linux/drivers/clk/sunxi-ng/ccu_nkmp.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

233 lines
5.8 KiB
C

// 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,
};