[mirror_ubuntu-jammy-kernel.git] / drivers / rtc / rtc-stk17ta8.c

/*
 * A RTC driver for the Simtek STK17TA8
 *
 * By Thomas Hommel <thomas.hommel@ge.com>
 *
 * Based on the DS1553 driver from
 * Atsushi Nemoto <anemo@mba.ocn.ne.jp>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/bcd.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/delay.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/module.h>

#define RTC_REG_SIZE		0x20000
#define RTC_OFFSET		0x1fff0

#define RTC_FLAGS		(RTC_OFFSET + 0)
#define RTC_CENTURY		(RTC_OFFSET + 1)
#define RTC_SECONDS_ALARM	(RTC_OFFSET + 2)
#define RTC_MINUTES_ALARM	(RTC_OFFSET + 3)
#define RTC_HOURS_ALARM		(RTC_OFFSET + 4)
#define RTC_DATE_ALARM		(RTC_OFFSET + 5)
#define RTC_INTERRUPTS		(RTC_OFFSET + 6)
#define RTC_WATCHDOG		(RTC_OFFSET + 7)
#define RTC_CALIBRATION		(RTC_OFFSET + 8)
#define RTC_SECONDS		(RTC_OFFSET + 9)
#define RTC_MINUTES		(RTC_OFFSET + 10)
#define RTC_HOURS		(RTC_OFFSET + 11)
#define RTC_DAY			(RTC_OFFSET + 12)
#define RTC_DATE		(RTC_OFFSET + 13)
#define RTC_MONTH		(RTC_OFFSET + 14)
#define RTC_YEAR		(RTC_OFFSET + 15)

#define RTC_SECONDS_MASK	0x7f
#define RTC_DAY_MASK		0x07
#define RTC_CAL_MASK		0x3f

/* Bits in the Calibration register */
#define RTC_STOP		0x80

/* Bits in the Flags register */
#define RTC_FLAGS_AF		0x40
#define RTC_FLAGS_PF		0x20
#define RTC_WRITE		0x02
#define RTC_READ		0x01

/* Bits in the Interrupts register */
#define RTC_INTS_AIE		0x40

struct rtc_plat_data {
	struct rtc_device *rtc;
	void __iomem *ioaddr;
	unsigned long last_jiffies;
	int irq;
	unsigned int irqen;
	int alrm_sec;
	int alrm_min;
	int alrm_hour;
	int alrm_mday;
	spinlock_t lock;
};

static int stk17ta8_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
	void __iomem *ioaddr = pdata->ioaddr;
	u8 flags;

	flags = readb(pdata->ioaddr + RTC_FLAGS);
	writeb(flags | RTC_WRITE, pdata->ioaddr + RTC_FLAGS);

	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
	writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);

	writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
	return 0;
}

static int stk17ta8_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
	void __iomem *ioaddr = pdata->ioaddr;
	unsigned int year, month, day, hour, minute, second, week;
	unsigned int century;
	u8 flags;

	/* give enough time to update RTC in case of continuous read */
	if (pdata->last_jiffies == jiffies)
		msleep(1);
	pdata->last_jiffies = jiffies;

	flags = readb(pdata->ioaddr + RTC_FLAGS);
	writeb(flags | RTC_READ, ioaddr + RTC_FLAGS);
	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	minute = readb(ioaddr + RTC_MINUTES);
	hour = readb(ioaddr + RTC_HOURS);
	day = readb(ioaddr + RTC_DATE);
	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	month = readb(ioaddr + RTC_MONTH);
	year = readb(ioaddr + RTC_YEAR);
	century = readb(ioaddr + RTC_CENTURY);
	writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
	tm->tm_sec = bcd2bin(second);
	tm->tm_min = bcd2bin(minute);
	tm->tm_hour = bcd2bin(hour);
	tm->tm_mday = bcd2bin(day);
	tm->tm_wday = bcd2bin(week);
	tm->tm_mon = bcd2bin(month) - 1;
	/* year is 1900 + tm->tm_year */
	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;

