[PATCH v5 09/11] clk: mediatek: add new clkmux register API

Mars Cheng
2018-07-17T08:52:30Z

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

MT6765 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_clk_upd struct in new file "clk-mux"and
clk-upd".

Signed-off-by: Owen Chen <owen.chen@mediatek.com>
---
drivers/clk/mediatek/Makefile | 2 +-
drivers/clk/mediatek/clk-mtk.c | 41 +++++++
drivers/clk/mediatek/clk-mtk.h | 85 ++++++++++++---
drivers/clk/mediatek/clk-mux.c | 236 ++++++++++++++++++++++++++++++++++++++++
drivers/clk/mediatek/clk-mux.h | 38 +++++++
5 files changed, 388 insertions(+), 14 deletions(-)
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 844b55d..b97980d 100644
--- a/drivers/clk/mediatek/Makefile
+++ b/drivers/clk/mediatek/Makefile
@@ -1,5 +1,5 @@
# 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-mtk.c b/drivers/clk/mediatek/clk-mtk.c
index 9c0ae42..50becd0 100644
--- a/drivers/clk/mediatek/clk-mtk.c
+++ b/drivers/clk/mediatek/clk-mtk.c
@@ -22,6 +22,7 @@
#include <linux/mfd/syscon.h>

#include "clk-mtk.h"
+#include "clk-mux.h"
#include "clk-gate.h"

struct clk_onecell_data *mtk_alloc_clk_data(unsigned int clk_num)
@@ -144,6 +145,46 @@ int mtk_clk_register_gates(struct device_node *node,
return 0;
}

+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;
+
+ if (!clk_data)
+ return -ENOMEM;
+
+ 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 (clk_data && !IS_ERR_OR_NULL(clk_data->clks[mux->id]))
+ continue;
+
+ 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;
+ }
+
+ if (clk_data)
+ clk_data->clks[mux->id] = clk;
+ }
+
+ return 0;
+}
+
struct clk *mtk_clk_register_composite(const struct mtk_composite *mc,
void __iomem *base, spinlock_t *lock)
{
diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
index 1882221..61693f6 100644
--- a/drivers/clk/mediatek/clk-mtk.h
+++ b/drivers/clk/mediatek/clk-mtk.h
@@ -24,7 +24,9 @@

#define MAX_MUX_GATE_BIT 31
#define INVALID_MUX_GATE_BIT (MAX_MUX_GATE_BIT + 1)
-
+#define INVALID_OFS -1
+#define INVALID_SHFT -1
+#define INVALID_WIDTH -1
#define MHZ (1000 * 1000)

struct mtk_fixed_clk {
@@ -84,10 +86,72 @@ struct mtk_composite {
signed char num_parents;
};

+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;
+
+ signed char mux_shift;
+ signed char mux_width;
+ signed char gate_shift;
+ signed char upd_shift;
+
+ const struct clk_ops *ops;
+
+ signed char num_parents;
+};
+
/*
* In case the rate change propagation to parent clocks is undesirable,
* this macro allows to specify the clock flags manually.
*/
+#define 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_CLR_SET_UPD_FLAGS(_id, _name, _parents, _mux_ofs, _mux_set_ofs,\
+ _mux_clr_ofs, _shift, _width, _gate, \
+ _upd_ofs, _upd, _flags) \
+ CLR_SET_UPD_FLAGS(_id, _name, _parents, _mux_ofs, \
+ _mux_set_ofs, _mux_clr_ofs, _shift, _width, \
+ _gate, _upd_ofs, _upd, _flags, \
+ mtk_mux_clr_set_upd_ops)
+
+#define MUX_CLR_SET_UPD(_id, _name, _parents, _mux_ofs, _mux_set_ofs, \
+ _mux_clr_ofs, _shift, _width, _gate, \
+ _upd_ofs, _upd) \
+ MUX_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)
+
+#define MUX_UPD(_id, _name, _parents, _mux_ofs, _shift, _width, _gate, \
+ _upd_ofs, _upd) \
+ CLR_SET_UPD_FLAGS(_id, _name, _parents, _mux_ofs, \
+ INVALID_OFS, INVALID_OFS, _shift, _width, \
+ _gate, _upd_ofs, _upd, CLK_SET_RATE_PARENT, \
+ mtk_mux_upd_ops)
+
#define MUX_GATE_FLAGS(_id, _name, _parents, _reg, _shift, _width, \
_gate, _flags) { \
.id = _id, \
@@ -111,18 +175,8 @@ struct mtk_composite {
MUX_GATE_FLAGS(_id, _name, _parents, _reg, _shift, _width, \
_gate, CLK_SET_RATE_PARENT)

-#define MUX(_id, _name, _parents, _reg, _shift, _width) { \
- .id = _id, \
- .name = _name, \
- .mux_reg = _reg, \
- .mux_shift = _shift, \
- .mux_width = _width, \
- .gate_shift = -1, \
- .divider_shift = -1, \
- .parent_names = _parents, \
- .num_parents = ARRAY_SIZE(_parents), \
- .flags = CLK_SET_RATE_PARENT, \
- }
+#define MUX(_id, _name, _parents, _reg, _shift, _width) \
+ MUX_GATE(_id, _name, _parents, _reg, _shift, _width, INVALID_SHFT)

#define DIV_GATE(_id, _name, _parent, _gate_reg, _gate_shift, _div_reg, \
_div_width, _div_shift) { \
@@ -138,6 +192,11 @@ struct mtk_composite {
.flags = 0, \
}

