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Commit 9d8af78b authored by Bernhard Walle's avatar Bernhard Walle Committed by Linus Torvalds
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rtc: add HPET RTC emulation to RTC_DRV_CMOS 



That patch adds the RTC emulation of the HPET timer to the new RTC_DRV_CMOS.
The old drivers/char/rtc.ko driver had that functionality and it's important
on new systems.

[akpm@linux-foundation.org: unbreak alpha build]
Signed-off-by: default avatarBernhard Walle <bwalle@suse.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Robert Picco <Robert.Picco@hp.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 095b9d54

arch/x86/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -415,7 +415,7 @@ config HPET_TIMER 


config HPET_EMULATE_RTC

	def_bool y

	depends on HPET_TIMER && (RTC=y || RTC=m)

	depends on HPET_TIMER && (RTC=y || RTC=m || RTC_DRV_CMOS=m || RTC_DRV_CMOS=y)



# Mark as embedded because too many people got it wrong.

# The code disables itself when not needed.

drivers/rtc/rtc-cmos.c

+69 −13
Original line number Diff line number Diff line
@@ -36,9 +36,24 @@ 
#include <linux/platform_device.h>

#include <linux/mod_devicetable.h>



#ifdef CONFIG_HPET_EMULATE_RTC

#include <asm/hpet.h>

#endif



/* this is for "generic access to PC-style RTC" using CMOS_READ/CMOS_WRITE */

#include <asm-generic/rtc.h>



#ifndef CONFIG_HPET_EMULATE_RTC

#define is_hpet_enabled()			0

#define hpet_set_alarm_time(hrs, min, sec) 	do { } while (0)

#define hpet_set_periodic_freq(arg) 		0

#define hpet_mask_rtc_irq_bit(arg) 		do { } while (0)

#define hpet_set_rtc_irq_bit(arg) 		do { } while (0)

#define hpet_rtc_timer_init() 			do { } while (0)

#define hpet_register_irq_handler(h) 		0

#define hpet_unregister_irq_handler(h)		do { } while (0)

extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);

#endif



struct cmos_rtc {

	struct rtc_device	*rtc;
@@ -199,6 +214,7 @@ static int cmos_set_alarm(struct device *dev, struct rtc_wkalrm *t) 
	sec = t->time.tm_sec;

	sec = (sec < 60) ? BIN2BCD(sec) : 0xff;



	hpet_set_alarm_time(t->time.tm_hour, t->time.tm_min, t->time.tm_sec);

	spin_lock_irq(&rtc_lock);



	/* next rtc irq must not be from previous alarm setting */
@@ -252,6 +268,7 @@ static int cmos_irq_set_freq(struct device *dev, int freq) 
	f = 16 - f;



	spin_lock_irqsave(&rtc_lock, flags);

	if (!hpet_set_periodic_freq(freq))

		CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);

	spin_unlock_irqrestore(&rtc_lock, flags);
@@ -314,28 +331,37 @@ cmos_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 
	switch (cmd) {

	case RTC_AIE_OFF:	/* alarm off */

		rtc_control &= ~RTC_AIE;

		hpet_mask_rtc_irq_bit(RTC_AIE);

		break;

	case RTC_AIE_ON:	/* alarm on */

		rtc_control |= RTC_AIE;

		hpet_set_rtc_irq_bit(RTC_AIE);

		break;

	case RTC_UIE_OFF:	/* update off */

		rtc_control &= ~RTC_UIE;

		hpet_mask_rtc_irq_bit(RTC_UIE);

		break;

	case RTC_UIE_ON:	/* update on */

		rtc_control |= RTC_UIE;

		hpet_set_rtc_irq_bit(RTC_UIE);

		break;

	case RTC_PIE_OFF:	/* periodic off */

		rtc_control &= ~RTC_PIE;

		hpet_mask_rtc_irq_bit(RTC_PIE);

		break;

	case RTC_PIE_ON:	/* periodic on */

		rtc_control |= RTC_PIE;

		hpet_set_rtc_irq_bit(RTC_PIE);

		break;

