2 * rtc-twl.c -- TWL Real Time Clock interface
4 * Copyright (C) 2007 MontaVista Software, Inc
5 * Author: Alexandre Rusev <source@mvista.com>
7 * Based on original TI driver twl4030-rtc.c
8 * Copyright (C) 2006 Texas Instruments, Inc.
11 * Copyright (C) 2003 MontaVista Software, Inc.
12 * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
13 * Copyright (C) 2006 David Brownell
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/init.h>
24 #include <linux/module.h>
25 #include <linux/types.h>
26 #include <linux/rtc.h>
27 #include <linux/bcd.h>
28 #include <linux/platform_device.h>
29 #include <linux/interrupt.h>
32 #include <linux/i2c/twl.h>
36 * RTC block register offsets (use TWL_MODULE_RTC)
47 REG_ALARM_SECONDS_REG
,
48 REG_ALARM_MINUTES_REG
,
56 REG_RTC_INTERRUPTS_REG
,
61 static const u8 twl4030_rtc_reg_map
[] = {
62 [REG_SECONDS_REG
] = 0x00,
63 [REG_MINUTES_REG
] = 0x01,
64 [REG_HOURS_REG
] = 0x02,
65 [REG_DAYS_REG
] = 0x03,
66 [REG_MONTHS_REG
] = 0x04,
67 [REG_YEARS_REG
] = 0x05,
68 [REG_WEEKS_REG
] = 0x06,
70 [REG_ALARM_SECONDS_REG
] = 0x07,
71 [REG_ALARM_MINUTES_REG
] = 0x08,
72 [REG_ALARM_HOURS_REG
] = 0x09,
73 [REG_ALARM_DAYS_REG
] = 0x0A,
74 [REG_ALARM_MONTHS_REG
] = 0x0B,
75 [REG_ALARM_YEARS_REG
] = 0x0C,
77 [REG_RTC_CTRL_REG
] = 0x0D,
78 [REG_RTC_STATUS_REG
] = 0x0E,
79 [REG_RTC_INTERRUPTS_REG
] = 0x0F,
81 [REG_RTC_COMP_LSB_REG
] = 0x10,
82 [REG_RTC_COMP_MSB_REG
] = 0x11,
84 static const u8 twl6030_rtc_reg_map
[] = {
85 [REG_SECONDS_REG
] = 0x00,
86 [REG_MINUTES_REG
] = 0x01,
87 [REG_HOURS_REG
] = 0x02,
88 [REG_DAYS_REG
] = 0x03,
89 [REG_MONTHS_REG
] = 0x04,
90 [REG_YEARS_REG
] = 0x05,
91 [REG_WEEKS_REG
] = 0x06,
93 [REG_ALARM_SECONDS_REG
] = 0x08,
94 [REG_ALARM_MINUTES_REG
] = 0x09,
95 [REG_ALARM_HOURS_REG
] = 0x0A,
96 [REG_ALARM_DAYS_REG
] = 0x0B,
97 [REG_ALARM_MONTHS_REG
] = 0x0C,
98 [REG_ALARM_YEARS_REG
] = 0x0D,
100 [REG_RTC_CTRL_REG
] = 0x10,
101 [REG_RTC_STATUS_REG
] = 0x11,
102 [REG_RTC_INTERRUPTS_REG
] = 0x12,
104 [REG_RTC_COMP_LSB_REG
] = 0x13,
105 [REG_RTC_COMP_MSB_REG
] = 0x14,
108 /* RTC_CTRL_REG bitfields */
109 #define BIT_RTC_CTRL_REG_STOP_RTC_M 0x01
110 #define BIT_RTC_CTRL_REG_ROUND_30S_M 0x02
111 #define BIT_RTC_CTRL_REG_AUTO_COMP_M 0x04
112 #define BIT_RTC_CTRL_REG_MODE_12_24_M 0x08
113 #define BIT_RTC_CTRL_REG_TEST_MODE_M 0x10
114 #define BIT_RTC_CTRL_REG_SET_32_COUNTER_M 0x20
115 #define BIT_RTC_CTRL_REG_GET_TIME_M 0x40
116 #define BIT_RTC_CTRL_REG_RTC_V_OPT 0x80
118 /* RTC_STATUS_REG bitfields */
119 #define BIT_RTC_STATUS_REG_RUN_M 0x02
120 #define BIT_RTC_STATUS_REG_1S_EVENT_M 0x04
121 #define BIT_RTC_STATUS_REG_1M_EVENT_M 0x08
122 #define BIT_RTC_STATUS_REG_1H_EVENT_M 0x10
123 #define BIT_RTC_STATUS_REG_1D_EVENT_M 0x20
124 #define BIT_RTC_STATUS_REG_ALARM_M 0x40
125 #define BIT_RTC_STATUS_REG_POWER_UP_M 0x80
127 /* RTC_INTERRUPTS_REG bitfields */
128 #define BIT_RTC_INTERRUPTS_REG_EVERY_M 0x03
129 #define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M 0x04
130 #define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M 0x08
133 /* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
134 #define ALL_TIME_REGS 6
136 /*----------------------------------------------------------------------*/
137 static u8
*rtc_reg_map
;
140 * Supports 1 byte read from TWL RTC register.
