diff options
author | Andrew Victor <andrew@sanpeople.com> | 2007-02-05 10:42:07 (GMT) |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2007-02-08 14:50:56 (GMT) |
commit | 9d0412680e6c7b685ee466842047bcfb924d6dc5 (patch) | |
tree | c79300964ef1aca5d24571696f95e76b37c14679 /arch/arm/mach-at91/at91sam926x_time.c | |
parent | a93d48cc6019f84394b31d10c0d830a3b71696be (diff) | |
download | linux-9d0412680e6c7b685ee466842047bcfb924d6dc5.tar.xz |
[ARM] 4124/1: Rename mach-at91rm9200 and arch-at91rm9200 directories
Now that Linux includes support for the Atmel AT91SAM9260 and
AT91SAM9261 processors in addition to the original Atmel AT91RM9200
(with support for more AT91 processors pending), the "mach-at91rm9200"
and "arch-at91rm9200" directories should be renamed to indicate their
more generic nature.
The following git commands should be run BEFORE applying this patch:
git-mv arch/arm/mach-at91rm9200 arch/arm/mach-at91
git-mv include/asm-arm/arch-at91rm9200 include/asm-arm/arch-at91
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mach-at91/at91sam926x_time.c')
-rw-r--r-- | arch/arm/mach-at91/at91sam926x_time.c | 114 |
1 files changed, 114 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 0000000..59cbbe1 --- /dev/null +++ b/arch/arm/mach-at91/at91sam926x_time.c @@ -0,0 +1,114 @@ +/* + * 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. + * 'tick' is usecs per jiffy (linux/timex.h). + */ +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 * 1000000) / 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, +}; + |