	return 0;
}

static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
{
	void __iomem *ioaddr = pdata->ioaddr;
	unsigned long irqflags;
	u8 flags;

	spin_lock_irqsave(&pdata->lock, irqflags);

	flags = readb(ioaddr + RTC_FLAGS);
	writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);

	writeb(pdata->alrm_mday < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_mday),
	       ioaddr + RTC_DATE_ALARM);
	writeb(pdata->alrm_hour < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_hour),
	       ioaddr + RTC_HOURS_ALARM);
	writeb(pdata->alrm_min < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_min),
	       ioaddr + RTC_MINUTES_ALARM);
	writeb(pdata->alrm_sec < 0 || (pdata->irqen & RTC_UF) ?
	       0x80 : bin2bcd(pdata->alrm_sec),
	       ioaddr + RTC_SECONDS_ALARM);
	writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
	readb(ioaddr + RTC_FLAGS);	/* clear interrupts */
	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
	spin_unlock_irqrestore(&pdata->lock, irqflags);
}

static int stk17ta8_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct rtc_plat_data *pdata = dev_get_drvdata(dev);

	if (pdata->irq <= 0)
		return -EINVAL;
	pdata->alrm_mday = alrm->time.tm_mday;
	pdata->alrm_hour = alrm->time.tm_hour;
	pdata->alrm_min = alrm->time.tm_min;
	pdata->alrm_sec = alrm->time.tm_sec;
	if (alrm->enabled)
		pdata->irqen |= RTC_AF;
	stk17ta8_rtc_update_alarm(pdata);
	return 0;
}

static int stk17ta8_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
{
	struct rtc_plat_data *pdata = dev_get_drvdata(dev);

	if (pdata->irq <= 0)
		return -EINVAL;
	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	return 0;
}

static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
{
	struct platform_device *pdev = dev_id;
	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	void __iomem *ioaddr = pdata->ioaddr;
	unsigned long events = 0;

	spin_lock(&pdata->lock);
	/* read and clear interrupt */
	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
		events = RTC_IRQF;
		if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
			events |= RTC_UF;
		else
			events |= RTC_AF;
		rtc_update_irq(pdata->rtc, 1, events);
	}
	spin_unlock(&pdata->lock);
	return events ? IRQ_HANDLED : IRQ_NONE;
}

static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
	unsigned int enabled)
{
	struct rtc_plat_data *pdata = dev_get_drvdata(dev);

	if (pdata->irq <= 0)
		return -EINVAL;
	if (enabled)
		pdata->irqen |= RTC_AF;
	else
		pdata->irqen &= ~RTC_AF;
	stk17ta8_rtc_update_alarm(pdata);
	return 0;
}

static const struct rtc_class_ops stk17ta8_rtc_ops = {
	.read_time		= stk17ta8_rtc_read_time,
	.set_time		= stk17ta8_rtc_set_time,
	.read_alarm		= stk17ta8_rtc_read_alarm,
	.set_alarm		= stk17ta8_rtc_set_alarm,
	.alarm_irq_enable	= stk17ta8_rtc_alarm_irq_enable,
};

static int stk17ta8_nvram_read(void *priv, unsigned int pos, void *val,
			       size_t bytes)
{
	struct rtc_plat_data *pdata = priv;
	void __iomem *ioaddr = pdata->ioaddr;
	u8 *buf = val;

	for (; bytes; bytes--)
		*buf++ = readb(ioaddr + pos++);
	return 0;
}

static int stk17ta8_nvram_write(void *priv, unsigned int pos, void *val,
				size_t bytes)
{
	struct rtc_plat_data *pdata = priv;
	void __iomem *ioaddr = pdata->ioaddr;
	u8 *buf = val;

	for (; bytes; bytes--)
		writeb(*buf++, ioaddr + pos++);
	return 0;
}

static int stk17ta8_rtc_probe(struct platform_device *pdev)
{
	struct resource *res;
	unsigned int cal;
	unsigned int flags;
	struct rtc_plat_data *pdata;
	void __iomem *ioaddr;
	int ret = 0;
	struct nvmem_config nvmem_cfg = {
		.name = "stk17ta8_nvram",
		.word_size = 1,
		.stride = 1,
		.size = RTC_OFFSET,
		.reg_read = stk17ta8_nvram_read,
		.reg_write = stk17ta8_nvram_write,
	};

