// SPDX-License-Identifier: GPL-2.0-only/* * Copyright (C) ST-Ericsson SA 2010 * * Author: Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com> * * RTC clock driver for the RTC part of the AB8500 Power management chip. * Based on RTC clock driver for the AB3100 Analog Baseband Chip by * Linus Walleij <linus.walleij@stericsson.com> */ #include <linux/module.h>#include <linux/kernel.h>#include <linux/init.h>#include <linux/platform_device.h>#include <linux/rtc.h>#include <linux/mfd/abx500.h>#include <linux/mfd/abx500/ab8500.h>#include <linux/delay.h>#include <linux/of.h>#include <linux/pm_wakeirq.h> #define AB8500_RTC_SOFF_STAT_REG	0x00#define AB8500_RTC_CC_CONF_REG		0x01#define AB8500_RTC_READ_REQ_REG		0x02#define AB8500_RTC_WATCH_TSECMID_REG	0x03#define AB8500_RTC_WATCH_TSECHI_REG	0x04#define AB8500_RTC_WATCH_TMIN_LOW_REG	0x05#define AB8500_RTC_WATCH_TMIN_MID_REG	0x06#define AB8500_RTC_WATCH_TMIN_HI_REG	0x07#define AB8500_RTC_ALRM_MIN_LOW_REG	0x08#define AB8500_RTC_ALRM_MIN_MID_REG	0x09#define AB8500_RTC_ALRM_MIN_HI_REG	0x0A#define AB8500_RTC_STAT_REG		0x0B#define AB8500_RTC_BKUP_CHG_REG		0x0C#define AB8500_RTC_FORCE_BKUP_REG	0x0D#define AB8500_RTC_CALIB_REG		0x0E#define AB8500_RTC_SWITCH_STAT_REG	0x0F /* RtcReadRequest bits */#define RTC_READ_REQUEST		0x01#define RTC_WRITE_REQUEST		0x02 /* RtcCtrl bits */#define RTC_ALARM_ENA			0x04#define RTC_STATUS_DATA			0x01 #define COUNTS_PER_SEC			(0xF000 / 60) static const u8 ab8500_rtc_time_regs[] = {	AB8500_RTC_WATCH_TMIN_HI_REG, AB8500_RTC_WATCH_TMIN_MID_REG,	AB8500_RTC_WATCH_TMIN_LOW_REG, AB8500_RTC_WATCH_TSECHI_REG,	AB8500_RTC_WATCH_TSECMID_REG}; static const u8 ab8500_rtc_alarm_regs[] = {	AB8500_RTC_ALRM_MIN_HI_REG, AB8500_RTC_ALRM_MIN_MID_REG,	AB8500_RTC_ALRM_MIN_LOW_REG}; static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm){	unsigned long timeout = jiffies + HZ;	int retval, i;	unsigned long mins, secs;	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];	u8 value; 	/* Request a data read */	retval = abx500_set_register_interruptible(dev,		AB8500_RTC, AB8500_RTC_READ_REQ_REG, RTC_READ_REQUEST);	if (retval < 0)		return retval; 	/* Wait for some cycles after enabling the rtc read in ab8500 */	while (time_before(jiffies, timeout)) {		retval = abx500_get_register_interruptible(dev,			AB8500_RTC, AB8500_RTC_READ_REQ_REG, &value);		if (retval < 0)			return retval; 		if (!(value & RTC_READ_REQUEST))			break; 		usleep_range(1000, 5000);	} 	/* Read the Watchtime registers */	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {		retval = abx500_get_register_interruptible(dev,			AB8500_RTC, ab8500_rtc_time_regs[i], &value);		if (retval < 0)			return retval;		buf[i] = value;	} 	mins = (buf[0] << 16) | (buf[1] << 8) | buf[2]; 	secs =	(buf[3] << 8) | buf[4];	secs =	secs / COUNTS_PER_SEC;	secs =	secs + (mins * 60); 	rtc_time64_to_tm(secs, tm);	return 0;} static int ab8500_rtc_set_time(struct device *dev, struct rtc_time *tm){	int retval, i;	unsigned char buf[ARRAY_SIZE(ab8500_rtc_time_regs)];	unsigned long no_secs, no_mins, secs = 0; 	secs = rtc_tm_to_time64(tm); 	no_mins = secs / 60; 	no_secs = secs % 60;	/* Make the seconds count as per the RTC resolution */	no_secs = no_secs * COUNTS_PER_SEC; 	buf[4] = no_secs & 0xFF;	buf[3] = (no_secs >> 8) & 0xFF; 	buf[2] = no_mins & 0xFF;	buf[1] = (no_mins >> 8) & 0xFF;	buf[0] = (no_mins >> 16) & 0xFF; 	