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/* * drivers/rtc/rtc-pl031.c * * Real Time Clock interface for ARM AMBA PrimeCell 031 RTC * * Author: Deepak Saxena <dsaxena@plexity.net> * * Copyright 2006 (c) MontaVista Software, Inc. * * Author: Mian Yousaf Kaukab <mian.yousaf.kaukab@stericsson.com> * Copyright 2010 (c) ST-Ericsson AB * * 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/module.h>#include <linux/rtc.h>#include <linux/init.h>#include <linux/interrupt.h>#include <linux/amba/bus.h>#include <linux/io.h>#include <linux/bcd.h>#include <linux/delay.h>#include <linux/slab.h> /* * Register definitions */#define	RTC_DR		0x00	/* Data read register */#define	RTC_MR		0x04	/* Match register */#define	RTC_LR		0x08	/* Data load register */#define	RTC_CR		0x0c	/* Control register */#define	RTC_IMSC	0x10	/* Interrupt mask and set register */#define	RTC_RIS		0x14	/* Raw interrupt status register */#define	RTC_MIS		0x18	/* Masked interrupt status register */#define	RTC_ICR		0x1c	/* Interrupt clear register *//* ST variants have additional timer functionality */#define RTC_TDR		0x20	/* Timer data read register */#define RTC_TLR		0x24	/* Timer data load register */#define RTC_TCR		0x28	/* Timer control register */#define RTC_YDR		0x30	/* Year data read register */#define RTC_YMR		0x34	/* Year match register */#define RTC_YLR		0x38	/* Year data load register */ #define RTC_CR_EN	(1 << 0)	/* counter enable bit */#define RTC_CR_CWEN	(1 << 26)	/* Clockwatch enable bit */ #define RTC_TCR_EN	(1 << 1) /* Periodic timer enable bit */ /* Common bit definitions for Interrupt status and control registers */#define RTC_BIT_AI	(1 << 0) /* Alarm interrupt bit */#define RTC_BIT_PI	(1 << 1) /* Periodic interrupt bit. ST variants only. */ /* Common bit definations for ST v2 for reading/writing time */#define RTC_SEC_SHIFT 0#define RTC_SEC_MASK (0x3F << RTC_SEC_SHIFT) /* Second [0-59] */#define RTC_MIN_SHIFT 6#define RTC_MIN_MASK (0x3F << RTC_MIN_SHIFT) /* Minute [0-59] */#define RTC_HOUR_SHIFT 12#define RTC_HOUR_MASK (0x1F << RTC_HOUR_SHIFT) /* Hour [0-23] */#define RTC_WDAY_SHIFT 17#define RTC_WDAY_MASK (0x7 << RTC_WDAY_SHIFT) /* Day of Week [1-7] 1=Sunday */#define RTC_MDAY_SHIFT 20#define RTC_MDAY_MASK (0x1F << RTC_MDAY_SHIFT) /* Day of Month [1-31] */#define RTC_MON_SHIFT 25#define RTC_MON_MASK (0xF << RTC_MON_SHIFT) /* Month [1-12] 1=January */ #define RTC_TIMER_FREQ 32768 /** * struct pl031_vendor_data - per-vendor variations * @ops: the vendor-specific operations used on this silicon version * @clockwatch: if this is an ST Microelectronics silicon version with a *	clockwatch function * @st_weekday: if this is an ST Microelectronics silicon version that need *	the weekday fix * @irqflags: special IRQ flags per variant */struct pl031_vendor_data {	struct rtc_class_ops ops;	bool clockwatch;	bool st_weekday;	unsigned long irqflags;}; struct pl031_local {	struct pl031_vendor_data *vendor;	struct rtc_device *rtc;	void __iomem *base;}; static int pl031_alarm_irq_enable(struct device *dev,	unsigned int enabled){	struct pl031_local *ldata = dev_get_drvdata(dev);	unsigned long imsc; 	/* Clear any pending alarm interrupts. */	writel(RTC_BIT_AI, ldata->base + RTC_ICR); 	imsc = readl(ldata->base + RTC_IMSC); 	if (enabled == 1)		writel(imsc | RTC_BIT_AI, ldata->base + RTC_IMSC);	else		writel(imsc & ~RTC_BIT_AI, ldata->base + RTC_IMSC); 	return 0;} /* * Convert Gregorian date to ST v2 RTC format. */static int pl031_stv2_tm_to_time(struct device *dev,				 struct rtc_time *tm, unsigned long *st_time,	unsigned long *bcd_year){	int year = tm->tm_year + 1900;	int wday = tm->tm_wday; 	/* wday masking is not working in hardware so wday must be valid */	if (wday < -1 || wday > 6) {		dev_err(dev, "invalid wday value %d\n", tm->tm_wday);		return -EINVAL;	} else if (wday == -1) {		/* wday is not provided, calculate it here */		unsigned long time;		struct rtc_time calc_tm; 		rtc_tm_to_time(tm, &time);		rtc_time_to_tm(time, &calc_tm);		wday = calc_tm.tm_wday;	} 	*bcd_year = (bin2bcd(year % 100) | bin2bcd(year / 100) << 8); 	*st_time = ((tm->tm_mon + 1) << RTC_MON_SHIFT)			|	(tm->tm_mday << RTC_MDAY_SHIFT)			|	((wday + 1) << RTC_WDAY_SHIFT)			|	(tm->tm_hour << RTC_HOUR_SHIFT)			|	(tm->tm_min << RTC_MIN_SHIFT)			|	(tm->tm_sec << RTC_SEC_SHIFT); 	return 0;} /* * Convert ST v2 RTC format to Gregorian date. */static int pl031_stv2_time_to_tm(unsigned long st_time, unsigned long bcd_year,	struct rtc_time *tm){	tm->tm_year = bcd2bin(bcd_year) + (bcd2bin(bcd_year >> 8) * 100);	tm->tm_mon  = ((st_time & RTC_MON_MASK) >> RTC_MON_SHIFT) - 1;	tm->tm_mday = ((st_time & RTC_MDAY_MASK) >> RTC_MDAY_SHIFT);	tm->tm_wday = ((st_time & RTC_WDAY_MASK) >> RTC_WDAY_SHIFT) - 1;	tm->tm_hour = ((st_time & RTC_HOUR_MASK) >> RTC_HOUR_SHIFT);	tm->tm_min  = ((st_time & RTC_MIN_MASK) >> RTC_MIN_SHIFT);	tm->tm_sec  = ((st_time & RTC_SEC_MASK) >> RTC_SEC_SHIFT); 	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);	tm->tm_year -= 1900; 	return 0;} static int pl031_stv2_read_time(struct device *dev, struct rtc_time *tm){	struct pl031_local *ldata = dev_get_drvdata(dev); 	pl031_stv2_time_to_tm(readl(ldata->base + RTC_DR),			readl(ldata->base + RTC_YDR), tm); 	return 0;} static int pl031_stv2_set_time(struct device *dev, struct rtc_time *tm){	unsigned long time;	unsigned long bcd_year;	struct pl031_local *ldata = dev_get_drvdata(dev);	int ret; 	ret = pl031_stv2_tm_to_time(dev, tm, &time, &bcd_year);	if (ret == 0) {		writel(bcd_year, ldata->base + RTC_YLR);		writel(time, ldata->base + RTC_LR);	} 	return ret;} static int pl031_stv2_read_alarm(struct device *dev, struct rtc_wkalrm *alarm){	struct pl031_local *ldata = dev_get_drvdata(dev);	int ret; 	ret = pl031_stv2_time_to_tm(readl(ldata->base + RTC_MR),			readl(ldata->base + RTC_YMR), &alarm->time); 	alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;	alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 	return ret;} static int