	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
		return -ENOMEM;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	ioaddr = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(ioaddr))
		return PTR_ERR(ioaddr);
	pdata->ioaddr = ioaddr;
	pdata->irq = platform_get_irq(pdev, 0);

	/* turn RTC on if it was not on */
	cal = readb(ioaddr + RTC_CALIBRATION);
	if (cal & RTC_STOP) {
		cal &= RTC_CAL_MASK;
		flags = readb(ioaddr + RTC_FLAGS);
		writeb(flags | RTC_WRITE, ioaddr + RTC_FLAGS);
		writeb(cal, ioaddr + RTC_CALIBRATION);
		writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
	}
	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
		dev_warn(&pdev->dev, "voltage-low detected.\n");

	spin_lock_init(&pdata->lock);
	pdata->last_jiffies = jiffies;
	platform_set_drvdata(pdev, pdata);
	if (pdata->irq > 0) {
		writeb(0, ioaddr + RTC_INTERRUPTS);
		if (devm_request_irq(&pdev->dev, pdata->irq,
				stk17ta8_rtc_interrupt,
				IRQF_SHARED,
				pdev->name, pdev) < 0) {
			dev_warn(&pdev->dev, "interrupt not available.\n");
			pdata->irq = 0;
		}
	}

	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
	if (IS_ERR(pdata->rtc))
		return PTR_ERR(pdata->rtc);

	pdata->rtc->ops = &stk17ta8_rtc_ops;
	pdata->rtc->nvram_old_abi = true;

	nvmem_cfg.priv = pdata;
	ret = rtc_nvmem_register(pdata->rtc, &nvmem_cfg);
	if (ret)
		return ret;

	return rtc_register_device(pdata->rtc);
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:stk17ta8");

static struct platform_driver stk17ta8_rtc_driver = {
	.probe		= stk17ta8_rtc_probe,
	.driver		= {
		.name	= "stk17ta8",
	},
};

module_platform_driver(stk17ta8_rtc_driver);

MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>");
MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
02964115 TH	1	/*
	2	* A RTC driver for the Simtek STK17TA8
	3	*
ab4364d3	4	* By Thomas Hommel <thomas.hommel@ge.com>
02964115 TH	5	*
	6	* Based on the DS1553 driver from
	7	* Atsushi Nemoto <anemo@mba.ocn.ne.jp>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/bcd.h>
	15	#include <linux/init.h>
	16	#include <linux/kernel.h>
5a0e3ad6	17	#include <linux/gfp.h>
02964115 TH	18	#include <linux/delay.h>
	19	#include <linux/jiffies.h>
	20	#include <linux/interrupt.h>
	21	#include <linux/rtc.h>
	22	#include <linux/platform_device.h>
	23	#include <linux/io.h>
2113852b	24	#include <linux/module.h>
02964115	25
02964115 TH	26	#define RTC_REG_SIZE 0x20000
	27	#define RTC_OFFSET 0x1fff0
	28
	29	#define RTC_FLAGS (RTC_OFFSET + 0)
	30	#define RTC_CENTURY (RTC_OFFSET + 1)
	31	#define RTC_SECONDS_ALARM (RTC_OFFSET + 2)
	32	#define RTC_MINUTES_ALARM (RTC_OFFSET + 3)
	33	#define RTC_HOURS_ALARM (RTC_OFFSET + 4)
	34	#define RTC_DATE_ALARM (RTC_OFFSET + 5)
	35	#define RTC_INTERRUPTS (RTC_OFFSET + 6)
	36	#define RTC_WATCHDOG (RTC_OFFSET + 7)
	37	#define RTC_CALIBRATION (RTC_OFFSET + 8)
	38	#define RTC_SECONDS (RTC_OFFSET + 9)
	39	#define RTC_MINUTES (RTC_OFFSET + 10)
	40	#define RTC_HOURS (RTC_OFFSET + 11)
	41	#define RTC_DAY (RTC_OFFSET + 12)
	42	#define RTC_DATE (RTC_OFFSET + 13)
	43	#define RTC_MONTH (RTC_OFFSET + 14)
	44	#define RTC_YEAR (RTC_OFFSET + 15)
	45
	46	#define RTC_SECONDS_MASK 0x7f
	47	#define RTC_DAY_MASK 0x07
	48	#define RTC_CAL_MASK 0x3f
	49
	50	/* Bits in the Calibration register */
	51	#define RTC_STOP 0x80
	52
	53	/* Bits in the Flags register */
	54	#define RTC_FLAGS_AF 0x40
	55	#define RTC_FLAGS_PF 0x20
	56	#define RTC_WRITE 0x02
	57	#define RTC_READ 0x01
	58
	59	/* Bits in the Interrupts register */
	60	#define RTC_INTS_AIE 0x40
	61
	62	struct rtc_plat_data {
	63	struct rtc_device *rtc;
	64	void __iomem *ioaddr;
02964115 TH	65	unsigned long last_jiffies;
	66	int irq;
	67	unsigned int irqen;
	68	int alrm_sec;
	69	int alrm_min;
	70	int alrm_hour;
	71	int alrm_mday;
3151520d	72	spinlock_t lock;
02964115 TH	73	};
	74
	75	static int stk17ta8_rtc_set_time(struct device dev, struct rtc_time tm)
	76	{
85368bb9	77	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
02964115 TH	78	void __iomem *ioaddr = pdata->ioaddr;
	79	u8 flags;
	80
	81	flags = readb(pdata->ioaddr + RTC_FLAGS);
	82	writeb(flags \| RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
	83
fe20ba70 AB	84	writeb(bin2bcd(tm->tm_year % 100), ioaddr + RTC_YEAR);
	85	writeb(bin2bcd(tm->tm_mon + 1), ioaddr + RTC_MONTH);
	86	writeb(bin2bcd(tm->tm_wday) & RTC_DAY_MASK, ioaddr + RTC_DAY);
	87	writeb(bin2bcd(tm->tm_mday), ioaddr + RTC_DATE);
	88	writeb(bin2bcd(tm->tm_hour), ioaddr + RTC_HOURS);
	89	writeb(bin2bcd(tm->tm_min), ioaddr + RTC_MINUTES);
	90	writeb(bin2bcd(tm->tm_sec) & RTC_SECONDS_MASK, ioaddr + RTC_SECONDS);
	91	writeb(bin2bcd((tm->tm_year + 1900) / 100), ioaddr + RTC_CENTURY);
02964115 TH	92
