linux-vybrid_public/include/asm-v850/v850e_utils.h

/*
 * include/asm-v850/v850e_utils.h -- Utility functions associated with
 *	V850E CPUs
 *
 *  Copyright (C) 2001,03  NEC Electronics Corporation
 *  Copyright (C) 2001,03  Miles Bader <miles@gnu.org>
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file COPYING in the main directory of this
 * archive for more details.
 *
 * Written by Miles Bader <miles@gnu.org>
 */

#ifndef __V850_V850E_UTILS_H__
#define __V850_V850E_UTILS_H__

/* Calculate counter clock-divider and count values to attain the
   desired frequency RATE from the base frequency BASE_FREQ.  The
   counter is expected to have a clock-divider, which can divide the
   system cpu clock by a power of two value from MIN_DIVLOG2 to
   MAX_DIV_LOG2, and a word-size of COUNTER_SIZE bits (the counter
   counts up and resets whenever it's equal to the compare register,
   generating an interrupt or whatever when it does so).  The returned
   values are: *DIVLOG2 -- log2 of the desired clock divider and *COUNT
   -- the counter compare value to use.  Returns true if it was possible
   to find a reasonable value, otherwise false (and the other return
   values will be set to be as good as possible).  */
extern int calc_counter_params (unsigned long base_freq,
				unsigned long rate,
				unsigned min_divlog2, unsigned max_divlog2,
				unsigned counter_size,
				unsigned *divlog2, unsigned *count);

#endif /* __V850_V850E_UTILS_H__ */