x86, rtc: make CONFIG_HPET_EMULATE_RTC usable from modules
enabled, then interrupts don't work for the rtc-cmos driver which results in
RTC_AIE*, RTC_PIE* and RTC_ALM being unusable. This affects hwclock from
util-linux-ng at least on i386 since that uses RTC_PIE_ON. (For x86-64, a
polling method is used for unknown reasons.)
This patch series now
1. export the functions from arch/x86/kernel/hpet.c that the old char/rtc
driver uses to work around that problem,
2. makes it possible to compile the old rtc driver as module, while still
having CONFIG_HPET_EMULATE_RTC enabled and
3. makes use of the exported functions in (1) in the new rtc-cmos driver.
This patch:
This patch makes the RTC emulation functions in arch/x86/kernel/hpet.c usable
for kernel modules. It
- exports the functions (EXPORT_SYMBOL_GPL()),
- adds an interface to register the interrupt callback function
instead of using only a fixed callback function and
- replaces the rtc_get_rtc_time() function which depends on
CONFIG_RTC with a call to get_rtc_time() which is defined in
include/asm-generic/rtc.h.
The only dependency to CONFIG_RTC is the call to rtc_interrupt() which is
removed by the next patch. After this, there's no (code) dependency of
this functions to CONFIG_RTC=y any more.
Signed-off-by: Bernhard Walle <bwalle@suse.de>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Robert Picco <Robert.Picco@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 5c17027..d65ced5 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -107,6 +107,7 @@
{
return is_hpet_capable() && hpet_legacy_int_enabled;
}
+EXPORT_SYMBOL_GPL(is_hpet_enabled);
/*
* When the hpet driver (/dev/hpet) is enabled, we need to reserve
@@ -475,6 +476,7 @@
*/
#include <linux/mc146818rtc.h>
#include <linux/rtc.h>
+#include <asm/rtc.h>
#define DEFAULT_RTC_INT_FREQ 64
#define DEFAULT_RTC_SHIFT 6
@@ -489,6 +491,38 @@
static unsigned long hpet_pie_delta;
static unsigned long hpet_pie_limit;
+static rtc_irq_handler irq_handler;
+
+/*
+ * Registers a IRQ handler.
+ */
+int hpet_register_irq_handler(rtc_irq_handler handler)
+{
+ if (!is_hpet_enabled())
+ return -ENODEV;
+ if (irq_handler)
+ return -EBUSY;
+
+ irq_handler = handler;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(hpet_register_irq_handler);
+
+/*
+ * Deregisters the IRQ handler registered with hpet_register_irq_handler()
+ * and does cleanup.
+ */
+void hpet_unregister_irq_handler(rtc_irq_handler handler)
+{
+ if (!is_hpet_enabled())
+ return;
+
+ irq_handler = NULL;
+ hpet_rtc_flags = 0;
+}
+EXPORT_SYMBOL_GPL(hpet_unregister_irq_handler);
+
/*
* Timer 1 for RTC emulation. We use one shot mode, as periodic mode
* is not supported by all HPET implementations for timer 1.
@@ -530,6 +564,7 @@
return 1;
}
+EXPORT_SYMBOL_GPL(hpet_rtc_timer_init);
/*
* The functions below are called from rtc driver.
@@ -544,6 +579,7 @@
hpet_rtc_flags &= ~bit_mask;
return 1;
}
+EXPORT_SYMBOL_GPL(hpet_mask_rtc_irq_bit);
int hpet_set_rtc_irq_bit(unsigned long bit_mask)
{
@@ -559,6 +595,7 @@
return 1;
}
+EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit);
int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
unsigned char sec)
@@ -572,6 +609,7 @@
return 1;
}
+EXPORT_SYMBOL_GPL(hpet_set_alarm_time);
int hpet_set_periodic_freq(unsigned long freq)
{
@@ -590,11 +628,13 @@
}
return 1;
}
+EXPORT_SYMBOL_GPL(hpet_set_periodic_freq);
int hpet_rtc_dropped_irq(void)
{
return is_hpet_enabled();
}
+EXPORT_SYMBOL_GPL(hpet_rtc_dropped_irq);
static void hpet_rtc_timer_reinit(void)
{
@@ -638,9 +678,10 @@
unsigned long rtc_int_flag = 0;
hpet_rtc_timer_reinit();
+ memset(&curr_time, 0, sizeof(struct rtc_time));
if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
- rtc_get_rtc_time(&curr_time);
+ get_rtc_time(&curr_time);
if (hpet_rtc_flags & RTC_UIE &&
curr_time.tm_sec != hpet_prev_update_sec) {
@@ -662,8 +703,12 @@
if (rtc_int_flag) {
rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
+ if (irq_handler)
+ irq_handler(rtc_int_flag, dev_id);
+
rtc_interrupt(rtc_int_flag, dev_id);
}
return IRQ_HANDLED;
}
+EXPORT_SYMBOL_GPL(hpet_rtc_interrupt);
#endif
