[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / drivers / rtc / rtc-twl4030.c

/*
 * rtc-twl4030.c -- TWL4030 Real Time Clock interface
 *
 * Copyright (C) 2007 MontaVista Software, Inc
 * Author: Alexandre Rusev <source@mvista.com>
 *
 * Based on original TI driver twl4030-rtc.c
 *   Copyright (C) 2006 Texas Instruments, Inc.
 *
 * Based on rtc-omap.c
 *   Copyright (C) 2003 MontaVista Software, Inc.
 *   Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
 *   Copyright (C) 2006 David Brownell
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/rtc.h>
#include <linux/bcd.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>

#include <linux/i2c/twl4030.h>


/*
 * RTC block register offsets (use TWL_MODULE_RTC)
 */
#define REG_SECONDS_REG                          0x00
#define REG_MINUTES_REG                          0x01
#define REG_HOURS_REG                            0x02
#define REG_DAYS_REG                             0x03
#define REG_MONTHS_REG                           0x04
#define REG_YEARS_REG                            0x05
#define REG_WEEKS_REG                            0x06

#define REG_ALARM_SECONDS_REG                    0x07
#define REG_ALARM_MINUTES_REG                    0x08
#define REG_ALARM_HOURS_REG                      0x09
#define REG_ALARM_DAYS_REG                       0x0A
#define REG_ALARM_MONTHS_REG                     0x0B
#define REG_ALARM_YEARS_REG                      0x0C

#define REG_RTC_CTRL_REG                         0x0D
#define REG_RTC_STATUS_REG                       0x0E
#define REG_RTC_INTERRUPTS_REG                   0x0F

#define REG_RTC_COMP_LSB_REG                     0x10
#define REG_RTC_COMP_MSB_REG                     0x11

/* RTC_CTRL_REG bitfields */
#define BIT_RTC_CTRL_REG_STOP_RTC_M              0x01
#define BIT_RTC_CTRL_REG_ROUND_30S_M             0x02
#define BIT_RTC_CTRL_REG_AUTO_COMP_M             0x04
#define BIT_RTC_CTRL_REG_MODE_12_24_M            0x08
#define BIT_RTC_CTRL_REG_TEST_MODE_M             0x10
#define BIT_RTC_CTRL_REG_SET_32_COUNTER_M        0x20
#define BIT_RTC_CTRL_REG_GET_TIME_M              0x40

/* RTC_STATUS_REG bitfields */
#define BIT_RTC_STATUS_REG_RUN_M                 0x02
#define BIT_RTC_STATUS_REG_1S_EVENT_M            0x04
#define BIT_RTC_STATUS_REG_1M_EVENT_M            0x08
#define BIT_RTC_STATUS_REG_1H_EVENT_M            0x10
#define BIT_RTC_STATUS_REG_1D_EVENT_M            0x20
#define BIT_RTC_STATUS_REG_ALARM_M               0x40
#define BIT_RTC_STATUS_REG_POWER_UP_M            0x80

/* RTC_INTERRUPTS_REG bitfields */
#define BIT_RTC_INTERRUPTS_REG_EVERY_M           0x03
#define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M        0x04
#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M        0x08


/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
#define ALL_TIME_REGS		6

/*----------------------------------------------------------------------*/

/*
 * Supports 1 byte read from TWL4030 RTC register.
 */
static int twl4030_rtc_read_u8(u8 *data, u8 reg)
{
	int ret;

	ret = twl4030_i2c_read_u8(TWL4030_MODULE_RTC, data, reg);
	if (ret < 0)
		pr_err("twl4030_rtc: Could not read TWL4030"
		       "register %X - error %d\n", reg, ret);
	return ret;
}

/*
 * Supports 1 byte write to TWL4030 RTC registers.
 */
static int twl4030_rtc_write_u8(u8 data, u8 reg)
{
	int ret;

	ret = twl4030_i2c_write_u8(TWL4030_MODULE_RTC, data, reg);
	if (ret < 0)
		pr_err("twl4030_rtc: Could not write TWL4030"
		       "register %X - error %d\n", reg, ret);
	return ret;
}

/*
 * Cache the value for timer/alarm interrupts register; this is
 * only changed by callers holding rtc ops lock (or resume).
 */
static unsigned char rtc_irq_bits;

