mirror of https://gitee.com/openkylin/linux.git
106 lines
2.9 KiB
C
106 lines
2.9 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>
|
|
#include <linux/of.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;
|
|
}
|
|
|
|
const struct clk_ops clk_fixed_rate_ops = {
|
|
.recalc_rate = clk_fixed_rate_recalc_rate,
|
|
};
|
|
EXPORT_SYMBOL_GPL(clk_fixed_rate_ops);
|
|
|
|
/**
|
|
* clk_register_fixed_rate - register fixed-rate clock with the clock framework
|
|
* @dev: device that is registering this clock
|
|
* @name: name of this clock
|
|
* @parent_name: name of clock's parent
|
|
* @flags: framework-specific flags
|
|
* @fixed_rate: non-adjustable clock rate
|
|
*/
|
|
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;
|
|
struct clk *clk;
|
|
struct clk_init_data init;
|
|
|
|
/* allocate fixed-rate clock */
|
|
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);
|
|
}
|
|
|
|
init.name = name;
|
|
init.ops = &clk_fixed_rate_ops;
|
|
init.flags = flags | CLK_IS_BASIC;
|
|
init.parent_names = (parent_name ? &parent_name: NULL);
|
|
init.num_parents = (parent_name ? 1 : 0);
|
|
|
|
/* struct clk_fixed_rate assignments */
|
|
fixed->fixed_rate = fixed_rate;
|
|
fixed->hw.init = &init;
|
|
|
|
/* register the clock */
|
|
clk = clk_register(dev, &fixed->hw);
|
|
|
|
if (IS_ERR(clk))
|
|
kfree(fixed);
|
|
|
|
return clk;
|
|
}
|
|
|
|
#ifdef CONFIG_OF
|
|
/**
|
|
* of_fixed_clk_setup() - Setup function for simple fixed rate clock
|
|
*/
|
|
void of_fixed_clk_setup(struct device_node *node)
|
|
{
|
|
struct clk *clk;
|
|
const char *clk_name = node->name;
|
|
u32 rate;
|
|
|
|
if (of_property_read_u32(node, "clock-frequency", &rate))
|
|
return;
|
|
|
|
of_property_read_string(node, "clock-output-names", &clk_name);
|
|
|
|
clk = clk_register_fixed_rate(NULL, clk_name, NULL, CLK_IS_ROOT, rate);
|
|
if (!IS_ERR(clk))
|
|
of_clk_add_provider(node, of_clk_src_simple_get, clk);
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_fixed_clk_setup);
|
|
CLK_OF_DECLARE(fixed_clk, "fixed-clock", of_fixed_clk_setup);
|
|
#endif
|