[PATCH CFT] ARM: orion: implement ARM delay timer
From: Gregory CLEMENT <hidden>
Date: 2016-01-27 07:58:50
Hi Russell, On lun., oct. 19 2015, Russell King [off-list ref] wrote:
Implement an ARM delay timer to be used for udelay() on orion legacy platforms. This allows us to skip the delay loop calibration at boot. It also means that udelay() will be unaffected by CPU frequency changes when cpufreq is enabled on these platforms. Signed-off-by: Russell King <redacted>
Applied on mvebu/drivers with Acked-by tag from Andrew Lunn Thanks, Gregory
quoted hunk
--- This needs to be tested beyond build testing... arch/arm/plat-orion/time.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)diff --git a/arch/arm/plat-orion/time.c b/arch/arm/plat-orion/time.c index 8085a8aac812..ffb93db68e9c 100644 --- a/arch/arm/plat-orion/time.c +++ b/arch/arm/plat-orion/time.c@@ -18,6 +18,7 @@ #include <linux/irq.h> #include <linux/sched_clock.h> #include <plat/time.h> +#include <asm/delay.h> /* * MBus bridge block registers.@@ -188,6 +189,15 @@ orion_time_set_base(void __iomem *_timer_base) timer_base = _timer_base; } +static unsigned long orion_delay_timer_read(void) +{ + return ~readl(timer_base + TIMER0_VAL_OFF); +} + +static struct delay_timer orion_delay_timer = { + .read_current_timer = orion_delay_timer_read, +}; + void __init orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask, unsigned int irq, unsigned int tclk)@@ -202,6 +212,9 @@ orion_time_init(void __iomem *_bridge_base, u32 _bridge_timer1_clr_mask, ticks_per_jiffy = (tclk + HZ/2) / HZ; + orion_delay_timer.freq = tclk; + register_current_timer_delay(&orion_delay_timer); + /* * Set scale and timer for sched_clock. */-- 2.1.0
-- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com