Add a platform clocksource by adapting the existing arch_gettimeoffset
implementation.
Cc: Joshua Thompson <funaho@xxxxxxxxx>
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
---
arch/m68k/mac/via.c | 31 +++++++++++++++++++++++--------
1 file changed, 23 insertions(+), 8 deletions(-)
diff --git a/arch/m68k/mac/via.c b/arch/m68k/mac/via.c
index 7130abec0b77..c4c304470fae 100644
--- a/arch/m68k/mac/via.c
+++ b/arch/m68k/mac/via.c
@@ -23,6 +23,7 @@
*
*/
+#include <linux/clocksource.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
@@ -556,13 +557,23 @@ EXPORT_SYMBOL(via2_scsi_drq_pending);
/* timer and clock source */
#define VIA_CLOCK_FREQ 783360 /* VIA "phase 2" clock in Hz */
-#define VIA_TIMER_INTERVAL (1000000 / HZ) /* microseconds per jiffy */
#define VIA_TIMER_CYCLES (VIA_CLOCK_FREQ / HZ) /* clock cycles per jiffy */
#define VIA_TC (VIA_TIMER_CYCLES - 2) /* including 0 and -1 */
#define VIA_TC_LOW (VIA_TC & 0xFF)
#define VIA_TC_HIGH (VIA_TC >> 8)
+static u64 mac_read_clk(struct clocksource *cs);
+
+static struct clocksource mac_clk = {
+ .name = "via1",
+ .rating = 250,
+ .read = mac_read_clk,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static u32 clk_total;
static bool lost_timer_intr;
static irqreturn_t via_timer_handler(int irq, void *data)
@@ -573,16 +584,18 @@ static irqreturn_t via_timer_handler(int irq, void *data)
local_irq_save(flags);
if (lost_timer_intr) {
lost_timer_intr = false;
- local_irq_restore(flags);
- func(irq, data);
- } else
- local_irq_restore(flags);
+ clk_total += VIA_TIMER_CYCLES;
+ }
+ clk_total += VIA_TIMER_CYCLES;
+ local_irq_restore(flags);
+
return func(irq, data);
}
void __init via_init_clock(irq_handler_t func)
{
- if (request_irq(IRQ_MAC_TIMER_1, via_timer_handler, 0, "timer", func)) {
+ if (request_irq(IRQ_MAC_TIMER_1, via_timer_handler, IRQF_TIMER,
+ "timer", func)) {
pr_err("Couldn't register %s interrupt\n", "timer");
return;
}
@@ -592,11 +605,13 @@ void __init via_init_clock(irq_handler_t func)
via1[vT1CL] = VIA_TC_LOW;
via1[vT1CH] = VIA_TC_HIGH;
via1[vACR] |= 0x40;
+
+ clocksource_register_hz(&mac_clk, VIA_CLOCK_FREQ);
}
#define VIA_T1_INT_FLAG BIT(6)
-u32 mac_gettimeoffset(void)
+static u64 mac_read_clk(struct clocksource *cs)
{
unsigned long flags;
u8 count_high, count_high_new, count_low;
@@ -631,5 +646,5 @@ u32 mac_gettimeoffset(void)
count = ((count_high << 8) | count_low) + 1;
count = VIA_TIMER_CYCLES - count + offset;
- return ((count * VIA_TIMER_INTERVAL) / VIA_TIMER_CYCLES) * 1000;
+ return clk_total + count;
}
--
2.18.1
