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Subject[RFC PATCH v2 13/14] m68k: mvme16x: Convert to clocksource API
Date
Add a platform clocksource by adapting the existing arch_gettimeoffset
implementation.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
---
Changed since v1:
- Moved clk_total access to within the irq lock.
---
arch/m68k/mvme16x/config.c | 39 +++++++++++++++++++++++++++++++-------
1 file changed, 32 insertions(+), 7 deletions(-)

diff --git a/arch/m68k/mvme16x/config.c b/arch/m68k/mvme16x/config.c
index 8bafa6a37593..2c109ee2a1a5 100644
--- a/arch/m68k/mvme16x/config.c
+++ b/arch/m68k/mvme16x/config.c
@@ -19,6 +19,7 @@
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/tty.h>
+#include <linux/clocksource.h>
#include <linux/console.h>
#include <linux/linkage.h>
#include <linux/init.h>
@@ -343,6 +344,21 @@ static irqreturn_t mvme16x_abort_int (int irq, void *dev_id)
return IRQ_HANDLED;
}

+static u64 mvme16x_read_clk(struct clocksource *cs);
+
+static struct clocksource mvme16x_clk = {
+ .name = "pcc",
+ .rating = 250,
+ .read = mvme16x_read_clk,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static u32 clk_total;
+
+#define PCC_TIMER_CLOCK_FREQ 1000000
+#define PCC_TIMER_CYCLES (PCC_TIMER_CLOCK_FREQ / HZ)
+
static irqreturn_t mvme16x_timer_int (int irq, void *dev_id)
{
irq_handler_t timer_routine = dev_id;
@@ -350,6 +366,7 @@ static irqreturn_t mvme16x_timer_int (int irq, void *dev_id)

local_irq_save(flags);
*(volatile unsigned char *)0xfff4201b |= 8;
+ clk_total += PCC_TIMER_CYCLES;
timer_routine(0, NULL);
local_irq_restore(flags);

@@ -363,13 +380,15 @@ void mvme16x_sched_init (irq_handler_t timer_routine)

/* Using PCCchip2 or MC2 chip tick timer 1 */
*(volatile unsigned long *)0xfff42008 = 0;
- *(volatile unsigned long *)0xfff42004 = 10000; /* 10ms */
+ *(volatile unsigned long *)0xfff42004 = PCC_TIMER_CYCLES;
*(volatile unsigned char *)0xfff42017 |= 3;
*(volatile unsigned char *)0xfff4201b = 0x16;
- if (request_irq(MVME16x_IRQ_TIMER, mvme16x_timer_int, 0,
- "timer", timer_routine))
+ if (request_irq(MVME16x_IRQ_TIMER, mvme16x_timer_int, IRQF_TIMER, "timer",
+ timer_routine))
panic ("Couldn't register timer int");

+ clocksource_register_hz(&mvme16x_clk, PCC_TIMER_CLOCK_FREQ);
+
if (brdno == 0x0162 || brdno == 0x172)
irq = MVME162_IRQ_ABORT;
else
@@ -379,11 +398,17 @@ void mvme16x_sched_init (irq_handler_t timer_routine)
panic ("Couldn't register abort int");
}

-
-/* This is always executed with interrupts disabled. */
-u32 mvme16x_gettimeoffset(void)
+static u64 mvme16x_read_clk(struct clocksource *cs)
{
- return (*(volatile u32 *)0xfff42008) * 1000;
+ unsigned long flags;
+ u32 ticks;
+
+ local_irq_save(flags);
+ ticks = *(volatile u32 *)0xfff42008;
+ ticks += clk_total;
+ local_irq_restore(flags);
+
+ return ticks;
}

int bcd2int (unsigned char b)
--
2.18.1
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