Add a platform clocksource by adapting the existing arch_gettimeoffset
implementation.
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
---
arch/m68k/include/asm/mvme147hw.h | 1 -
arch/m68k/mvme147/config.c | 43 +++++++++++++++++++++++--------
2 files changed, 32 insertions(+), 12 deletions(-)
diff --git a/arch/m68k/include/asm/mvme147hw.h b/arch/m68k/include/asm/mvme147hw.h
index 9c7ff67c5ffd..7c3dd513128e 100644
--- a/arch/m68k/include/asm/mvme147hw.h
+++ b/arch/m68k/include/asm/mvme147hw.h
@@ -66,7 +66,6 @@ struct pcc_regs {
#define PCC_INT_ENAB 0x08
#define PCC_TIMER_INT_CLR 0x80
-#define PCC_TIMER_PRELOAD 63936l
#define PCC_LEVEL_ABORT 0x07
#define PCC_LEVEL_SERIAL 0x04
diff --git a/arch/m68k/mvme147/config.c b/arch/m68k/mvme147/config.c
index ff7141cf27d1..e7bd40e510d9 100644
--- a/arch/m68k/mvme147/config.c
+++ b/arch/m68k/mvme147/config.c
@@ -17,6 +17,7 @@
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/tty.h>
+#include <linux/clocksource.h>
#include <linux/console.h>
#include <linux/linkage.h>
#include <linux/init.h>
@@ -44,12 +45,6 @@ extern void mvme147_reset (void);
static int bcd2int (unsigned char b);
-/* Save tick handler routine pointer, will point to xtime_update() in
- * kernel/time/timekeeping.c, called via mvme147_process_int() */
-
-irq_handler_t tick_handler;
-
-
int __init mvme147_parse_bootinfo(const struct bi_record *bi)
{
uint16_t tag = be16_to_cpu(bi->tag);
@@ -97,34 +92,59 @@ void __init config_mvme147(void)
vme_brdtype = VME_TYPE_MVME147;
}
+static u64 mvme147_read_clk(struct clocksource *cs);
+
+static struct clocksource mvme147_clk = {
+ .name = "pcc",
+ .rating = 250,
+ .read = mvme147_read_clk,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static u32 clk_total;
+
+#define PCC_TIMER_CLOCK_FREQ 160000
+#define PCC_TIMER_CYCLES (PCC_TIMER_CLOCK_FREQ / HZ)
+#define PCC_TIMER_PRELOAD (0x10000 - PCC_TIMER_CYCLES)
/* Using pcc tick timer 1 */
static irqreturn_t mvme147_timer_int (int irq, void *dev_id)
{
+ irq_handler_t tick_handler = dev_id;
+ unsigned long flags;
+
m147_pcc->t1_int_cntrl = PCC_TIMER_INT_CLR;
m147_pcc->t1_int_cntrl = PCC_INT_ENAB|PCC_LEVEL_TIMER1;
+
+ local_irq_save(flags);
+ clk_total += PCC_TIMER_CYCLES;
+ local_irq_restore(flags);
+
return tick_handler(irq, dev_id);
}
void mvme147_sched_init (irq_handler_t timer_routine)
{
- tick_handler = timer_routine;
- if (request_irq(PCC_IRQ_TIMER1, mvme147_timer_int, 0, "timer 1", NULL))
+ if (request_irq(PCC_IRQ_TIMER1, mvme147_timer_int, IRQF_TIMER,
+ "timer 1", timer_routine))
pr_err("Couldn't register timer interrupt\n");
/* Init the clock with a value */
- /* our clock goes off every 6.25us */
+ /* The clock counter increments until 0xFFFF then reloads */
m147_pcc->t1_preload = PCC_TIMER_PRELOAD;
m147_pcc->t1_cntrl = 0x0; /* clear timer */
m147_pcc->t1_cntrl = 0x3; /* start timer */
m147_pcc->t1_int_cntrl = PCC_TIMER_INT_CLR; /* clear pending ints */
m147_pcc->t1_int_cntrl = PCC_INT_ENAB|PCC_LEVEL_TIMER1;
+
+ clocksource_register_hz(&mvme147_clk, PCC_TIMER_CLOCK_FREQ);
}
/* XXX There are race hazards in this code XXX */
-u32 mvme147_gettimeoffset(void)
+static u64 mvme147_read_clk(struct clocksource *cs)
{
unsigned long flags;
volatile unsigned short *cp = (volatile unsigned short *)0xfffe1012;
@@ -139,7 +159,8 @@ u32 mvme147_gettimeoffset(void)
local_irq_restore(flags);
n -= PCC_TIMER_PRELOAD;
- return ((unsigned long)n * 25 / 4) * 1000;
+
+ return clk_total + n;
}
static int bcd2int (unsigned char b)
--
2.18.1
