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-rw-r--r--arch/alpha/kernel/time.c24
1 files changed, 17 insertions, 7 deletions
diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c
index ea33950..a6bcb31 100644
--- a/arch/alpha/kernel/time.c
+++ b/arch/alpha/kernel/time.c
@@ -201,16 +201,26 @@ irqreturn_t timer_interrupt(int irq, void *dev)
void __init
common_init_rtc(void)
{
- unsigned char x;
+ unsigned char x, sel = 0;
/* Reset periodic interrupt frequency. */
- x = CMOS_READ(RTC_FREQ_SELECT) & 0x3f;
- /* Test includes known working values on various platforms
- where 0x26 is wrong; we refuse to change those. */
- if (x != 0x26 && x != 0x25 && x != 0x19 && x != 0x06) {
- printk("Setting RTC_FREQ to 1024 Hz (%x)\n", x);
- CMOS_WRITE(0x26, RTC_FREQ_SELECT);
+#if CONFIG_HZ == 1024 || CONFIG_HZ == 1200
+ x = CMOS_READ(RTC_FREQ_SELECT) & 0x3f;
+ /* Test includes known working values on various platforms
+ where 0x26 is wrong; we refuse to change those. */
+ if (x != 0x26 && x != 0x25 && x != 0x19 && x != 0x06) {
+ sel = RTC_REF_CLCK_32KHZ + 6;
}
+#elif CONFIG_HZ == 256 || CONFIG_HZ == 128 || CONFIG_HZ == 64 || CONFIG_HZ == 32
+ sel = RTC_REF_CLCK_32KHZ + __builtin_ffs(32768 / CONFIG_HZ);
+#else
+# error "Unknown HZ from arch/alpha/Kconfig"
+#endif
+ if (sel) {
+ printk(KERN_INFO "Setting RTC_FREQ to %d Hz (%x)\n",
+ CONFIG_HZ, sel);
+ CMOS_WRITE(sel, RTC_FREQ_SELECT);
+ }
/* Turn on periodic interrupts. */
x = CMOS_READ(RTC_CONTROL);
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