2 * drivers/rtc/rtc-twl4030.c
4 * TWL4030 Real Time Clock interface
6 * Copyright (C) 2007 MontaVista Software, Inc
7 * Author: Alexandre Rusev <source@mvista.com>
9 * Based on original TI driver twl4030-rtc.c
10 * Copyright (C) 2006 Texas Instruments, Inc.
13 * Copyright (C) 2003 MontaVista Software, Inc.
14 * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
16 * Copyright (C) 2006 David Brownell
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
25 #include <linux/kernel.h>
26 #include <linux/init.h>
27 #include <linux/module.h>
28 #include <linux/ioport.h>
29 #include <linux/delay.h>
30 #include <linux/types.h>
31 #include <linux/rtc.h>
32 #include <linux/bcd.h>
33 #include <linux/platform_device.h>
34 #include <linux/spinlock.h>
35 #include <linux/interrupt.h>
36 #include <linux/device.h>
37 #include <linux/i2c/twl4030.h>
38 #include <linux/i2c/twl4030-rtc.h>
40 #include <linux/irq.h>
42 #include <asm/mach/time.h>
43 #include <asm/system.h>
44 #include <asm/hardware.h>
46 #define ALL_TIME_REGS 6
49 * If this driver ever becomes modularised, it will be really nice
50 * to make the epoch retain its value across module reload...
52 static int epoch = 1900; /* year corresponding to 0x00 */
55 * Supports 1 byte read from TWL4030 RTC register.
57 static int twl4030_rtc_read_u8(u8 *data, u8 reg)
61 ret = twl4030_i2c_read_u8(TWL4030_MODULE_RTC, data, reg);
63 printk(KERN_WARNING "twl4030_rtc: Could not read TWL4030"
64 "register %X - returned %d[%x]\n", reg, ret, ret);
70 * Supports 1 byte write to TWL4030 RTC registers.
72 static int twl4030_rtc_write_u8(u8 data, u8 reg)
76 ret = twl4030_i2c_write_u8(TWL4030_MODULE_RTC, data, reg);
78 printk(KERN_WARNING "twl4030_rtc: Could not write TWL4030"
79 "register %X - returned %d[%x]\n", reg, ret, ret);
85 * Enables timer or alarm interrupts.
87 static int set_rtc_irq_bit(unsigned char bit)
92 ret = twl4030_rtc_read_u8(&val, REG_RTC_INTERRUPTS_REG);
97 ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
105 * Read timer or alarm interrupts register.
107 static int get_rtc_irq_bit(unsigned char *val)
111 ret = twl4030_rtc_read_u8(val, REG_RTC_INTERRUPTS_REG);
116 * Disables timer or alarm interrupts.
118 static int mask_rtc_irq_bit(unsigned char bit)
123 ret = twl4030_rtc_read_u8(&val, REG_RTC_INTERRUPTS_REG);
128 ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
134 static int twl4030_rtc_alarm_irq_set_state(struct device *dev, int enabled)
138 /* Allow ints for RTC ALARM updates. */
140 ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
142 ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
148 * Gets current TWL4030 RTC time and date parameters.
150 static int get_rtc_time(struct rtc_time *rtc_tm)
152 unsigned char rtc_data[ALL_TIME_REGS + 1];
156 ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
160 save_control |= BIT_RTC_CTRL_REG_GET_TIME_M;
162 ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
166 ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
167 REG_SECONDS_REG, ALL_TIME_REGS);
170 printk(KERN_ERR "twl4030_rtc: twl4030_i2c_read error.\n");
174 rtc_tm->tm_sec = BCD2BIN(rtc_data[0]);
175 rtc_tm->tm_min = BCD2BIN(rtc_data[1]);
176 rtc_tm->tm_hour = BCD2BIN(rtc_data[2]);
177 rtc_tm->tm_mday = BCD2BIN(rtc_data[3]);
178 rtc_tm->tm_mon = BCD2BIN(rtc_data[4]);
179 rtc_tm->tm_year = BCD2BIN(rtc_data[5]);
182 * Account for differences between how the RTC uses the values
183 * and how they are defined in a struct rtc_time;
185 rtc_tm->tm_year += (epoch - 1900);
186 if (rtc_tm->tm_year <= 69)
187 rtc_tm->tm_year += 100;
194 static int twl4030_rtc_set_time(struct device *dev, struct rtc_time *tm)
196 unsigned char save_control;
197 unsigned char rtc_data[ALL_TIME_REGS + 1];
200 /* Month range is 01..12 */
203 rtc_data[1] = BIN2BCD(tm->tm_sec);
204 rtc_data[2] = BIN2BCD(tm->tm_min);
205 rtc_data[3] = BIN2BCD(tm->tm_hour);
206 rtc_data[4] = BIN2BCD(tm->tm_mday);
207 rtc_data[5] = BIN2BCD(tm->tm_mon);
208 rtc_data[6] = BIN2BCD(tm->tm_year);
210 /* Stop RTC while updating the TC registers */
211 ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
215 save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
216 twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
220 /* update all the alarm registers in one shot */
221 ret = twl4030_i2c_write(TWL4030_MODULE_RTC, rtc_data,
222 REG_SECONDS_REG, ALL_TIME_REGS);
224 printk(KERN_ERR "twl4030: twl4030_i2c_write error.\n");
229 save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
230 ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
237 * Gets current TWL4030 RTC alarm time.
