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author | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-19 13:18:39 -0800 |
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committer | Linus Torvalds <torvalds@woody.linux-foundation.org> | 2007-02-19 13:18:39 -0800 |
commit | 59b8175c771040afcd4ad67022b0cc80c216b866 (patch) | |
tree | 4ef5935bee1e342716d49b9d4b99e3fa835526e6 /arch/arm/mach-at91/at91sam926x_time.c | |
parent | 920841d8d1d61bc12b43f95a579a5374f6d98f81 (diff) | |
parent | 3b0eb4a195a124567cd0dd6f700f8388def542c6 (diff) | |
download | talos-obmc-linux-59b8175c771040afcd4ad67022b0cc80c216b866.tar.gz talos-obmc-linux-59b8175c771040afcd4ad67022b0cc80c216b866.zip |
Merge branch 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm
* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (117 commits)
[ARM] 4058/2: iop32x: set ->broken_parity_status on n2100 onboard r8169 ports
[ARM] 4140/1: AACI stability add ac97 timeout and retries
[ARM] 4139/1: AACI record support
[ARM] 4138/1: AACI: multiple channel support for IRQ handling
[ARM] 4211/1: Provide a defconfig for ns9xxx
[ARM] 4210/1: base for new machine type "NetSilicon NS9360"
[ARM] 4222/1: S3C2443: Remove reference to missing S3C2443_PM
[ARM] 4221/1: S3C2443: DMA support
[ARM] 4220/1: S3C24XX: DMA system initialised from sysdev
[ARM] 4219/1: S3C2443: DMA source definitions
[ARM] 4218/1: S3C2412: fix CONFIG_CPU_S3C2412_ONLY wrt to S3C2443
[ARM] 4217/1: S3C24XX: remove the dma channel show at startup
[ARM] 4090/2: avoid clash between PXA and SA1111 defines
[ARM] 4216/1: add .gitignore entries for ARM specific files
[ARM] 4214/2: S3C2410: Add Armzone QT2410
[ARM] 4215/1: s3c2410 usb device: per-platform vbus_draw
[ARM] 4213/1: S3C2410 - Update definition of ADCTSC_XY_PST
[ARM] 4098/1: ARM: rtc_lock only used with rtc_cmos
[ARM] 4137/1: Add kexec support
[ARM] 4201/1: SMP barriers pair needed for the secondary boot process
...
Fix up conflict due to typedef removal in sound/arm/aaci.h
Diffstat (limited to 'arch/arm/mach-at91/at91sam926x_time.c')
-rw-r--r-- | arch/arm/mach-at91/at91sam926x_time.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c new file mode 100644 index 000000000000..a4dded27fa16 --- /dev/null +++ b/arch/arm/mach-at91/at91sam926x_time.c @@ -0,0 +1,113 @@ +/* + * linux/arch/arm/mach-at91/at91sam926x_time.c + * + * Copyright (C) 2005-2006 M. Amine SAYA, ATMEL Rousset, France + * Revision 2005 M. Nicolas Diremdjian, ATMEL Rousset, France + * + * 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. + */ + +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/time.h> + +#include <asm/hardware.h> +#include <asm/io.h> +#include <asm/mach/time.h> + +#include <asm/arch/at91_pit.h> + + +#define PIT_CPIV(x) ((x) & AT91_PIT_CPIV) +#define PIT_PICNT(x) (((x) & AT91_PIT_PICNT) >> 20) + +/* + * Returns number of microseconds since last timer interrupt. Note that interrupts + * will have been disabled by do_gettimeofday() + * 'LATCH' is hwclock ticks (see CLOCK_TICK_RATE in timex.h) per jiffy. + */ +static unsigned long at91sam926x_gettimeoffset(void) +{ + unsigned long elapsed; + unsigned long t = at91_sys_read(AT91_PIT_PIIR); + + elapsed = (PIT_PICNT(t) * LATCH) + PIT_CPIV(t); /* hardware clock cycles */ + + return (unsigned long)(elapsed * jiffies_to_usecs(1)) / LATCH; +} + +/* + * IRQ handler for the timer. + */ +static irqreturn_t at91sam926x_timer_interrupt(int irq, void *dev_id) +{ + volatile long nr_ticks; + + if (at91_sys_read(AT91_PIT_SR) & AT91_PIT_PITS) { /* This is a shared interrupt */ + write_seqlock(&xtime_lock); + + /* Get number to ticks performed before interrupt and clear PIT interrupt */ + nr_ticks = PIT_PICNT(at91_sys_read(AT91_PIT_PIVR)); + do { + timer_tick(); + nr_ticks--; + } while (nr_ticks); + + write_sequnlock(&xtime_lock); + return IRQ_HANDLED; + } else + return IRQ_NONE; /* not handled */ +} + +static struct irqaction at91sam926x_timer_irq = { + .name = "at91_tick", + .flags = IRQF_SHARED | IRQF_DISABLED | IRQF_TIMER, + .handler = at91sam926x_timer_interrupt +}; + +void at91sam926x_timer_reset(void) +{ + /* Disable timer */ + at91_sys_write(AT91_PIT_MR, 0); + + /* Clear any pending interrupts */ + (void) at91_sys_read(AT91_PIT_PIVR); + + /* Set Period Interval timer and enable its interrupt */ + at91_sys_write(AT91_PIT_MR, (LATCH & AT91_PIT_PIV) | AT91_PIT_PITIEN | AT91_PIT_PITEN); +} + +/* + * Set up timer interrupt. + */ +void __init at91sam926x_timer_init(void) +{ + /* Initialize and enable the timer */ + at91sam926x_timer_reset(); + + /* Make IRQs happen for the system timer. */ + setup_irq(AT91_ID_SYS, &at91sam926x_timer_irq); +} + +#ifdef CONFIG_PM +static void at91sam926x_timer_suspend(void) +{ + /* Disable timer */ + at91_sys_write(AT91_PIT_MR, 0); +} +#else +#define at91sam926x_timer_suspend NULL +#endif + +struct sys_timer at91sam926x_timer = { + .init = at91sam926x_timer_init, + .offset = at91sam926x_gettimeoffset, + .suspend = at91sam926x_timer_suspend, + .resume = at91sam926x_timer_reset, +}; + |