GNU Linux-libre 4.4.289-gnu1
[releases.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/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/slab.h>
17 #include <linux/mutex.h>
18 #include <linux/rtc.h>
19 #include <linux/delay.h>
20 #include <linux/mfd/core.h>
21 #include <linux/mfd/88pm860x.h>
22
23 #define VRTC_CALIBRATION
24
25 struct pm860x_rtc_info {
26         struct pm860x_chip      *chip;
27         struct i2c_client       *i2c;
28         struct rtc_device       *rtc_dev;
29         struct device           *dev;
30         struct delayed_work     calib_work;
31
32         int                     irq;
33         int                     vrtc;
34         int                     (*sync)(unsigned int ticks);
35 };
36
37 #define REG_VRTC_MEAS1          0x7D
38
39 #define REG0_ADDR               0xB0
40 #define REG1_ADDR               0xB2
41 #define REG2_ADDR               0xB4
42 #define REG3_ADDR               0xB6
43
44 #define REG0_DATA               0xB1
45 #define REG1_DATA               0xB3
46 #define REG2_DATA               0xB5
47 #define REG3_DATA               0xB7
48
49 /* bit definitions of Measurement Enable Register 2 (0x51) */
50 #define MEAS2_VRTC              (1 << 0)
51
52 /* bit definitions of RTC Register 1 (0xA0) */
53 #define ALARM_EN                (1 << 3)
54 #define ALARM_WAKEUP            (1 << 4)
55 #define ALARM                   (1 << 5)
56 #define RTC1_USE_XO             (1 << 7)
57
58 #define VRTC_CALIB_INTERVAL     (HZ * 60 * 10)          /* 10 minutes */
59
60 static irqreturn_t rtc_update_handler(int irq, void *data)
61 {
62         struct pm860x_rtc_info *info = (struct pm860x_rtc_info *)data;
63         int mask;
64
65         mask = ALARM | ALARM_WAKEUP;
66         pm860x_set_bits(info->i2c, PM8607_RTC1, mask | ALARM_EN, mask);
67         rtc_update_irq(info->rtc_dev, 1, RTC_AF);
68         return IRQ_HANDLED;
69 }
70
71 static int pm860x_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)
72 {
73         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
74
75         if (enabled)
76                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, ALARM_EN);
77         else
78                 pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
79         return 0;
80 }
81
82 /*
83  * Calculate the next alarm time given the requested alarm time mask
84  * and the current time.
85  */
86 static void rtc_next_alarm_time(struct rtc_time *next, struct rtc_time *now,
87                                 struct rtc_time *alrm)
88 {
89         unsigned long next_time;
90         unsigned long now_time;
91
92         next->tm_year = now->tm_year;
93         next->tm_mon = now->tm_mon;
94         next->tm_mday = now->tm_mday;
95         next->tm_hour = alrm->tm_hour;
96         next->tm_min = alrm->tm_min;
97         next->tm_sec = alrm->tm_sec;
98
99         rtc_tm_to_time(now, &now_time);
100         rtc_tm_to_time(next, &next_time);
101
102         if (next_time < now_time) {
103                 /* Advance one day */
104                 next_time += 60 * 60 * 24;
105                 rtc_time_to_tm(next_time, next);
106         }
107 }
108
109 static int pm860x_rtc_read_time(struct device *dev, struct rtc_time *tm)
110 {
111         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
112         unsigned char buf[8];
113         unsigned long ticks, base, data;
114
115         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
116         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
117                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
118         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
119                 (buf[5] << 8) | buf[7];
120
121         /* load 32-bit read-only counter */
122         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
123         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
124                 (buf[1] << 8) | buf[0];
125         ticks = base + data;
126         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
127                 base, data, ticks);
128
129         rtc_time_to_tm(ticks, tm);
130
131         return 0;
132 }
133
134 static int pm860x_rtc_set_time(struct device *dev, struct rtc_time *tm)
135 {
136         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
137         unsigned char buf[4];
138         unsigned long ticks, base, data;
139
