1 /* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License version 2 and
5 * only version 2 as published by the Free Software Foundation.
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/rtc.h>
17 #include <linux/slab.h>
18 #include <linux/spinlock.h>
20 #include <linux/mfd/pm8xxx/core.h>
21 #include <linux/mfd/pm8xxx/rtc.h>
24 /* RTC Register offsets from RTC CTRL REG */
25 #define PM8XXX_ALARM_CTRL_OFFSET 0x01
26 #define PM8XXX_RTC_WRITE_OFFSET 0x02
27 #define PM8XXX_RTC_READ_OFFSET 0x06
28 #define PM8XXX_ALARM_RW_OFFSET 0x0A
30 /* RTC_CTRL register bit fields */
31 #define PM8xxx_RTC_ENABLE BIT(7)
32 #define PM8xxx_RTC_ALARM_ENABLE BIT(1)
33 #define PM8xxx_RTC_ALARM_CLEAR BIT(0)
35 #define NUM_8_BIT_RTC_REGS 0x4
38 * struct pm8xxx_rtc - rtc driver internal structure
39 * @rtc: rtc device for this driver.
40 * @rtc_alarm_irq: rtc alarm irq number.
41 * @rtc_base: address of rtc control register.
42 * @rtc_read_base: base address of read registers.
43 * @rtc_write_base: base address of write registers.
44 * @alarm_rw_base: base address of alarm registers.
45 * @ctrl_reg: rtc control register.
46 * @rtc_dev: device structure.
47 * @ctrl_reg_lock: spinlock protecting access to ctrl_reg.
50 struct rtc_device
*rtc
;
57 struct device
*rtc_dev
;
58 spinlock_t ctrl_reg_lock
;
62 * The RTC registers need to be read/written one byte at a time. This is a
63 * hardware limitation.
65 static int pm8xxx_read_wrapper(struct pm8xxx_rtc
*rtc_dd
, u8
*rtc_val
,
69 struct device
*parent
= rtc_dd
->rtc_dev
->parent
;
71 for (i
= 0; i
< count
; i
++) {
72 rc
= pm8xxx_readb(parent
, base
+ i
, &rtc_val
[i
]);
74 dev_err(rtc_dd
->rtc_dev
, "PMIC read failed\n");
82 static int pm8xxx_write_wrapper(struct pm8xxx_rtc
*rtc_dd
, u8
*rtc_val
,
86 struct device
*parent
= rtc_dd
->rtc_dev
->parent
;
88 for (i
= 0; i
< count
; i
++) {
89 rc
= pm8xxx_writeb(parent
, base
+ i
, rtc_val
[i
]);
91 dev_err(rtc_dd
->rtc_dev
, "PMIC write failed\n");
100 * Steps to write the RTC registers.
101 * 1. Disable alarm if enabled.
102 * 2. Write 0x00 to LSB.
103 * 3. Write Byte[1], Byte[2], Byte[3] then Byte[0].
104 * 4. Enable alarm if disabled in step 1.
