Commit e24b0bfa authored by Johan Hovold's avatar Johan Hovold Committed by Linus Torvalds
Browse files

Revert "drivers/rtc/rtc-at91rm9200.c: use a variable for storing IMR" 

This reverts commit 0ef1594c.

This patch introduced a few races which cannot be easily fixed with a
small follow-up patch. Furthermore, the SoC with the broken hardware
register, which this patch intended to add support for, can only be used
with device trees, which this driver currently does not support.

[ Here is the discussion that led to this "revert" patch:
  https://lkml.org/lkml/2013/4/3/176

 ]

Cc: stable <stable@vger.kernel.org>
Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c4c80f63

drivers/rtc/rtc-at91rm9200.c

+19 −31
Original line number Diff line number Diff line
@@ -44,7 +44,6 @@ static DECLARE_COMPLETION(at91_rtc_updated); 
static unsigned int at91_alarm_year = AT91_RTC_EPOCH;

static void __iomem *at91_rtc_regs;

static int irq;

static u32 at91_rtc_imr;



/*

 * Decode time/date into rtc_time structure
@@ -109,11 +108,9 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) 
	cr = at91_rtc_read(AT91_RTC_CR);

	at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM);



	at91_rtc_imr |= AT91_RTC_ACKUPD;

	at91_rtc_write(AT91_RTC_IER, AT91_RTC_ACKUPD);

	wait_for_completion(&at91_rtc_updated);	/* wait for ACKUPD interrupt */

	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD);

	at91_rtc_imr &= ~AT91_RTC_ACKUPD;



	at91_rtc_write(AT91_RTC_TIMR,

			  bin2bcd(tm->tm_sec) << 0
@@ -145,7 +142,7 @@ static int at91_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm) 
	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);

	tm->tm_year = at91_alarm_year - 1900;



	alrm->enabled = (at91_rtc_imr & AT91_RTC_ALARM)

	alrm->enabled = (at91_rtc_read(AT91_RTC_IMR) & AT91_RTC_ALARM)

			? 1 : 0;



	dev_dbg(dev, "%s(): %4d-%02d-%02d %02d:%02d:%02d\n", __func__,
@@ -171,7 +168,6 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 
	tm.tm_sec = alrm->time.tm_sec;



	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);

	at91_rtc_imr &= ~AT91_RTC_ALARM;

	at91_rtc_write(AT91_RTC_TIMALR,

		  bin2bcd(tm.tm_sec) << 0

		| bin2bcd(tm.tm_min) << 8
@@ -184,7 +180,6 @@ static int at91_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm) 


	if (alrm->enabled) {

		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);

		at91_rtc_imr |= AT91_RTC_ALARM;

		at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);

	}
@@ -201,12 +196,9 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 


	if (enabled) {

		at91_rtc_write(AT91_RTC_SCCR, AT91_RTC_ALARM);

		at91_rtc_imr |= AT91_RTC_ALARM;

		at91_rtc_write(AT91_RTC_IER, AT91_RTC_ALARM);

	} else {

	} else

		at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ALARM);

		at91_rtc_imr &= ~AT91_RTC_ALARM;

	}



	return 0;

}
@@ -215,10 +207,12 @@ static int at91_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) 
 */

static int at91_rtc_proc(struct device *dev, struct seq_file *seq)

{

	unsigned long imr = at91_rtc_read(AT91_RTC_IMR);



	seq_printf(seq, "update_IRQ\t: %s\n",

			(at91_rtc_imr & AT91_RTC_ACKUPD) ? "yes" : "no");

			(imr & AT91_RTC_ACKUPD) ? "yes" : "no");

	seq_printf(seq, "periodic_IRQ\t: %s\n",

			(at91_rtc_imr & AT91_RTC_SECEV) ? "yes" : "no");

			(imr & AT91_RTC_SECEV) ? "yes" : "no");



	return 0;

}
@@ -233,7 +227,7 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) 
	unsigned int rtsr;

	unsigned long events = 0;



	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_imr;

	rtsr = at91_rtc_read(AT91_RTC_SR) & at91_rtc_read(AT91_RTC_IMR);

	if (rtsr) {		/* this interrupt is shared!  Is it ours? */

		if (rtsr & AT91_RTC_ALARM)

			events |= (RTC_AF | RTC_IRQF);
@@ -297,7 +291,6 @@ static int __init at91_rtc_probe(struct platform_device *pdev) 
	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |

					AT91_RTC_SECEV | AT91_RTC_TIMEV |

					AT91_RTC_CALEV);

	at91_rtc_imr = 0;



	ret = request_irq(irq, at91_rtc_interrupt,

				IRQF_SHARED,
@@ -336,7 +329,6 @@ static int __exit at91_rtc_remove(struct platform_device *pdev) 
	at91_rtc_write(AT91_RTC_IDR, AT91_RTC_ACKUPD | AT91_RTC_ALARM |

					AT91_RTC_SECEV | AT91_RTC_TIMEV |

					AT91_RTC_CALEV);

	at91_rtc_imr = 0;

	free_irq(irq, pdev);



	rtc_device_unregister(rtc);
@@ -349,35 +341,31 @@ static int __exit at91_rtc_remove(struct platform_device *pdev) 


/* AT91RM9200 RTC Power management control */



static u32 at91_rtc_bkpimr;



static u32 at91_rtc_imr;



static int at91_rtc_suspend(struct device *dev)

{

	/* this IRQ is shared with DBGU and other hardware which isn't

	 * necessarily doing PM like we are...

	 */

	at91_rtc_bkpimr = at91_rtc_imr & (AT91_RTC_ALARM|AT91_RTC_SECEV);

	if (at91_rtc_bkpimr) {

		if (device_may_wakeup(dev)) {

	at91_rtc_imr = at91_rtc_read(AT91_RTC_IMR)

			& (AT91_RTC_ALARM|AT91_RTC_SECEV);

	if (at91_rtc_imr) {

		if (device_may_wakeup(dev))

			enable_irq_wake(irq);

		} else {

			at91_rtc_write(AT91_RTC_IDR, at91_rtc_bkpimr);

			at91_rtc_imr &= ~at91_rtc_bkpimr;

		}

		else

			at91_rtc_write(AT91_RTC_IDR, at91_rtc_imr);

	}

	return 0;

}



static int at91_rtc_resume(struct device *dev)

{

	if (at91_rtc_bkpimr) {

		if (device_may_wakeup(dev)) {

	if (at91_rtc_imr) {

		if (device_may_wakeup(dev))

			disable_irq_wake(irq);

		} else {

			at91_rtc_imr |= at91_rtc_bkpimr;

			at91_rtc_write(AT91_RTC_IER, at91_rtc_bkpimr);

		}

		else

			at91_rtc_write(AT91_RTC_IER, at91_rtc_imr);

	}

	return 0;

}

drivers/rtc/rtc-at91rm9200.h

+1 −0
Original line number Diff line number Diff line
@@ -64,6 +64,7 @@ 
#define	AT91_RTC_SCCR		0x1c			/* Status Clear Command Register */

#define	AT91_RTC_IER		0x20			/* Interrupt Enable Register */

#define	AT91_RTC_IDR		0x24			/* Interrupt Disable Register */

#define	AT91_RTC_IMR		0x28			/* Interrupt Mask Register */



#define	AT91_RTC_VER		0x2c			/* Valid Entry Register */

#define		AT91_RTC_NVTIM		(1 <<  0)		/* Non valid Time */

CRA Git | Maintained and supported by SUSTech CRA and CCSE