/*
 * Enable timer and/or alarm interrupts.
 */
static int set_rtc_irq_bit(unsigned char bit)
{
	unsigned char val;
	int ret;

	val = rtc_irq_bits | bit;
	ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
	if (ret == 0)
		rtc_irq_bits = val;

	return ret;
}

/*
 * Disable timer and/or alarm interrupts.
 */
static int mask_rtc_irq_bit(unsigned char bit)
{
	unsigned char val;
	int ret;

	val = rtc_irq_bits & ~bit;
	ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
	if (ret == 0)
		rtc_irq_bits = val;

	return ret;
}

static inline int twl4030_rtc_alarm_irq_set_state(int enabled)
{
	int ret;

	if (enabled)
		ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
	else
		ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);

	return ret;
}

static inline int twl4030_rtc_irq_set_state(int enabled)
{
	int ret;

	if (enabled)
		ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
	else
		ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);

	return ret;
}

/*
 * Gets current TWL4030 RTC time and date parameters.
 *
 * The RTC's time/alarm representation is not what gmtime(3) requires
 * Linux to use:
 *
 *  - Months are 1..12 vs Linux 0-11
 *  - Years are 0..99 vs Linux 1900..N (we assume 21st century)
 */
static int twl4030_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char rtc_data[ALL_TIME_REGS + 1];
	int ret;
	u8 save_control;

	ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
	if (ret < 0)
		return ret;

	save_control |= BIT_RTC_CTRL_REG_GET_TIME_M;

	ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
	if (ret < 0)
		return ret;

	ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
			       REG_SECONDS_REG, ALL_TIME_REGS);

	if (ret < 0) {
		dev_err(dev, "rtc_read_time error %d\n", ret);
		return ret;
	}

	tm->tm_sec = bcd2bin(rtc_data[0]);
	tm->tm_min = bcd2bin(rtc_data[1]);
	tm->tm_hour = bcd2bin(rtc_data[2]);
	tm->tm_mday = bcd2bin(rtc_data[3]);
	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
	tm->tm_year = bcd2bin(rtc_data[5]) + 100;

	return ret;
}

static int twl4030_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	unsigned char save_control;
	unsigned char rtc_data[ALL_TIME_REGS + 1];
	int ret;

	rtc_data[1] = bin2bcd(tm->tm_sec);
	rtc_data[2] = bin2bcd(tm->tm_min);
	rtc_data[3] = bin2bcd(tm->tm_hour);
	rtc_data[4] = bin2bcd(tm->tm_mday);
	rtc_data[5] = bin2bcd(tm->tm_mon + 1);
	rtc_data[6] = bin2bcd(tm->tm_year - 100);

	/* Stop RTC while updating the TC registers */
	ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
	if (ret < 0)
		goto out;

	save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
	twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
	if (ret < 0)
		goto out;

	/* update all the time registers in one shot */
	ret = twl4030_i2c_write(TWL4030_MODULE_RTC, rtc_data,
			REG_SECONDS_REG, ALL_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "rtc_set_time error %d\n", ret);
		goto out;
	}

	/* Start back RTC */
	save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
	ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);

out:
	return ret;
}

/*
 * Gets current TWL4030 RTC alarm time.
 */
static int twl4030_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	unsigned char rtc_data[ALL_TIME_REGS + 1];
	int ret;

	ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
			       REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
	if (ret < 0) {
		dev_err(dev, "rtc_read_alarm error %d\n", ret);
		return ret;
	}

	/* some of these fields may be wildcard/"match all" */
	alm->time.tm_sec = bcd2bin(rtc_data[0]);
	alm->time.tm_min = bcd2bin(rtc_data[1]);
	alm->time.tm_hour = bcd2bin(rtc_data[2]);
	alm->time.tm_mday = bcd2bin(rtc_data[3]);
	alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
	alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;

	/* report cached alarm enable state */
	if (rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
		alm->enabled = 1;

	return ret;
}

static int twl4030_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
{
	unsigned char alarm_data[ALL_TIME_REGS + 1];
	int ret;

	ret = twl4030_rtc_alarm_irq_set_state(0);
	if (ret)
		goto out;

	alarm_data[1] = bin2bcd(alm->time.tm_sec);
	alarm_data[2] = bin2bcd(alm->time.tm_min);
	alarm_data[3] = bin2bcd(alm->time.tm_hour);
	alarm_data[4] = bin2bcd(alm->time.tm_mday);
	alarm_data[5] = bin2bcd(alm->time.tm_mon + 1);
	alarm_data[6] = bin2bcd(alm->time.tm_year - 100);

