incubator-nuttx/drivers/clk/clk_fixed_factor.c

99 lines
3.6 KiB
C

/****************************************************************************
* drivers/clk/clk_fixed_factor.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/clk/clk.h>
#include <nuttx/clk/clk_provider.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define to_clk_fixed_factor(_clk) (FAR struct clk_fixed_factor_s *) \
(_clk->private_data)
/****************************************************************************
* Private Functions
****************************************************************************/
static uint32_t clk_factor_recalc_rate(FAR struct clk_s *clk,
uint32_t parent_rate)
{
FAR struct clk_fixed_factor_s *fixed = to_clk_fixed_factor(clk);
uint64_t rate = parent_rate;
rate *= fixed->mult;
rate /= fixed->div;
return rate;
}
static uint32_t clk_factor_round_rate(FAR struct clk_s *clk,
uint32_t rate,
FAR uint32_t *prate)
{
FAR struct clk_fixed_factor_s *fixed = to_clk_fixed_factor(clk);
if (clk->flags & CLK_SET_RATE_PARENT)
{
uint32_t best_parent;
best_parent = ((uint64_t)rate * fixed->div) / fixed->mult;
*prate = clk_round_rate(clk_get_parent(clk), best_parent);
}
return ((uint64_t)*prate * fixed->mult) / fixed->div;
}
/****************************************************************************
* Public Data
****************************************************************************/
const struct clk_ops_s g_clk_fixed_factor_ops =
{
.round_rate = clk_factor_round_rate,
.recalc_rate = clk_factor_recalc_rate,
};
/****************************************************************************
* Public Functions
****************************************************************************/
FAR struct clk_s *clk_register_fixed_factor(FAR const char *name,
FAR const char *parent_name,
uint8_t flags, uint8_t mult,
uint8_t div)
{
struct clk_fixed_factor_s fixed;
FAR const char **parent_names;
uint8_t num_parents;
parent_names = parent_name ? &parent_name : NULL;
num_parents = parent_name ? 1 : 0;
fixed.mult = mult;
fixed.div = div;
return clk_register(name, parent_names, num_parents, flags,
&g_clk_fixed_factor_ops, &fixed, sizeof(fixed));
}