Staging
v0.7.0
v0.7.0
https://github.com/torvalds/linux
Tip revision: 6da6c0db5316275015e8cc2959f12a17584aeb64 authored by Linus Torvalds on 29 April 2018, 21:17:42 UTC
Linux v4.17-rc3
Linux v4.17-rc3
Tip revision: 6da6c0d
ccu_nk.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 "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,
};