140         if ((tm->tm_year < 70) || (tm->tm_year > 138)) {
141                 dev_dbg(info->dev, "Set time %d out of range. "
142                         "Please set time between 1970 to 2038.\n",
143                         1900 + tm->tm_year);
144                 return -EINVAL;
145         }
146         rtc_tm_to_time(tm, &ticks);
147
148         /* load 32-bit read-only counter */
149         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
150         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
151                 (buf[1] << 8) | buf[0];
152         base = ticks - data;
153         dev_dbg(info->dev, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
154                 base, data, ticks);
155
156         pm860x_page_reg_write(info->i2c, REG0_DATA, (base >> 24) & 0xFF);
157         pm860x_page_reg_write(info->i2c, REG1_DATA, (base >> 16) & 0xFF);
158         pm860x_page_reg_write(info->i2c, REG2_DATA, (base >> 8) & 0xFF);
159         pm860x_page_reg_write(info->i2c, REG3_DATA, base & 0xFF);
160
161         if (info->sync)
162                 info->sync(ticks);
163         return 0;
164 }
165
166 static int pm860x_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
167 {
168         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
169         unsigned char buf[8];
170         unsigned long ticks, base, data;
171         int ret;
172
173         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
174         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
175                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
176         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
177                 (buf[5] << 8) | buf[7];
178
179         pm860x_bulk_read(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
180         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
181                 (buf[1] << 8) | buf[0];
182         ticks = base + data;
183         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
184                 base, data, ticks);
185
186         rtc_time_to_tm(ticks, &alrm->time);
187         ret = pm860x_reg_read(info->i2c, PM8607_RTC1);
188         alrm->enabled = (ret & ALARM_EN) ? 1 : 0;
189         alrm->pending = (ret & (ALARM | ALARM_WAKEUP)) ? 1 : 0;
190         return 0;
191 }
192
193 static int pm860x_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
194 {
195         struct pm860x_rtc_info *info = dev_get_drvdata(dev);
196         struct rtc_time now_tm, alarm_tm;
197         unsigned long ticks, base, data;
198         unsigned char buf[8];
199         int mask;
200
201         pm860x_set_bits(info->i2c, PM8607_RTC1, ALARM_EN, 0);
202
203         pm860x_page_bulk_read(info->i2c, REG0_ADDR, 8, buf);
204         dev_dbg(info->dev, "%x-%x-%x-%x-%x-%x-%x-%x\n", buf[0], buf[1],
205                 buf[2], buf[3], buf[4], buf[5], buf[6], buf[7]);
206         base = ((unsigned long)buf[1] << 24) | (buf[3] << 16) |
207                 (buf[5] << 8) | buf[7];
208
209         /* load 32-bit read-only counter */
210         pm860x_bulk_read(info->i2c, PM8607_RTC_COUNTER1, 4, buf);
211         data = ((unsigned long)buf[3] << 24) | (buf[2] << 16) |
212                 (buf[1] << 8) | buf[0];
213         ticks = base + data;
214         dev_dbg(info->dev, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
215                 base, data, ticks);
216
217         rtc_time_to_tm(ticks, &now_tm);
218         rtc_next_alarm_time(&alarm_tm, &now_tm, &alrm->time);
219         /* get new ticks for alarm in 24 hours */
220         rtc_tm_to_time(&alarm_tm, &ticks);
221         data = ticks - base;
222
223         buf[0] = data & 0xff;
224         buf[1] = (data >> 8) & 0xff;
225         buf[2] = (data >> 16) & 0xff;
226         buf[3] = (data >> 24) & 0xff;
227         pm860x_bulk_write(info->i2c, PM8607_RTC_EXPIRE1, 4, buf);
228         if (alrm->enabled) {
229                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
230                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask, mask);
231         } else {
232                 mask = ALARM | ALARM_WAKEUP | ALARM_EN;
233                 pm860x_set_bits(info->i2c, PM8607_RTC1, mask,
234                                 ALARM | ALARM_WAKEUP);
235         }
236         return 0;
237 }
238
239 static const struct rtc_class_ops pm860x_rtc_ops = {
240         .read_time      = pm860x_rtc_read_time,
