clk-pll.c
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/*
* Copyright 2012 Freescale Semiconductor, Inc.
*
* The code contained herein is licensed under the GNU General Public
* License. You may obtain a copy of the GNU General Public License
* Version 2 or later at the following locations:
*
* http://www.opensource.org/licenses/gpl-license.html
* http://www.gnu.org/copyleft/gpl.html
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/slab.h>
#include "clk.h"
/**
* struct clk_pll - mxs pll clock
* @hw: clk_hw for the pll
* @base: base address of the pll
* @power: the shift of power bit
* @rate: the clock rate of the pll
*
* The mxs pll is a fixed rate clock with power and gate control,
* and the shift of gate bit is always 31.
*/
struct clk_pll {
struct clk_hw hw;
void __iomem *base;
u8 power;
unsigned long rate;
};
#define to_clk_pll(_hw) container_of(_hw, struct clk_pll, hw)
static int clk_pll_prepare(struct clk_hw *hw)
{
struct clk_pll *pll = to_clk_pll(hw);
writel_relaxed(1 << pll->power, pll->base + SET);
udelay(10);
return 0;
}
static void clk_pll_unprepare(struct clk_hw *hw)
{
struct clk_pll *pll = to_clk_pll(hw);
writel_relaxed(1 << pll->power, pll->base + CLR);
}
static int clk_pll_enable(struct clk_hw *hw)
{
struct clk_pll *pll = to_clk_pll(hw);
writel_relaxed(1 << 31, pll->base + CLR);
return 0;
}
static void clk_pll_disable(struct clk_hw *hw)
{
struct clk_pll *pll = to_clk_pll(hw);
writel_relaxed(1 << 31, pll->base + SET);
}
static unsigned long clk_pll_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_pll *pll = to_clk_pll(hw);
return pll->rate;
}
static const struct clk_ops clk_pll_ops = {
.prepare = clk_pll_prepare,
.unprepare = clk_pll_unprepare,
.enable = clk_pll_enable,
.disable = clk_pll_disable,
.recalc_rate = clk_pll_recalc_rate,
};
struct clk *mxs_clk_pll(const char *name, const char *parent_name,
void __iomem *base, u8 power, unsigned long rate)
{
struct clk_pll *pll;
struct clk *clk;
struct clk_init_data init;
pll = kzalloc(sizeof(*pll), GFP_KERNEL);
if (!pll)
return ERR_PTR(-ENOMEM);
init.name = name;
init.ops = &clk_pll_ops;
init.flags = 0;
init.parent_names = (parent_name ? &parent_name: NULL);
init.num_parents = (parent_name ? 1 : 0);
pll->base = base;
pll->rate = rate;
pll->power = power;
pll->hw.init = &init;
clk = clk_register(NULL, &pll->hw);
if (IS_ERR(clk))
kfree(pll);
return clk;
}