Skip to content
Snippets Groups Projects
Select Git revision
  • b25114817a73bbd2b84ce9dba02ee1ef8989a947
  • vme-testing default
  • ci-test
  • master
  • remoteproc
  • am625-sk-ov5640
  • pcal6534-upstreaming
  • lps22df-upstreaming
  • msc-upstreaming
  • imx8mp
  • iio/noa1305
  • vme-next
  • vme-next-4.14-rc4
  • v4.14-rc4
  • v4.14-rc3
  • v4.14-rc2
  • v4.14-rc1
  • v4.13
  • vme-next-4.13-rc7
  • v4.13-rc7
  • v4.13-rc6
  • v4.13-rc5
  • v4.13-rc4
  • v4.13-rc3
  • v4.13-rc2
  • v4.13-rc1
  • v4.12
  • v4.12-rc7
  • v4.12-rc6
  • v4.12-rc5
  • v4.12-rc4
  • v4.12-rc3
32 results

header.c

Blame
  • rtc-pl031.c 11.46 KiB
    /*
     * 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_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_local {
    	struct rtc_device *rtc;
    	void __iomem *base;
    	u8 hw_designer;
    	u8 hw_revision:4;
    };
    
    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) {
    		writel(rtcmis, ldata->base + RTC_ICR);
    
    		if (rtcmis & RTC_BIT_AI)
    			events |= (RTC_AF | RTC_IRQF);
    
    		/* Timer interrupt is only available in ST variants */
    		if ((rtcmis & RTC_BIT_PI) &&
    			(ldata->hw_designer == AMBA_VENDOR_ST))
    			events |= (RTC_PF | 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);
    
    	amba_set_drvdata(adev, NULL);
    	free_irq(adev->irq[0], ldata->rtc);
    	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 rtc_class_ops *ops = id->data;
    	unsigned long time;
    
    	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->base = ioremap(adev->res.start, resource_size(&adev->res));
    
    	if (!ldata->base) {
    		ret = -ENOMEM;
    		goto out_no_remap;
    	}
    
    	amba_set_drvdata(adev, ldata);
    
    	ldata->hw_designer = amba_manf(adev);
    	ldata->hw_revision = amba_rev(adev);
    
    	dev_dbg(&adev->dev, "designer ID = 0x%02x\n", ldata->hw_designer);
    	dev_dbg(&adev->dev, "revision = 0x%01x\n", ldata->hw_revision);
    
    	/* Enable the clockwatch on ST Variants */
    	if (ldata->hw_designer == AMBA_VENDOR_ST)
    		writel(readl(ldata->base + RTC_CR) | RTC_CR_CWEN,
    		       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 (ldata->hw_designer == AMBA_VENDOR_ST) {
    		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);
    			}
    		}
    	}
    
    	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,
    			0, "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);
    	amba_set_drvdata(adev, NULL);
    out_no_remap:
    	kfree(ldata);
    out:
    	amba_release_regions(adev);
    err_req:
    
    	return ret;
    }
    
    /* Operations for the original ARM version */
    static struct rtc_class_ops 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,
    };
    
    /* The First ST derivative */
    static struct rtc_class_ops 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,
    };
    
    /* And the second ST derivative */
    static struct rtc_class_ops 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,
    };
    
    static struct amba_id pl031_ids[] = {
    	{
    		.id = 0x00041031,
    		.mask = 0x000fffff,
    		.data = &arm_pl031_ops,
    	},
    	/* ST Micro variants */
    	{
    		.id = 0x00180031,
    		.mask = 0x00ffffff,
    		.data = &stv1_pl031_ops,
    	},
    	{
    		.id = 0x00280031,
    		.mask = 0x00ffffff,
    		.data = &stv2_pl031_ops,
    	},
    	{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");