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/*
* Copyright 2012 Freescale Semiconductor, Inc.
* Copyright 2012 Linaro Ltd.
*
* 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/io.h>
#include <linux/slab.h>
#include <linux/err.h>
#include "clk.h"
/**
* struct clk_pfd - IMX PFD clock
* @clk_hw: clock source
* @reg: PFD register address
* @idx: the index of PFD encoded in the register
*
* PFD clock found on i.MX6 series. Each register for PFD has 4 clk_pfd
* data encoded, and member idx is used to specify the one. And each
* register has SET, CLR and TOG registers at offset 0x4 0x8 and 0xc.
*/
struct clk_pfd {
struct clk_hw hw;
void __iomem *reg;
u8 idx;
};
#define to_clk_pfd(_hw) container_of(_hw, struct clk_pfd, hw)
#define SET 0x4
#define CLR 0x8
#define OTG 0xc
static int clk_pfd_enable(struct clk_hw *hw)
{
struct clk_pfd *pfd = to_clk_pfd(hw);
writel_relaxed(1 << ((pfd->idx + 1) * 8 - 1), pfd->reg + CLR);
return 0;
}
static void clk_pfd_disable(struct clk_hw *hw)
{
struct clk_pfd *pfd = to_clk_pfd(hw);
writel_relaxed(1 << ((pfd->idx + 1) * 8 - 1), pfd->reg + SET);
}
static unsigned long clk_pfd_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct clk_pfd *pfd = to_clk_pfd(hw);
u64 tmp = parent_rate;
u8 frac = (readl_relaxed(pfd->reg) >> (pfd->idx * 8)) & 0x3f;
tmp *= 18;
do_div(tmp, frac);
return tmp;
}
static long clk_pfd_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *prate)
{
u64 tmp = *prate;
u8 frac;
tmp = tmp * 18 + rate / 2;
do_div(tmp, rate);
frac = tmp;
if (frac < 12)
frac = 12;
else if (frac > 35)
frac = 35;
tmp = *prate;
tmp *= 18;
do_div(tmp, frac);
return tmp;
}
static int clk_pfd_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct clk_pfd *pfd = to_clk_pfd(hw);
u64 tmp = parent_rate;
u8 frac;
tmp = tmp * 18 + rate / 2;
do_div(tmp, rate);
frac = tmp;
if (frac < 12)
frac = 12;
else if (frac > 35)
frac = 35;
writel_relaxed(0x3f << (pfd->idx * 8), pfd->reg + CLR);
writel_relaxed(frac << (pfd->idx * 8), pfd->reg + SET);
return 0;
}
static const struct clk_ops clk_pfd_ops = {
.enable = clk_pfd_enable,
.disable = clk_pfd_disable,
.recalc_rate = clk_pfd_recalc_rate,
.round_rate = clk_pfd_round_rate,
.set_rate = clk_pfd_set_rate,
};
struct clk *imx_clk_pfd(const char *name, const char *parent_name,
void __iomem *reg, u8 idx)
{
struct clk_pfd *pfd;
struct clk *clk;
struct clk_init_data init;
pfd = kzalloc(sizeof(*pfd), GFP_KERNEL);
if (!pfd)
return ERR_PTR(-ENOMEM);
pfd->reg = reg;
pfd->idx = idx;
init.name = name;
init.ops = &clk_pfd_ops;
init.flags = 0;
init.parent_names = &parent_name;
init.num_parents = 1;
pfd->hw.init = &init;
clk = clk_register(NULL, &pfd->hw);
if (IS_ERR(clk))
kfree(pfd);
return clk;
}
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