linuxdebug/drivers/clk/mediatek/clk-mux.c

311 lines
7.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018 MediaTek Inc.
* Author: Owen Chen <owen.chen@mediatek.com>
*/
#include <linux/clk.h>
#include <linux/clk-provider.h>
#include <linux/compiler_types.h>
#include <linux/container_of.h>
#include <linux/err.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include "clk-mux.h"
struct mtk_clk_mux {
struct clk_hw hw;
struct regmap *regmap;
const struct mtk_mux *data;
spinlock_t *lock;
bool reparent;
};
static inline struct mtk_clk_mux *to_mtk_clk_mux(struct clk_hw *hw)
{
return container_of(hw, struct mtk_clk_mux, hw);
}
static int mtk_clk_mux_enable_setclr(struct clk_hw *hw)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
unsigned long flags = 0;
if (mux->lock)
spin_lock_irqsave(mux->lock, flags);
else
__acquire(mux->lock);
regmap_write(mux->regmap, mux->data->clr_ofs,
BIT(mux->data->gate_shift));
/*
* If the parent has been changed when the clock was disabled, it will
* not be effective yet. Set the update bit to ensure the mux gets
* updated.
*/
if (mux->reparent && mux->data->upd_shift >= 0) {
regmap_write(mux->regmap, mux->data->upd_ofs,
BIT(mux->data->upd_shift));
mux->reparent = false;
}
if (mux->lock)
spin_unlock_irqrestore(mux->lock, flags);
else
__release(mux->lock);
return 0;
}
static void mtk_clk_mux_disable_setclr(struct clk_hw *hw)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
regmap_write(mux->regmap, mux->data->set_ofs,
BIT(mux->data->gate_shift));
}
static int mtk_clk_mux_is_enabled(struct clk_hw *hw)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
u32 val;
regmap_read(mux->regmap, mux->data->mux_ofs, &val);
return (val & BIT(mux->data->gate_shift)) == 0;
}
static u8 mtk_clk_mux_get_parent(struct clk_hw *hw)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
u32 mask = GENMASK(mux->data->mux_width - 1, 0);
u32 val;
regmap_read(mux->regmap, mux->data->mux_ofs, &val);
val = (val >> mux->data->mux_shift) & mask;
return val;
}
static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
u32 mask = GENMASK(mux->data->mux_width - 1, 0);
u32 val, orig;
unsigned long flags = 0;
if (mux->lock)
spin_lock_irqsave(mux->lock, flags);
else
__acquire(mux->lock);
regmap_read(mux->regmap, mux->data->mux_ofs, &orig);
val = (orig & ~(mask << mux->data->mux_shift))
| (index << mux->data->mux_shift);
if (val != orig) {
regmap_write(mux->regmap, mux->data->clr_ofs,
mask << mux->data->mux_shift);
regmap_write(mux->regmap, mux->data->set_ofs,
index << mux->data->mux_shift);
if (mux->data->upd_shift >= 0) {
regmap_write(mux->regmap, mux->data->upd_ofs,
BIT(mux->data->upd_shift));
mux->reparent = true;
}
}
if (mux->lock)
spin_unlock_irqrestore(mux->lock, flags);
else
__release(mux->lock);
return 0;
}
static int mtk_clk_mux_determine_rate(struct clk_hw *hw,
struct clk_rate_request *req)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
return clk_mux_determine_rate_flags(hw, req, mux->data->flags);
}
const struct clk_ops mtk_mux_clr_set_upd_ops = {
.get_parent = mtk_clk_mux_get_parent,
.set_parent = mtk_clk_mux_set_parent_setclr_lock,
.determine_rate = mtk_clk_mux_determine_rate,
};
EXPORT_SYMBOL_GPL(mtk_mux_clr_set_upd_ops);
const struct clk_ops mtk_mux_gate_clr_set_upd_ops = {
.enable = mtk_clk_mux_enable_setclr,
.disable = mtk_clk_mux_disable_setclr,
.is_enabled = mtk_clk_mux_is_enabled,
