linux/drivers/clk/mediatek/clk-mux.c
Owen Chen a3ae549917 clk: mediatek: Add new clkmux register API
On both MT8183 & MT6765, there add "set/clr" register for
each clkmux setting, and one update register to trigger value change.
It is designed to prevent read-modify-write racing issue.
The sw design need to add a new API to handle this hw change with
a new mtk_clk_mux/mtk_mux struct in new file "clk-mux.c", "clk-mux.h".

Signed-off-by: Owen Chen <owen.chen@mediatek.com>
Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
Reviewed-by: James Liao <jamesjj.liao@mediatek.com>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>
Tested-by: Nicolas Boichat <drinkcat@chromium.org>
[sboyd@kernel.org: Squash in flags=0 to silence warning]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
2019-04-11 13:12:40 -07:00

224 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2018 MediaTek Inc.
* Author: Owen Chen <owen.chen@mediatek.com>
*/
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/slab.h>
#include <linux/mfd/syscon.h>
#include "clk-mtk.h"
#include "clk-mux.h"
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(struct clk_hw *hw)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
u32 mask = BIT(mux->data->gate_shift);
return regmap_update_bits(mux->regmap, mux->data->mux_ofs,
mask, ~mask);
}
static void mtk_clk_mux_disable(struct clk_hw *hw)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
u32 mask = BIT(mux->data->gate_shift);
regmap_update_bits(mux->regmap, mux->data->mux_ofs, mask, mask);
}
static int mtk_clk_mux_enable_setclr(struct clk_hw *hw)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
return regmap_write(mux->regmap, mux->data->clr_ofs,
BIT(mux->data->gate_shift));
}
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_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);
unsigned long flags = 0;
if (mux->lock)
spin_lock_irqsave(mux->lock, flags);
else
__acquire(mux->lock);
regmap_update_bits(mux->regmap, mux->data->mux_ofs, mask,
index << mux->data->mux_shift);
if (mux->lock)
spin_unlock_irqrestore(mux->lock, flags);
else
__release(mux->lock);
return 0;
}
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));
}
if (mux->lock)
spin_unlock_irqrestore(mux->lock, flags);
else
__release(mux->lock);
return 0;
}
const struct clk_ops mtk_mux_ops = {
.get_parent = mtk_clk_mux_get_parent,
.set_parent = mtk_clk_mux_set_parent_lock,
};
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,
};
const struct clk_ops mtk_mux_gate_ops = {
.enable = mtk_clk_mux_enable,
.disable = mtk_clk_mux_disable,
.is_enabled = mtk_clk_mux_is_enabled,
.get_parent = mtk_clk_mux_get_parent,
.set_parent = mtk_clk_mux_set_parent_lock,
};
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,
};
struct clk *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;
struct clk *clk;
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;
clk = clk_register(NULL, &clk_mux->hw);
if (IS_ERR(clk)) {
kfree(clk_mux);
return clk;
}
return clk;
}
int mtk_clk_register_muxes(const struct mtk_mux *muxes,
int num, struct device_node *node,
spinlock_t *lock,
struct clk_onecell_data *clk_data)
{
struct regmap *regmap;
struct clk *clk;
int i;
regmap = syscon_node_to_regmap(node);
if (IS_ERR(regmap)) {
pr_err("Cannot find regmap for %pOF: %ld\n", node,
PTR_ERR(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->clks[mux->id])) {
clk = mtk_clk_register_mux(mux, regmap, lock);
if (IS_ERR(clk)) {
pr_err("Failed to register clk %s: %ld\n",
mux->name, PTR_ERR(clk));
continue;
}
clk_data->clks[mux->id] = clk;
}
}
return 0;
}