[PATCH 04/11] ARM: set arch_gettimeoffset directly
Ryan Mallon
rmallon at gmail.com
Thu Nov 8 18:06:15 EST 2012
On 09/11/12 08:01, Stephen Warren wrote:
> From: Stephen Warren <swarren at nvidia.com>
>
> remove ARM's struct sys_timer .offset function pointer, and instead
> directly set the arch_gettimeoffset function pointer when the timer
> driver is initialized. This requires multiplying all function results
> by 1000, since the removed arm_gettimeoffset() did this. Also,
> s/unsigned long/u32/ just to make the function prototypes exactly
> match that of arch_gettimeoffset.
>
> Cc: Russell King <linux at arm.linux.org.uk>
> Cc: Andrew Victor <linux at maxim.org.za>
> Cc: Nicolas Ferre <nicolas.ferre at atmel.com>
> Cc: Jean-Christophe Plagniol-Villard <plagnioj at jcrosoft.com>
> Cc: Hartley Sweeten <hsweeten at visionengravers.com>
> Cc: Ryan Mallon <rmallon at gmail.com>
> Cc: Ben Dooks <ben-linux at fluff.org>
> Cc: Kukjin Kim <kgene.kim at samsung.com>
> Signed-off-by: Stephen Warren <swarren at nvidia.com>
> ---
> arch/arm/include/asm/mach/time.h | 3 ---
> arch/arm/kernel/time.c | 14 --------------
> arch/arm/mach-at91/at91x40_time.c | 8 +++++---
> arch/arm/mach-ebsa110/core.c | 7 ++++---
> arch/arm/mach-ep93xx/core.c | 23 ++++++++++++-----------
> arch/arm/mach-h720x/common.c | 6 +++---
> arch/arm/mach-h720x/common.h | 2 +-
> arch/arm/mach-h720x/cpu-h7201.c | 3 ++-
> arch/arm/mach-h720x/cpu-h7202.c | 3 ++-
> arch/arm/mach-rpc/time.c | 6 +++---
> arch/arm/plat-samsung/time.c | 7 ++++---
> 11 files changed, 36 insertions(+), 46 deletions(-)
<snip>
> +static u32 ep93xx_gettimeoffset(void)
> +{
> + int offset;
> +
> + offset = __raw_readl(EP93XX_TIMER4_VALUE_LOW) - last_jiffy_time;
> +
> + /* Calculate (1000000 / 983040) * offset. */
This comment is now incorrect, it should say:
/* Calculate (1000000000 / 983040) * offset */
or perhaps to better explain what is being done:
/*
* Timer 4 is based on a 983.04 kHz reference clock,
* so dividing by 983040 gives a milli-second value.
* Refactor the calculation to avoid overflow.
*/
> + return (offset + (53 * offset / 3072)) * 1000;
> +}
~Ryan
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