106 static int pm8xxx_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
109 unsigned long secs
, irq_flags
;
110 u8 value
[NUM_8_BIT_RTC_REGS
], reg
= 0, alarm_enabled
= 0, ctrl_reg
;
111 struct pm8xxx_rtc
*rtc_dd
= dev_get_drvdata(dev
);
113 rtc_tm_to_time(tm
, &secs
);
115 for (i
= 0; i
< NUM_8_BIT_RTC_REGS
; i
++) {
116 value
[i
] = secs
& 0xFF;
120 dev_dbg(dev
, "Seconds value to be written to RTC = %lu\n", secs
);
122 spin_lock_irqsave(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
123 ctrl_reg
= rtc_dd
->ctrl_reg
;
125 if (ctrl_reg
& PM8xxx_RTC_ALARM_ENABLE
) {
127 ctrl_reg
&= ~PM8xxx_RTC_ALARM_ENABLE
;
128 rc
= pm8xxx_write_wrapper(rtc_dd
, &ctrl_reg
, rtc_dd
->rtc_base
,
131 dev_err(dev
, "Write to RTC control register "
135 rtc_dd
->ctrl_reg
= ctrl_reg
;
137 spin_unlock_irqrestore(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
139 /* Write 0 to Byte[0] */
141 rc
= pm8xxx_write_wrapper(rtc_dd
, ®
, rtc_dd
->rtc_write_base
, 1);
143 dev_err(dev
, "Write to RTC write data register failed\n");
147 /* Write Byte[1], Byte[2], Byte[3] */
148 rc
= pm8xxx_write_wrapper(rtc_dd
, value
+ 1,
149 rtc_dd
->rtc_write_base
+ 1, 3);
151 dev_err(dev
, "Write to RTC write data register failed\n");
156 rc
= pm8xxx_write_wrapper(rtc_dd
, value
, rtc_dd
->rtc_write_base
, 1);
158 dev_err(dev
, "Write to RTC write data register failed\n");
163 ctrl_reg
|= PM8xxx_RTC_ALARM_ENABLE
;
164 rc
= pm8xxx_write_wrapper(rtc_dd
, &ctrl_reg
, rtc_dd
->rtc_base
,
167 dev_err(dev
, "Write to RTC control register "
171 rtc_dd
->ctrl_reg
= ctrl_reg
;
176 spin_unlock_irqrestore(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
181 static int pm8xxx_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
184 u8 value
[NUM_8_BIT_RTC_REGS
], reg
;
186 struct pm8xxx_rtc
*rtc_dd
= dev_get_drvdata(dev
);
188 rc
= pm8xxx_read_wrapper(rtc_dd
, value
, rtc_dd
->rtc_read_base
,
191 dev_err(dev
, "RTC read data register failed\n");
196 * Read the LSB again and check if there has been a carry over.
197 * If there is, redo the read operation.
199 rc
= pm8xxx_read_wrapper(rtc_dd
, ®
, rtc_dd
->rtc_read_base
, 1);
201 dev_err(dev
, "RTC read data register failed\n");
205 if (unlikely(reg
< value
[0])) {
206 rc
= pm8xxx_read_wrapper(rtc_dd
, value
,
207 rtc_dd
->rtc_read_base
, NUM_8_BIT_RTC_REGS
);
209 dev_err(dev
, "RTC read data register failed\n");
214 secs
= value
[0] | (value
[1] << 8) | (value
[2] << 16) | (value
[3] << 24);
216 rtc_time_to_tm(secs
, tm
);
218 rc
= rtc_valid_tm(tm
);
220 dev_err(dev
, "Invalid time read from RTC\n");
224 dev_dbg(dev
, "secs = %lu, h:m:s == %d:%d:%d, d/m/y = %d/%d/%d\n",
225 secs
, tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
,
226 tm
->tm_mday
