From: John Stultz <johnstul@us.ibm.com>
To: lkml <linux-kernel@vger.kernel.org>
Cc: John Stultz <johnstul@us.ibm.com>,
Mike Frysinger <vapier@gentoo.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH 08/10] blackfin: convert to clocksource_register_hz
Date: Mon, 1 Nov 2010 13:12:28 -0700 [thread overview]
Message-ID: <1288642350-1599-9-git-send-email-johnstul@us.ibm.com> (raw)
In-Reply-To: <1288642350-1599-1-git-send-email-johnstul@us.ibm.com>
This converts the blackfin clocksource to use clocksource_register_hz.
This is untested, so any assistance in testing would be appreciated!
CC: Mike Frysinger <vapier@gentoo.org>
CC: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: John Stultz <johnstul@us.ibm.com>
---
arch/blackfin/kernel/time-ts.c | 35 ++---------------------------------
1 files changed, 2 insertions(+), 33 deletions(-)
diff --git a/arch/blackfin/kernel/time-ts.c b/arch/blackfin/kernel/time-ts.c
index 8c9a43d..4a01371 100644
--- a/arch/blackfin/kernel/time-ts.c
+++ b/arch/blackfin/kernel/time-ts.c
@@ -23,29 +23,6 @@
#include <asm/gptimers.h>
#include <asm/nmi.h>
-/* Accelerators for sched_clock()
- * convert from cycles(64bits) => nanoseconds (64bits)
- * basic equation:
- * ns = cycles / (freq / ns_per_sec)
- * ns = cycles * (ns_per_sec / freq)
- * ns = cycles * (10^9 / (cpu_khz * 10^3))
- * ns = cycles * (10^6 / cpu_khz)
- *
- * Then we use scaling math (suggested by george@mvista.com) to get:
- * ns = cycles * (10^6 * SC / cpu_khz) / SC
- * ns = cycles * cyc2ns_scale / SC
- *
- * And since SC is a constant power of two, we can convert the div
- * into a shift.
- *
- * We can use khz divisor instead of mhz to keep a better precision, since
- * cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
- * (mathieu.desnoyers@polymtl.ca)
- *
- * -johnstul@us.ibm.com "math is hard, lets go shopping!"
- */
-
-#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
#if defined(CONFIG_CYCLES_CLOCKSOURCE)
@@ -63,7 +40,6 @@ static struct clocksource bfin_cs_cycles = {
.rating = 400,
.read = bfin_read_cycles,
.mask = CLOCKSOURCE_MASK(64),
- .shift = CYC2NS_SCALE_FACTOR,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
@@ -75,10 +51,7 @@ static inline unsigned long long bfin_cs_cycles_sched_clock(void)
static int __init bfin_cs_cycles_init(void)
{
- bfin_cs_cycles.mult = \
- clocksource_hz2mult(get_cclk(), bfin_cs_cycles.shift);
-
- if (clocksource_register(&bfin_cs_cycles))
+ if (clocksource_register_hz(&bfin_cs_cycles, get_cclk()))
panic("failed to register clocksource");
return 0;
@@ -111,7 +84,6 @@ static struct clocksource bfin_cs_gptimer0 = {
.rating = 350,
.read = bfin_read_gptimer0,
.mask = CLOCKSOURCE_MASK(32),
- .shift = CYC2NS_SCALE_FACTOR,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
@@ -125,10 +97,7 @@ static int __init bfin_cs_gptimer0_init(void)
{
setup_gptimer0();
- bfin_cs_gptimer0.mult = \
- clocksource_hz2mult(get_sclk(), bfin_cs_gptimer0.shift);
-
- if (clocksource_register(&bfin_cs_gptimer0))
+ if (clocksource_register_hz(&bfin_cs_gptimer0, get_sclk()))
panic("failed to register clocksource");
return 0;
--
1.7.3.2.146.gca209
next prev parent reply other threads:[~2010-11-01 20:13 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-01 20:12 [PATCH 00/10] clocksource_register_khz/hz cleanups (for 2.6.38) John Stultz
2010-11-01 20:12 ` [PATCH 01/10] x86: Convert untested clocksources to clocksource_register_hz/khz John Stultz
2010-11-01 20:12 ` [PATCH 02/10] ia64: convert " John Stultz
2010-11-01 20:12 ` [PATCH 03/10] cris: convert to clocksource_register_khz John Stultz
2010-11-01 20:12 ` [PATCH 04/10] tile: convert to use clocksource_register_hz John Stultz
2010-11-11 21:21 ` Chris Metcalf
2010-11-11 22:06 ` john stultz
2010-11-11 22:22 ` Peter Zijlstra
2010-11-11 23:21 ` john stultz
2010-11-11 22:17 ` john stultz
2010-11-01 20:12 ` [PATCH 05/10] parisc: convert to clocksource_register_hz/khz John Stultz
2010-11-01 20:12 ` [PATCH 06/10] microblaze: " John Stultz
2010-11-10 13:10 ` Michal Simek
2010-11-01 20:12 ` [PATCH 07/10] avr32: Convert to clocksource_register_hz John Stultz
2010-11-01 20:12 ` John Stultz [this message]
2010-11-01 20:12 ` [PATCH 09/10] xtensa: convert to clocksource_register_hz/khz John Stultz
2010-11-01 20:12 ` [PATCH 10/10] sparc: " John Stultz
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