summaryrefslogtreecommitdiff
path: root/arch/m68k/hp300/time.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/m68k/hp300/time.c')
-rw-r--r--arch/m68k/hp300/time.c73
1 files changed, 55 insertions, 18 deletions
diff --git a/arch/m68k/hp300/time.c b/arch/m68k/hp300/time.c
index 289d928a46cb..bfee13e1d0fe 100644
--- a/arch/m68k/hp300/time.c
+++ b/arch/m68k/hp300/time.c
@@ -8,6 +8,7 @@
*/
#include <asm/ptrace.h>
+#include <linux/clocksource.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/sched.h>
@@ -19,6 +20,18 @@
#include <asm/traps.h>
#include <asm/blinken.h>
+static u64 hp300_read_clk(struct clocksource *cs);
+
+static struct clocksource hp300_clk = {
+ .name = "timer",
+ .rating = 250,
+ .read = hp300_read_clk,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static u32 clk_total, clk_offset;
+
/* Clock hardware definitions */
#define CLOCKBASE 0xf05f8000
@@ -28,39 +41,61 @@
#define CLKCR3 CLKCR1
#define CLKSR CLKCR2
#define CLKMSB1 0x5
+#define CLKLSB1 0x7
#define CLKMSB2 0x9
#define CLKMSB3 0xD
+#define CLKSR_INT1 BIT(0)
+
/* This is for machines which generate the exact clock. */
-#define USECS_PER_JIFFY (1000000/HZ)
-#define INTVAL ((10000 / 4) - 1)
+#define HP300_TIMER_CLOCK_FREQ 250000
+#define HP300_TIMER_CYCLES (HP300_TIMER_CLOCK_FREQ / HZ)
+#define INTVAL (HP300_TIMER_CYCLES - 1)
static irqreturn_t hp300_tick(int irq, void *dev_id)
{
+ irq_handler_t timer_routine = dev_id;
+ unsigned long flags;
unsigned long tmp;
- irq_handler_t vector = dev_id;
+
+ local_irq_save(flags);
in_8(CLOCKBASE + CLKSR);
asm volatile ("movpw %1@(5),%0" : "=d" (tmp) : "a" (CLOCKBASE));
+ clk_total += INTVAL;
+ clk_offset = 0;
+ timer_routine(0, NULL);
+ local_irq_restore(flags);
+
/* Turn off the network and SCSI leds */
blinken_leds(0, 0xe0);
- return vector(irq, NULL);
+ return IRQ_HANDLED;
}
-u32 hp300_gettimeoffset(void)
+static u64 hp300_read_clk(struct clocksource *cs)
{
- /* Read current timer 1 value */
- unsigned char lsb, msb1, msb2;
- unsigned short ticks;
-
- msb1 = in_8(CLOCKBASE + 5);
- lsb = in_8(CLOCKBASE + 7);
- msb2 = in_8(CLOCKBASE + 5);
- if (msb1 != msb2)
- /* A carry happened while we were reading. Read it again */
- lsb = in_8(CLOCKBASE + 7);
- ticks = INTVAL - ((msb2 << 8) | lsb);
- return ((USECS_PER_JIFFY * ticks) / INTVAL) * 1000;
+ unsigned long flags;
+ unsigned char lsb, msb, msb_new;
+ u32 ticks;
+
+ local_irq_save(flags);
+ /* Read current timer 1 value */
+ msb = in_8(CLOCKBASE + CLKMSB1);
+again:
+ if ((in_8(CLOCKBASE + CLKSR) & CLKSR_INT1) && msb > 0)
+ clk_offset = INTVAL;
+ lsb = in_8(CLOCKBASE + CLKLSB1);
+ msb_new = in_8(CLOCKBASE + CLKMSB1);
+ if (msb_new != msb) {
+ msb = msb_new;
+ goto again;
+ }
+
+ ticks = INTVAL - ((msb << 8) | lsb);
+ ticks += clk_offset + clk_total;
+ local_irq_restore(flags);
+
+ return ticks;
}
void __init hp300_sched_init(irq_handler_t vector)
@@ -70,9 +105,11 @@ void __init hp300_sched_init(irq_handler_t vector)
asm volatile(" movpw %0,%1@(5)" : : "d" (INTVAL), "a" (CLOCKBASE));
- if (request_irq(IRQ_AUTO_6, hp300_tick, 0, "timer tick", vector))
+ if (request_irq(IRQ_AUTO_6, hp300_tick, IRQF_TIMER, "timer tick", vector))
pr_err("Couldn't register timer interrupt\n");
out_8(CLOCKBASE + CLKCR2, 0x1); /* select CR1 */
out_8(CLOCKBASE + CLKCR1, 0x40); /* enable irq */
+
+ clocksource_register_hz(&hp300_clk, HP300_TIMER_CLOCK_FREQ);
}