.get_parent = mtk_clk_mux_get_parent,
.set_parent = mtk_clk_mux_set_parent_setclr_lock,
.determine_rate = mtk_clk_mux_determine_rate,
};
EXPORT_SYMBOL_GPL(mtk_mux_gate_clr_set_upd_ops);
static struct clk_hw *mtk_clk_register_mux(const struct mtk_mux *mux,
struct regmap *regmap,
spinlock_t *lock)
{
struct mtk_clk_mux *clk_mux;
struct clk_init_data init = {};
int ret;
clk_mux = kzalloc(sizeof(*clk_mux), GFP_KERNEL);
if (!clk_mux)
return ERR_PTR(-ENOMEM);
init.name = mux->name;
init.flags = mux->flags | CLK_SET_RATE_PARENT;
init.parent_names = mux->parent_names;
init.num_parents = mux->num_parents;
init.ops = mux->ops;
clk_mux->regmap = regmap;
clk_mux->data = mux;
clk_mux->lock = lock;
clk_mux->hw.init = &init;
ret = clk_hw_register(NULL, &clk_mux->hw);
if (ret) {
kfree(clk_mux);
return ERR_PTR(ret);
}
return &clk_mux->hw;
}
static void mtk_clk_unregister_mux(struct clk_hw *hw)
{
struct mtk_clk_mux *mux;
if (!hw)
return;
mux = to_mtk_clk_mux(hw);
clk_hw_unregister(hw);
kfree(mux);
}
int mtk_clk_register_muxes(const struct mtk_mux *muxes,
int num, struct device_node *node,
spinlock_t *lock,
struct clk_hw_onecell_data *clk_data)
{
struct regmap *regmap;
struct clk_hw *hw;
int i;
regmap = device_node_to_regmap(node);
if (IS_ERR(regmap)) {
pr_err("Cannot find regmap for %pOF: %pe\n", node, regmap);
return PTR_ERR(regmap);
}
for (i = 0; i < num; i++) {
const struct mtk_mux *mux = &muxes[i];
if (!IS_ERR_OR_NULL(clk_data->hws[mux->id])) {
pr_warn("%pOF: Trying to register duplicate clock ID: %d\n",
node, mux->id);
continue;
}
hw = mtk_clk_register_mux(mux, regmap, lock);
if (IS_ERR(hw)) {
pr_err("Failed to register clk %s: %pe\n", mux->name,
hw);
goto err;
}
clk_data->hws[mux->id] = hw;
}
return 0;
err:
while (--i >= 0) {
const struct mtk_mux *mux = &muxes[i];
if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
continue;
mtk_clk_unregister_mux(clk_data->hws[mux->id]);
clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
}
return PTR_ERR(hw);
}
EXPORT_SYMBOL_GPL(mtk_clk_register_muxes);
void mtk_clk_unregister_muxes(const struct mtk_mux *muxes, int num,
struct clk_hw_onecell_data *clk_data)
{
int i;
if (!clk_data)
return;
for (i = num; i > 0; i--) {
const struct mtk_mux *mux = &muxes[i - 1];
if (IS_ERR_OR_NULL(clk_data->hws[mux->id]))
continue;
mtk_clk_unregister_mux(clk_data->hws[mux->id]);
clk_data->hws[mux->id] = ERR_PTR(-ENOENT);
}
}
EXPORT_SYMBOL_GPL(mtk_clk_unregister_muxes);
/*
* This clock notifier is called when the frequency 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 mtk_clk_mux_notifier_cb(struct notifier_block *nb,
unsigned long event, void *_data)
{
struct clk_notifier_data *data = _data;
struct clk_hw *hw = __clk_get_hw(data->clk);
struct mtk_mux_nb *mux_nb = to_mtk_mux_nb(nb);
int ret = 0;
switch (event) {
case PRE_RATE_CHANGE:
mux_nb->original_index = mux_nb->ops->get_parent(hw);
ret = mux_nb->ops->set_parent(hw, mux_nb->bypass_index);
break;
case POST_RATE_CHANGE:
case ABORT_RATE_CHANGE:
ret = mux_nb->ops->set_parent(hw, mux_nb->original_index);
break;
}
return notifier_from_errno(ret);
}
int devm_mtk_clk_mux_notifier_register(struct device *dev, struct clk *clk,
struct mtk_mux_nb *mux_nb)
{
mux_nb->nb.notifier_call = mtk_clk_mux_notifier_cb;
return devm_clk_notifier_register(dev, clk, &mux_nb->nb);
}
EXPORT_SYMBOL_GPL(devm_mtk_clk_mux_notifier_register);
MODULE_LICENSE("GPL");