164 lines
3.7 KiB
C
164 lines
3.7 KiB
C
/*
|
|
* Copyright (C) 2016 Maxime Ripard
|
|
* Maxime Ripard <maxime.ripard@free-electrons.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License as
|
|
* published by the Free Software Foundation; either version 2 of
|
|
* the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/clk-provider.h>
|
|
#include <linux/io.h>
|
|
|
|
#include "ccu_gate.h"
|
|
#include "ccu_nk.h"
|
|
|
|
struct _ccu_nk {
|
|
unsigned long n, min_n, max_n;
|
|
unsigned long k, min_k, max_k;
|
|
};
|
|
|
|
static void ccu_nk_find_best(unsigned long parent, unsigned long rate,
|
|
struct _ccu_nk *nk)
|
|
{
|
|
unsigned long best_rate = 0;
|
|
unsigned int best_k = 0, best_n = 0;
|
|
unsigned int _k, _n;
|
|
|
|
for (_k = nk->min_k; _k <= nk->max_k; _k++) {
|
|
for (_n = nk->min_n; _n <= nk->max_n; _n++) {
|
|
unsigned long tmp_rate = parent * _n * _k;
|
|
|
|
if (tmp_rate > rate)
|
|
continue;
|
|
|
|
if ((rate - tmp_rate) < (rate - best_rate)) {
|
|
best_rate = tmp_rate;
|
|
best_k = _k;
|
|
best_n = _n;
|
|
}
|
|
}
|
|
}
|
|
|
|
nk->k = best_k;
|
|
nk->n = best_n;
|
|
}
|
|
|
|
static void ccu_nk_disable(struct clk_hw *hw)
|
|
{
|
|
struct ccu_nk *nk = hw_to_ccu_nk(hw);
|
|
|
|
return ccu_gate_helper_disable(&nk->common, nk->enable);
|
|
}
|
|
|
|
static int ccu_nk_enable(struct clk_hw *hw)
|
|
{
|
|
struct ccu_nk *nk = hw_to_ccu_nk(hw);
|
|
|
|
return ccu_gate_helper_enable(&nk->common, nk->enable);
|
|
}
|
|
|
|
static int ccu_nk_is_enabled(struct clk_hw *hw)
|
|
{
|
|
struct ccu_nk *nk = hw_to_ccu_nk(hw);
|
|
|
|
return ccu_gate_helper_is_enabled(&nk->common, nk->enable);
|
|
}
|
|
|
|
static unsigned long ccu_nk_recalc_rate(struct clk_hw *hw,
|
|
unsigned long parent_rate)
|
|
{
|
|
struct ccu_nk *nk = hw_to_ccu_nk(hw);
|
|
unsigned long rate, n, k;
|
|
u32 reg;
|
|
|
|
reg = readl(nk->common.base + nk->common.reg);
|
|
|
|
n = reg >> nk->n.shift;
|
|
n &= (1 << nk->n.width) - 1;
|
|
n += nk->n.offset;
|
|
if (!n)
|
|
n++;
|
|
|
|
k = reg >> nk->k.shift;
|
|
k &= (1 << nk->k.width) - 1;
|
|
k += nk->k.offset;
|
|
if (!k)
|
|
k++;
|
|
|
|
rate = parent_rate * n * k;
|
|
if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
|
|
rate /= nk->fixed_post_div;
|
|
|
|
return rate;
|
|
}
|
|
|
|
static long ccu_nk_round_rate(struct clk_hw *hw, unsigned long rate,
|
|
unsigned long *parent_rate)
|
|
{
|
|
struct ccu_nk *nk = hw_to_ccu_nk(hw);
|
|
struct _ccu_nk _nk;
|
|
|
|
if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
|
|
rate *= nk->fixed_post_div;
|
|
|
|
_nk.min_n = nk->n.min ?: 1;
|
|
_nk.max_n = nk->n.max ?: 1 << nk->n.width;
|
|
_nk.min_k = nk->k.min ?: 1;
|
|
_nk.max_k = nk->k.max ?: 1 << nk->k.width;
|
|
|
|
ccu_nk_find_best(*parent_rate, rate, &_nk);
|
|
rate = *parent_rate * _nk.n * _nk.k;
|
|
|
|
if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
|
|
rate = rate / nk->fixed_post_div;
|
|
|
|
return rate;
|
|
}
|
|
|
|
static int ccu_nk_set_rate(struct clk_hw *hw, unsigned long rate,
|
|
unsigned long parent_rate)
|
|
{
|
|
struct ccu_nk *nk = hw_to_ccu_nk(hw);
|
|
unsigned long flags;
|
|
struct _ccu_nk _nk;
|
|
u32 reg;
|
|
|
|
if (nk->common.features & CCU_FEATURE_FIXED_POSTDIV)
|
|
rate = rate * nk->fixed_post_div;
|
|
|
|
_nk.min_n = nk->n.min ?: 1;
|
|
_nk.max_n = nk->n.max ?: 1 << nk->n.width;
|
|
_nk.min_k = nk->k.min ?: 1;
|
|
_nk.max_k = nk->k.max ?: 1 << nk->k.width;
|
|
|
|
ccu_nk_find_best(parent_rate, rate, &_nk);
|
|
|
|
spin_lock_irqsave(nk->common.lock, flags);
|
|
|
|
reg = readl(nk->common.base + nk->common.reg);
|
|
reg &= ~GENMASK(nk->n.width + nk->n.shift - 1, nk->n.shift);
|
|
reg &= ~GENMASK(nk->k.width + nk->k.shift - 1, nk->k.shift);
|
|
|
|
reg |= (_nk.k - nk->k.offset) << nk->k.shift;
|
|
reg |= (_nk.n - nk->n.offset) << nk->n.shift;
|
|
writel(reg, nk->common.base + nk->common.reg);
|
|
|
|
spin_unlock_irqrestore(nk->common.lock, flags);
|
|
|
|
ccu_helper_wait_for_lock(&nk->common, nk->lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
const struct clk_ops ccu_nk_ops = {
|
|
.disable = ccu_nk_disable,
|
|
.enable = ccu_nk_enable,
|
|
.is_enabled = ccu_nk_is_enabled,
|
|
|
|
.recalc_rate = ccu_nk_recalc_rate,
|
|
.round_rate = ccu_nk_round_rate,
|
|
.set_rate = ccu_nk_set_rate,
|
|
};
|