linux/drivers/clk/sunxi-ng/ccu_nkm.c
Maxime Ripard 10a8d9b906 clk: sunxi-ng: Pass the parent and a pointer to the clocks round rate
The clocks might need to modify their parent clocks. In order to make that
possible, give them access to the parent clock being evaluated, and to a
pointer to the parent rate so that they can modify it if needed.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
2017-06-07 15:32:13 +02:00

196 lines
4.6 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 "ccu_gate.h"
#include "ccu_nkm.h"
struct _ccu_nkm {
unsigned long n, min_n, max_n;
unsigned long k, min_k, max_k;
unsigned long m, min_m, max_m;
};
static void ccu_nkm_find_best(unsigned long parent, unsigned long rate,
struct _ccu_nkm *nkm)
{
unsigned long best_rate = 0;
unsigned long best_n = 0, best_k = 0, best_m = 0;
unsigned long _n, _k, _m;
for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
unsigned long tmp_rate;
tmp_rate = parent * _n * _k / _m;
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;
}
}
}
}
nkm->n = best_n;
nkm->k = best_k;
nkm->m = best_m;
}
static void ccu_nkm_disable(struct clk_hw *hw)
{
struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
return ccu_gate_helper_disable(&nkm->common, nkm->enable);
}
static int ccu_nkm_enable(struct clk_hw *hw)
{
struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
return ccu_gate_helper_enable(&nkm->common, nkm->enable);
}
static int ccu_nkm_is_enabled(struct clk_hw *hw)
{
struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
return ccu_gate_helper_is_enabled(&nkm->common, nkm->enable);
}
static unsigned long ccu_nkm_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
unsigned long n, m, k;
u32 reg;
reg = readl(nkm->common.base + nkm->common.reg);
n = reg >> nkm->n.shift;
n &= (1 << nkm->n.width) - 1;
n += nkm->n.offset;
if (!n)
n++;
k = reg >> nkm->k.shift;
k &= (1 << nkm->k.width) - 1;
k += nkm->k.offset;
if (!k)
k++;
m = reg >> nkm->m.shift;
m &= (1 << nkm->m.width) - 1;
m += nkm->m.offset;
if (!m)
m++;
return parent_rate * n * k / m;
}
static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
struct clk_hw *hw,
unsigned long *parent_rate,
unsigned long rate,
void *data)
{
struct ccu_nkm *nkm = data;
struct _ccu_nkm _nkm;
_nkm.min_n = nkm->n.min ?: 1;
_nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
_nkm.min_k = nkm->k.min ?: 1;
_nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
_nkm.min_m = 1;
_nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
ccu_nkm_find_best(*parent_rate, rate, &_nkm);
return *parent_rate * _nkm.n * _nkm.k / _nkm.m;
}
static int ccu_nkm_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
return ccu_mux_helper_determine_rate(&nkm->common, &nkm->mux,
req, ccu_nkm_round_rate, nkm);
}
static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
unsigned long parent_rate)
{
struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
struct _ccu_nkm _nkm;
unsigned long flags;
u32 reg;
_nkm.min_n = nkm->n.min ?: 1;
_nkm.max_n = nkm->n.max ?: 1 << nkm->n.width;
_nkm.min_k = nkm->k.min ?: 1;
_nkm.max_k = nkm->k.max ?: 1 << nkm->k.width;
_nkm.min_m = 1;
_nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
ccu_nkm_find_best(parent_rate, rate, &_nkm);
spin_lock_irqsave(nkm->common.lock, flags);
reg = readl(nkm->common.base + nkm->common.reg);
reg &= ~GENMASK(nkm->n.width + nkm->n.shift - 1, nkm->n.shift);
reg &= ~GENMASK(nkm->k.width + nkm->k.shift - 1, nkm->k.shift);
reg &= ~GENMASK(nkm->m.width + nkm->m.shift - 1, nkm->m.shift);
reg |= (_nkm.n - nkm->n.offset) << nkm->n.shift;
reg |= (_nkm.k - nkm->k.offset) << nkm->k.shift;
reg |= (_nkm.m - nkm->m.offset) << nkm->m.shift;
writel(reg, nkm->common.base + nkm->common.reg);
spin_unlock_irqrestore(nkm->common.lock, flags);
ccu_helper_wait_for_lock(&nkm->common, nkm->lock);
return 0;
}
static u8 ccu_nkm_get_parent(struct clk_hw *hw)
{
struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
return ccu_mux_helper_get_parent(&nkm->common, &nkm->mux);
}
static int ccu_nkm_set_parent(struct clk_hw *hw, u8 index)
{
struct ccu_nkm *nkm = hw_to_ccu_nkm(hw);
return ccu_mux_helper_set_parent(&nkm->common, &nkm->mux, index);
}
const struct clk_ops ccu_nkm_ops = {
.disable = ccu_nkm_disable,
.enable = ccu_nkm_enable,
.is_enabled = ccu_nkm_is_enabled,
.get_parent = ccu_nkm_get_parent,
.set_parent = ccu_nkm_set_parent,
.determine_rate = ccu_nkm_determine_rate,
.recalc_rate = ccu_nkm_recalc_rate,
.set_rate = ccu_nkm_set_rate,
};