142 static int twl_rtc_read_u8(u8
*data
, u8 reg
)
146 ret
= twl_i2c_read_u8(TWL_MODULE_RTC
, data
, (rtc_reg_map
[reg
]));
148 pr_err("twl_rtc: Could not read TWL"
149 "register %X - error %d\n", reg
, ret
);
154 * Supports 1 byte write to TWL RTC registers.
156 static int twl_rtc_write_u8(u8 data
, u8 reg
)
160 ret
= twl_i2c_write_u8(TWL_MODULE_RTC
, data
, (rtc_reg_map
[reg
]));
162 pr_err("twl_rtc: Could not write TWL"
163 "register %X - error %d\n", reg
, ret
);
168 * Cache the value for timer/alarm interrupts register; this is
169 * only changed by callers holding rtc ops lock (or resume).
171 static unsigned char rtc_irq_bits
;
174 * Enable 1/second update and/or alarm interrupts.
176 static int set_rtc_irq_bit(unsigned char bit
)
181 /* if the bit is set, return from here */
182 if (rtc_irq_bits
& bit
)
185 val
= rtc_irq_bits
| bit
;
186 val
&= ~BIT_RTC_INTERRUPTS_REG_EVERY_M
;
187 ret
= twl_rtc_write_u8(val
, REG_RTC_INTERRUPTS_REG
);
195 * Disable update and/or alarm interrupts.
197 static int mask_rtc_irq_bit(unsigned char bit
)
202 /* if the bit is clear, return from here */
203 if (!(rtc_irq_bits
& bit
))
206 val
= rtc_irq_bits
& ~bit
;
207 ret
= twl_rtc_write_u8(val
, REG_RTC_INTERRUPTS_REG
);
214 static int twl_rtc_alarm_irq_enable(struct device
*dev
, unsigned enabled
)
219 ret
= set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M
);
221 ret
= mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M
);
227 * Gets current TWL RTC time and date parameters.
