158 lines
3.7 KiB
C
158 lines
3.7 KiB
C
/*
|
|
* mmp factor clock operation source file
|
|
*
|
|
* Copyright (C) 2012 Marvell
|
|
* Chao Xie <xiechao.mail@gmail.com>
|
|
*
|
|
* This file is licensed under the terms of the GNU General Public
|
|
* License version 2. This program is licensed "as is" without any
|
|
* warranty of any kind, whether express or implied.
|
|
*/
|
|
|
|
#include <linux/clk-provider.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/io.h>
|
|
#include <linux/err.h>
|
|
|
|
#include "clk.h"
|
|
/*
|
|
* It is M/N clock
|
|
*
|
|
* Fout from synthesizer can be given from two equations:
|
|
* numerator/denominator = Fin / (Fout * factor)
|
|
*/
|
|
|
|
#define to_clk_factor(hw) container_of(hw, struct clk_factor, hw)
|
|
struct clk_factor {
|
|
struct clk_hw hw;
|
|
void __iomem *base;
|
|
struct clk_factor_masks *masks;
|
|
struct clk_factor_tbl *ftbl;
|
|
unsigned int ftbl_cnt;
|
|
};
|
|
|
|
static long clk_factor_round_rate(struct clk_hw *hw, unsigned long drate,
|
|
unsigned long *prate)
|
|
{
|
|
struct clk_factor *factor = to_clk_factor(hw);
|
|
unsigned long rate = 0, prev_rate;
|
|
int i;
|
|
|
|
for (i = 0; i < factor->ftbl_cnt; i++) {
|
|
prev_rate = rate;
|
|
rate = (((*prate / 10000) * factor->ftbl[i].den) /
|
|
(factor->ftbl[i].num * factor->masks->factor)) * 10000;
|
|
if (rate > drate)
|
|
break;
|
|
}
|
|
if ((i == 0) || (i == factor->ftbl_cnt)) {
|
|
return rate;
|
|
} else {
|
|
if ((drate - prev_rate) > (rate - drate))
|
|
return rate;
|
|
else
|
|
return prev_rate;
|
|
}
|
|
}
|
|
|
|
static unsigned long clk_factor_recalc_rate(struct clk_hw *hw,
|
|
unsigned long parent_rate)
|
|
{
|
|
struct clk_factor *factor = to_clk_factor(hw);
|
|
struct clk_factor_masks *masks = factor->masks;
|
|
unsigned int val, num, den;
|
|
|
|
val = readl_relaxed(factor->base);
|
|
|
|
/* calculate numerator */
|
|
num = (val >> masks->num_shift) & masks->num_mask;
|
|
|
|
/* calculate denominator */
|
|
den = (val >> masks->den_shift) & masks->den_mask;
|
|
|
|
if (!den)
|
|
return 0;
|
|
|
|
return (((parent_rate / 10000) * den) /
|
|
(num * factor->masks->factor)) * 10000;
|
|
}
|
|
|
|
/* Configures new clock rate*/
|
|
static int clk_factor_set_rate(struct clk_hw *hw, unsigned long drate,
|
|
unsigned long prate)
|
|
{
|
|
struct clk_factor *factor = to_clk_factor(hw);
|
|
struct clk_factor_masks *masks = factor->masks;
|
|
int i;
|
|
unsigned long val;
|
|
unsigned long prev_rate, rate = 0;
|
|
|
|
for (i = 0; i < factor->ftbl_cnt; i++) {
|
|
prev_rate = rate;
|
|
rate = (((prate / 10000) * factor->ftbl[i].den) /
|
|
(factor->ftbl[i].num * factor->masks->factor)) * 10000;
|
|
if (rate > drate)
|
|
break;
|
|
}
|
|
if (i > 0)
|
|
i--;
|
|
|
|
val = readl_relaxed(factor->base);
|
|
|
|
val &= ~(masks->num_mask << masks->num_shift);
|
|
val |= (factor->ftbl[i].num & masks->num_mask) << masks->num_shift;
|
|
|
|
val &= ~(masks->den_mask << masks->den_shift);
|
|
val |= (factor->ftbl[i].den & masks->den_mask) << masks->den_shift;
|
|
|
|
writel_relaxed(val, factor->base);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct clk_ops clk_factor_ops = {
|
|
.recalc_rate = clk_factor_recalc_rate,
|
|
.round_rate = clk_factor_round_rate,
|
|
.set_rate = clk_factor_set_rate,
|
|
};
|
|
|
|
struct clk *mmp_clk_register_factor(const char *name, const char *parent_name,
|
|
unsigned long flags, void __iomem *base,
|
|
struct clk_factor_masks *masks, struct clk_factor_tbl *ftbl,
|
|
unsigned int ftbl_cnt)
|
|
{
|
|
struct clk_factor *factor;
|
|
struct clk_init_data init;
|
|
struct clk *clk;
|
|
|
|
if (!masks) {
|
|
pr_err("%s: must pass a clk_factor_mask\n", __func__);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
factor = kzalloc(sizeof(*factor), GFP_KERNEL);
|
|
if (!factor) {
|
|
pr_err("%s: could not allocate factor clk\n", __func__);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
/* struct clk_aux assignments */
|
|
factor->base = base;
|
|
factor->masks = masks;
|
|
factor->ftbl = ftbl;
|
|
factor->ftbl_cnt = ftbl_cnt;
|
|
factor->hw.init = &init;
|
|
|
|
init.name = name;
|
|
init.ops = &clk_factor_ops;
|
|
init.flags = flags;
|
|
init.parent_names = &parent_name;
|
|
init.num_parents = 1;
|
|
|
|
clk = clk_register(NULL, &factor->hw);
|
|
if (IS_ERR_OR_NULL(clk))
|
|
kfree(factor);
|
|
|
|
return clk;
|
|
}
|