	}

	if (!is_hpet_enabled())

		CMOS_WRITE(rtc_control, RTC_CONTROL);



	rtc_intr = CMOS_READ(RTC_INTR_FLAGS);

	rtc_intr &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;

	if (is_intr(rtc_intr))

		rtc_update_irq(cmos->rtc, 1, rtc_intr);



	spin_unlock_irqrestore(&rtc_lock, flags);

	return 0;

}
@@ -475,15 +501,25 @@ static irqreturn_t cmos_interrupt(int irq, void *p) 
	u8		rtc_control;



	spin_lock(&rtc_lock);

	/*

	 * In this case it is HPET RTC interrupt handler

	 * calling us, with the interrupt information

	 * passed as arg1, instead of irq.

	 */

	if (is_hpet_enabled())

		irqstat = (unsigned long)irq & 0xF0;

	else {

		irqstat = CMOS_READ(RTC_INTR_FLAGS);

		rtc_control = CMOS_READ(RTC_CONTROL);

		irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;

	}



	/* All Linux RTC alarms should be treated as if they were oneshot.

	 * Similar code may be needed in system wakeup paths, in case the

	 * alarm woke the system.

	 */

	if (irqstat & RTC_AIE) {

		rtc_control = CMOS_READ(RTC_CONTROL);

		rtc_control &= ~RTC_AIE;

		CMOS_WRITE(rtc_control, RTC_CONTROL);

		CMOS_READ(RTC_INTR_FLAGS);
@@ -591,8 +627,9 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) 
	 * doesn't use 32KHz here ... for portability we might need to

	 * do something about other clock frequencies.

	 */

	CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);

	cmos_rtc.rtc->irq_freq = 1024;

	if (!hpet_set_periodic_freq(cmos_rtc.rtc->irq_freq))

		CMOS_WRITE(RTC_REF_CLCK_32KHZ | 0x06, RTC_FREQ_SELECT);



	/* disable irqs.

	 *
@@ -615,14 +652,31 @@ cmos_do_probe(struct device *dev, struct resource *ports, int rtc_irq) 
		goto cleanup1;

	}



	if (is_valid_irq(rtc_irq))

		retval = request_irq(rtc_irq, cmos_interrupt, IRQF_DISABLED,

				cmos_rtc.rtc->dev.bus_id,

	if (is_valid_irq(rtc_irq)) {

		irq_handler_t rtc_cmos_int_handler;



		if (is_hpet_enabled()) {

			int err;



			rtc_cmos_int_handler = hpet_rtc_interrupt;

			err = hpet_register_irq_handler(cmos_interrupt);

			if (err != 0) {

				printk(KERN_WARNING "hpet_register_irq_handler "

						" failed in rtc_init().");

				goto cleanup1;

			}

		} else

			rtc_cmos_int_handler = cmos_interrupt;



		retval = request_irq(rtc_irq, rtc_cmos_int_handler,

				IRQF_DISABLED, cmos_rtc.rtc->dev.bus_id,

				cmos_rtc.rtc);

		if (retval < 0) {

			dev_dbg(dev, "IRQ %d is already in use\n", rtc_irq);

			goto cleanup1;

		}

	}

	hpet_rtc_timer_init();



	/* export at least the first block of NVRAM */

	nvram.size = address_space - NVRAM_OFFSET;
@@ -677,8 +731,10 @@ static void __exit cmos_do_remove(struct device *dev) 


	sysfs_remove_bin_file(&dev->kobj, &nvram);



	if (is_valid_irq(cmos->irq))

	if (is_valid_irq(cmos->irq)) {

		free_irq(cmos->irq, cmos->rtc);

		hpet_unregister_irq_handler(cmos_interrupt);

	}



	rtc_device_unregister(cmos->rtc);

	cmos->rtc = NULL;