[RFC PATCH 07/13] m68k: amiga: Convert to clocksource API

From: Finn Thain
Date: Sun Nov 11 2018 - 23:47:48 EST


Add a platform clocksource by adapting the existing arch_gettimeoffset
implementation.

Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
---
arch/m68k/amiga/config.c | 38 +++++++++++++++++++++++++++++++-------
1 file changed, 31 insertions(+), 7 deletions(-)

diff --git a/arch/m68k/amiga/config.c b/arch/m68k/amiga/config.c
index a575ad419b23..40ebd471cc3c 100644
--- a/arch/m68k/amiga/config.c
+++ b/arch/m68k/amiga/config.c
@@ -17,6 +17,7 @@
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/tty.h>
+#include <linux/clocksource.h>
#include <linux/console.h>
#include <linux/rtc.h>
#include <linux/init.h>
@@ -461,7 +462,30 @@ void __init config_amiga(void)
*(unsigned char *)ZTWO_VADDR(0xde0002) |= 0x80;
}

+static u64 amiga_read_clk(struct clocksource *cs);
+
+static struct clocksource amiga_clk = {
+ .name = "ciab",
+ .rating = 250,
+ .read = amiga_read_clk,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
static unsigned short jiffy_ticks;
+static u32 clk_total;
+
+static irqreturn_t ciab_timer_handler(int irq, void *data)
+{
+ irq_handler_t timer_routine = data;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ clk_total += jiffy_ticks;
+ local_irq_restore(flags);
+
+ return timer_routine(irq, data);
+}

static void __init amiga_sched_init(irq_handler_t timer_routine)
{
@@ -481,15 +505,16 @@ static void __init amiga_sched_init(irq_handler_t timer_routine)
* Please don't change this to use ciaa, as it interferes with the
* SCSI code. We'll have to take a look at this later
*/
- if (request_irq(IRQ_AMIGA_CIAB_TA, timer_routine, 0, "timer", NULL))
+ if (request_irq(IRQ_AMIGA_CIAB_TA, ciab_timer_handler, IRQF_TIMER,
+ "timer", timer_routine))
pr_err("Couldn't register timer interrupt\n");
/* start timer */
ciab.cra |= 0x11;
-}

-#define TICK_SIZE 10000
+ clocksource_register_hz(&amiga_clk, amiga_eclock);
+}

-static u32 amiga_gettimeoffset(void)
+static u64 amiga_read_clk(struct clocksource *cs)
{
unsigned long flags;
unsigned short hi, lo, hi2;
@@ -512,14 +537,13 @@ static u32 amiga_gettimeoffset(void)
if (ticks > jiffy_ticks / 2)
/* check for pending interrupt */
if (cia_set_irq(&ciab_base, 0) & CIA_ICR_TA)
- offset = 10000;
+ offset = jiffy_ticks;

local_irq_restore(flags);

ticks = jiffy_ticks - ticks;
- ticks = (10000 * ticks) / jiffy_ticks;

- return (ticks + offset) * 1000;
+ return clk_total + ticks + offset;
}

static void amiga_reset(void) __noreturn;
--
2.18.1