	/* update all the alarm registers in one shot */
	ret = twl4030_i2c_write(TWL4030_MODULE_RTC, alarm_data,
			REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
	if (ret) {
		dev_err(dev, "rtc_set_alarm error %d\n", ret);
		goto out;
	}

	if (alm->enabled)
		ret = twl4030_rtc_alarm_irq_set_state(1);
out:
	return ret;
}

#ifdef	CONFIG_RTC_INTF_DEV

static int twl4030_rtc_ioctl(struct device *dev, unsigned int cmd,
			     unsigned long arg)
{
	switch (cmd) {
	case RTC_AIE_OFF:
		return twl4030_rtc_alarm_irq_set_state(0);
	case RTC_AIE_ON:
		return twl4030_rtc_alarm_irq_set_state(1);
	case RTC_UIE_OFF:
		return twl4030_rtc_irq_set_state(0);
	case RTC_UIE_ON:
		return twl4030_rtc_irq_set_state(1);

	default:
		return -ENOIOCTLCMD;
	}
}

#else
#define	twl4030_rtc_ioctl	NULL
#endif

static irqreturn_t twl4030_rtc_interrupt(int irq, void *rtc)
{
	unsigned long events = 0;
	int ret = IRQ_NONE;
	int res;
	u8 rd_reg;

#ifdef CONFIG_LOCKDEP
	/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
	 * we don't want and can't tolerate.  Although it might be
	 * friendlier not to borrow this thread context...
	 */
	local_irq_enable();
#endif

	res = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
	if (res)
		goto out;
	/*
	 * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
	 * only one (ALARM or RTC) interrupt source may be enabled
	 * at time, we also could check our results
	 * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
	 */
	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
		events |= RTC_IRQF | RTC_AF;
	else
		events |= RTC_IRQF | RTC_UF;

	res = twl4030_rtc_write_u8(rd_reg | BIT_RTC_STATUS_REG_ALARM_M,
				   REG_RTC_STATUS_REG);
	if (res)
		goto out;

	/* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
	 * needs 2 reads to clear the interrupt. One read is done in
	 * do_twl4030_pwrirq(). Doing the second read, to clear
	 * the bit.
	 *
	 * FIXME the reason PWR_ISR1 needs an extra read is that
	 * RTC_IF retriggered until we cleared REG_ALARM_M above.
	 * But re-reading like this is a bad hack; by doing so we
	 * risk wrongly clearing status for some other IRQ (losing
	 * the interrupt).  Be smarter about handling RTC_UF ...
	 */
	res = twl4030_i2c_read_u8(TWL4030_MODULE_INT,
			&rd_reg, TWL4030_INT_PWR_ISR1);
	if (res)
		goto out;

	/* Notify RTC core on event */
	rtc_update_irq(rtc, 1, events);

	ret = IRQ_HANDLED;
out:
	return ret;
}

static struct rtc_class_ops twl4030_rtc_ops = {
	.ioctl		= twl4030_rtc_ioctl,
	.read_time	= twl4030_rtc_read_time,
	.set_time	= twl4030_rtc_set_time,
	.read_alarm	= twl4030_rtc_read_alarm,
	.set_alarm	= twl4030_rtc_set_alarm,
};

/*----------------------------------------------------------------------*/

static int __devinit twl4030_rtc_probe(struct platform_device *pdev)
{
	struct rtc_device *rtc;
	int ret = 0;
	int irq = platform_get_irq(pdev, 0);
	u8 rd_reg;

	if (irq < 0)
		return irq;

	rtc = rtc_device_register(pdev->name,
				  &pdev->dev, &twl4030_rtc_ops, THIS_MODULE);
	if (IS_ERR(rtc)) {
		ret = -EINVAL;
		dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
			PTR_ERR(rtc));
		goto out0;

	}

	platform_set_drvdata(pdev, rtc);

	ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);

	if (ret < 0)
		goto out1;

	if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
		dev_warn(&pdev->dev, "Power up reset detected.\n");

	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
		dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");

	/* Clear RTC Power up reset and pending alarm interrupts */
	ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_STATUS_REG);
	if (ret < 0)
		goto out1;

	ret = request_irq(irq, twl4030_rtc_interrupt,
				IRQF_TRIGGER_RISING,
				rtc->dev.bus_id, rtc);
	if (ret < 0) {
		dev_err(&pdev->dev, "IRQ is not free.\n");
		goto out1;
	}