229 * The RTC's time/alarm representation is not what gmtime(3) requires
232 * - Months are 1..12 vs Linux 0-11
233 * - Years are 0..99 vs Linux 1900..N (we assume 21st century)
235 static int twl_rtc_read_time(struct device
*dev
, struct rtc_time
*tm
)
237 unsigned char rtc_data
[ALL_TIME_REGS
];
242 ret
= twl_rtc_read_u8(&save_control
, REG_RTC_CTRL_REG
);
244 dev_err(dev
, "%s: reading CTRL_REG, error %d\n", __func__
, ret
);
247 /* for twl6030/32 make sure BIT_RTC_CTRL_REG_GET_TIME_M is clear */
248 if (twl_class_is_6030()) {
249 if (save_control
& BIT_RTC_CTRL_REG_GET_TIME_M
) {
250 save_control
&= ~BIT_RTC_CTRL_REG_GET_TIME_M
;
251 ret
= twl_rtc_write_u8(save_control
, REG_RTC_CTRL_REG
);
253 dev_err(dev
, "%s clr GET_TIME, error %d\n",
260 /* Copy RTC counting registers to static registers or latches */
261 rtc_control
= save_control
| BIT_RTC_CTRL_REG_GET_TIME_M
;
263 /* for twl6030/32 enable read access to static shadowed registers */
264 if (twl_class_is_6030())
265 rtc_control
|= BIT_RTC_CTRL_REG_RTC_V_OPT
;
267 ret
= twl_rtc_write_u8(rtc_control
, REG_RTC_CTRL_REG
);
269 dev_err(dev
, "%s: writing CTRL_REG, error %d\n", __func__
, ret
);
273 ret
= twl_i2c_read(TWL_MODULE_RTC
, rtc_data
,
274 (rtc_reg_map
[REG_SECONDS_REG
]), ALL_TIME_REGS
);
277 dev_err(dev
, "%s: reading data, error %d\n", __func__
, ret
);
281 /* for twl6030 restore original state of rtc control register */
282 if (twl_class_is_6030()) {
283 ret
= twl_rtc_write_u8(save_control
, REG_RTC_CTRL_REG
);
285 dev_err(dev
, "%s: restore CTRL_REG, error %d\n",
291 tm
->tm_sec
= bcd2bin(rtc_data
[0]);
292 tm
->tm_min
= bcd2bin(rtc_data
[1]);
293 tm
->tm_hour
= bcd2bin(rtc_data
[2]);
294 tm
->tm_mday
= bcd2bin(rtc_data
[3]);
295 tm
->tm_mon
= bcd2bin(rtc_data
[4]) - 1;
296 tm
->tm_year
= bcd2bin(rtc_data
[5]) + 100;
301 static int twl_rtc_set_time(struct device
*dev
, struct rtc_time
*tm
)
303 unsigned char save_control
;
304 unsigned char rtc_data
[ALL_TIME_REGS
];
307 rtc_data
[0] = bin2bcd(tm
->tm_sec
);
308 rtc_data
[1] = bin2bcd(tm
->tm_min
);
309 rtc_data
[2] = bin2bcd(tm
->tm_hour
);
310 rtc_data
[3] = bin2bcd(tm
->tm_mday
);
311 rtc_data
[4] = bin2bcd(tm
->tm_mon
+ 1);
312 rtc_data
[5] = bin2bcd(tm
->tm_year
- 100);
314 /* Stop RTC while updating the TC registers */
315 ret
= twl_rtc_read_u8(&save_control
, REG_RTC_CTRL_REG
);
319 save_control
&= ~BIT_RTC_CTRL_REG_STOP_RTC_M
;
320 ret
= twl_rtc_write_u8(save_control
, REG_RTC_CTRL_REG
);
324 /* update all the time registers in one shot */
325 ret
= twl_i2c_write(TWL_MODULE_RTC
, rtc_data
,
326 (rtc_reg_map
[REG_SECONDS_REG
]), ALL_TIME_REGS
);
328 dev_err(dev
, "rtc_set_time error %d\n", ret
);
333 save_control
|= BIT_RTC_CTRL_REG_STOP_RTC_M
;
334 ret
= twl_rtc_write_u8(save_control
, REG_RTC_CTRL_REG
);
341 * Gets current TWL RTC alarm time.
