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author | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2012-09-03 09:26:33 +0300 |
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committer | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2012-09-03 09:26:33 +0300 |
commit | c50e86ce7c2961a41f2f7aa6e4fd6c99229ba205 (patch) | |
tree | 4ea36009719bd8fc523239fe1bdccb90f0dce3ae /arch/arm/lib/delay.c | |
parent | 14d33d384693eb6083396199de516fdef320f7af (diff) | |
parent | 4cbe5a555fa58a79b6ecbb6c531b8bab0650778d (diff) |
Merge tag 'v3.6-rc4'
Merge 3.6-rc4 to get latest OMAP and device tree fixes.
Diffstat (limited to 'arch/arm/lib/delay.c')
-rw-r--r-- | arch/arm/lib/delay.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/arch/arm/lib/delay.c b/arch/arm/lib/delay.c new file mode 100644 index 00000000000..d6dacc69254 --- /dev/null +++ b/arch/arm/lib/delay.c @@ -0,0 +1,71 @@ +/* + * Delay loops based on the OpenRISC implementation. + * + * Copyright (C) 2012 ARM Limited + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Author: Will Deacon <will.deacon@arm.com> + */ + +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/timex.h> + +/* + * Default to the loop-based delay implementation. + */ +struct arm_delay_ops arm_delay_ops = { + .delay = __loop_delay, + .const_udelay = __loop_const_udelay, + .udelay = __loop_udelay, +}; + +#ifdef ARCH_HAS_READ_CURRENT_TIMER +static void __timer_delay(unsigned long cycles) +{ + cycles_t start = get_cycles(); + + while ((get_cycles() - start) < cycles) + cpu_relax(); +} + +static void __timer_const_udelay(unsigned long xloops) +{ + unsigned long long loops = xloops; + loops *= loops_per_jiffy; + __timer_delay(loops >> UDELAY_SHIFT); +} + +static void __timer_udelay(unsigned long usecs) +{ + __timer_const_udelay(usecs * UDELAY_MULT); +} + +void __init init_current_timer_delay(unsigned long freq) +{ + pr_info("Switching to timer-based delay loop\n"); + lpj_fine = freq / HZ; + arm_delay_ops.delay = __timer_delay; + arm_delay_ops.const_udelay = __timer_const_udelay; + arm_delay_ops.udelay = __timer_udelay; +} + +unsigned long __cpuinit calibrate_delay_is_known(void) +{ + return lpj_fine; +} +#endif |