	/* Check RTC module status, Enable if it is off */
	ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_CTRL_REG);
	if (ret < 0)
		goto out2;

	if (!(rd_reg & BIT_RTC_CTRL_REG_STOP_RTC_M)) {
		dev_info(&pdev->dev, "Enabling TWL4030-RTC.\n");
		rd_reg = BIT_RTC_CTRL_REG_STOP_RTC_M;
		ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_CTRL_REG);
		if (ret < 0)
			goto out2;
	}

	/* init cached IRQ enable bits */
	ret = twl4030_rtc_read_u8(&rtc_irq_bits, REG_RTC_INTERRUPTS_REG);
	if (ret < 0)
		goto out2;

	return ret;


out2:
	free_irq(irq, rtc);
out1:
	rtc_device_unregister(rtc);
out0:
	return ret;
}

/*
 * Disable all TWL4030 RTC module interrupts.
 * Sets status flag to free.
 */
static int __devexit twl4030_rtc_remove(struct platform_device *pdev)
{
	/* leave rtc running, but disable irqs */
	struct rtc_device *rtc = platform_get_drvdata(pdev);
	int irq = platform_get_irq(pdev, 0);

	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);

	free_irq(irq, rtc);

	rtc_device_unregister(rtc);
	platform_set_drvdata(pdev, NULL);
	return 0;
}

static void twl4030_rtc_shutdown(struct platform_device *pdev)
{
	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M |
			 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
}

#ifdef CONFIG_PM

static unsigned char irqstat;

static int twl4030_rtc_suspend(struct platform_device *pdev, pm_message_t state)
{
	irqstat = rtc_irq_bits;

	/* REVISIT alarm may need to wake us from sleep */
	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M |
			 BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
	return 0;
}

static int twl4030_rtc_resume(struct platform_device *pdev)
{
	set_rtc_irq_bit(irqstat);
	return 0;
}

#else
#define twl4030_rtc_suspend NULL
#define twl4030_rtc_resume  NULL
#endif

MODULE_ALIAS("platform:twl4030_rtc");

static struct platform_driver twl4030rtc_driver = {
	.probe		= twl4030_rtc_probe,
	.remove		= __devexit_p(twl4030_rtc_remove),
	.shutdown	= twl4030_rtc_shutdown,
	.suspend	= twl4030_rtc_suspend,
	.resume		= twl4030_rtc_resume,
	.driver		= {
		.owner	= THIS_MODULE,
		.name	= "twl4030_rtc",
	},
};

static int __init twl4030_rtc_init(void)
{
	return platform_driver_register(&twl4030rtc_driver);
}
module_init(twl4030_rtc_init);

static void __exit twl4030_rtc_exit(void)
{
	platform_driver_unregister(&twl4030rtc_driver);
}
module_exit(twl4030_rtc_exit);