pl031_stv2_set_alarm(struct device *dev, struct rtc_wkalrm *alarm){	struct pl031_local *ldata = dev_get_drvdata(dev);	unsigned long time;	unsigned long bcd_year;	int ret; 	/* At the moment, we can only deal with non-wildcarded alarm times. */	ret = rtc_valid_tm(&alarm->time);	if (ret == 0) {		ret = pl031_stv2_tm_to_time(dev, &alarm->time,					    &time, &bcd_year);		if (ret == 0) {			writel(bcd_year, ldata->base + RTC_YMR);			writel(time, ldata->base + RTC_MR); 			pl031_alarm_irq_enable(dev, alarm->enabled);		}	} 	return ret;} static irqreturn_t pl031_interrupt(int irq, void *dev_id){	struct pl031_local *ldata = dev_id;	unsigned long rtcmis;	unsigned long events = 0; 	rtcmis = readl(ldata->base + RTC_MIS);	if (rtcmis & RTC_BIT_AI) {		writel(RTC_BIT_AI, ldata->base + RTC_ICR);		events |= (RTC_AF | RTC_IRQF);		rtc_update_irq(ldata->rtc, 1, events); 		return IRQ_HANDLED;	} 	return IRQ_NONE;} static int pl031_read_time(struct device *dev, struct rtc_time *tm){	struct pl031_local *ldata = dev_get_drvdata(dev); 	rtc_time_to_tm(readl(ldata->base + RTC_DR), tm); 	return 0;} static int pl031_set_time(struct device *dev, struct rtc_time *tm){	unsigned long time;	struct pl031_local *ldata = dev_get_drvdata(dev);	int ret; 	ret = rtc_tm_to_time(tm, &time); 	if (ret == 0)		writel(time, ldata->base + RTC_LR); 	return ret;} static int pl031_read_alarm(struct device *dev, struct rtc_wkalrm *alarm){	struct pl031_local *ldata = dev_get_drvdata(dev); 	rtc_time_to_tm(readl(ldata->base + RTC_MR), &alarm->time); 	alarm->pending = readl(ldata->base + RTC_RIS) & RTC_BIT_AI;	alarm->enabled = readl(ldata->base + RTC_IMSC) & RTC_BIT_AI; 	return 0;} static int pl031_set_alarm(struct device *dev, struct rtc_wkalrm *alarm){	struct pl031_local *ldata = dev_get_drvdata(dev);	unsigned long time;	int ret; 	/* At the moment, we can only deal with non-wildcarded alarm times. */	ret = rtc_valid_tm(&alarm->time);	if (ret == 0) {		ret = rtc_tm_to_time(&alarm->time, &time);		if (ret == 0) {			writel(time, ldata->base + RTC_MR);			pl031_alarm_irq_enable(dev, alarm->enabled);		}	} 	return ret;} static int pl031_remove(struct amba_device *adev){	struct pl031_local *ldata = dev_get_drvdata(&adev->dev); 	free_irq(adev->irq[0], ldata);	rtc_device_unregister(ldata->rtc);	iounmap(ldata->base);	kfree(ldata);	amba_release_regions(adev); 	return 0;} static int pl031_probe(struct amba_device *adev, const struct amba_id *id){	int ret;	struct pl031_local *ldata;	struct pl031_vendor_data *vendor = id->data;	struct rtc_class_ops *ops = &vendor->ops;	unsigned long time, data; 	ret = amba_request_regions(adev, NULL);	if (ret)		goto err_req; 	ldata = kzalloc(sizeof(struct pl031_local), GFP_KERNEL);	if (!ldata) {		ret = -ENOMEM;		goto out;	}	ldata->vendor = vendor; 	ldata->base = ioremap(adev->res.start, resource_size(&adev->res)); 	if (!ldata->base) {		ret = -ENOMEM;		goto out_no_remap;	} 	amba_set_drvdata(adev, ldata); 	dev_dbg(&adev->dev, "designer ID = 0x%02x\n", amba_manf(adev));	dev_dbg(&adev->dev, "revision = 0x%01x\n", amba_rev(adev)); 	data = readl(ldata->base + RTC_CR);	/* Enable the clockwatch on ST Variants */	if (vendor->clockwatch)		data |= RTC_CR_CWEN;	else		data |= RTC_CR_EN;	writel(data, ldata->base + RTC_CR); 	/*	 * On ST PL031 variants, the RTC reset value does not provide correct	 * weekday for 2000-01-01. Correct the erroneous sunday to saturday.	 */	if (vendor->st_weekday) {		if (readl(ldata->base + RTC_YDR) == 0x2000) {			time = readl(ldata->base + RTC_DR);			if ((time &			     (RTC_MON_MASK | RTC_MDAY_MASK | RTC_WDAY_MASK))			    == 0x02120000) {				time = time | (0x7 << RTC_WDAY_SHIFT);				writel(0x2000, ldata->base + RTC_YLR);				writel(time, ldata->base + RTC_LR);			}		}	} 	device_init_wakeup(&adev->dev, 1);	ldata->rtc = rtc_device_register("pl031", &adev->dev, ops,					THIS_MODULE);	if (IS_ERR(ldata->rtc)) {		ret = PTR_ERR(ldata->rtc);		goto out_no_rtc;	} 	if (request_irq(adev->irq[0], pl031_interrupt,			vendor->irqflags, "rtc-pl031", ldata)) {		ret = -EIO;		goto out_no_irq;	} 	return 0; out_no_irq:	rtc_device_unregister(ldata->rtc);out_no_rtc:	iounmap(ldata->base);out_no_remap:	kfree(ldata);out:	amba_release_regions(adev);err_req: 	return ret;} /* Operations for the original ARM version */static struct pl031_vendor_data arm_pl031 = {	.ops = {		.read_time = pl031_read_time,		.set_time = pl031_set_time,		.read_alarm = pl031_read_alarm,		.set_alarm = pl031_set_alarm,		.alarm_irq_enable = pl031_alarm_irq_enable,	},	.irqflags = IRQF_NO_SUSPEND,}; /* The First ST derivative */static struct pl031_vendor_data stv1_pl031 = {	.ops = {		.read_time = pl031_read_time,		.set_time = pl031_set_time,		.read_alarm = pl031_read_alarm,		.set_alarm = pl031_set_alarm,		.alarm_irq_enable = pl031_alarm_irq_enable,	},	.clockwatch = true,	.st_weekday = true,	.irqflags = IRQF_NO_SUSPEND,}; /* And the second ST derivative */static struct pl031_vendor_data stv2_pl031 = {	.ops = {		.read_time = pl031_stv2_read_time,		.set_time = pl031_stv2_set_time,		.read_alarm = pl031_stv2_read_alarm,		.set_alarm = pl031_stv2_set_alarm,		.alarm_irq_enable = pl031_alarm_irq_enable,	},	.clockwatch = true,	.st_weekday = true,	/*	 * This variant shares the IRQ with another block and must not	 * suspend that IRQ line.	 */	.irqflags = IRQF_SHARED | IRQF_NO_SUSPEND,}; static struct amba_id pl031_ids[] = {	{		.id = 0x00041031,		.mask = 0x000fffff,		.data = &arm_pl031,	},	/* ST Micro variants */	{		.id = 0x00180031,		.mask = 0x00ffffff,		.data = &stv1_pl031,	},	{		.id = 0x00280031,		.mask = 0x00ffffff,		.data = &stv2_pl031,	},	{0, 0},}; MODULE_DEVICE_TABLE(amba, pl031_ids); static struct amba_driver pl031_driver = {	.drv = {		.name = "rtc-pl031",	},	.id_table = pl031_ids,	.probe = pl031_probe,	.remove = pl031_remove,}; module_amba_driver(pl031_driver); MODULE_AUTHOR("Deepak Saxena <dsaxena@plexity.net");MODULE_DESCRIPTION("ARM AMBA PL031 RTC Driver");MODULE_LICENSE("GPL");

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