// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright (C) 2016 Maxime Ripard
* Maxime Ripard <[email protected]>
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/io.h>
#include "ccu_gate.h"
#include "ccu_mux.h"
#define CCU_MUX_KEY_VALUE 0x16aa0000
static u16 ccu_mux_get_prediv(struct ccu_common *common,
struct ccu_mux_internal *cm,
int parent_index)
{
u16 prediv = 1;
u32 reg;
if (!((common->features & CCU_FEATURE_FIXED_PREDIV) ||
(common->features & CCU_FEATURE_VARIABLE_PREDIV) ||
(common->features & CCU_FEATURE_ALL_PREDIV)))
return 1;
if (common->features & CCU_FEATURE_ALL_PREDIV)
return common->prediv;
reg = readl(common->base + common->reg);
if (parent_index < 0) {
parent_index = reg >> cm->shift;
parent_index &= (1 << cm->width) - 1;
}
if (common->features & CCU_FEATURE_FIXED_PREDIV) {
int i;
for (i = 0; i < cm->n_predivs; i++)
if (parent_index == cm->fixed_predivs[i].index)
prediv = cm->fixed_predivs[i].div;
}
if (common->features & CCU_FEATURE_VARIABLE_PREDIV) {
int i;
for (i = 0; i < cm->n_var_predivs; i++)
if (parent_index == cm->var_predivs[i].index) {
u8 div;
div = reg >> cm->var_predivs[i].shift;
div &= (1 << cm->var_predivs[i].width) - 1;
prediv = div + 1;
}
}
return prediv;
}
unsigned long ccu_mux_helper_apply_prediv(struct ccu_common *common,
struct ccu_mux_internal *cm,
int parent_index,
unsigned long parent_rate)
{
return parent_rate / ccu_mux_get_prediv(common, cm, parent_index);
}
EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_apply_prediv, SUNXI_CCU);
static unsigned long ccu_mux_helper_unapply_prediv(struct ccu_common *common,
struct ccu_mux_internal *cm,
int parent_index,
unsigned long parent_rate)
{
return parent_rate * ccu_mux_get_prediv(common, cm, parent_index);
}
int ccu_mux_helper_determine_rate(struct ccu_common *common,
struct ccu_mux_internal *cm,
struct clk_rate_request *req,
unsigned long (*round)(struct ccu_mux_internal *,
struct clk_hw *,
unsigned long *,
unsigned long,
void *),
void *data)
{
unsigned long best_parent_rate = 0, best_rate = 0;
struct clk_hw *best_parent, *hw = &common->hw;
unsigned int i;
if (clk_hw_get_flags(hw) & CLK_SET_RATE_NO_REPARENT) {
unsigned long adj_parent_rate;
best_parent = clk_hw_get_parent(hw);
best_parent_rate = clk_hw_get_rate(best_parent);
adj_parent_rate = ccu_mux_helper_apply_prediv(common, cm, -1,
best_parent_rate);
best_rate = round(cm, best_parent, &adj_parent_rate,
req->rate, data);
/*
* adj_parent_rate might have been modified by our clock.
* Unapply the pre-divider if there's one, and give
* the actual frequency the parent needs to run at.
*/
best_parent_rate = ccu_mux_helper_unapply_prediv(common, cm, -1,
adj_parent_rate);
goto out;
}
for (i = 0; i < clk_hw_get_num_parents(hw); i++) {
unsigned long tmp_rate, parent_rate;
struct clk_hw *parent;
parent = clk_hw_get_parent_by_index(hw, i);
if (!parent)
continue;
parent_rate = ccu_mux_helper_apply_prediv(common, cm, i,
clk_hw_get_rate(parent));
tmp_rate = round(cm, parent, &parent_rate, req->rate, data);
/*
* parent_rate might have been modified by our clock.
* Unapply the pre-divider if there's one, and give
* the actual frequency the parent needs to run at.