MODULE_AUTHOR("Texas Instruments, MontaVista Software");
MODULE_LICENSE("GPL");
Commit	Line	Data
f96411ab DB	1	/*
	2	* rtc-twl4030.c -- TWL4030 Real Time Clock interface
	3	*
	4	* Copyright (C) 2007 MontaVista Software, Inc
	5	* Author: Alexandre Rusev <source@mvista.com>
	6	*
	7	* Based on original TI driver twl4030-rtc.c
	8	* Copyright (C) 2006 Texas Instruments, Inc.
	9	*
	10	* Based on rtc-omap.c
	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
	14	*
	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.
	19	*/
	20
	21	#include <linux/kernel.h>
	22	#include <linux/init.h>
	23	#include <linux/module.h>
	24	#include <linux/types.h>
	25	#include <linux/rtc.h>
	26	#include <linux/bcd.h>
	27	#include <linux/platform_device.h>
	28	#include <linux/interrupt.h>
	29
	30	#include <linux/i2c/twl4030.h>
	31
	32
	33	/*
	34	* RTC block register offsets (use TWL_MODULE_RTC)
	35	*/
	36	#define REG_SECONDS_REG 0x00
	37	#define REG_MINUTES_REG 0x01
	38	#define REG_HOURS_REG 0x02
	39	#define REG_DAYS_REG 0x03
	40	#define REG_MONTHS_REG 0x04
	41	#define REG_YEARS_REG 0x05
	42	#define REG_WEEKS_REG 0x06
	43
	44	#define REG_ALARM_SECONDS_REG 0x07
	45	#define REG_ALARM_MINUTES_REG 0x08
	46	#define REG_ALARM_HOURS_REG 0x09
	47	#define REG_ALARM_DAYS_REG 0x0A
	48	#define REG_ALARM_MONTHS_REG 0x0B
	49	#define REG_ALARM_YEARS_REG 0x0C
	50
	51	#define REG_RTC_CTRL_REG 0x0D
	52	#define REG_RTC_STATUS_REG 0x0E
	53	#define REG_RTC_INTERRUPTS_REG 0x0F
	54
	55	#define REG_RTC_COMP_LSB_REG 0x10
	56	#define REG_RTC_COMP_MSB_REG 0x11
	57
	58	/* RTC_CTRL_REG bitfields */
	59	#define BIT_RTC_CTRL_REG_STOP_RTC_M 0x01
	60	#define BIT_RTC_CTRL_REG_ROUND_30S_M 0x02
	61	#define BIT_RTC_CTRL_REG_AUTO_COMP_M 0x04
	62	#define BIT_RTC_CTRL_REG_MODE_12_24_M 0x08
	63	#define BIT_RTC_CTRL_REG_TEST_MODE_M 0x10
	64	#define BIT_RTC_CTRL_REG_SET_32_COUNTER_M 0x20
65	#define BIT_RTC_CTRL_REG_GET_TIME_M 0x40
66
67	/* RTC_STATUS_REG bitfields */
68	#define BIT_RTC_STATUS_REG_RUN_M 0x02
69	#define BIT_RTC_STATUS_REG_1S_EVENT_M 0x04
70	#define BIT_RTC_STATUS_REG_1M_EVENT_M 0x08
71	#define BIT_RTC_STATUS_REG_1H_EVENT_M 0x10
72	#define BIT_RTC_STATUS_REG_1D_EVENT_M 0x20
73	#define BIT_RTC_STATUS_REG_ALARM_M 0x40
74	#define BIT_RTC_STATUS_REG_POWER_UP_M 0x80
75
76	/* RTC_INTERRUPTS_REG bitfields */
77	#define BIT_RTC_INTERRUPTS_REG_EVERY_M 0x03
78	#define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M 0x04
79	#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M 0x08
80
81
82	/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
83	#define ALL_TIME_REGS 6
84
85	/----------------------------------------------------------------------/
86
87	/*
88	* Supports 1 byte read from TWL4030 RTC register.
89	*/
90	static int twl4030_rtc_read_u8(u8 *data, u8 reg)
91	{
92	int ret;
93
94	ret = twl4030_i2c_read_u8(TWL4030_MODULE_RTC, data, reg);
95	if (ret < 0)
96	pr_err("twl4030_rtc: Could not read TWL4030"
97	"register %X - error %d\n", reg, ret);
98	return ret;
99	}
100
101	/*
102	* Supports 1 byte write to TWL4030 RTC registers.
103	*/
104	static int twl4030_rtc_write_u8(u8 data, u8 reg)
105	{
106	int ret;
107
108	ret = twl4030_i2c_write_u8(TWL4030_MODULE_RTC, data, reg);
109	if (ret < 0)
110	pr_err("twl4030_rtc: Could not write TWL4030"
111	"register %X - error %d\n", reg, ret);
112	return ret;
113	}
114
115	/*
116	* Cache the value for timer/alarm interrupts register; this is
117	* only changed by callers holding rtc ops lock (or resume).
118	*/
119	static unsigned char rtc_irq_bits;
120
121	/*
122	* Enable timer and/or alarm interrupts.
123	*/
124	static int set_rtc_irq_bit(unsigned char bit)
125	{
126	unsigned char val;
127	int ret;
128
129	val = rtc_irq_bits \| bit;
130	ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
131	if (ret == 0)
132	rtc_irq_bits = val;
133
134	return ret;
135	}
136
137	/*
138	* Disable timer and/or alarm interrupts.
139	*/