241         .set_time       = pm860x_rtc_set_time,
242         .read_alarm     = pm860x_rtc_read_alarm,
243         .set_alarm      = pm860x_rtc_set_alarm,
244         .alarm_irq_enable = pm860x_rtc_alarm_irq_enable,
245 };
246
247 #ifdef VRTC_CALIBRATION
248 static void calibrate_vrtc_work(struct work_struct *work)
249 {
250         struct pm860x_rtc_info *info = container_of(work,
251                 struct pm860x_rtc_info, calib_work.work);
252         unsigned char buf[2];
253         unsigned int sum, data, mean, vrtc_set;
254         int i;
255
256         for (i = 0, sum = 0; i < 16; i++) {
257                 msleep(100);
258                 pm860x_bulk_read(info->i2c, REG_VRTC_MEAS1, 2, buf);
259                 data = (buf[0] << 4) | buf[1];
260                 data = (data * 5400) >> 12;     /* convert to mv */
261                 sum += data;
262         }
263         mean = sum >> 4;
264         vrtc_set = 2700 + (info->vrtc & 0x3) * 200;
265         dev_dbg(info->dev, "mean:%d, vrtc_set:%d\n", mean, vrtc_set);
266
267         sum = pm860x_reg_read(info->i2c, PM8607_RTC_MISC1);
268         data = sum & 0x3;
269         if ((mean + 200) < vrtc_set) {
270                 /* try higher voltage */
271                 if (++data == 4)
272                         goto out;
273                 data = (sum & 0xf8) | (data & 0x3);
274                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
275         } else if ((mean - 200) > vrtc_set) {
276                 /* try lower voltage */
277                 if (data-- == 0)
278                         goto out;
279                 data = (sum & 0xf8) | (data & 0x3);
280                 pm860x_reg_write(info->i2c, PM8607_RTC_MISC1, data);
281         } else
282                 goto out;
283         dev_dbg(info->dev, "set 0x%x to RTC_MISC1\n", data);
284         /* trigger next calibration since VRTC is updated */
285         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
286         return;
287 out:
288         /* disable measurement */
289         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
290         dev_dbg(info->dev, "finish VRTC calibration\n");
291         return;
292 }
293 #endif
294
295 #ifdef CONFIG_OF
296 static int pm860x_rtc_dt_init(struct platform_device *pdev,
297                               struct pm860x_rtc_info *info)
298 {
299         struct device_node *np = pdev->dev.parent->of_node;
300         int ret;
301         if (!np)
302                 return -ENODEV;
303         np = of_get_child_by_name(np, "rtc");
304         if (!np) {
305                 dev_err(&pdev->dev, "failed to find rtc node\n");
306                 return -ENODEV;
307         }
308         ret = of_property_read_u32(np, "marvell,88pm860x-vrtc", &info->vrtc);
309         if (ret)
310                 info->vrtc = 0;
311         of_node_put(np);
312         return 0;
313 }
314 #else
315 #define pm860x_rtc_dt_init(x, y)        (-1)
316 #endif
317
318 static int pm860x_rtc_probe(struct platform_device *pdev)
319 {
320         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
321         struct pm860x_rtc_pdata *pdata = NULL;
322         struct pm860x_rtc_info *info;
323         struct rtc_time tm;
324         unsigned long ticks = 0;
325         int ret;
326
327         pdata = dev_get_platdata(&pdev->dev);
328
329         info = devm_kzalloc(&pdev->dev, sizeof(struct pm860x_rtc_info),
330                             GFP_KERNEL);
331         if (!info)
332                 return -ENOMEM;
333         info->irq = platform_get_irq(pdev, 0);
334         if (info->irq < 0) {
335                 dev_err(&pdev->dev, "No IRQ resource!\n");
336                 return info->irq;
337         }
338
339         info->chip = chip;
340         info->i2c = (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
341         info->dev = &pdev->dev;
342         dev_set_drvdata(&pdev->dev, info);
343
344         ret = devm_request_threaded_irq(&pdev->dev, info->irq, NULL,
345                                         rtc_update_handler, IRQF_ONESHOT, "rtc",
346                                         info);
347         if (ret < 0) {
348                 dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
349                         info->irq, ret);
350                 return ret;
351         }
352