	93	writeb(flags & ~RTC_WRITE, pdata->ioaddr + RTC_FLAGS);
	94	return 0;
	95	}
	96
	97	static int stk17ta8_rtc_read_time(struct device dev, struct rtc_time tm)
	98	{
85368bb9	99	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
02964115 TH	100	void __iomem *ioaddr = pdata->ioaddr;
	101	unsigned int year, month, day, hour, minute, second, week;
	102	unsigned int century;
	103	u8 flags;
	104
	105	/* give enough time to update RTC in case of continuous read */
	106	if (pdata->last_jiffies == jiffies)
	107	msleep(1);
	108	pdata->last_jiffies = jiffies;
	109
	110	flags = readb(pdata->ioaddr + RTC_FLAGS);
	111	writeb(flags \| RTC_READ, ioaddr + RTC_FLAGS);
	112	second = readb(ioaddr + RTC_SECONDS) & RTC_SECONDS_MASK;
	113	minute = readb(ioaddr + RTC_MINUTES);
	114	hour = readb(ioaddr + RTC_HOURS);
	115	day = readb(ioaddr + RTC_DATE);
	116	week = readb(ioaddr + RTC_DAY) & RTC_DAY_MASK;
	117	month = readb(ioaddr + RTC_MONTH);
	118	year = readb(ioaddr + RTC_YEAR);
	119	century = readb(ioaddr + RTC_CENTURY);
	120	writeb(flags & ~RTC_READ, ioaddr + RTC_FLAGS);
fe20ba70 AB	121	tm->tm_sec = bcd2bin(second);
	122	tm->tm_min = bcd2bin(minute);
	123	tm->tm_hour = bcd2bin(hour);
	124	tm->tm_mday = bcd2bin(day);
	125	tm->tm_wday = bcd2bin(week);
	126	tm->tm_mon = bcd2bin(month) - 1;
02964115	127	/* year is 1900 + tm->tm_year */
fe20ba70	128	tm->tm_year = bcd2bin(year) + bcd2bin(century) * 100 - 1900;
02964115	129
02964115 TH	130	return 0;
	131	}
	132
	133	static void stk17ta8_rtc_update_alarm(struct rtc_plat_data *pdata)
	134	{
	135	void __iomem *ioaddr = pdata->ioaddr;
	136	unsigned long irqflags;
	137	u8 flags;
	138
3151520d	139	spin_lock_irqsave(&pdata->lock, irqflags);
02964115 TH	140
	141	flags = readb(ioaddr + RTC_FLAGS);
	142	writeb(flags \| RTC_WRITE, ioaddr + RTC_FLAGS);
	143
	144	writeb(pdata->alrm_mday < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	145	0x80 : bin2bcd(pdata->alrm_mday),
02964115 TH	146	ioaddr + RTC_DATE_ALARM);
02964115 TH	147	writeb(pdata->alrm_hour < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	148	0x80 : bin2bcd(pdata->alrm_hour),
02964115 TH	149	ioaddr + RTC_HOURS_ALARM);
02964115 TH	150	writeb(pdata->alrm_min < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	151	0x80 : bin2bcd(pdata->alrm_min),
02964115 TH	152	ioaddr + RTC_MINUTES_ALARM);
02964115 TH	153	writeb(pdata->alrm_sec < 0 \|\| (pdata->irqen & RTC_UF) ?
fe20ba70	154	0x80 : bin2bcd(pdata->alrm_sec),
02964115 TH	155	ioaddr + RTC_SECONDS_ALARM);
	156	writeb(pdata->irqen ? RTC_INTS_AIE : 0, ioaddr + RTC_INTERRUPTS);
	157	readb(ioaddr + RTC_FLAGS); /* clear interrupts */
	158	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
3151520d	159	spin_unlock_irqrestore(&pdata->lock, irqflags);
02964115 TH	160	}
	161
	162	static int stk17ta8_rtc_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	163	{
85368bb9	164	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
02964115	165
2fac6674	166	if (pdata->irq <= 0)
02964115 TH	167	return -EINVAL;
	168	pdata->alrm_mday = alrm->time.tm_mday;
	169	pdata->alrm_hour = alrm->time.tm_hour;
