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Haojian Zhuang008b3042011-05-06 17:21:20 +08001/*
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
24struct 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
59static 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
70static 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 */
85static 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
108static 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
131static 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
162static 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
187static 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
231static 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
240static 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;
279out:
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
287static 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;
380out_rtc:
381 free_irq(info->irq, info);
382out:
383 kfree(info);
384 return ret;
385}
386
387static 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
404static 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
Axel Lin0c4eae62012-01-10 15:10:48 -0800413module_platform_driver(pm860x_rtc_driver);
Haojian Zhuang008b3042011-05-06 17:21:20 +0800414
415MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
416MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
417MODULE_LICENSE("GPL");