, tm
->tm_mon
, tm
->tm_year
);
231 static int pm8xxx_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alarm
)
234 u8 value
[NUM_8_BIT_RTC_REGS
], ctrl_reg
;
235 unsigned long secs
, irq_flags
;
236 struct pm8xxx_rtc
*rtc_dd
= dev_get_drvdata(dev
);
238 rtc_tm_to_time(&alarm
->time
, &secs
);
240 for (i
= 0; i
< NUM_8_BIT_RTC_REGS
; i
++) {
241 value
[i
] = secs
& 0xFF;
245 spin_lock_irqsave(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
247 rc
= pm8xxx_write_wrapper(rtc_dd
, value
, rtc_dd
->alarm_rw_base
,
250 dev_err(dev
, "Write to RTC ALARM register failed\n");
254 ctrl_reg
= rtc_dd
->ctrl_reg
;
255 ctrl_reg
= alarm
->enabled
? (ctrl_reg
| PM8xxx_RTC_ALARM_ENABLE
) :
256 (ctrl_reg
& ~PM8xxx_RTC_ALARM_ENABLE
);
258 rc
= pm8xxx_write_wrapper(rtc_dd
, &ctrl_reg
, rtc_dd
->rtc_base
, 1);
260 dev_err(dev
, "Write to RTC control register failed\n");
264 rtc_dd
->ctrl_reg
= ctrl_reg
;
266 dev_dbg(dev
, "Alarm Set for h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
267 alarm
->time
.tm_hour
, alarm
->time
.tm_min
,
268 alarm
->time
.tm_sec
, alarm
->time
.tm_mday
,
269 alarm
->time
.tm_mon
, alarm
->time
.tm_year
);
271 spin_unlock_irqrestore(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
275 static int pm8xxx_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alarm
)
278 u8 value
[NUM_8_BIT_RTC_REGS
];
280 struct pm8xxx_rtc
*rtc_dd
= dev_get_drvdata(dev
);
282 rc
= pm8xxx_read_wrapper(rtc_dd
, value
, rtc_dd
->alarm_rw_base
,
285 dev_err(dev
, "RTC alarm time read failed\n");
289 secs
= value
[0] | (value
[1] << 8) | (value
[2] << 16) | (value
[3] << 24);
291 rtc_time_to_tm(secs
, &alarm
->time
);
293 rc
= rtc_valid_tm(&alarm
->time
);
295 dev_err(dev
, "Invalid alarm time read from RTC\n");
299 dev_dbg(dev
, "Alarm set for - h:r:s=%d:%d:%d, d/m/y=%d/%d/%d\n",
300 alarm
->time
.tm_hour
, alarm
->time
.tm_min
,
301 alarm
->time
.tm_sec
, alarm
->time
.tm_mday
,
302 alarm
->time
.tm_mon
, alarm
->time
.tm_year
);
307 static int pm8xxx_rtc_alarm_irq_enable(struct device
*dev
, unsigned int enable
)
310 unsigned long irq_flags
;
311 struct pm8xxx_rtc
*rtc_dd
= dev_get_drvdata(dev
);
314 spin_lock_irqsave(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
315 ctrl_reg
= rtc_dd
->ctrl_reg
;
316 ctrl_reg
= (enable
) ? (ctrl_reg
| PM8xxx_RTC_ALARM_ENABLE
) :
317 (ctrl_reg
& ~PM8xxx_RTC_ALARM_ENABLE
);
319 rc
= pm8xxx_write_wrapper(rtc_dd
, &ctrl_reg
, rtc_dd
->rtc_base
, 1);
321 dev_err(dev
, "Write to RTC control register failed\n");
325 rtc_dd
->ctrl_reg
= ctrl_reg
;
328 spin_unlock_irqrestore(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
332 static struct rtc_class_ops pm8xxx_rtc_ops
= {
333 .read_time
= pm8xxx_rtc_read_time
,
334 .set_alarm