140	static int mask_rtc_irq_bit(unsigned char bit)
141	{
142	unsigned char val;
143	int ret;
144
145	val = rtc_irq_bits & ~bit;
146	ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
147	if (ret == 0)
148	rtc_irq_bits = val;
149
150	return ret;
151	}
152
153	static inline int twl4030_rtc_alarm_irq_set_state(int enabled)
154	{
155	int ret;
156
157	if (enabled)
158	ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
159	else
160	ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
161
162	return ret;
163	}
164
165	static inline int twl4030_rtc_irq_set_state(int enabled)
166	{
167	int ret;
168
169	if (enabled)
170	ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
171	else
172	ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
173
174	return ret;
175	}
176
177	/*
178	* Gets current TWL4030 RTC time and date parameters.
179	*
180	* The RTC's time/alarm representation is not what gmtime(3) requires
181	* Linux to use:
182	*
183	* - Months are 1..12 vs Linux 0-11
184	* - Years are 0..99 vs Linux 1900..N (we assume 21st century)
185	*/
186	static int twl4030_rtc_read_time(struct device dev, struct rtc_time tm)
187	{
188	unsigned char rtc_data[ALL_TIME_REGS + 1];
189	int ret;
190	u8 save_control;
191
192	ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
193	if (ret < 0)
194	return ret;
195
196	save_control \|= BIT_RTC_CTRL_REG_GET_TIME_M;
197
198	ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
199	if (ret < 0)
200	return ret;
201
202	ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
203	REG_SECONDS_REG, ALL_TIME_REGS);
204
205	if (ret < 0) {
206	dev_err(dev, "rtc_read_time error %d\n", ret);
207	return ret;
208	}
209
210	tm->tm_sec = bcd2bin(rtc_data[0]);
211	tm->tm_min = bcd2bin(rtc_data[1]);
212	tm->tm_hour = bcd2bin(rtc_data[2]);
213	tm->tm_mday = bcd2bin(rtc_data[3]);
214	tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
215	tm->tm_year = bcd2bin(rtc_data[5]) + 100;
216
217	return ret;
218	}
219
220	static int twl4030_rtc_set_time(struct device dev, struct rtc_time tm)
221	{
222	unsigned char save_control;
223	unsigned char rtc_data[ALL_TIME_REGS + 1];
224	int ret;
225
226	rtc_data[1] = bin2bcd(tm->tm_sec);
227	rtc_data[2] = bin2bcd(tm->tm_min);
228	rtc_data[3] = bin2bcd(tm->tm_hour);
229	rtc_data[4] = bin2bcd(tm->tm_mday);
230	rtc_data[5] = bin2bcd(tm->tm_mon + 1);
231	rtc_data[6] = bin2bcd(tm->tm_year - 100);
232
233	/* Stop RTC while updating the TC registers */
234	ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
235	if (ret < 0)
236	goto out;
237
238	save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
239	twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
240	if (ret < 0)
241	goto out;
242
243	/* update all the time registers in one shot */
244	ret = twl4030_i2c_write(TWL4030_MODULE_RTC, rtc_data,
245	REG_SECONDS_REG, ALL_TIME_REGS);
246	if (ret < 0) {
247	dev_err(dev, "rtc_set_time error %d\n", ret);
248	goto out;
249	}
250
251	/* Start back RTC */
252	save_control \|= BIT_RTC_CTRL_REG_STOP_RTC_M;
253	ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
254
255	out:
256	return ret;
257	}
258
259	/*
260	* Gets current TWL4030 RTC alarm time.
261	*/
262	static int twl4030_rtc_read_alarm(struct device dev, struct rtc_wkalrm alm)
263	{
264	unsigned char rtc_data[ALL_TIME_REGS + 1];
265	int ret;
266
267	ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
268	REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
269	if (ret < 0) {
270	dev_err(dev, "rtc_read_alarm error %d\n", ret);
271	return ret;
272	}
273
274	/* some of these fields may be wildcard/"match all" */
275	alm->time.tm_sec = bcd2bin(rtc_data[0]);
276	alm->time.tm_min = bcd2bin(rtc_data[1]);
277	alm->time.tm_hour = bcd2bin(rtc_data[2]);
278	alm->time.tm_mday = bcd2bin(rtc_data[3]);
279	alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
280	alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;
281
282	/* report cached alarm enable state */
