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// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 Maxime Ripard
* Maxime Ripard <maxime.ripard@free-electrons.com>
*/
#include <linux/clk-provider.h>
#include <linux/io.h>
#include "ccu_gate.h"
#include "ccu_nkmp.h"
struct _ccu_nkmp {
unsigned long n, min_n, max_n;
unsigned long k, min_k, max_k;
unsigned long m, min_m, max_m;
unsigned long p, min_p, max_p;
};
static unsigned long ccu_nkmp_calc_rate(unsigned long parent,
unsigned long n, unsigned long k,
unsigned long m, unsigned long p)
{
u64 rate = parent;
rate *= n * k;
do_div(rate, m * p);
return rate;
}
static void ccu_nkmp_find_best(unsigned long parent, unsigned long rate,
struct _ccu_nkmp *nkmp)
{
unsigned long best_rate = 0;
unsigned long best_n = 0, best_k = 0, best_m = 0, best_p = 0;
unsigned long _n, _k, _m, _p;
for (_k = nkmp->min_k; _k <= nkmp->max_k; _k++) {
for (_n = nkmp->min_n; _n <= nkmp->max_n; _n++) {
for (_m = nkmp->min_m; _m <= nkmp->max_m; _m++) {
for (_p = nkmp->min_p; _p <= nkmp->max_p; _p <<= 1) {
unsigned long tmp_rate;
tmp_rate = ccu_nkmp_calc_rate(parent,
_n, _k,
_m, _p);
if (tmp_rate > rate)
continue;
if ((rate - tmp_rate) < (rate - best_rate)) {
best_rate = tmp_rate;
best_n = _n;
best_k = _k;
best_m = _m;
best_p = _p;
}
}
}
}
}
nkmp->n = best_n;
nkmp->k = best_k;
nkmp->m = best_m;
nkmp->p = best_p;
}
static void ccu_nkmp_disable(struct clk_hw *hw)
{
struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
return ccu_gate_helper_disable(&nkmp->common, nkmp->enable);
}
static int ccu_nkmp_enable(struct clk_hw *hw)
{
struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
return ccu_gate_helper_enable(&nkmp->common, nkmp->enable);
}
static int ccu_nkmp_is_enabled(struct clk_hw *hw)
{
struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
return ccu_gate_helper_is_enabled(&nkmp->common, nkmp->enable);
}
static unsigned long ccu_nkmp_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
unsigned long n, m, k, p, rate;
u32 reg;
reg = readl(nkmp->common.base + nkmp->common.reg);
n = reg >> nkmp->n.shift;
n &= (1 << nkmp->n.width) - 1;
n += nkmp->n.offset;
if (!n)
n++;
k = reg >> nkmp->k.shift;
k &= (1 << nkmp->k.width) - 1;
k += nkmp->k.offset;
if (!k)
k++;
m = reg >> nkmp->m.shift;
m &= (1 << nkmp->m.width) - 1;
m += nkmp->m.offset;
if (!m)
m++;
p = reg >> nkmp->p.shift;
p &= (1 << nkmp->p.width) - 1;
rate = ccu_nkmp_calc_rate(parent_rate, n, k, m, 1 << p);
if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nkmp->fixed_post_div;
return rate;
}
static long ccu_nkmp_round_rate(struct clk_hw *hw, unsigned long rate,
unsigned long *parent_rate)
{
struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
struct _ccu_nkmp _nkmp;
if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate *= nkmp->fixed_post_div;
if (nkmp->max_rate && rate > nkmp->max_rate) {
rate = nkmp->max_rate;
if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate /= nkmp->fixed_post_div;
return rate;
}
_nkmp.min_n = nkmp->n.min ?: 1;
_nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width;
_nkmp.min_k = nkmp->k.min ?: 1;
_nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width;
_nkmp.min_m = 1;
_nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width;
_nkmp.min_p = 1;
_nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1);
ccu_nkmp_find_best(*parent_rate, rate, &_nkmp);
rate = ccu_nkmp_calc_rate(*parent_rate, _nkmp.n, _nkmp.k,
_nkmp.m, _nkmp.p);
if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate = rate / nkmp->fixed_post_div;
return rate;
}
static int ccu_nkmp_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct ccu_nkmp *nkmp = hw_to_ccu_nkmp(hw);
u32 n_mask = 0, k_mask = 0, m_mask = 0, p_mask = 0;
struct _ccu_nkmp _nkmp;
unsigned long flags;
u32 reg;
if (nkmp->common.features & CCU_FEATURE_FIXED_POSTDIV)
rate = rate * nkmp->fixed_post_div;
_nkmp.min_n = nkmp->n.min ?: 1;
_nkmp.max_n = nkmp->n.max ?: 1 << nkmp->n.width;
_nkmp.min_k = nkmp->k.min ?: 1;
_nkmp.max_k = nkmp->k.max ?: 1 << nkmp->k.width;
_nkmp.min_m = 1;
_nkmp.max_m = nkmp->m.max ?: 1 << nkmp->m.width;
_nkmp.min_p = 1;
_nkmp.max_p = nkmp->p.max ?: 1 << ((1 << nkmp->p.width) - 1);
ccu_nkmp_find_best(parent_rate, rate, &_nkmp);
/*
* If width is 0, GENMASK() macro may not generate expected mask (0)
* as it falls under undefined behaviour by C standard due to shifts
* which are equal or greater than width of left operand. This can
* be easily avoided by explicitly checking if width is 0.
*/
if (nkmp->n.width)
n_mask = GENMASK(nkmp->n.width + nkmp->n.shift - 1,
nkmp->n.shift);
if (nkmp->k.width)
k_mask = GENMASK(nkmp->k.width + nkmp->k.shift - 1,
nkmp->k.shift);
if (nkmp->m.width)
m_mask = GENMASK(nkmp->m.width + nkmp->m.shift - 1,
nkmp->m.shift);
if (nkmp->p.width)
p_mask = GENMASK(nkmp->p.width + nkmp->p.shift - 1,
nkmp->p.shift);
spin_lock_irqsave(nkmp->common.lock, flags);
reg = readl(nkmp->common.base + nkmp->common.reg);
reg &= ~(n_mask | k_mask | m_mask | p_mask);
reg |= ((_nkmp.n - nkmp->n.offset) << nkmp->n.shift) & n_mask;
reg |= ((_nkmp.k - nkmp->k.offset) << nkmp->k.shift) & k_mask;
reg |= ((_nkmp.m - nkmp->m.offset) << nkmp->m.shift) & m_mask;
reg |= (ilog2(_nkmp.p) << nkmp->p.shift) & p_mask;
writel(reg, nkmp->common.base + nkmp->common.reg);
spin_unlock_irqrestore(nkmp->common.lock, flags);
ccu_helper_wait_for_lock(&nkmp->common, nkmp->lock);
return 0;
}
const struct clk_ops ccu_nkmp_ops = {
.disable = ccu_nkmp_disable,
.enable = ccu_nkmp_enable,
.is_enabled = ccu_nkmp_is_enabled,
.recalc_rate = ccu_nkmp_recalc_rate,
.round_rate = ccu_nkmp_round_rate,
.set_rate = ccu_nkmp_set_rate,
};
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