diff options
Diffstat (limited to 'clients/net-snk/kernel/timer.c')
-rw-r--r-- | clients/net-snk/kernel/timer.c | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/clients/net-snk/kernel/timer.c b/clients/net-snk/kernel/timer.c new file mode 100644 index 0000000..630a9b4 --- /dev/null +++ b/clients/net-snk/kernel/timer.c @@ -0,0 +1,67 @@ +/****************************************************************************** + * 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 <types.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 +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 devide + // 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 devide + // because 1.000 is relatively huge compared to msecs + wait_ticks((msecs*tb_freq)/1000); +} |