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-rw-r--r--arch/blackfin/cpu/interrupts.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/arch/blackfin/cpu/interrupts.c b/arch/blackfin/cpu/interrupts.c
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+/*
+ * 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();
+}