239 static int get_rtc_alm_time(struct rtc_time *alm_tm)
241 unsigned char rtc_data[ALL_TIME_REGS + 1];
244 ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
245 REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
247 printk(KERN_ERR "twl4030_rtc: twl4030_i2c_read error.\n");
251 alm_tm->tm_sec = BCD2BIN(rtc_data[0]);
252 alm_tm->tm_min = BCD2BIN(rtc_data[1]);
253 alm_tm->tm_hour = BCD2BIN(rtc_data[2]);
254 alm_tm->tm_mday = BCD2BIN(rtc_data[3]);
255 alm_tm->tm_mon = BCD2BIN(rtc_data[4]);
256 alm_tm->tm_year = BCD2BIN(rtc_data[5]);
259 * Account for differences between how the RTC uses the values
260 * and how they are defined in a struct rtc_time;
262 alm_tm->tm_year += (epoch - 1900);
263 if (alm_tm->tm_year <= 69)
264 alm_tm->tm_year += 100;
271 static int twl4030_rtc_read_time(struct device *dev, struct rtc_time *tm)
275 memset(tm, 0, sizeof(struct rtc_time));
276 ret = get_rtc_time(tm);
282 * Gets current TWL4030 RTC alarm time.
284 static int twl4030_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
287 u8 rtc_interrupts_reg = 0;
290 * This returns a struct rtc_time. Reading >= 0xc0
291 * means "don't care" or "match all". Only the tm_hour,
292 * tm_min, and tm_sec values are filled in.
294 memset(&alm->time, 0, sizeof(struct rtc_time));
295 ret = get_rtc_alm_time(&alm->time);
300 /* Check alarm enabled flag state */
302 ret | twl4030_i2c_read_u8(TWL4030_MODULE_RTC, &rtc_interrupts_reg,
303 REG_RTC_INTERRUPTS_REG);
308 if ((rtc_interrupts_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) != 0)
317 static int twl4030_rtc_irq_set_state(struct device *dev, int enabled)
321 /* Allow ints for RTC updates. */
323 ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
325 ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
330 static int twl4030_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
332 unsigned char alarm_data[ALL_TIME_REGS + 1];
335 /* Month range is 01..12 */
338 alarm_data[1] = BIN2BCD(alm->time.tm_sec);
339 alarm_data[2] = BIN2BCD(alm->time.tm_min);
340 alarm_data[3] = BIN2BCD(alm->time.tm_hour);
341 alarm_data[4] = BIN2BCD(alm->time.tm_mday);
342 alarm_data[5] = BIN2BCD(alm->time.tm_mon);
343 alarm_data[6] = BIN2BCD(alm->time.tm_year);
345 /* update all the alarm registers in one shot */
346 ret = twl4030_i2c_write(TWL4030_MODULE_RTC, alarm_data,
347 REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
349 printk(KERN_ERR "twl4030: twl4030_i2c_write error.\n");
353 ret = twl4030_rtc_alarm_irq_set_state(dev, alm->enabled);
359 * We will just handle setting the frequency and make use the framework for
360 * reading the periodic interupts.
361 * @freq: Current periodic IRQ freq
363 static int twl4030_rtc_irq_set_freq(struct device *dev, int freq)
365 struct rtc_device *rtc = dev_get_drvdata(dev);
367 if (freq < 0 || freq > 3)
370 rtc->irq_freq = freq;
372 /* set rtc irq freq to user defined value */
373 set_rtc_irq_bit(freq);
378 #ifdef CONFIG_RTC_INTF_DEV
380 static int twl4030_rtc_ioctl(struct device *dev, unsigned int cmd,
386 return twl4030_rtc_alarm_irq_set_state(dev, 0);
388 return twl4030_rtc_alarm_irq_set_state(dev, 1);
393 /* Mask ints from RTC updates. */
394 return twl4030_rtc_irq_set_state(dev, 0);
398 /* Allow ints for RTC updates. */
399 return twl4030_rtc_irq_set_state(dev, 1);
402 return put_user(epoch, (unsigned long *)arg);
405 * There were no RTC clocks before 1900.
410 if (!capable(CAP_SYS_TIME))
421 #define omap_rtc_ioctl NULL
424 static irqreturn_t twl4030_rtc_interrupt(int irq, void *rtc)
426 unsigned long events = 0;
431 res = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
435 * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
436 * only one (ALARM or RTC) interrupt source may be enabled
437 * at time, we also could check our results
438 * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
440 if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
441 events |= RTC_IRQF | RTC_AF;
443 events |= RTC_IRQF | RTC_UF;
445 res = twl4030_rtc_write_u8(rd_reg | BIT_RTC_STATUS_REG_ALARM_M,
450 * Workaround for strange behaviour with T2. Need to write into ISR
451 * register one more time to clear the interrupt. Otherwise, the same
452 * RTC event generates 2 interrupts in a row.
