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Diffstat (limited to 'kernel/arch/mn10300/lib/delay.c')
| -rw-r--r-- | kernel/arch/mn10300/lib/delay.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/kernel/arch/mn10300/lib/delay.c b/kernel/arch/mn10300/lib/delay.c new file mode 100644 index 000000000..8e7ceb8ba --- /dev/null +++ b/kernel/arch/mn10300/lib/delay.c @@ -0,0 +1,51 @@ +/* MN10300 Short delay interpolation routines + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/delay.h> +#include <asm/div64.h> + +/* + * basic delay loop + */ +void __delay(unsigned long loops) +{ + int d0; + + asm volatile( + " bra 1f \n" + " .align 4 \n" + "1: bra 2f \n" + " .align 4 \n" + "2: add -1,%0 \n" + " bne 2b \n" + : "=&d" (d0) + : "0" (loops) + : "cc"); +} +EXPORT_SYMBOL(__delay); + +/* + * handle a delay specified in terms of microseconds + */ +void __udelay(unsigned long usecs) +{ + unsigned long start, stop, cnt; + + /* usecs * CLK / 1E6 */ + stop = __muldiv64u(usecs, MN10300_TSCCLK, 1000000); + start = TMTSCBC; + + do { + cnt = start - TMTSCBC; + } while (cnt < stop); +} +EXPORT_SYMBOL(__udelay); |