m68k: amiga: Convert to clocksource API

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>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
This commit is contained in:
Finn Thain 2018-12-01 11:53:10 +11:00 committed by Geert Uytterhoeven
parent 7d6ca23554
commit 5afd3d06e5
1 changed files with 37 additions and 9 deletions

View File

@ -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 +462,29 @@ 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, clk_offset;
static irqreturn_t ciab_timer_handler(int irq, void *dev_id)
{
irq_handler_t timer_routine = dev_id;
clk_total += jiffy_ticks;
clk_offset = 0;
timer_routine(0, NULL);
return IRQ_HANDLED;
}
static void __init amiga_sched_init(irq_handler_t timer_routine)
{
@ -481,19 +504,22 @@ 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;
clocksource_register_hz(&amiga_clk, amiga_eclock);
}
#define TICK_SIZE 10000
/* This is always executed with interrupts disabled. */
static u32 amiga_gettimeoffset(void)
static u64 amiga_read_clk(struct clocksource *cs)
{
unsigned short hi, lo, hi2;
u32 ticks, offset = 0;
unsigned long flags;
u32 ticks;
local_irq_save(flags);
/* read CIA B timer A current value */
hi = ciab.tahi;
@ -510,12 +536,14 @@ 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;
clk_offset = jiffy_ticks;
ticks = jiffy_ticks - ticks;
ticks = (10000 * ticks) / jiffy_ticks;
ticks += clk_offset + clk_total;
return (ticks + offset) * 1000;
local_irq_restore(flags);
return ticks;
}
static void amiga_reset(void) __noreturn;