linux/drivers/clk/sunxi-ng/ccu_nk.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

160 lines
3.5 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_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,
};