2 * Real Time Clock driver for Marvell 88PM860x PMIC
4 * Copyright (c) 2010 Marvell International Ltd.
5 * Author: Haojian Zhuang <haojian.zhuang@marvell.com>
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.
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>
22 #define VRTC_CALIBRATION
24 struct pm860x_rtc_info
{
25 struct pm860x_chip
*chip
;
26 struct i2c_client
*i2c
;
27 struct rtc_device
*rtc_dev
;
29 struct delayed_work calib_work
;
33 int (*sync
)(unsigned int ticks
);
36 #define REG_VRTC_MEAS1 0x7D
38 #define REG0_ADDR 0xB0
39 #define REG1_ADDR 0xB2
40 #define REG2_ADDR 0xB4
41 #define REG3_ADDR 0xB6
43 #define REG0_DATA 0xB1
44 #define REG1_DATA 0xB3
45 #define REG2_DATA 0xB5
46 #define REG3_DATA 0xB7
48 /* bit definitions of Measurement Enable Register 2 (0x51) */
49 #define MEAS2_VRTC (1 << 0)
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)
57 #define VRTC_CALIB_INTERVAL (HZ * 60 * 10) /* 10 minutes */
59 static irqreturn_t
rtc_update_handler(int irq
, void *data
)
61 struct pm860x_rtc_info
*info
= (struct pm860x_rtc_info
*)data
;
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
);
70 static int pm860x_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enabled
)
72 struct pm860x_rtc_info
*info
= dev_get_drvdata(dev
);
75 pm860x_set_bits(info
->i2c
, PM8607_RTC1
, ALARM
, ALARM
);
77 pm860x_set_bits(info
->i2c
, PM8607_RTC1
, ALARM
, 0);
82 * Calculate the next alarm time given the requested alarm time mask
83 * and the current time.
85 static void rtc_next_alarm_time(struct rtc_time
*next
, struct rtc_time
*now
,
86 struct rtc_time
*alrm
)
88 unsigned long next_time
;
89 unsigned long now_time
;
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
;
98 rtc_tm_to_time(now
, &now_time
);
99 rtc_tm_to_time(next
, &next_time
);
101 if (next_time
< now_time
) {
102 /* Advance one day */
103 next_time
+= 60 * 60 * 24;
104 rtc_time_to_tm(next_time
, next
);
108 static int pm860x_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
110 struct pm860x_rtc_info
*info
= dev_get_drvdata(dev
);
111 unsigned char buf
[8];
112 unsigned long ticks
, base
, data
;
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];
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];
123 dev_dbg(info
->dev
, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
126 rtc_time_to_tm(ticks
, tm
);
131 static int pm860x_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
133 struct pm860x_rtc_info
*info
= dev_get_drvdata(dev
);
134 unsigned char buf
[4];
135 unsigned long ticks
, base
, data
;
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",
143 rtc_tm_to_time(tm
, &ticks
);
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];
149 dev_dbg(info
->dev
, "set base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
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);
162 static int pm860x_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
164 struct pm860x_rtc_info
*info
= dev_get_drvdata(dev
);
165 unsigned char buf
[8];
166 unsigned long ticks
, base
, data
;
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];
174 pm860x_bulk_read(info
->i2c
, PM8607_RTC_EXPIRE1
, 4, buf
);
175 data
= (buf
[3] << 24) | (buf
[2] << 16) | (buf
[1] << 8) | buf
[0];
177 dev_dbg(info
->dev
, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
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;
187 static int pm860x_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alrm
)
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];
195 pm860x_set_bits(info
->i2c
, PM8607_RTC1
, ALARM_EN
, 0);
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];
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];
206 dev_dbg(info
->dev