	170	pdata->alrm_min = alrm->time.tm_min;
	171	pdata->alrm_sec = alrm->time.tm_sec;
	172	if (alrm->enabled)
	173	pdata->irqen \|= RTC_AF;
	174	stk17ta8_rtc_update_alarm(pdata);
	175	return 0;
	176	}
	177
	178	static int stk17ta8_rtc_read_alarm(struct device dev, struct rtc_wkalrm alrm)
	179	{
85368bb9	180	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
02964115	181
2fac6674	182	if (pdata->irq <= 0)
02964115 TH	183	return -EINVAL;
	184	alrm->time.tm_mday = pdata->alrm_mday < 0 ? 0 : pdata->alrm_mday;
	185	alrm->time.tm_hour = pdata->alrm_hour < 0 ? 0 : pdata->alrm_hour;
	186	alrm->time.tm_min = pdata->alrm_min < 0 ? 0 : pdata->alrm_min;
	187	alrm->time.tm_sec = pdata->alrm_sec < 0 ? 0 : pdata->alrm_sec;
	188	alrm->enabled = (pdata->irqen & RTC_AF) ? 1 : 0;
	189	return 0;
	190	}
	191
	192	static irqreturn_t stk17ta8_rtc_interrupt(int irq, void *dev_id)
	193	{
	194	struct platform_device *pdev = dev_id;
	195	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
	196	void __iomem *ioaddr = pdata->ioaddr;
3151520d	197	unsigned long events = 0;
02964115	198
3151520d	199	spin_lock(&pdata->lock);
02964115	200	/* read and clear interrupt */
3151520d AN	201	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_AF) {
	202	events = RTC_IRQF;
	203	if (readb(ioaddr + RTC_SECONDS_ALARM) & 0x80)
	204	events \|= RTC_UF;
	205	else
	206	events \|= RTC_AF;
0d71915d	207	rtc_update_irq(pdata->rtc, 1, events);
3151520d AN	208	}
	209	spin_unlock(&pdata->lock);
	210	return events ? IRQ_HANDLED : IRQ_NONE;
02964115 TH	211	}
02964115 TH	212
3151520d AN	213	static int stk17ta8_rtc_alarm_irq_enable(struct device *dev,
3151520d AN	214	unsigned int enabled)
02964115	215	{
85368bb9	216	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
02964115	217
2fac6674	218	if (pdata->irq <= 0)
3151520d AN	219	return -EINVAL;
3151520d AN	220	if (enabled)
02964115	221	pdata->irqen \|= RTC_AF;
3151520d AN	222	else
	223	pdata->irqen &= ~RTC_AF;
	224	stk17ta8_rtc_update_alarm(pdata);
02964115 TH	225	return 0;
	226	}
	227
	228	static const struct rtc_class_ops stk17ta8_rtc_ops = {
3151520d AN	229	.read_time = stk17ta8_rtc_read_time,
	230	.set_time = stk17ta8_rtc_set_time,
	231	.read_alarm = stk17ta8_rtc_read_alarm,
	232	.set_alarm = stk17ta8_rtc_set_alarm,
	233	.alarm_irq_enable = stk17ta8_rtc_alarm_irq_enable,
02964115 TH	234	};
02964115 TH	235
d7ca4299 AB	236	static int stk17ta8_nvram_read(void priv, unsigned int pos, void val,
d7ca4299 AB	237	size_t bytes)
02964115	238	{
d7ca4299	239	struct rtc_plat_data *pdata = priv;
02964115	240	void __iomem *ioaddr = pdata->ioaddr;
d7ca4299	241	u8 *buf = val;
02964115	242
d7ca4299	243	for (; bytes; bytes--)
02964115	244	*buf++ = readb(ioaddr + pos++);
d7ca4299	245	return 0;
02964115 TH	246	}
02964115 TH	247
d7ca4299 AB	248	static int stk17ta8_nvram_write(void priv, unsigned int pos, void val,
d7ca4299 AB	249	size_t bytes)
02964115	250	{
d7ca4299	251	struct rtc_plat_data *pdata = priv;
02964115	252	void __iomem *ioaddr = pdata->ioaddr;
d7ca4299	253	u8 *buf = val;
02964115	254