*/
parent_rate = ccu_mux_helper_unapply_prediv(common, cm, i,
parent_rate);
if (tmp_rate == req->rate) {
best_parent = parent;
best_parent_rate = parent_rate;
best_rate = tmp_rate;
goto out;
}
if (ccu_is_better_rate(common, req->rate, tmp_rate, best_rate)) {
best_rate = tmp_rate;
best_parent_rate = parent_rate;
best_parent = parent;
}
}
if (best_rate == 0)
return -EINVAL;
out:
req->best_parent_hw = best_parent;
req->best_parent_rate = best_parent_rate;
req->rate = best_rate;
return 0;
}
EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_determine_rate, SUNXI_CCU);
u8 ccu_mux_helper_get_parent(struct ccu_common *common,
struct ccu_mux_internal *cm)
{
u32 reg;
u8 parent;
reg = readl(common->base + common->reg);
parent = reg >> cm->shift;
parent &= (1 << cm->width) - 1;
if (cm->table) {
int num_parents = clk_hw_get_num_parents(&common->hw);
int i;
for (i = 0; i < num_parents; i++)
if (cm->table[i] == parent)
return i;
}
return parent;
}
EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_get_parent, SUNXI_CCU);
int ccu_mux_helper_set_parent(struct ccu_common *common,
struct ccu_mux_internal *cm,
u8 index)
{
unsigned long flags;
u32 reg;
if (cm->table)
index = cm->table[index];
spin_lock_irqsave(common->lock, flags);
reg = readl(common->base + common->reg);
/* The key field always reads as zero. */
if (common->features & CCU_FEATURE_KEY_FIELD)
reg |= CCU_MUX_KEY_VALUE;
reg &= ~GENMASK(cm->width + cm->shift - 1, cm->shift);
writel(reg | (index << cm->shift), common->base + common->reg);
spin_unlock_irqrestore(common->lock, flags);
return 0;
}
EXPORT_SYMBOL_NS_GPL(ccu_mux_helper_set_parent, SUNXI_CCU);
static void ccu_mux_disable(struct clk_hw *hw)
{
struct ccu_mux *cm = hw_to_ccu_mux(hw);
return ccu_gate_helper_disable(&cm->common, cm->enable);
}
static int ccu_mux_enable(struct clk_hw *hw)
{
struct ccu_mux *cm = hw_to_ccu_mux(hw);
return ccu_gate_helper_enable(&cm->common, cm->enable);
}
static int ccu_mux_is_enabled(struct clk_hw *hw)
{
struct ccu_mux *cm = hw_to_ccu_mux(hw);
return ccu_gate_helper_is_enabled(&cm->common, cm->enable);
}
static u8 ccu_mux_get_parent(struct clk_hw *hw)
{
struct ccu_mux *cm = hw_to_ccu_mux(hw);
return ccu_mux_helper_get_parent(&cm->common, &cm->mux);
}
static int ccu_mux_set_parent(struct clk_hw *hw, u8 index)
{
struct ccu_mux *cm = hw_to_ccu_mux(hw);
return ccu_mux_helper_set_parent(&cm->common, &cm->mux, index);
}
static int ccu_mux_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct ccu_mux *cm = hw_to_ccu_mux(hw);
if (cm->common.features & CCU_FEATURE_CLOSEST_RATE)
return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
return clk_mux_determine_rate_flags(hw, req, 0);
}
static unsigned long ccu_mux_recalc_rate(struct clk_hw *hw,
unsigned long parent_rate)
{
struct ccu_mux *cm = hw_to_ccu_mux(hw);
return ccu_mux_helper_apply_prediv(&cm->common, &cm->mux, -1,
parent_rate);
}
const struct clk_ops ccu_mux_ops = {
.disable = ccu_mux_disable,
.enable = ccu_mux_enable,
.is_enabled = ccu_mux_is_enabled,
.get_parent = ccu_mux_get_parent,
.set_parent = ccu_mux_set_parent,
.determine_rate = ccu_mux_determine_rate,
.recalc_rate = ccu_mux_recalc_rate,
};
EXPORT_SYMBOL_NS_GPL(ccu_mux_ops, SUNXI_CCU);
/*
* This clock notifier is called when the frequency of the of the parent
* PLL clock is to be changed. The idea is to switch the parent to a
* stable clock, such as the main oscillator, while the PLL frequency
* stabilizes.
*/
static int ccu_mux_notifier_cb(struct notifier_block *nb,
unsigned long event, void *data)
{
struct ccu_mux_nb *mux = to_ccu_mux_nb(nb);
int ret = 0;
if (event == PRE_RATE_CHANGE) {
mux->original_index = ccu_mux_helper_get_parent(mux->common,
mux->cm);
ret = ccu_mux_helper_set_parent(mux->common, mux->cm,
mux->bypass_index);
} else if (event == POST_RATE_CHANGE) {
ret = ccu_mux_helper_set_parent(mux->common, mux->cm,
mux->original_index);
}
udelay(mux->delay_us);
return notifier_from_errno(ret);
}
int ccu_mux_notifier_register(struct clk *clk, struct ccu_mux_nb *mux_nb)
{
mux_nb->clk_nb.notifier_call = ccu_mux_notifier_cb;
return clk_notifier_register(clk, &mux_nb->clk_nb);
}
EXPORT_SYMBOL_NS_GPL(ccu_mux_notifier_register, SUNXI_CCU);
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