453 * (no errata document available)
455 res = twl4030_i2c_write_u8(TWL4030_MODULE_INT,
456 PWR_RTC_INT_CLR, REG_PWR_ISR1);
460 /* Notify RTC core on event */
461 rtc_update_irq(rtc, 1, events);
468 static struct rtc_class_ops twl4030_rtc_ops = {
469 .ioctl = twl4030_rtc_ioctl,
470 .read_time = twl4030_rtc_read_time,
471 .set_time = twl4030_rtc_set_time,
472 .read_alarm = twl4030_rtc_read_alarm,
473 .set_alarm = twl4030_rtc_set_alarm,
474 .irq_set_freq = twl4030_rtc_irq_set_freq,
477 static int __devinit twl4030_rtc_probe(struct platform_device *pdev)
479 struct twl4030rtc_platform_data *pdata = pdev->dev.platform_data;
480 struct rtc_device *rtc;
484 if (pdata != NULL && pdata->init != NULL) {
490 rtc = rtc_device_register(pdev->name,
491 &pdev->dev, &twl4030_rtc_ops, THIS_MODULE);
494 dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
500 /* Set the irq freq to every second */
503 platform_set_drvdata(pdev, rtc);
505 ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
510 if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
511 dev_warn(&pdev->dev, "Power up reset detected.\n");
513 if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
514 dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
516 /* Clear RTC Power up reset and pending alarm interrupts */
517 ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_STATUS_REG);
521 ret = request_irq(TWL4030_PWRIRQ_RTC, twl4030_rtc_interrupt,
522 0, rtc->dev.bus_id, rtc);
524 dev_err(&pdev->dev, "IRQ is not free.\n");
528 /* Check RTC module status, Enable if it is off */
529 ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_CTRL_REG);
533 if (!(rd_reg & BIT_RTC_CTRL_REG_STOP_RTC_M)) {
534 dev_info(&pdev->dev, "Enabling TWL4030-RTC.\n");
535 rd_reg = BIT_RTC_CTRL_REG_STOP_RTC_M;
536 ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_CTRL_REG);
541 ret = twl4030_i2c_read_u8(TWL4030_MODULE_INT, &rd_reg, REG_PWR_IMR1);
545 rd_reg &= PWR_RTC_IT_UNMASK;
546 /* MASK PWR - we will need this */
547 ret = twl4030_i2c_write_u8(TWL4030_MODULE_INT, rd_reg, REG_PWR_IMR1);
551 ret = twl4030_i2c_read_u8(TWL4030_MODULE_INT, &rd_reg, REG_PWR_EDR1);
555 /* Rising edge detection enabled, needed for RTC alarm */
557 ret = twl4030_i2c_write_u8(TWL4030_MODULE_INT, rd_reg, REG_PWR_EDR1);
565 free_irq(TWL4030_MODIRQ_PWR, rtc);
567 rtc_device_unregister(rtc);
569 if (pdata != NULL && pdata->exit != NULL)
576 * Disable all TWL4030 RTC module interrupts.
577 * Sets status flag to free.
579 static int __devexit twl4030_rtc_remove(struct platform_device *pdev)
581 /* leave rtc running, but disable irqs */
582 struct twl4030rtc_platform_data *pdata = pdev->dev.platform_data;
583 struct rtc_device *rtc = platform_get_drvdata(pdev);
585 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
586 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
588 free_irq(TWL4030_MODIRQ_PWR, rtc);
590 if (pdata != NULL && pdata->exit != NULL)
593 rtc_device_unregister(rtc);
594 platform_set_drvdata(pdev, NULL);
598 static void twl4030_rtc_shutdown(struct platform_device *pdev)
600 twl4030_rtc_alarm_irq_set_state(&pdev->dev, 0);
601 twl4030_rtc_irq_set_state(&pdev->dev, 0);
606 static unsigned char irqstat;
608 static int twl4030_rtc_suspend(struct platform_device *pdev, pm_message_t state)
610 get_rtc_irq_bit(&irqstat);
612 mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M |
613 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
617 static int twl4030_rtc_resume(struct platform_device *pdev)
619 set_rtc_irq_bit(irqstat);
623 #define twl4030_rtc_suspend NULL
624 #define twl4030_rtc_resume NULL
627 MODULE_ALIAS("twl4030_rtc");
628 static struct platform_driver twl4030rtc_driver = {
629 .probe = twl4030_rtc_probe,
630 .remove = __devexit_p(twl4030_rtc_remove),
631 .shutdown = twl4030_rtc_shutdown,
632 .suspend = twl4030_rtc_suspend,
633 .resume = twl4030_rtc_resume,
635 .owner = THIS_MODULE,
636 .name = "twl4030_rtc",
640 static int __init twl4030_rtc_init(void)
642 return platform_driver_register(&twl4030rtc_driver);
645 static void __exit twl4030_rtc_exit(void)
647 platform_driver_unregister(&twl4030rtc_driver);
650 MODULE_AUTHOR("Texas Instruments, MontaVista Software");
651 MODULE_LICENSE("GPL");;
653 module_init(twl4030_rtc_init);
654 module_exit(twl4030_rtc_exit);