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Diffstat (limited to 'cpu/at32ap/interrupts.c')
-rw-r--r-- | cpu/at32ap/interrupts.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/cpu/at32ap/interrupts.c b/cpu/at32ap/interrupts.c new file mode 100644 index 0000000000..d720cfa942 --- /dev/null +++ b/cpu/at32ap/interrupts.c @@ -0,0 +1,154 @@ +/* + * Copyright (C) 2004-2006 Atmel Corporation + * + * See file CREDITS for list of people who contributed to this + * project. + * + * 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 <common.h> + +#include <asm/div64.h> +#include <asm/errno.h> +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/sysreg.h> + +#include <asm/arch/platform.h> + +#define HANDLER_MASK 0x00ffffff +#define INTLEV_SHIFT 30 +#define INTLEV_MASK 0x00000003 + +DECLARE_GLOBAL_DATA_PTR; + +/* Incremented whenever COUNT reaches 0xffffffff by timer_interrupt_handler */ +volatile unsigned long timer_overflow; + +/* + * Instead of dividing by get_tbclk(), multiply by this constant and + * right-shift the result by 32 bits. + */ +static unsigned long tb_factor; + +static const struct device *intc_dev; + +unsigned long get_tbclk(void) +{ + return gd->cpu_hz; +} + +unsigned long long get_ticks(void) +{ + unsigned long lo, hi_now, hi_prev; + + do { + hi_prev = timer_overflow; + lo = sysreg_read(COUNT); + hi_now = timer_overflow; + } while (hi_prev != hi_now); + + return ((unsigned long long)hi_now << 32) | lo; +} + +void reset_timer(void) +{ + sysreg_write(COUNT, 0); + cpu_sync_pipeline(); /* process any pending interrupts */ + timer_overflow = 0; +} + +unsigned long get_timer(unsigned long base) +{ + u64 now = get_ticks(); + + now *= tb_factor; + return (unsigned long)(now >> 32) - base; +} + +void set_timer(unsigned long t) +{ + unsigned long long ticks = t; + unsigned long lo, hi, hi_new; + + ticks = (ticks * get_tbclk()) / CFG_HZ; + hi = ticks >> 32; + lo = ticks & 0xffffffffUL; + + do { + timer_overflow = hi; + sysreg_write(COUNT, lo); + hi_new = timer_overflow; + } while (hi_new != hi); +} + +/* + * For short delays only. It will overflow after a few seconds. + */ +void udelay(unsigned long usec) +{ + unsigned long now, end; + + now = sysreg_read(COUNT); + + end = ((usec * (get_tbclk() / 10000)) + 50) / 100; + end += now; + + while (now > end) + now = sysreg_read(COUNT); + + while (now < end) + now = sysreg_read(COUNT); +} + +static int set_interrupt_handler(unsigned int nr, void (*handler)(void), + unsigned int priority) +{ + unsigned long intpr; + unsigned long handler_addr = (unsigned long)handler; + + if ((handler_addr & HANDLER_MASK) != handler_addr + || (priority & INTLEV_MASK) != priority) + return -EINVAL; + + intpr = (handler_addr & HANDLER_MASK); + intpr |= (priority & INTLEV_MASK) << INTLEV_SHIFT; + writel(intpr, intc_dev->regs + 4 * nr); + + return 0; +} + +void timer_init(void) +{ + extern void timer_interrupt_handler(void); + u64 tmp; + + sysreg_write(COUNT, 0); + + tmp = (u64)CFG_HZ << 32; + tmp += gd->cpu_hz / 2; + do_div(tmp, gd->cpu_hz); + tb_factor = (u32)tmp; + + intc_dev = get_device(DEVICE_INTC); + + if (!intc_dev + || set_interrupt_handler(0, &timer_interrupt_handler, 3)) + return; + + /* For all practical purposes, this gives us an overflow interrupt */ + sysreg_write(COMPARE, 0xffffffff); +} |