283	if (rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
284	alm->enabled = 1;
285
286	return ret;
287	}
288
289	static int twl4030_rtc_set_alarm(struct device dev, struct rtc_wkalrm alm)
290	{
291	unsigned char alarm_data[ALL_TIME_REGS + 1];
292	int ret;
293
294	ret = twl4030_rtc_alarm_irq_set_state(0);
295	if (ret)
296	goto out;
297
298	alarm_data[1] = bin2bcd(alm->time.tm_sec);
299	alarm_data[2] = bin2bcd(alm->time.tm_min);
300	alarm_data[3] = bin2bcd(alm->time.tm_hour);
301	alarm_data[4] = bin2bcd(alm->time.tm_mday);
302	alarm_data[5] = bin2bcd(alm->time.tm_mon + 1);
303	alarm_data[6] = bin2bcd(alm->time.tm_year - 100);
304
305	/* update all the alarm registers in one shot */
306	ret = twl4030_i2c_write(TWL4030_MODULE_RTC, alarm_data,
307	REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
308	if (ret) {
309	dev_err(dev, "rtc_set_alarm error %d\n", ret);
310	goto out;
311	}
312
313	if (alm->enabled)
314	ret = twl4030_rtc_alarm_irq_set_state(1);
315	out:
316	return ret;
317	}
318
319	#ifdef CONFIG_RTC_INTF_DEV
320
321	static int twl4030_rtc_ioctl(struct device *dev, unsigned int cmd,
322	unsigned long arg)
323	{
324	switch (cmd) {
325	case RTC_AIE_OFF:
326	return twl4030_rtc_alarm_irq_set_state(0);
327	case RTC_AIE_ON:
328	return twl4030_rtc_alarm_irq_set_state(1);
329	case RTC_UIE_OFF:
330	return twl4030_rtc_irq_set_state(0);
331	case RTC_UIE_ON:
332	return twl4030_rtc_irq_set_state(1);
333
334	default:
335	return -ENOIOCTLCMD;
336	}
337	}
338
339	#else
cc616860	340	#define twl4030_rtc_ioctl NULL
f96411ab DB	341	#endif
	342
	343	static irqreturn_t twl4030_rtc_interrupt(int irq, void *rtc)
	344	{
	345	unsigned long events = 0;
	346	int ret = IRQ_NONE;
	347	int res;
	348	u8 rd_reg;
	349
	350	#ifdef CONFIG_LOCKDEP
	351	/* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
	352	* we don't want and can't tolerate. Although it might be
	353	* friendlier not to borrow this thread context...
	354	*/
	355	local_irq_enable();
	356	#endif
	357
	358	res = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
	359	if (res)
	360	goto out;
	361	/*
	362	* Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
	363	* only one (ALARM or RTC) interrupt source may be enabled
	364	* at time, we also could check our results
	365	* by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
	366	*/
	367	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
	368	events \|= RTC_IRQF \| RTC_AF;
	369	else
	370	events \|= RTC_IRQF \| RTC_UF;
	371
	372	res = twl4030_rtc_write_u8(rd_reg \| BIT_RTC_STATUS_REG_ALARM_M,
	373	REG_RTC_STATUS_REG);
	374	if (res)
	375	goto out;
	376
	377	/* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
	378	* needs 2 reads to clear the interrupt. One read is done in
	379	* do_twl4030_pwrirq(). Doing the second read, to clear
	380	* the bit.
	381	*
	382	* FIXME the reason PWR_ISR1 needs an extra read is that
	383	* RTC_IF retriggered until we cleared REG_ALARM_M above.
	384	* But re-reading like this is a bad hack; by doing so we
	385	* risk wrongly clearing status for some other IRQ (losing
	386	* the interrupt). Be smarter about handling RTC_UF ...
	387	*/
	388	res = twl4030_i2c_read_u8(TWL4030_MODULE_INT,
	389	&rd_reg, TWL4030_INT_PWR_ISR1);
	390	if (res)
	391	goto out;
	392
	393	/* Notify RTC core on event */
	394	rtc_update_irq(rtc, 1, events);
	395
	396	ret = IRQ_HANDLED;
	397	out:
	398	return ret;
	399	}
	400
	401	static struct rtc_class_ops twl4030_rtc_ops = {
	402	.ioctl = twl4030_rtc_ioctl,
	403	.read_time = twl4030_rtc_read_time,
	404	.set_time = twl4030_rtc_set_time,
405	.read_alarm = twl4030_rtc_read_alarm,
406	.set_alarm = twl4030_rtc_set_alarm,
407	};
408
409	/----------------------------------------------------------------------/
410
411	static int __devinit twl4030_rtc_probe(struct platform_device *pdev)
412	{
413	struct rtc_device *rtc;
414	int ret = 0;
415	int irq = platform_get_irq(pdev, 0);