d7ca4299	255	for (; bytes; bytes--)
02964115	256	writeb(*buf++, ioaddr + pos++);
d7ca4299	257	return 0;
02964115 TH	258	}
02964115 TH	259
5a167f45	260	static int stk17ta8_rtc_probe(struct platform_device *pdev)
02964115	261	{
02964115 TH	262	struct resource *res;
	263	unsigned int cal;
	264	unsigned int flags;
	265	struct rtc_plat_data *pdata;
3151520d	266	void __iomem *ioaddr;
02964115	267	int ret = 0;
d7ca4299 AB	268	struct nvmem_config nvmem_cfg = {
	269	.name = "stk17ta8_nvram",
	270	.word_size = 1,
	271	.stride = 1,
	272	.size = RTC_OFFSET,
	273	.reg_read = stk17ta8_nvram_read,
	274	.reg_write = stk17ta8_nvram_write,
	275	};
02964115	276
3151520d	277	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
02964115 TH	278	if (!pdata)
02964115 TH	279	return -ENOMEM;
7c1d69ee JL	280
	281	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	282	ioaddr = devm_ioremap_resource(&pdev->dev, res);
	283	if (IS_ERR(ioaddr))
	284	return PTR_ERR(ioaddr);
02964115 TH	285	pdata->ioaddr = ioaddr;
	286	pdata->irq = platform_get_irq(pdev, 0);
	287
	288	/* turn RTC on if it was not on */
	289	cal = readb(ioaddr + RTC_CALIBRATION);
	290	if (cal & RTC_STOP) {
	291	cal &= RTC_CAL_MASK;
	292	flags = readb(ioaddr + RTC_FLAGS);
	293	writeb(flags \| RTC_WRITE, ioaddr + RTC_FLAGS);
	294	writeb(cal, ioaddr + RTC_CALIBRATION);
	295	writeb(flags & ~RTC_WRITE, ioaddr + RTC_FLAGS);
	296	}
	297	if (readb(ioaddr + RTC_FLAGS) & RTC_FLAGS_PF)
	298	dev_warn(&pdev->dev, "voltage-low detected.\n");
	299
3151520d AN	300	spin_lock_init(&pdata->lock);
	301	pdata->last_jiffies = jiffies;
	302	platform_set_drvdata(pdev, pdata);
2fac6674	303	if (pdata->irq > 0) {
02964115	304	writeb(0, ioaddr + RTC_INTERRUPTS);
3151520d AN	305	if (devm_request_irq(&pdev->dev, pdata->irq,
3151520d AN	306	stk17ta8_rtc_interrupt,
2f6e5f94	307	IRQF_SHARED,
02964115 TH	308	pdev->name, pdev) < 0) {
02964115 TH	309	dev_warn(&pdev->dev, "interrupt not available.\n");
2fac6674	310	pdata->irq = 0;
02964115 TH	311	}
	312	}
	313
91cb6774	314	pdata->rtc = devm_rtc_allocate_device(&pdev->dev);
3151520d AN	315	if (IS_ERR(pdata->rtc))
3151520d AN	316	return PTR_ERR(pdata->rtc);
b74d2caa	317
91cb6774	318	pdata->rtc->ops = &stk17ta8_rtc_ops;
d7ca4299	319	pdata->rtc->nvram_old_abi = true;
91cb6774	320
d7ca4299 AB	321	nvmem_cfg.priv = pdata;
d7ca4299 AB	322	ret = rtc_nvmem_register(pdata->rtc, &nvmem_cfg);
91cb6774 AB	323	if (ret)
	324	return ret;
	325
d7ca4299	326	return rtc_register_device(pdata->rtc);
02964115 TH	327	}
02964115 TH	328
ad28a07b KS	329	/* work with hotplug and coldplug */
	330	MODULE_ALIAS("platform:stk17ta8");
	331
02964115 TH	332	static struct platform_driver stk17ta8_rtc_driver = {
02964115 TH	333	.probe = stk17ta8_rtc_probe,
02964115 TH	334	.driver = {
02964115 TH	335	.name = "stk17ta8",
02964115 TH	336	},
	337	};
	338
0c4eae66	339	module_platform_driver(stk17ta8_rtc_driver);
02964115	340
ab4364d3	341	MODULE_AUTHOR("Thomas Hommel <thomas.hommel@ge.com>");
02964115 TH	342	MODULE_DESCRIPTION("Simtek STK17TA8 RTC driver");
02964115 TH	343	MODULE_LICENSE("GPL");