, "get base:0x%lx, RO count:0x%lx, ticks:0x%lx\n",
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
);
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
);
221 mask
= ALARM
| ALARM_WAKEUP
| ALARM_EN
;
222 pm860x_set_bits(info
->i2c
, PM8607_RTC1
, mask
, mask
);
224 mask
= ALARM
| ALARM_WAKEUP
| ALARM_EN
;
225 pm860x_set_bits(info
->i2c
, PM8607_RTC1
, mask
,
226 ALARM
| ALARM_WAKEUP
);
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
,
239 #ifdef VRTC_CALIBRATION
240 static void calibrate_vrtc_work(struct work_struct
*work
)
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
;
248 for (i
= 0, sum
= 0; i
< 16; i
++) {
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 */
256 vrtc_set
= 2700 + (info
->vrtc
& 0x3) * 200;
257 dev_dbg(info
->dev
, "mean:%d, vrtc_set:%d\n", mean
, vrtc_set
);
259 sum
= pm860x_reg_read(info
->i2c
, PM8607_RTC_MISC1
);
261 if ((mean
+ 200) < vrtc_set
) {
262 /* try higher voltage */
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 */
271 data
= (sum
& 0xf8) | (data
& 0x3);
272 pm860x_reg_write(info
->i2c
, PM8607_RTC_MISC1
, data
);
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
);
280 /* disable measurement */
281 pm860x_set_bits(info
->i2c
, PM8607_MEAS_EN2
, MEAS2_VRTC
, 0);
282 dev_dbg(info
->dev
, "finish VRTC calibration\n");
287 static int __devinit
pm860x_rtc_probe(struct platform_device
*pdev
)
289 struct pm860x_chip
*chip
= dev_get_drvdata(pdev
->dev
.parent
);
290 struct pm860x_rtc_pdata
*pdata
= NULL
;
291 struct pm860x_rtc_info
*info
;
293 unsigned long ticks
= 0;
296 pdata
= pdev
->dev
.platform_data
;
298 dev_warn(&pdev
->dev
, "No platform data!\n");
300 info
= kzalloc(sizeof(struct pm860x_rtc_info
), GFP_KERNEL
);
303 info
->irq
= platform_get_irq(pdev
, 0);
305 dev_err(&pdev
->dev
, "No IRQ resource!\n");
311 info
->i2c
= (chip
->id
== CHIP_PM8607
) ? chip
->client
: chip
->companion
;
312 info
->dev
= &pdev
->dev
;
313 dev_set_drvdata(&pdev
->dev
, info
);
315 ret
= request_threaded_irq(info
->irq
, NULL
, rtc_update_handler
,
316 IRQF_ONESHOT
, "rtc", info
);
318 dev_err(chip
->dev
, "Failed to request IRQ: #%d: %d\n",
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
);
329 ret
= pm860x_rtc_read_time(&pdev
->dev
, &tm
);
331 dev_err(&pdev
->dev
, "Failed to read initial time.\n");
334 if ((tm
.tm_year
< 70) || (tm
.tm_year
> 138)) {
341 ret
= pm860x_rtc_set_time(&pdev
->dev
, &tm
);
343 dev_err(&pdev
->dev
, "Failed to set initial time.\n");
347 rtc_tm_to_time(&tm
, &ticks
);
348 if (pdata
&& pdata
->sync
) {
350 info
->sync
= pdata
->sync
;
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
);
362 * enable internal XO instead of internal 3.25MHz clock since it can
363 * free running in PMIC power-down state.
365 pm860x_set_bits(info
->i2c
, PM8607_RTC1
, RTC1_USE_XO
, RTC1_USE_XO
);
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;
373 pm860x_set_bits(info
->i2c
, PM8607_MEAS_EN2
, MEAS2_VRTC
, MEAS2_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 */
381 free_irq(info
->irq
, info
);
387 static int __devexit
pm860x_rtc_remove(struct platform_device
*pdev
)
389 struct pm860x_rtc_info
*info
= platform_get_drvdata(pdev
);
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 */
397 platform_set_drvdata(pdev
, NULL
);
398 rtc_device_unregister(info
->rtc_dev
);
399 free_irq(info
->irq
, info
);
404 static struct platform_driver pm860x_rtc_driver
= {
406 .name
= "88pm860x-rtc",
407 .owner
= THIS_MODULE
,
409 .probe
= pm860x_rtc_probe
,
410 .remove
= __devexit_p(pm860x_rtc_remove
),
413 module_platform_driver(pm860x_rtc_driver
);
415 MODULE_DESCRIPTION("Marvell 88PM860x RTC driver");
416 MODULE_AUTHOR("Haojian Zhuang <haojian.zhuang@marvell.com>");
417 MODULE_LICENSE("GPL");