From: Finn Thain <fthain@telegraphics.com.au>
To: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>,
Arnd Bergmann <arnd@arndb.de>,
Stephen N Chivers <schivers@csc.com.au>,
Thomas Gleixner <tglx@linutronix.de>,
Kars de Jong <jongk@linux-m68k.org>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Michael Schmitz <schmitzmic@gmail.com>,
John Stultz <john.stultz@linaro.org>,
Linus Walleij <linus.walleij@linaro.org>,
linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org
Subject: [PATCH v4 05/14] m68k: amiga: Convert to clocksource API
Date: Sat, 01 Dec 2018 11:53:10 +1100 [thread overview]
Message-ID: <b0f8afebfa9f6cc487fd9c6fd73904ffd16e7b0c.1543625590.git.fthain@telegraphics.com.au> (raw)
In-Reply-To: <cover.1543625590.git.fthain@telegraphics.com.au>
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>
---
Changed since v3:
- Don't test for timer counter > 0 as that should always be true.
- Use clk_offset variable to track the offset when the irq check is skipped.
Changed since v2:
- Don't check for timer interrupt in amiga_read_clk() when the timer is
about to be reloaded.
Changed since v1:
- Moved clk_total access to within the irq lock.
---
arch/m68k/amiga/config.c | 46 ++++++++++++++++++++++++++++++++--------
1 file changed, 37 insertions(+), 9 deletions(-)
diff --git a/arch/m68k/amiga/config.c b/arch/m68k/amiga/config.c
index d4976c1aa0cc..c32ab8041cf6 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 +462,29 @@ 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;
-}
-#define TICK_SIZE 10000
+ clocksource_register_hz(&amiga_clk, amiga_eclock);
+}
-/* 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;
+
+ local_irq_restore(flags);
- return (ticks + offset) * 1000;
+ return ticks;
}
static void amiga_reset(void) __noreturn;
--
2.18.1
next prev parent reply other threads:[~2018-12-01 1:01 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-01 0:53 [PATCH v4 00/14] m68k: Drop arch_gettimeoffset and adopt clocksource API Finn Thain
2018-12-01 0:53 ` Finn Thain [this message]
2018-12-01 0:53 ` [PATCH v4 02/14] m68k: mac: Fix VIA timer counter accesses Finn Thain
2018-12-01 0:53 ` [PATCH v4 01/14] m68k: Call timer_interrupt() with interrupts disabled Finn Thain
2018-12-01 0:53 ` [PATCH v4 09/14] m68k: hp300: Handle timer counter overflow Finn Thain
2018-12-01 0:53 ` [PATCH v4 03/14] m68k: apollo, q40, sun3, sun3x: Remove arch_gettimeoffset implementations Finn Thain
2018-12-01 0:53 ` [PATCH v4 12/14] m68k: mvme147: Handle timer counter overflow Finn Thain
2018-12-01 0:53 ` [PATCH v4 13/14] m68k: mvme16x: Convert to clocksource API Finn Thain
2018-12-01 0:53 ` [PATCH v4 10/14] m68k: mac: " Finn Thain
2018-12-01 0:53 ` [PATCH v4 04/14] m68k: Drop ARCH_USES_GETTIMEOFFSET Finn Thain
2018-12-01 0:53 ` [PATCH v4 07/14] m68k: bvme6000: Convert to clocksource API Finn Thain
2018-12-01 0:53 ` [PATCH v4 14/14] m68k: mvme16x: Handle timer counter overflow Finn Thain
2018-12-01 0:53 ` [PATCH v4 08/14] m68k: hp300: Convert to clocksource API Finn Thain
2018-12-01 0:53 ` [PATCH v4 06/14] m68k: atari: " Finn Thain
2018-12-01 0:53 ` [PATCH v4 11/14] m68k: mvme147: " Finn Thain
2019-03-05 6:13 ` [PATCH v4 00/14] m68k: Drop arch_gettimeoffset and adopt " Finn Thain
2019-03-05 7:50 ` Geert Uytterhoeven
2019-03-05 9:55 ` Finn Thain
2019-03-05 12:01 ` Linus Walleij
2019-03-25 9:25 ` Geert Uytterhoeven
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