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_time_regs); i++) {		retval = abx500_set_register_interruptible(dev, AB8500_RTC,			ab8500_rtc_time_regs[i], buf[i]);		if (retval < 0)			return retval;	} 	/* Request a data write */	return abx500_set_register_interruptible(dev, AB8500_RTC,		AB8500_RTC_READ_REQ_REG, RTC_WRITE_REQUEST);} static int ab8500_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm){	int retval, i;	u8 rtc_ctrl, value;	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];	unsigned long secs, mins; 	/* Check if the alarm is enabled or not */	retval = abx500_get_register_interruptible(dev, AB8500_RTC,		AB8500_RTC_STAT_REG, &rtc_ctrl);	if (retval < 0)		return retval; 	if (rtc_ctrl & RTC_ALARM_ENA)		alarm->enabled = 1;	else		alarm->enabled = 0; 	alarm->pending = 0; 	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {		retval = abx500_get_register_interruptible(dev, AB8500_RTC,			ab8500_rtc_alarm_regs[i], &value);		if (retval < 0)			return retval;		buf[i] = value;	} 	mins = (buf[0] << 16) | (buf[1] << 8) | (buf[2]);	secs = mins * 60; 	rtc_time64_to_tm(secs, &alarm->time); 	return 0;} static int ab8500_rtc_irq_enable(struct device *dev, unsigned int enabled){	return abx500_mask_and_set_register_interruptible(dev, AB8500_RTC,		AB8500_RTC_STAT_REG, RTC_ALARM_ENA,		enabled ? RTC_ALARM_ENA : 0);} static int ab8500_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm){	int retval, i;	unsigned char buf[ARRAY_SIZE(ab8500_rtc_alarm_regs)];	unsigned long mins; 	mins = (unsigned long)rtc_tm_to_time64(&alarm->time) / 60; 	buf[2] = mins & 0xFF;	buf[1] = (mins >> 8) & 0xFF;	buf[0] = (mins >> 16) & 0xFF; 	/* Set the alarm time */	for (i = 0; i < ARRAY_SIZE(ab8500_rtc_alarm_regs); i++) {		retval = abx500_set_register_interruptible(dev, AB8500_RTC,			ab8500_rtc_alarm_regs[i], buf[i]);		if (retval < 0)			return retval;	} 	return ab8500_rtc_irq_enable(dev, alarm->enabled);} static int ab8500_rtc_set_calibration(struct device *dev, int calibration){	int retval;	u8  rtccal = 0; 	/*	 * Check that the calibration value (which is in units of 0.5	 * parts-per-million) is in the AB8500's range for RtcCalibration	 * register. -128 (0x80) is not permitted because the AB8500 uses	 * a sign-bit rather than two's complement, so 0x80 is just another	 * representation of zero.	 */	if ((calibration < -127) || (calibration > 127)) {		dev_err(dev, "RtcCalibration value outside permitted range\n");		return -EINVAL;	} 	/*	 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)	 * so need to convert to this sort of representation before writing	 * into RtcCalibration register...	 */	if (calibration >= 0)		rtccal = 0x7F & calibration;	else		rtccal = ~(calibration - 1) | 0x80; 	retval = abx500_set_register_interruptible(dev, AB8500_RTC,			AB8500_RTC_CALIB_REG, rtccal); 	return retval;} static int ab8500_rtc_get_calibration(struct device *dev, int *calibration){	int retval;	u8  rtccal = 0; 	retval =  abx500_get_register_interruptible(dev, AB8500_RTC,			AB8500_RTC_CALIB_REG, &rtccal);	if (retval >= 0) {		/*		 * The AB8500 uses sign (in bit7) and magnitude (in bits0-7)		 * so need to convert value from RtcCalibration register into		 * a two's complement signed value...		 */		if (rtccal & 0x80)			*calibration = 0 - (rtccal & 0x7F);		else			*calibration = 0x7F & rtccal;	} 	return retval;} static ssize_t ab8500_sysfs_store_rtc_calibration(struct device *dev,				struct device_attribute *attr,				const char *buf, size_t count){	int retval;	int calibration = 0; 	if (sscanf(buf, " %i ", &calibration) != 1) {		dev_err(dev, "Failed to store RTC calibration attribute\n");		return -EINVAL;	} 	retval = ab8500_rtc_set_calibration(dev, calibration); 	return retval ? retval : count;} static ssize_t ab8500_sysfs_show_rtc_calibration(struct device *dev,				struct device_attribute *attr, char *buf){	int  retval = 0;	int  calibration = 0; 	retval = ab8500_rtc_get_calibration(dev, &calibration);	if (retval < 0) {		dev_err(dev, "Failed to read RTC calibration attribute\n");		return retval;	} 	return sysfs_emit(buf, "%d\n", calibration);} static DEVICE_ATTR(rtc_calibration, S_IRUGO | S_IWUSR,		   ab8500_sysfs_show_rtc_calibration,		   ab8500_sysfs_store_rtc_calibration); static struct attribute *ab8500_rtc_attrs[] = {	&dev_attr_rtc_calibration.attr,	NULL}; static const struct attribute_group ab8500_rtc_sysfs_files = {	.attrs	= ab8500_rtc_attrs,}; static irqreturn_t rtc_alarm_handler(int irq, void *data){	struct rtc_device *rtc = data;	unsigned long events = RTC_IRQF | RTC_AF; 	dev_dbg(&rtc->dev, "%s\n", __func__);	rtc_update_irq(rtc, 1, events); 	return IRQ_HANDLED;} static const struct rtc_class_ops ab8500_rtc_ops = {	.read_time		= ab8500_rtc_read_time,	.set_time		= ab8500_rtc_set_time,	.read_alarm		= ab8500_rtc_read_alarm,	.set_alarm		= ab8500_rtc_set_alarm,	.alarm_irq_enable	= ab8500_rtc_irq_enable,}; static const struct platform_device_id ab85xx_rtc_ids[] = {	{ .name = "ab8500-rtc" },	{ /* sentinel */ }};MODULE_DEVICE_TABLE(platform, ab85xx_rtc_ids); static int ab8500_rtc_probe(struct platform_device *pdev){	int err;	struct rtc_device *rtc;	u8 rtc_ctrl;	int irq; 	irq = platform_get_irq_byname(pdev, "ALARM");	if (irq < 0)		return irq; 	/* For RTC supply test */	err = abx500_mask_and_set_register_interruptible(&pdev->dev, AB8500_RTC,		AB8500_RTC_STAT_REG, RTC_STATUS_DATA, RTC_STATUS_DATA);	if (err < 0)		return err; 	/* Wait for reset by the PorRtc */	usleep_range(1000, 5000); 	err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,		AB8500_RTC_STAT_REG, &rtc_ctrl);	if (err < 0)		return err; 	/* Check if the RTC Supply fails */	if (!(rtc_ctrl & RTC_STATUS_DATA)) {		dev_err(&pdev->dev, "RTC supply failure\n");		return -ENODEV;	} 	devm_device_init_wakeup(&pdev->dev); 	rtc = devm_rtc_allocate_device(&pdev->dev);	if (IS_ERR(rtc))		return PTR_ERR(rtc); 	rtc->ops = &ab8500_rtc_ops; 	err = devm_request_threaded_irq(&pdev->dev, irq, NULL,			rtc_alarm_handler, IRQF_ONESHOT,			"ab8500-rtc", rtc);	if (err < 0)		return err; 	devm_pm_set_wake_irq(&pdev->dev, irq);	platform_set_drvdata(pdev, rtc); 	set_bit(RTC_FEATURE_ALARM_RES_MINUTE, rtc->features);	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features); 	rtc->range_max = (1ULL << 24) * 60 - 1; // 24-bit minutes + 59 secs	rtc->start_secs = RTC_TIMESTAMP_BEGIN_2000;	rtc->set_start_time = true; 	err = rtc_add_group(rtc, &ab8500_rtc_sysfs_files);	if (err)		return err; 	return devm_rtc_register_device(rtc);} static struct platform_driver ab8500_rtc_driver = {	.driver = {		.name = "ab8500-rtc",	},	.probe	= ab8500_rtc_probe,	.id_table = ab85xx_rtc_ids,}; module_platform_driver(ab8500_rtc_driver); MODULE_AUTHOR("Virupax Sadashivpetimath <virupax.sadashivpetimath@stericsson.com>");MODULE_DESCRIPTION("AB8500 RTC Driver");MODULE_LICENSE("GPL v2");