diff options
| -rw-r--r-- | arch/arm/mach-at91rm9200/Makefile | 4 | ||||
| -rw-r--r-- | arch/arm/mach-at91rm9200/at91sam926x_time.c | 114 | ||||
| -rw-r--r-- | include/asm-arm/arch-at91rm9200/at91_pit.h | 29 |
3 files changed, 145 insertions, 2 deletions
diff --git a/arch/arm/mach-at91rm9200/Makefile b/arch/arm/mach-at91rm9200/Makefile index 40e89bf459f..b8684ba60ce 100644 --- a/arch/arm/mach-at91rm9200/Makefile +++ b/arch/arm/mach-at91rm9200/Makefile @@ -11,8 +11,8 @@ obj-$(CONFIG_PM) += pm.o # CPU-specific support obj-$(CONFIG_ARCH_AT91RM9200) += at91rm9200.o at91rm9200_time.o at91rm9200_devices.c -obj-$(CONFIG_ARCH_AT91SAM9260) += at91sam9260.o -obj-$(CONFIG_ARCH_AT91SAM9261) += at91sam9261.o +obj-$(CONFIG_ARCH_AT91SAM9260) += at91sam9260.o at91sam926x_time.o +obj-$(CONFIG_ARCH_AT91SAM9261) += at91sam9261.o at91sam926x_time.o # AT91RM9200 board-specific support obj-$(CONFIG_MACH_ONEARM) += board-1arm.o diff --git a/arch/arm/mach-at91rm9200/at91sam926x_time.c b/arch/arm/mach-at91rm9200/at91sam926x_time.c new file mode 100644 index 00000000000..99df5f6ee42 --- /dev/null +++ b/arch/arm/mach-at91rm9200/at91sam926x_time.c @@ -0,0 +1,114 @@ +/* + * linux/arch/arm/mach-at91rm9200/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, +}; + diff --git a/include/asm-arm/arch-at91rm9200/at91_pit.h b/include/asm-arm/arch-at91rm9200/at91_pit.h new file mode 100644 index 00000000000..4a30d009c58 --- /dev/null +++ b/include/asm-arm/arch-at91rm9200/at91_pit.h @@ -0,0 +1,29 @@ +/* + * include/asm-arm/arch-at91rm9200/at91_pit.h + * + * Periodic Interval Timer (PIT) - System peripherals regsters. + * Based on AT91SAM9261 datasheet revision D. + * + * 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. + */ + +#ifndef AT91_PIT_H +#define AT91_PIT_H + +#define AT91_PIT_MR (AT91_PIT + 0x00) /* Mode Register */ +#define AT91_PIT_PITIEN (1 << 25) /* Timer Interrupt Enable */ +#define AT91_PIT_PITEN (1 << 24) /* Timer Enabled */ +#define AT91_PIT_PIV (0xfffff) /* Periodic Interval Value */ + +#define AT91_PIT_SR (AT91_PIT + 0x04) /* Status Register */ +#define AT91_PIT_PITS (1 << 0) /* Timer Status */ + +#define AT91_PIT_PIVR (AT91_PIT + 0x08) /* Periodic Interval Value Register */ +#define AT91_PIT_PIIR (AT91_PIT + 0x0c) /* Periodic Interval Image Register */ +#define AT91_PIT_PICNT (0xfff << 20) /* Interval Counter */ +#define AT91_PIT_CPIV (0xfffff) /* Inverval Value */ + +#endif |