343 static int twl_rtc_read_alarm(struct device
*dev
, struct rtc_wkalrm
*alm
)
345 unsigned char rtc_data
[ALL_TIME_REGS
];
348 ret
= twl_i2c_read(TWL_MODULE_RTC
, rtc_data
,
349 (rtc_reg_map
[REG_ALARM_SECONDS_REG
]), ALL_TIME_REGS
);
351 dev_err(dev
, "rtc_read_alarm error %d\n", ret
);
355 /* some of these fields may be wildcard/"match all" */
356 alm
->time
.tm_sec
= bcd2bin(rtc_data
[0]);
357 alm
->time
.tm_min
= bcd2bin(rtc_data
[1]);
358 alm
->time
.tm_hour
= bcd2bin(rtc_data
[2]);
359 alm
->time
.tm_mday
= bcd2bin(rtc_data
[3]);
360 alm
->time
.tm_mon
= bcd2bin(rtc_data
[4]) - 1;
361 alm
->time
.tm_year
= bcd2bin(rtc_data
[5]) + 100;
363 /* report cached alarm enable state */
364 if (rtc_irq_bits
& BIT_RTC_INTERRUPTS_REG_IT_ALARM_M
)
370 static int twl_rtc_set_alarm(struct device
*dev
, struct rtc_wkalrm
*alm
)
372 unsigned char alarm_data
[ALL_TIME_REGS
];
375 ret
= twl_rtc_alarm_irq_enable(dev
, 0);
379 alarm_data
[0] = bin2bcd(alm
->time
.tm_sec
);
380 alarm_data
[1] = bin2bcd(alm
->time
.tm_min
);
381 alarm_data
[2] = bin2bcd(alm
->time
.tm_hour
);
382 alarm_data
[3] = bin2bcd(alm
->time
.tm_mday
);
383 alarm_data
[4] = bin2bcd(alm
->time
.tm_mon
+ 1);
384 alarm_data
[5] = bin2bcd(alm
->time
.tm_year
- 100);
386 /* update all the alarm registers in one shot */
387 ret
= twl_i2c_write(TWL_MODULE_RTC
, alarm_data
,
388 (rtc_reg_map
[REG_ALARM_SECONDS_REG
]), ALL_TIME_REGS
);
390 dev_err(dev
, "rtc_set_alarm error %d\n", ret
);
395 ret
= twl_rtc_alarm_irq_enable(dev
, 1);
400 static irqreturn_t
twl_rtc_interrupt(int irq
, void *rtc
)
402 unsigned long events
;
407 res
= twl_rtc_read_u8(&rd_reg
, REG_RTC_STATUS_REG
);
411 * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
412 * only one (ALARM or RTC) interrupt source may be enabled
413 * at time, we also could check our results
414 * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
416 if (rd_reg
& BIT_RTC_STATUS_REG_ALARM_M
)
417 events
= RTC_IRQF
| RTC_AF
;
419 events
= RTC_IRQF
| RTC_PF
;
421 res
= twl_rtc_write_u8(BIT_RTC_STATUS_REG_ALARM_M
,
426 if (twl_class_is_4030()) {
427 /* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
428 * needs 2 reads to clear the interrupt. One read is done in
429 * do_twl_pwrirq(). Doing the second read, to clear
432 * FIXME the reason PWR_ISR1 needs an extra read is that
433 * RTC_IF retriggered until we cleared REG_ALARM_M above.
434 * But re-reading like this is a bad hack; by doing so we
435 * risk wrongly clearing status for some other IRQ (losing
436 * the interrupt). Be smarter about handling RTC_UF ...
438 res
= twl_i2c_read_u8(TWL4030_MODULE_INT
,
439 &rd_reg
, TWL4030_INT_PWR_ISR1
);
444 /* Notify RTC core on event */
445 rtc_update_irq(rtc
, 1, events
);
452 static struct rtc_class_ops twl_rtc_ops
= {
453 .read_time
= twl_rtc_read_time
,
454 .set_time
= twl_rtc_set_time
,
455 .read_alarm
= twl_rtc_read_alarm
,
456 .set_alarm
= twl_rtc_set_alarm
,
457 .alarm_irq_enable
= twl_rtc_alarm_irq_enable
,
460 /*----------------------------------------------------------------------*/
462 static int twl_rtc_probe(struct platform_device
*pdev
)
464 struct rtc_device
*rtc
;
466 int irq
= platform_get_irq(pdev
, 0);
472 ret
= twl_rtc_read_u8(&rd_reg
, REG_RTC_STATUS_REG
);
476 if (rd_reg
& BIT_RTC_STATUS_REG_POWER_UP_M
)
477 dev_warn(&pdev
->dev
, "Power up reset detected.\n");
479 if (rd_reg
