OpenCloudOS-Kernel/drivers/clk/clk-fixed-rate.c

83 lines
2.1 KiB
C

/*
* Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
* Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Fixed rate clock implementation
*/
#include <linux/clk-provider.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/err.h>
/*
* DOC: basic fixed-rate clock that cannot gate
*
* Traits of this clock:
* prepare - clk_(un)prepare only ensures parents are prepared
* enable - clk_enable only ensures parents are enabled
* rate - rate is always a fixed value. No clk_set_rate support
* parent - fixed parent. No clk_set_parent support
*/
#define to_clk_fixed_rate(_hw) container_of(_hw, struct clk_fixed_rate, hw)
static unsigned long clk_fixed_rate_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
return to_clk_fixed_rate(hw)->fixed_rate;
}
EXPORT_SYMBOL_GPL(clk_fixed_rate_recalc_rate);
struct clk_ops clk_fixed_rate_ops = {
.recalc_rate = clk_fixed_rate_recalc_rate,
};
EXPORT_SYMBOL_GPL(clk_fixed_rate_ops);
struct clk *clk_register_fixed_rate(struct device *dev, const char *name,
const char *parent_name, unsigned long flags,
unsigned long fixed_rate)
{
struct clk_fixed_rate *fixed;
char **parent_names = NULL;
u8 len;
fixed = kzalloc(sizeof(struct clk_fixed_rate), GFP_KERNEL);
if (!fixed) {
pr_err("%s: could not allocate fixed clk\n", __func__);
return ERR_PTR(-ENOMEM);
}
/* struct clk_fixed_rate assignments */
fixed->fixed_rate = fixed_rate;
if (parent_name) {
parent_names = kmalloc(sizeof(char *), GFP_KERNEL);
if (! parent_names)
goto out;
len = sizeof(char) * strlen(parent_name);
parent_names[0] = kmalloc(len, GFP_KERNEL);
if (!parent_names[0])
goto out;
strncpy(parent_names[0], parent_name, len);
}
out:
return clk_register(dev, name,
&clk_fixed_rate_ops, &fixed->hw,
parent_names,
(parent_name ? 1 : 0),
flags);
}