= pm8xxx_rtc_set_alarm
,
335 .read_alarm
= pm8xxx_rtc_read_alarm
,
336 .alarm_irq_enable
= pm8xxx_rtc_alarm_irq_enable
,
339 static irqreturn_t
pm8xxx_alarm_trigger(int irq
, void *dev_id
)
341 struct pm8xxx_rtc
*rtc_dd
= dev_id
;
344 unsigned long irq_flags
;
346 rtc_update_irq(rtc_dd
->rtc
, 1, RTC_IRQF
| RTC_AF
);
348 spin_lock_irqsave(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
350 /* Clear the alarm enable bit */
351 ctrl_reg
= rtc_dd
->ctrl_reg
;
352 ctrl_reg
&= ~PM8xxx_RTC_ALARM_ENABLE
;
354 rc
= pm8xxx_write_wrapper(rtc_dd
, &ctrl_reg
, rtc_dd
->rtc_base
, 1);
356 spin_unlock_irqrestore(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
357 dev_err(rtc_dd
->rtc_dev
, "Write to RTC control register "
359 goto rtc_alarm_handled
;
362 rtc_dd
->ctrl_reg
= ctrl_reg
;
363 spin_unlock_irqrestore(&rtc_dd
->ctrl_reg_lock
, irq_flags
);
365 /* Clear RTC alarm register */
366 rc
= pm8xxx_read_wrapper(rtc_dd
, &ctrl_reg
, rtc_dd
->rtc_base
+
367 PM8XXX_ALARM_CTRL_OFFSET
, 1);
369 dev_err(rtc_dd
->rtc_dev
, "RTC Alarm control register read "
371 goto rtc_alarm_handled
;
374 ctrl_reg
&= ~PM8xxx_RTC_ALARM_CLEAR
;
375 rc
= pm8xxx_write_wrapper(rtc_dd
, &ctrl_reg
, rtc_dd
->rtc_base
+
376 PM8XXX_ALARM_CTRL_OFFSET
, 1);
378 dev_err(rtc_dd
->rtc_dev
, "Write to RTC Alarm control register"
385 static int __devinit
pm8xxx_rtc_probe(struct platform_device
*pdev
)
389 bool rtc_write_enable
= false;
390 struct pm8xxx_rtc
*rtc_dd
;
391 struct resource
*rtc_resource
;
392 const struct pm8xxx_rtc_platform_data
*pdata
=
393 dev_get_platdata(&pdev
->dev
);
396 rtc_write_enable
= pdata
->rtc_write_enable
;
398 rtc_dd
= kzalloc(sizeof(*rtc_dd
), GFP_KERNEL
);
399 if (rtc_dd
== NULL
) {
400 dev_err(&pdev
->dev
, "Unable to allocate memory!\n");
404 /* Initialise spinlock to protect RTC control register */
405 spin_lock_init(&rtc_dd
->ctrl_reg_lock
);
407 rtc_dd
->rtc_alarm_irq
= platform_get_irq(pdev
, 0);
408 if (rtc_dd
->rtc_alarm_irq
< 0) {
409 dev_err(&pdev
->dev
, "Alarm IRQ resource absent!\n");
411 goto fail_rtc_enable
;
414 rtc_resource
= platform_get_resource_byname(pdev
, IORESOURCE_IO
,
416 if (!(rtc_resource
&& rtc_resource
->start
)) {
417 dev_err(&pdev
->dev
, "RTC IO resource absent!\n");
419 goto fail_rtc_enable
;
422 rtc_dd
->rtc_base
= rtc_resource
->start
;
424 /* Setup RTC register addresses */
425 rtc_dd
->rtc_write_base
= rtc_dd
->rtc_base
+ PM8XXX_RTC_WRITE_OFFSET
;
426 rtc_dd
->rtc_read_base
= rtc_dd
->rtc_base
+ PM8XXX_RTC_READ_OFFSET
;
427 rtc_dd
->alarm_rw_base
= rtc_dd
->rtc_base
+ PM8XXX_ALARM_RW_OFFSET
;
429 rtc_dd
->rtc_dev
= &pdev
->dev
;
431 /* Check if the RTC is on, else turn it on */
432 rc
= pm8xxx_read_wrapper(rtc_dd
, &ctrl_reg
, rtc_dd
