diff options
Diffstat (limited to 'arch/arm/mach-at91rm9200/at91rm9200_time.c')
| -rw-r--r-- | arch/arm/mach-at91rm9200/at91rm9200_time.c | 146 |
1 files changed, 0 insertions, 146 deletions
diff --git a/arch/arm/mach-at91rm9200/at91rm9200_time.c b/arch/arm/mach-at91rm9200/at91rm9200_time.c deleted file mode 100644 index b999e192a7e9..000000000000 --- a/arch/arm/mach-at91rm9200/at91rm9200_time.c +++ /dev/null @@ -1,146 +0,0 @@ -/* - * linux/arch/arm/mach-at91rm9200/at91rm9200_time.c - * - * Copyright (C) 2003 SAN People - * Copyright (C) 2003 ATMEL - * - * 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. - * - * 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 - */ - -#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_st.h> - -static unsigned long last_crtr; - -/* - * The ST_CRTR is updated asynchronously to the master clock. It is therefore - * necessary to read it twice (with the same value) to ensure accuracy. - */ -static inline unsigned long read_CRTR(void) { - unsigned long x1, x2; - - do { - x1 = at91_sys_read(AT91_ST_CRTR); - x2 = at91_sys_read(AT91_ST_CRTR); - } while (x1 != x2); - - return x1; -} - -/* - * 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 at91rm9200_gettimeoffset(void) -{ - unsigned long elapsed; - - elapsed = (read_CRTR() - last_crtr) & AT91_ST_ALMV; - - return (unsigned long)(elapsed * (tick_nsec / 1000)) / LATCH; -} - -/* - * IRQ handler for the timer. - */ -static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id) -{ - if (at91_sys_read(AT91_ST_SR) & AT91_ST_PITS) { /* This is a shared interrupt */ - write_seqlock(&xtime_lock); - - while (((read_CRTR() - last_crtr) & AT91_ST_ALMV) >= LATCH) { - timer_tick(); - last_crtr = (last_crtr + LATCH) & AT91_ST_ALMV; - } - - write_sequnlock(&xtime_lock); - - return IRQ_HANDLED; - } - else - return IRQ_NONE; /* not handled */ -} - -static struct irqaction at91rm9200_timer_irq = { - .name = "at91_tick", - .flags = IRQF_SHARED | IRQF_DISABLED | IRQF_TIMER, - .handler = at91rm9200_timer_interrupt -}; - -void at91rm9200_timer_reset(void) -{ - last_crtr = 0; - - /* Real time counter incremented every 30.51758 microseconds */ - at91_sys_write(AT91_ST_RTMR, 1); - - /* Set Period Interval timer */ - at91_sys_write(AT91_ST_PIMR, LATCH); - - /* Clear any pending interrupts */ - (void) at91_sys_read(AT91_ST_SR); - - /* Enable Period Interval Timer interrupt */ - at91_sys_write(AT91_ST_IER, AT91_ST_PITS); -} - -/* - * Set up timer interrupt. - */ -void __init at91rm9200_timer_init(void) -{ - /* Disable all timer interrupts */ - at91_sys_write(AT91_ST_IDR, AT91_ST_PITS | AT91_ST_WDOVF | AT91_ST_RTTINC | AT91_ST_ALMS); - (void) at91_sys_read(AT91_ST_SR); /* Clear any pending interrupts */ - - /* Make IRQs happen for the system timer */ - setup_irq(AT91_ID_SYS, &at91rm9200_timer_irq); - - /* Change the kernel's 'tick' value to 10009 usec. (the default is 10000) */ - tick_usec = (LATCH * 1000000) / CLOCK_TICK_RATE; - - /* Initialize and enable the timer interrupt */ - at91rm9200_timer_reset(); -} - -#ifdef CONFIG_PM -static void at91rm9200_timer_suspend(void) -{ - /* disable Period Interval Timer interrupt */ - at91_sys_write(AT91_ST_IDR, AT91_ST_PITS); -} -#else -#define at91rm9200_timer_suspend NULL -#endif - -struct sys_timer at91rm9200_timer = { - .init = at91rm9200_timer_init, - .offset = at91rm9200_gettimeoffset, - .suspend = at91rm9200_timer_suspend, - .resume = at91rm9200_timer_reset, -}; - |