& BIT_RTC_STATUS_REG_ALARM_M
)
480 dev_warn(&pdev
->dev
, "Pending Alarm interrupt detected.\n");
482 /* Clear RTC Power up reset and pending alarm interrupts */
483 ret
= twl_rtc_write_u8(rd_reg
, REG_RTC_STATUS_REG
);
487 if (twl_class_is_6030()) {
488 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK
,
490 twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK
,
494 dev_info(&pdev
->dev
, "Enabling TWL-RTC\n");
495 ret
= twl_rtc_write_u8(BIT_RTC_CTRL_REG_STOP_RTC_M
, REG_RTC_CTRL_REG
);
499 /* ensure interrupts are disabled, bootloaders can be strange */
500 ret
= twl_rtc_write_u8(0, REG_RTC_INTERRUPTS_REG
);
502 dev_warn(&pdev
->dev
, "unable to disable interrupt\n");
504 /* init cached IRQ enable bits */
505 ret
= twl_rtc_read_u8(&rtc_irq_bits
, REG_RTC_INTERRUPTS_REG
);
509 rtc
= rtc_device_register(pdev
->name
,
510 &pdev
->dev
, &twl_rtc_ops
, THIS_MODULE
);
513 dev_err(&pdev
->dev
, "can't register RTC device, err %ld\n",
518 ret
= request_threaded_irq(irq
, NULL
, twl_rtc_interrupt
,
519 IRQF_TRIGGER_RISING
| IRQF_ONESHOT
,
520 dev_name(&rtc
->dev
), rtc
);
522 dev_err(&pdev
->dev
, "IRQ is not free.\n");
526 platform_set_drvdata(pdev
, rtc
);
530 rtc_device_unregister(rtc
);
536 * Disable all TWL RTC module interrupts.
537 * Sets status flag to free.
539 static int twl_rtc_remove(struct platform_device
*pdev
)
541 /* leave rtc running, but disable irqs */
542 struct rtc_device
*rtc
= platform_get_drvdata(pdev
);
543 int irq
= platform_get_irq(pdev
, 0);
545 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M
);
546 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M
);
547 if (twl_class_is_6030()) {
548 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK
,
550 twl6030_interrupt_mask(TWL6030_RTC_INT_MASK
,
557 rtc_device_unregister(rtc
);
558 platform_set_drvdata(pdev
, NULL
);
562 static void twl_rtc_shutdown(struct platform_device
*pdev
)
564 /* mask timer interrupts, but leave alarm interrupts on to enable
565 power-on when alarm is triggered */
566 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M
);
569 #ifdef CONFIG_PM_SLEEP
570 static unsigned char irqstat
;
572 static int twl_rtc_suspend(struct device
*dev
)
574 irqstat
= rtc_irq_bits
;
576 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M
);
580 static int twl_rtc_resume(struct device
*dev
)
582 set_rtc_irq_bit(irqstat
);
587 static SIMPLE_DEV_PM_OPS(twl_rtc_pm_ops
, twl_rtc_suspend
, twl_rtc_resume
);
590 static const struct of_device_id twl_rtc_of_match
[] = {
591 {.compatible
= "ti,twl4030-rtc", },
594 MODULE_DEVICE_TABLE(of
, twl_rtc_of_match
);
597 MODULE_ALIAS("platform:twl_rtc");
599 static struct platform_driver twl4030rtc_driver
= {
600 .probe
= twl_rtc_probe
,
601 .remove
= twl_rtc_remove
,
602 .shutdown
= twl_rtc_shutdown
,
604 .owner
= THIS_MODULE
,
606 .pm
= &twl_rtc_pm_ops
,
607 .of_match_table
= of_match_ptr(twl_rtc_of_match
),
611 static int __init
twl_rtc_init(void)
613 if (twl_class_is_4030())
614 rtc_reg_map
= (u8
*) twl4030_rtc_reg_map
;
616 rtc_reg_map
= (u8
*) twl6030_rtc_reg_map
;
618 return platform_driver_register(&twl4030rtc_driver
);
620 module_init(twl_rtc_init
);
622 static void __exit
twl_rtc_exit(void)
624 platform_driver_unregister(&twl4030rtc_driver
);
626 module_exit(twl_rtc_exit
);
628 MODULE_AUTHOR("Texas Instruments, MontaVista Software");
629 MODULE_LICENSE("GPL");