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 <[email protected]>
---
arch/x86/kernel/hpet.c | 47 ++++++++++++++++++++++++++++++++++++++++++++++-
include/asm-x86/hpet.h | 3 +++
2 files changed, 49 insertions(+), 1 deletion(-)
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -107,6 +107,7 @@ int is_hpet_enabled(void)
{
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
@@ -478,6 +479,7 @@ void hpet_disable(void)
*/
#include <linux/mc146818rtc.h>
#include <linux/rtc.h>
+#include <asm/rtc.h>
#define DEFAULT_RTC_INT_FREQ 64
#define DEFAULT_RTC_SHIFT 6
@@ -492,6 +494,38 @@ static unsigned long hpet_default_delta;
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.
@@ -533,6 +567,7 @@ int hpet_rtc_timer_init(void)
return 1;
}
+EXPORT_SYMBOL_GPL(hpet_rtc_timer_init);
/*
* The functions below are called from rtc driver.
@@ -547,6 +582,7 @@ int hpet_mask_rtc_irq_bit(unsigned long
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)
{
@@ -562,6 +598,7 @@ int hpet_set_rtc_irq_bit(unsigned long b
return 1;
}
+EXPORT_SYMBOL_GPL(hpet_set_rtc_irq_bit);
int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
unsigned char sec)
@@ -575,6 +612,7 @@ int hpet_set_alarm_time(unsigned char hr
return 1;
}
+EXPORT_SYMBOL_GPL(hpet_set_alarm_time);
int hpet_set_periodic_freq(unsigned long freq)
{
@@ -593,11 +631,13 @@ int hpet_set_periodic_freq(unsigned long
}
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)
{
@@ -641,9 +681,10 @@ irqreturn_t hpet_rtc_interrupt(int irq,
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) {
@@ -665,8 +706,12 @@ irqreturn_t hpet_rtc_interrupt(int irq,
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
--- a/include/asm-x86/hpet.h
+++ b/include/asm-x86/hpet.h
@@ -69,6 +69,7 @@ extern void force_hpet_resume(void);
#include <linux/interrupt.h>
+typedef irqreturn_t (*rtc_irq_handler)(int interrupt, void *cookie);
extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask);
extern int hpet_set_rtc_irq_bit(unsigned long bit_mask);
extern int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
@@ -77,6 +78,8 @@ extern int hpet_set_periodic_freq(unsign
extern int hpet_rtc_dropped_irq(void);
extern int hpet_rtc_timer_init(void);
extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
+extern int hpet_register_irq_handler(rtc_irq_handler handler);
+extern void hpet_unregister_irq_handler(rtc_irq_handler handler);
#endif /* CONFIG_HPET_EMULATE_RTC */