416	u8 rd_reg;
417
418	if (irq < 0)
419	return irq;
420
421	rtc = rtc_device_register(pdev->name,
422	&pdev->dev, &twl4030_rtc_ops, THIS_MODULE);
423	if (IS_ERR(rtc)) {
424	ret = -EINVAL;
425	dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
426	PTR_ERR(rtc));
427	goto out0;
428
429	}
430
431	platform_set_drvdata(pdev, rtc);
432
433	ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
434
435	if (ret < 0)
436	goto out1;
437
438	if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
439	dev_warn(&pdev->dev, "Power up reset detected.\n");
440
441	if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
442	dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
443
444	/* Clear RTC Power up reset and pending alarm interrupts */
445	ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_STATUS_REG);
446	if (ret < 0)
447	goto out1;
448
449	ret = request_irq(irq, twl4030_rtc_interrupt,
450	IRQF_TRIGGER_RISING,
451	rtc->dev.bus_id, rtc);
452	if (ret < 0) {
453	dev_err(&pdev->dev, "IRQ is not free.\n");
454	goto out1;
455	}
456
457	/* Check RTC module status, Enable if it is off */
458	ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_CTRL_REG);
459	if (ret < 0)
460	goto out2;
461
462	if (!(rd_reg & BIT_RTC_CTRL_REG_STOP_RTC_M)) {
463	dev_info(&pdev->dev, "Enabling TWL4030-RTC.\n");
464	rd_reg = BIT_RTC_CTRL_REG_STOP_RTC_M;
465	ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_CTRL_REG);
466	if (ret < 0)
467	goto out2;
468	}
469
470	/* init cached IRQ enable bits */
471	ret = twl4030_rtc_read_u8(&rtc_irq_bits, REG_RTC_INTERRUPTS_REG);
472	if (ret < 0)
473	goto out2;
474
475	return ret;
476
477
478	out2:
479	free_irq(irq, rtc);
480	out1:
481	rtc_device_unregister(rtc);
482	out0:
483	return ret;
484	}
485
486	/*
487	* Disable all TWL4030 RTC module interrupts.
488	* Sets status flag to free.
489	*/
490	static int __devexit twl4030_rtc_remove(struct platform_device *pdev)
491	{
492	/* leave rtc running, but disable irqs */
493	struct rtc_device *rtc = platform_get_drvdata(pdev);
494	int irq = platform_get_irq(pdev, 0);
495
496	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
497	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
498
499	free_irq(irq, rtc);
500
501	rtc_device_unregister(rtc);
502	platform_set_drvdata(pdev, NULL);
503	return 0;
504	}
505
506	static void twl4030_rtc_shutdown(struct platform_device *pdev)
507	{
508	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M \|
509	BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
510	}
511
512	#ifdef CONFIG_PM
513
514	static unsigned char irqstat;
515
516	static int twl4030_rtc_suspend(struct platform_device *pdev, pm_message_t state)
517	{
518	irqstat = rtc_irq_bits;
519
520	/* REVISIT alarm may need to wake us from sleep */
521	mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M \|
522	BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
523	return 0;
524	}
525
526	static int twl4030_rtc_resume(struct platform_device *pdev)
527	{
528	set_rtc_irq_bit(irqstat);
529	return 0;
530	}
531
532	#else
533	#define twl4030_rtc_suspend NULL
534	#define twl4030_rtc_resume NULL
535	#endif
536
537	MODULE_ALIAS("platform:twl4030_rtc");
538
539	static struct platform_driver twl4030rtc_driver = {
540	.probe = twl4030_rtc_probe,
541	.remove = __devexit_p(twl4030_rtc_remove),
542	.shutdown = twl4030_rtc_shutdown,
543	.suspend = twl4030_rtc_suspend,
544	.resume = twl4030_rtc_resume,
545	.driver = {
546	.owner = THIS_MODULE,
547	.name = "twl4030_rtc",
548	},
549	};
550
551	static int __init twl4030_rtc_init(void)
552	{
553	return platform_driver_register(&twl4030rtc_driver);
554	}
555	module_init(twl4030_rtc_init);
556
557	static void __exit twl4030_rtc_exit(void)
558	{
559	platform_driver_unregister(&twl4030rtc_driver);
560	}
561	module_exit(twl4030_rtc_exit);
562
563	MODULE_AUTHOR("Texas Instruments, MontaVista Software");
564	MODULE_LICENSE("GPL");