[PATCH v4 02/12] clk: mediatek: add new clkmux register API

Weiyi Lu
2019-02-01T08:31:32Z

From: Owen Chen <owen.chen@mediatek.com>

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>
---
drivers/clk/mediatek/Makefile | 3 +-
drivers/clk/mediatek/clk-mux.c | 223 +++++++++++++++++++++++++++++++++
drivers/clk/mediatek/clk-mux.h | 89 +++++++++++++
3 files changed, 314 insertions(+), 1 deletion(-)
create mode 100644 drivers/clk/mediatek/clk-mux.c
create mode 100644 drivers/clk/mediatek/clk-mux.h

diff --git a/drivers/clk/mediatek/Makefile b/drivers/clk/mediatek/Makefile
index ee4410ff43ab..20cf9eea4171 100644
--- a/drivers/clk/mediatek/Makefile
+++ b/drivers/clk/mediatek/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_COMMON_CLK_MEDIATEK) += clk-mtk.o clk-pll.o clk-gate.o clk-apmixed.o clk-cpumux.o reset.o
+obj-$(CONFIG_COMMON_CLK_MEDIATEK) += clk-mtk.o clk-pll.o clk-gate.o clk-apmixed.o clk-cpumux.o reset.o clk-mux.o
+
obj-$(CONFIG_COMMON_CLK_MT6797) += clk-mt6797.o
obj-$(CONFIG_COMMON_CLK_MT6797_IMGSYS) += clk-mt6797-img.o
obj-$(CONFIG_COMMON_CLK_MT6797_MMSYS) += clk-mt6797-mm.o
diff --git a/drivers/clk/mediatek/clk-mux.c b/drivers/clk/mediatek/clk-mux.c
new file mode 100644
index 000000000000..877a883fa616
--- /dev/null
+++ b/drivers/clk/mediatek/clk-mux.c
@@ -0,0 +1,223 @@
+// 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;
+
+ 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;
+
+ 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;
+}
diff --git a/drivers/clk/mediatek/clk-mux.h b/drivers/clk/mediatek/clk-mux.h
new file mode 100644
index 000000000000..f5625f4d9e6c
--- /dev/null
+++ b/drivers/clk/mediatek/clk-mux.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018 MediaTek Inc.
+ * Author: Owen Chen <owen.chen@mediatek.com>
+ */
+
+#ifndef __DRV_CLK_MTK_MUX_H
+#define __DRV_CLK_MTK_MUX_H
+
+#include <linux/clk-provider.h>
+
+struct mtk_clk_mux {
+ struct clk_hw hw;
+ struct regmap *regmap;
+ const struct mtk_mux *data;
+ spinlock_t *lock;
+};
+
+struct mtk_mux {
+ int id;
+ const char *name;
+ const char * const *parent_names;
+ unsigned int flags;
+
+ u32 mux_ofs;
+ u32 set_ofs;
+ u32 clr_ofs;
+ u32 upd_ofs;
+
+ u8 mux_shift;
+ u8 mux_width;
+ u8 gate_shift;
+ s8 upd_shift;
+
+ const struct clk_ops *ops;
+
+ signed char num_parents;
+};
+
+extern const struct clk_ops mtk_mux_ops;
+extern const struct clk_ops mtk_mux_clr_set_upd_ops;
+extern const struct clk_ops mtk_mux_gate_ops;
+extern const struct clk_ops mtk_mux_gate_clr_set_upd_ops;
+
+#define GATE_CLR_SET_UPD_FLAGS(_id, _name, _parents, _mux_ofs, \
+ _mux_set_ofs, _mux_clr_ofs, _shift, _width, \
+ _gate, _upd_ofs, _upd, _flags, _ops) { \
+ .id = _id, \
+ .name = _name, \
+ .mux_ofs = _mux_ofs, \
+ .set_ofs = _mux_set_ofs, \
+ .clr_ofs = _mux_clr_ofs, \
+ .upd_ofs = _upd_ofs, \
+ .mux_shift = _shift, \
+ .mux_width = _width, \
+ .gate_shift = _gate, \
+ .upd_shift = _upd, \
+ .parent_names = _parents, \
+ .num_parents = ARRAY_SIZE(_parents), \
+ .flags = _flags, \
+ .ops = &_ops, \
+ }
+
+#define MUX_GATE_CLR_SET_UPD_FLAGS(_id, _name, _parents, _mux_ofs, \
+ _mux_set_ofs, _mux_clr_ofs, _shift, _width, \
+ _gate, _upd_ofs, _upd, _flags) \
+ GATE_CLR_SET_UPD_FLAGS(_id, _name, _parents, _mux_ofs, \
+ _mux_set_ofs, _mux_clr_ofs, _shift, _width, \
+ _gate, _upd_ofs, _upd, _flags, \
+ mtk_mux_gate_clr_set_upd_ops)
+
+#define MUX_GATE_CLR_SET_UPD(_id, _name, _parents, _mux_ofs, \
+ _mux_set_ofs, _mux_clr_ofs, _shift, _width, \
+ _gate, _upd_ofs, _upd) \
+ MUX_GATE_CLR_SET_UPD_FLAGS(_id, _name, _parents, \
+ _mux_ofs, _mux_set_ofs, _mux_clr_ofs, _shift, \
+ _width, _gate, _upd_ofs, _upd, \
+ CLK_SET_RATE_PARENT)
+
+struct clk *mtk_clk_register_mux(const struct mtk_mux *mux,
+ struct regmap *regmap,
+ spinlock_t *lock);
+
+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);
+
+#endif /* __DRV_CLK_MTK_MUX_H */
--
2.18.0