->rtc_base
, 1);
434 dev_err(&pdev
->dev
, "RTC control register read failed!\n");
435 goto fail_rtc_enable
;
438 if (!(ctrl_reg
& PM8xxx_RTC_ENABLE
)) {
439 ctrl_reg
|= PM8xxx_RTC_ENABLE
;
440 rc
= pm8xxx_write_wrapper(rtc_dd
, &ctrl_reg
, rtc_dd
->rtc_base
,
443 dev_err(&pdev
->dev
, "Write to RTC control register "
445 goto fail_rtc_enable
;
449 rtc_dd
->ctrl_reg
= ctrl_reg
;
450 if (rtc_write_enable
== true)
451 pm8xxx_rtc_ops
.set_time
= pm8xxx_rtc_set_time
;
453 platform_set_drvdata(pdev
, rtc_dd
);
455 /* Register the RTC device */
456 rtc_dd
->rtc
= rtc_device_register("pm8xxx_rtc", &pdev
->dev
,
457 &pm8xxx_rtc_ops
, THIS_MODULE
);
458 if (IS_ERR(rtc_dd
->rtc
)) {
459 dev_err(&pdev
->dev
, "%s: RTC registration failed (%ld)\n",
460 __func__
, PTR_ERR(rtc_dd
->rtc
));
461 rc
= PTR_ERR(rtc_dd
->rtc
);
462 goto fail_rtc_enable
;
465 /* Request the alarm IRQ */
466 rc
= request_any_context_irq(rtc_dd
->rtc_alarm_irq
,
467 pm8xxx_alarm_trigger
, IRQF_TRIGGER_RISING
,
468 "pm8xxx_rtc_alarm", rtc_dd
);
470 dev_err(&pdev
->dev
, "Request IRQ failed (%d)\n", rc
);
474 device_init_wakeup(&pdev
->dev
, 1);
476 dev_dbg(&pdev
->dev
, "Probe success !!\n");
481 rtc_device_unregister(rtc_dd
->rtc
);
483 platform_set_drvdata(pdev
, NULL
);
488 static int __devexit
pm8xxx_rtc_remove(struct platform_device
*pdev
)
490 struct pm8xxx_rtc
*rtc_dd
= platform_get_drvdata(pdev
);
492 device_init_wakeup(&pdev
->dev
, 0);
493 free_irq(rtc_dd
->rtc_alarm_irq
, rtc_dd
);
494 rtc_device_unregister(rtc_dd
->rtc
);
495 platform_set_drvdata(pdev
, NULL
);
501 #ifdef CONFIG_PM_SLEEP
502 static int pm8xxx_rtc_resume(struct device
*dev
)
504 struct pm8xxx_rtc
*rtc_dd
= dev_get_drvdata(dev
);
506 if (device_may_wakeup(dev
))
507 disable_irq_wake(rtc_dd
->rtc_alarm_irq
);
512 static int pm8xxx_rtc_suspend(struct device
*dev
)
514 struct pm8xxx_rtc
*rtc_dd
= dev_get_drvdata(dev
);
516 if (device_may_wakeup(dev
))
517 enable_irq_wake(rtc_dd
->rtc_alarm_irq
);
523 SIMPLE_DEV_PM_OPS(pm8xxx_rtc_pm_ops
, pm8xxx_rtc_suspend
, pm8xxx_rtc_resume
);
525 static struct platform_driver pm8xxx_rtc_driver
= {
526 .probe
= pm8xxx_rtc_probe
,
527 .remove
= __devexit_p(pm8xxx_rtc_remove
),
529 .name
= PM8XXX_RTC_DEV_NAME
,
530 .owner
= THIS_MODULE
,
531 .pm
= &pm8xxx_rtc_pm_ops
,
535 static int __init
pm8xxx_rtc_init(void)
537 return platform_driver_register(&pm8xxx_rtc_driver
);
539 module_init(pm8xxx_rtc_init
);
541 static void __exit
pm8xxx_rtc_exit(void)
543 platform_driver_unregister(&pm8xxx_rtc_driver
);
545 module_exit(pm8xxx_rtc_exit
);
547 MODULE_ALIAS("platform:rtc-pm8xxx");
548 MODULE_DESCRIPTION("PMIC8xxx RTC driver");
549 MODULE_LICENSE("GPL v2");
550 MODULE_AUTHOR("Anirudh Ghayal <aghayal@codeaurora.org>");