[patch 3/3] Add HPET RTC emulation to RTC_DRV_CMOS
From: Bernhard Walle
Date: Thu Dec 20 2007 - 10:49:06 EST
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.
Signed-off-by: Bernhard Walle <bwalle@xxxxxxx>
---
arch/x86/Kconfig | 2 -
drivers/rtc/rtc-cmos.c | 79 ++++++++++++++++++++++++++++++++++++++++---------
2 files changed, 67 insertions(+), 14 deletions(-)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -405,7 +405,7 @@ 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.
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -35,10 +35,22 @@
#include <linux/spinlock.h>
#include <linux/platform_device.h>
#include <linux/mod_devicetable.h>
+#include <asm/hpet.h>
/* 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 +211,7 @@ static int cmos_set_alarm(struct device
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 */
@@ -252,7 +265,8 @@ static int cmos_irq_set_freq(struct devi
f = 16 - f;
spin_lock_irqsave(&rtc_lock, flags);
- CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
+ if (!hpet_set_periodic_freq(freq))
+ CMOS_WRITE(RTC_REF_CLCK_32KHZ | f, RTC_FREQ_SELECT);
spin_unlock_irqrestore(&rtc_lock, flags);
return 0;
@@ -314,28 +328,37 @@ cmos_rtc_ioctl(struct device *dev, unsig
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;
}
- CMOS_WRITE(rtc_control, RTC_CONTROL);
+ 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 +498,25 @@ static irqreturn_t cmos_interrupt(int ir
u8 rtc_control;
spin_lock(&rtc_lock);
- irqstat = CMOS_READ(RTC_INTR_FLAGS);
- rtc_control = CMOS_READ(RTC_CONTROL);
- irqstat &= (rtc_control & RTC_IRQMASK) | RTC_IRQF;
+ /*
+ * 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 +624,9 @@ cmos_do_probe(struct device *dev, struct
* 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 +649,31 @@ cmos_do_probe(struct device *dev, struct
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;
+ 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 +728,10 @@ static void __exit cmos_do_remove(struct
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;
--
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