| /****************************************************************************** |
| * Copyright (c) 2004, 2008 IBM Corporation |
| * All rights reserved. |
| * This program and the accompanying materials |
| * are made available under the terms of the BSD License |
| * which accompanies this distribution, and is available at |
| * http://www.opensource.org/licenses/bsd-license.php |
| * |
| * Contributors: |
| * IBM Corporation - initial implementation |
| *****************************************************************************/ |
| |
| #include <stdint.h> |
| #include "kernel.h" |
| |
| //******************************************************************* |
| // variable "tb_freq" contains the frequency in Hz |
| // and is read from the device tree (setup by LLFW) in "init.c" |
| uint64_t tb_freq; |
| |
| //------------------------------------------------------------------- |
| // Read the current timebase |
| uint64_t get_time(void) |
| { |
| uint64_t act; |
| |
| __asm__ __volatile__( |
| "0: mftbu %0 ;\ |
| mftbl %%r0 ; \ |
| mftbu %%r4 ; \ |
| cmpw %0,%%r4 ; \ |
| bne 0b; \ |
| sldi %0,%0,32; \ |
| or %0,%0,%%r0" |
| : "=r"(act) |
| : /* no inputs */ |
| : "r0", "r4"); |
| return act; |
| } |
| |
| //------------------------------------------------------------------- |
| // wait for ticks/scale timebase ticks |
| static void wait_ticks(uint64_t ticks) |
| { |
| uint64_t timeout = get_time() + ticks; |
| while (get_time() < timeout) { |
| unsigned int i; |
| for (i = 1000; i > 0; i--) |
| __asm__ __volatile__ ("" : : : "memory"); |
| } |
| } |
| |
| //------------------------------------------------------------------- |
| // wait for (at least) usecs microseconds |
| void udelay(unsigned int usecs) |
| { |
| // first multiply the usec with timebase and then divide |
| // because 1.000.000 is relatively huge compared to usecs |
| wait_ticks((usecs*tb_freq)/1000000); |
| } |
| |
| //------------------------------------------------------------------- |
| // wait for (at least) msecs milliseconds |
| void mdelay(unsigned int msecs) |
| { |
| // first multiply the msec and timebase and then divide |
| // because 1.000 is relatively huge compared to msecs |
| wait_ticks((msecs*tb_freq)/1000); |
| } |
