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Diffstat (limited to 'arch/blackfin/cpu/interrupts.c')
| -rw-r--r-- | arch/blackfin/cpu/interrupts.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/arch/blackfin/cpu/interrupts.c b/arch/blackfin/cpu/interrupts.c new file mode 100644 index 0000000..54a67b4 --- /dev/null +++ b/arch/blackfin/cpu/interrupts.c @@ -0,0 +1,159 @@ +/* + * U-boot - interrupts.c Interrupt related routines + * + * Copyright (c) 2005-2008 Analog Devices Inc. + * + * This file is based on interrupts.c + * Copyright 1996 Roman Zippel + * Copyright 1999 D. Jeff Dionne <jeff@uclinux.org> + * Copyright 2000-2001 Lineo, Inc. D. Jefff Dionne <jeff@lineo.ca> + * Copyright 2002 Arcturus Networks Inc. MaTed <mated@sympatico.ca> + * Copyright 2003 Metrowerks/Motorola + * Copyright 2003 Bas Vermeulen <bas@buyways.nl>, + * BuyWays B.V. (www.buyways.nl) + * + * (C) Copyright 2000-2004 + * Wolfgang Denk, DENX Software Engineering, wd@denx.de. + * + * Licensed under the GPL-2 or later. + */ + +#include <common.h> +#include <config.h> +#include <watchdog.h> +#include <asm/blackfin.h> +#include "cpu.h" + +static ulong timestamp; +static ulong last_time; +static int int_flag; + +int irq_flags; /* needed by asm-blackfin/system.h */ + +/* Functions just to satisfy the linker */ + +/* + * This function is derived from PowerPC code (read timebase as long long). + * On Blackfin it just returns the timer value. + */ +unsigned long long get_ticks(void) +{ + return get_timer(0); +} + +/* + * This function is derived from PowerPC code (timebase clock frequency). + * On Blackfin it returns the number of timer ticks per second. + */ +ulong get_tbclk(void) +{ + ulong tbclk; + + tbclk = CONFIG_SYS_HZ; + return tbclk; +} + +void enable_interrupts(void) +{ + local_irq_restore(int_flag); +} + +int disable_interrupts(void) +{ + local_irq_save(int_flag); + return 1; +} + +void __udelay(unsigned long usec) +{ + unsigned long delay, start, stop; + unsigned long cclk; + cclk = (CONFIG_CCLK_HZ); + + while (usec > 1) { + WATCHDOG_RESET(); + + /* + * how many clock ticks to delay? + * - request(in useconds) * clock_ticks(Hz) / useconds/second + */ + if (usec < 1000) { + delay = (usec * (cclk / 244)) >> 12; + usec = 0; + } else { + delay = (1000 * (cclk / 244)) >> 12; + usec -= 1000; + } + + asm volatile (" %0 = CYCLES;" : "=r" (start)); + do { + asm volatile (" %0 = CYCLES; " : "=r" (stop)); + } while (stop - start < delay); + } + + return; +} + +#define MAX_TIM_LOAD 0xFFFFFFFF +int timer_init(void) +{ + bfin_write_TCNTL(0x1); + CSYNC(); + bfin_write_TSCALE(0x0); + bfin_write_TCOUNT(MAX_TIM_LOAD); + bfin_write_TPERIOD(MAX_TIM_LOAD); + bfin_write_TCNTL(0x7); + CSYNC(); + + timestamp = 0; + last_time = 0; + + return 0; +} + +/* + * Any network command or flash + * command is started get_timer shall + * be called before TCOUNT gets reset, + * to implement the accurate timeouts. + * + * How ever milliconds doesn't return + * the number that has been elapsed from + * the last reset. + * + * As get_timer is used in the u-boot + * only for timeouts this should be + * sufficient + */ +ulong get_timer(ulong base) +{ + ulong milisec; + + /* Number of clocks elapsed */ + ulong clocks = (MAX_TIM_LOAD - bfin_read_TCOUNT()); + + /* + * Find if the TCOUNT is reset + * timestamp gives the number of times + * TCOUNT got reset + */ + if (clocks < last_time) + timestamp++; + last_time = clocks; + + /* Get the number of milliseconds */ + milisec = clocks / (CONFIG_CCLK_HZ / 1000); + + /* + * Find the number of millisonds that + * got elapsed before this TCOUNT cycle + */ + milisec += timestamp * (MAX_TIM_LOAD / (CONFIG_CCLK_HZ / 1000)); + + return (milisec - base); +} + +void reset_timer(void) +{ + timer_init(); +} |