diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/mach-iop3xx/iop321-time.c |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/arm/mach-iop3xx/iop321-time.c')
-rw-r--r-- | arch/arm/mach-iop3xx/iop321-time.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/arch/arm/mach-iop3xx/iop321-time.c b/arch/arm/mach-iop3xx/iop321-time.c new file mode 100644 index 00000000000..9b7dd64d1b8 --- /dev/null +++ b/arch/arm/mach-iop3xx/iop321-time.c @@ -0,0 +1,109 @@ +/* + * arch/arm/mach-iop3xx/iop321-time.c + * + * Timer code for IOP321 based systems + * + * Author: Deepak Saxena <dsaxena@mvista.com> + * + * Copyright 2002-2003 MontaVista Software Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/time.h> +#include <linux/init.h> +#include <linux/timex.h> + +#include <asm/hardware.h> +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/uaccess.h> +#include <asm/mach-types.h> +#include <asm/mach/irq.h> +#include <asm/mach/time.h> + +#define IOP321_TIME_SYNC 0 + +static inline unsigned long get_elapsed(void) +{ + return LATCH - *IOP321_TU_TCR0; +} + +static unsigned long iop321_gettimeoffset(void) +{ + unsigned long elapsed, usec; + u32 tisr1, tisr2; + + /* + * If an interrupt was pending before we read the timer, + * we've already wrapped. Factor this into the time. + * If an interrupt was pending after we read the timer, + * it may have wrapped between checking the interrupt + * status and reading the timer. Re-read the timer to + * be sure its value is after the wrap. + */ + + asm volatile("mrc p6, 0, %0, c6, c1, 0" : "=r" (tisr1)); + elapsed = get_elapsed(); + asm volatile("mrc p6, 0, %0, c6, c1, 0" : "=r" (tisr2)); + + if(tisr1 & 1) + elapsed += LATCH; + else if (tisr2 & 1) + elapsed = LATCH + get_elapsed(); + + /* + * Now convert them to usec. + */ + usec = (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH; + + return usec; +} + +static irqreturn_t +iop321_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) +{ + u32 tisr; + + write_seqlock(&xtime_lock); + + asm volatile("mrc p6, 0, %0, c6, c1, 0" : "=r" (tisr)); + tisr |= 1; + asm volatile("mcr p6, 0, %0, c6, c1, 0" : : "r" (tisr)); + + timer_tick(regs); + + write_sequnlock(&xtime_lock); + + return IRQ_HANDLED; +} + +static struct irqaction iop321_timer_irq = { + .name = "IOP321 Timer Tick", + .handler = iop321_timer_interrupt, + .flags = SA_INTERRUPT +}; + +static void __init iop321_timer_init(void) +{ + u32 timer_ctl; + + setup_irq(IRQ_IOP321_TIMER0, &iop321_timer_irq); + + timer_ctl = IOP321_TMR_EN | IOP321_TMR_PRIVILEGED | IOP321_TMR_RELOAD | + IOP321_TMR_RATIO_1_1; + + asm volatile("mcr p6, 0, %0, c4, c1, 0" : : "r" (LATCH)); + + asm volatile("mcr p6, 0, %0, c0, c1, 0" : : "r" (timer_ctl)); +} + +struct sys_timer iop321_timer = { + .init = &iop321_timer_init, + .offset = iop321_gettimeoffset, +}; |