On Tue, Mar 5, 2019 at 1:06 PM Weiyi Lu weiyi.lu@mediatek.com wrote:
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;
Guenter reported the following issue (https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/1...): "" The construct conditionally acquiring a spinlock is too complex for gcc to understand. This results in the following build warning.
drivers/clk/mediatek/clk-mux.c: In function 'mtk_clk_mux_set_parent_lock': ./include/linux/spinlock.h:279:3: warning: 'flags' may be used uninitialized in this function
Other clock drivers avoid the problem by initializing flags with 0. Lets do that here as well. """
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;
Same here.
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