, sum = 0; i < 16; i++) {
249                 msleep(100);
250                 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
251                 data = (buf[0] << 4) | buf[1];
252                 data = (data * 5400) >> 12;     /* convert to mv */
253                 sum += data;
254         }
255         mean = sum >> 4;
256         vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
257         dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
258
259         sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
260         data = sum & 0x3;
261         if ((mean + 200) < vrtc_set) {
262                 /* try higher voltage */
263                 if (++data == 4)
264                         goto out;
265                 data = (sum & 0xf8) | (data & 0x3);
266                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
267         } else if ((mean - 200) > vrtc_set) {
268                 /* try lower voltage */
269                 if (data-- == 0)
270                         goto out;
271                 data = (sum & 0xf8) | (data & 0x3);
272                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
273         } else
274                 goto out;
275         dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
276         /* trigger next calibration since VRTC is updated */
277         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
278         return;
279 out:
280         /* disable measurement */
281         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
282         dev_dbg(info->dev, "finish VRTC calibration\n");
283         return;
284 }
285 #endif
286
287 static int __devinit pm860x_rtc_probe(struct platform_device *pdev)
288 {
289         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
290         struct pm860x_rtc_pdata *pdata = NULL;
291         struct pm860x_rtc_info *info;
292         struct rtc_time tm;
293         unsigned long ticks = 0;
294         int ret;
295
296         pdata = pdev->dev.platform_data;
297         if (pdata == NULL)
298                 dev_warn(&pdev->dev, "No platform data!\n");
299
300         info = kzalloc(sizeof(struct pm860x_rtc_info), GFP_KERNEL);
301         if (!info)
302                 return -ENOMEM;
303         info->irq = platform_get_irq(pdev, 0);
304         if (info->irq < 0) {
305                 dev_err(&pdev->dev, "No IRQ resource!\n");
306                 ret = -EINVAL;
307                 goto out;
308         }
309
310         info->chip = chip;
311         info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
312         info->dev = &pdev->dev;
313         dev_set_drvdata(&pdev->dev, info);
314
315         ret = request_threaded_irq(info->irq, NULL, rtc_update_handler,
316                                    IRQF_ONESHOT, "rtc", info);
317         if (ret < 0) {
318                 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
319                         info->irq, ret);
320                 goto out;
321         }
322
323         /* set addresses of 32-bit base value for RTC time */
324         pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
325         pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
326         pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
327         pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
328
329         ret = pm860x_rtc_read_time(&pdev->dev, &tm);
330         if (ret < 0) {
331                 dev_err(&pdev->dev, "Failed to read initial time.\n");
332                 goto out_rtc;
333         }
334         if ((tm.tm_year < 70) || (tm.tm_year > 138)) {
335                 tm.tm_year = 70;
336                 tm.tm_mon = 0;
337                 tm.tm_mday = 1;
338                 tm.tm_hour = 0;
339                 tm.tm_min = 0;
340                 tm.tm_sec = 0;
341                 ret = pm860x_rtc_set_time(&pdev->dev, &tm);
342                 if (ret < 0) {
343                         dev_err(&pdev->dev, "Failed to set initial time.\n");
344                         goto out_rtc;
345                 }
346         }
347         rtc_tm_to_time(&tm, &ticks);
348         if (pdata && pdata->sync) {
349                 pdata->sync(ticks);
350                 info->sync = pdata->sync;
351         }
352
353         info->rtc_dev = rtc_device_register("88pm860x-rtc", &pdev->dev,
354                                             &pm860x_rtc_ops, THIS_MODULE);
355         ret = PTR_ERR(info->rtc_dev);
356         if (IS_ERR(info->rtc_dev)) {
357                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
358                 goto out_rtc;
359         }
360
361         /*
362          * enable internal XO instead of internal 3.25MHz clock since it can
363          * free running in PMIC power-down state.
364          */
365         pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
366
367 #ifdef VRTC_CALIBRATION
368         /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
369         if (pdata && pdata->vrtc)
370                 info->vrtc = pdata->vrtc & 0x3;
371         else
372                 info->vrtc = 1;
373         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
374
375         /* calibrate VRTC */
376         INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
377         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
378 #endif  /* VRTC_CALIBRATION */
379         return 0;
380 out_rtc:
381         free_irq(info->irq, info);
382 out:
383         kfree(info);
384         return ret;
385 }
386
387 static int __devexit pm860x_rtc_remove(struct platform_device *pdev)
388 {
389         struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
390
391 #ifdef VRTC_CALIBRATION
392         flush_scheduled_work();
393         /* disable measurement */
394         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
395 #endif  /* VRTC_CALIBRATION */
396
397         platform_set_drvdata(pdev, NULL);
398         rtc_device_unregister(info->rtc_dev);
399         free_irq(info->irq, info);
400         kfree(info);
401         return 0;
402 }
403
404 static struct platform_driver pm860x_rtc_driver = {
405         .driver         = {
406                 .name   = "88pm860x-rtc",
407                 .owner  = THIS_MODULE,
408         },
409         .probe          = pm860x_rtc_probe,
410         .remove         = __devexit_p(pm860x_rtc_remove),
411 };
412
413 module_platform_driver(pm860x_rtc_driver);
414
415 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
416 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
417 MODULE_LICENSE("GPL");