353         /* set addresses of 32-bit base value for RTC time */
354         pm860x_page_reg_write(info->i2c, REG0_ADDR, REG0_DATA);
355         pm860x_page_reg_write(info->i2c, REG1_ADDR, REG1_DATA);
356         pm860x_page_reg_write(info->i2c, REG2_ADDR, REG2_DATA);
357         pm860x_page_reg_write(info->i2c, REG3_ADDR, REG3_DATA);
358
359         ret = pm860x_rtc_read_time(&pdev->dev, &tm);
360         if (ret < 0) {
361                 dev_err(&pdev->dev, "Failed to read initial time.\n");
362                 return ret;
363         }
364         if ((tm.tm_year < 70) || (tm.tm_year > 138)) {
365                 tm.tm_year = 70;
366                 tm.tm_mon = 0;
367                 tm.tm_mday = 1;
368                 tm.tm_hour = 0;
369                 tm.tm_min = 0;
370                 tm.tm_sec = 0;
371                 ret = pm860x_rtc_set_time(&pdev->dev, &tm);
372                 if (ret < 0) {
373                         dev_err(&pdev->dev, "Failed to set initial time.\n");
374                         return ret;
375                 }
376         }
377         rtc_tm_to_time(&tm, &ticks);
378         if (pm860x_rtc_dt_init(pdev, info)) {
379                 if (pdata && pdata->sync) {
380                         pdata->sync(ticks);
381                         info->sync = pdata->sync;
382                 }
383         }
384
385         info->rtc_dev = devm_rtc_device_register(&pdev->dev, "88pm860x-rtc",
386                                             &pm860x_rtc_ops, THIS_MODULE);
387         ret = PTR_ERR(info->rtc_dev);
388         if (IS_ERR(info->rtc_dev)) {
389                 dev_err(&pdev->dev, "Failed to register RTC device: %d\n", ret);
390                 return ret;
391         }
392
393         /*
394          * enable internal XO instead of internal 3.25MHz clock since it can
395          * free running in PMIC power-down state.
396          */
397         pm860x_set_bits(info->i2c, PM8607_RTC1, RTC1_USE_XO, RTC1_USE_XO);
398
399 #ifdef VRTC_CALIBRATION
400         /* <00> -- 2.7V, <01> -- 2.9V, <10> -- 3.1V, <11> -- 3.3V */
401         if (pm860x_rtc_dt_init(pdev, info)) {
402                 if (pdata && pdata->vrtc)
403                         info->vrtc = pdata->vrtc & 0x3;
404                 else
405                         info->vrtc = 1;
406         }
407         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, MEAS2_VRTC);
408
409         /* calibrate VRTC */
410         INIT_DELAYED_WORK(&info->calib_work, calibrate_vrtc_work);
411         schedule_delayed_work(&info->calib_work, VRTC_CALIB_INTERVAL);
412 #endif  /* VRTC_CALIBRATION */
413
414         device_init_wakeup(&pdev->dev, 1);
415
416         return 0;
417 }
418
419 static int pm860x_rtc_remove(struct platform_device *pdev)
420 {
421         struct pm860x_rtc_info *info = platform_get_drvdata(pdev);
422
423 #ifdef VRTC_CALIBRATION
424         cancel_delayed_work_sync(&info->calib_work);
425         /* disable measurement */
426         pm860x_set_bits(info->i2c, PM8607_MEAS_EN2, MEAS2_VRTC, 0);
427 #endif  /* VRTC_CALIBRATION */
428
429         return 0;
430 }
431
432 #ifdef CONFIG_PM_SLEEP
433 static int pm860x_rtc_suspend(struct device *dev)
434 {
435         struct platform_device *pdev = to_platform_device(dev);
436         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
437
438         if (device_may_wakeup(dev))
439                 chip->wakeup_flag |= 1 << PM8607_IRQ_RTC;
440         return 0;
441 }
442 static int pm860x_rtc_resume(struct device *dev)
443 {
444         struct platform_device *pdev = to_platform_device(dev);
445         struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
446
447         if (device_may_wakeup(dev))
448                 chip->wakeup_flag &= ~(1 << PM8607_IRQ_RTC);
449         return 0;
450 }
451 #endif
452
453 static SIMPLE_DEV_PM_OPS(pm860x_rtc_pm_ops, pm860x_rtc_suspend, pm860x_rtc_resume);
454
455 static struct platform_driver pm860x_rtc_driver = {
456         .driver         = {
457                 .name   = "88pm860x-rtc",
458                 .pm     = &pm860x_rtc_pm_ops,
459         },
460         .probe          = pm860x_rtc_probe,
461         .remove         = pm860x_rtc_remove,
462 };
463
464 module_platform_driver(pm860x_rtc_driver);
465
466 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
467 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
468 MODULE_LICENSE("GPL");