| 1 | /* |
|---|
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
|---|
| 3 | * License. See the file "COPYING" in the main directory of this archive |
|---|
| 4 | * for more details. |
|---|
| 5 | * |
|---|
| 6 | * Copyright (C) 1994 by Waldorf Electronics |
|---|
| 7 | * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle |
|---|
| 8 | * Copyright (C) 1999, 2000 Silicon Graphics, Inc. |
|---|
| 9 | * Copyright (C) 2007, 2014 Maciej W. Rozycki |
|---|
| 10 | */ |
|---|
| 11 | #include <linux/delay.h> |
|---|
| 12 | #include <linux/export.h> |
|---|
| 13 | #include <linux/param.h> |
|---|
| 14 | #include <linux/smp.h> |
|---|
| 15 | #include <linux/stringify.h> |
|---|
| 16 | |
|---|
| 17 | #include <asm/asm.h> |
|---|
| 18 | #include <asm/compiler.h> |
|---|
| 19 | |
|---|
| 20 | #ifndef CONFIG_CPU_DADDI_WORKAROUNDS |
|---|
| 21 | #define GCC_DADDI_IMM_ASM() "I" |
|---|
| 22 | #else |
|---|
| 23 | #define GCC_DADDI_IMM_ASM() "r" |
|---|
| 24 | #endif |
|---|
| 25 | |
|---|
| 26 | #ifndef CONFIG_HAVE_PLAT_DELAY |
|---|
| 27 | |
|---|
| 28 | void __delay(unsigned long loops) |
|---|
| 29 | { |
|---|
| 30 | __asm__ __volatile__ ( |
|---|
| 31 | " .set noreorder \n" |
|---|
| 32 | " .align 3 \n" |
|---|
| 33 | "1: bnez %0, 1b \n" |
|---|
| 34 | " " __stringify(LONG_SUBU) " %0, %1 \n" |
|---|
| 35 | " .set reorder \n" |
|---|
| 36 | : "=r" (loops) |
|---|
| 37 | : GCC_DADDI_IMM_ASM() (1), "0" (loops)); |
|---|
| 38 | } |
|---|
| 39 | EXPORT_SYMBOL(__delay); |
|---|
| 40 | |
|---|
| 41 | /* |
|---|
| 42 | * Division by multiplication: you don't have to worry about |
|---|
| 43 | * loss of precision. |
|---|
| 44 | * |
|---|
| 45 | * Use only for very small delays ( < 1 msec). Should probably use a |
|---|
| 46 | * lookup table, really, as the multiplications take much too long with |
|---|
| 47 | * short delays. This is a "reasonable" implementation, though (and the |
|---|
| 48 | * first constant multiplications gets optimized away if the delay is |
|---|
| 49 | * a constant) |
|---|
| 50 | */ |
|---|
| 51 | |
|---|
| 52 | void __udelay(unsigned long us) |
|---|
| 53 | { |
|---|
| 54 | unsigned int lpj = raw_current_cpu_data.udelay_val; |
|---|
| 55 | |
|---|
| 56 | __delay((us * 0x000010c7ull * HZ * lpj) >> 32); |
|---|
| 57 | } |
|---|
| 58 | EXPORT_SYMBOL(__udelay); |
|---|
| 59 | |
|---|
| 60 | void __ndelay(unsigned long ns) |
|---|
| 61 | { |
|---|
| 62 | unsigned int lpj = raw_current_cpu_data.udelay_val; |
|---|
| 63 | |
|---|
| 64 | __delay((ns * 0x00000005ull * HZ * lpj) >> 32); |
|---|
| 65 | } |
|---|
| 66 | EXPORT_SYMBOL(__ndelay); |
|---|
| 67 | |
|---|
| 68 | #endif |
|---|
| 69 | |
|---|