+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 clk *mtk_clk_register_composite(const struct mtk_composite *mc,
void __iomem *base, spinlock_t *lock);

diff --git a/drivers/clk/mediatek/clk-mux.c b/drivers/clk/mediatek/clk-mux.c
new file mode 100644
index 0000000..219181b
--- /dev/null
+++ b/drivers/clk/mediatek/clk-mux.c
@@ -0,0 +1,236 @@
+// 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 "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_mux_enable(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 mask = BIT(mux->gate_shift);
+ unsigned long flags = 0;
+
+ if (mux->lock)
+ spin_lock_irqsave(mux->lock, flags);
+
+ regmap_update_bits(mux->regmap, mux->mux_ofs, mask, 0);
+
+ if (mux->lock)
+ spin_unlock_irqrestore(mux->lock, flags);
+ return 0;
+}
+
+static void mtk_mux_disable(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 mask = BIT(mux->gate_shift);
+ unsigned long flags = 0;
+
+ if (mux->lock)
+ spin_lock_irqsave(mux->lock, flags);
+
+ regmap_update_bits(mux->regmap, mux->mux_ofs, mask, mask);
+
+ if (mux->lock)
+ spin_unlock_irqrestore(mux->lock, flags);
+}
+
+static int mtk_mux_enable_setclr(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 val;
+ unsigned long flags = 0;
+
+ if (mux->lock)
+ spin_lock_irqsave(mux->lock, flags);
+
+ val = BIT(mux->gate_shift);
+ regmap_write(mux->regmap, mux->mux_clr_ofs, val);
+
+ if (mux->lock)
+ spin_unlock_irqrestore(mux->lock, flags);
+ return 0;
+}
+
+static void mtk_mux_disable_setclr(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 val;
+ unsigned long flags = 0;
+
+ if (mux->lock)
+ spin_lock_irqsave(mux->lock, flags);
+
+ val = BIT(mux->gate_shift);
+ regmap_write(mux->regmap, mux->mux_set_ofs, val);
+
+ if (mux->lock)
+ spin_unlock_irqrestore(mux->lock, flags);
+}
+
+static int mtk_mux_is_enabled(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 val = 0;
+
+ if (mux->gate_shift < 0)
+ return true;
+
+ regmap_read(mux->regmap, mux->mux_ofs, &val);
+
+ return (val & BIT(mux->gate_shift)) == 0;
+}
+
+static u8 mtk_mux_get_parent(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ int num_parents = clk_hw_get_num_parents(hw);
+ u32 mask = GENMASK(mux->mux_width - 1, 0);
+ u32 val;
+
+ regmap_read(mux->regmap, mux->mux_ofs, &val);
+ val = (val >> mux->mux_shift) & mask;
+
+ if (val >= num_parents)
+ return -EINVAL;
+
+ return val;
+}
+
+static int mtk_mux_set_parent(struct clk_hw *hw, u8 index)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 mask = GENMASK(mux->mux_width - 1, 0);
+ u32 val, orig;
+ unsigned long flags = 0;
+
+ if (mux->lock)
+ spin_lock_irqsave(mux->lock, flags);
+
+ regmap_read(mux->regmap, mux->mux_ofs, &val);
+ orig = val;
+ val &= ~(mask << mux->mux_shift);
+ val |= index << mux->mux_shift;
+
+ if (val != orig) {
+ regmap_write(mux->regmap, mux->mux_ofs, val);
+
+ if (mux->upd_shift >= 0)
+ regmap_write(mux->regmap, mux->upd_ofs,
+ BIT(mux->upd_shift));
+ }
+
+ if (mux->lock)
+ spin_unlock_irqrestore(mux->lock, flags);
+
+ return 0;
+}
+
+static int mtk_mux_set_parent_setclr(struct clk_hw *hw, u8 index)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 mask = GENMASK(mux->mux_width - 1, 0);
+ u32 val, orig;
+ unsigned long flags = 0;
+
+ if (mux->lock)
+ spin_lock_irqsave(mux->lock, flags);
+
+ regmap_read(mux->regmap, mux->mux_ofs, &val);
+ orig = val;
+ val &= ~(mask << mux->mux_shift);
+ val |= index << mux->mux_shift;
+
+ if (val != orig) {
+ val = (mask << mux->mux_shift);
+ regmap_write(mux->regmap, mux->mux_clr_ofs, val);
+ val = (index << mux->mux_shift);
+ regmap_write(mux->regmap, mux->mux_set_ofs, val);
+
+ if (mux->upd_shift >= 0)
+ regmap_write(mux->regmap, mux->upd_ofs,
+ BIT(mux->upd_shift));
+ }
+
+ if (mux->lock)
+ spin_unlock_irqrestore(mux->lock, flags);
+
+ return 0;
+}
+
+const struct clk_ops mtk_mux_upd_ops = {
+ .enable = mtk_mux_enable,
+ .disable = mtk_mux_disable,
+ .is_enabled = mtk_mux_is_enabled,
+ .get_parent = mtk_mux_get_parent,
+ .set_parent = mtk_mux_set_parent,
+ .determine_rate = NULL,
+};
+
+const struct clk_ops mtk_mux_clr_set_upd_ops = {
+ .enable = mtk_mux_enable_setclr,
+ .disable = mtk_mux_disable_setclr,
+ .is_enabled = mtk_mux_is_enabled,
+ .get_parent = mtk_mux_get_parent,
+ .set_parent = mtk_mux_set_parent_setclr,
+ .determine_rate = NULL,
+};
+
+struct clk *mtk_clk_register_mux(const struct mtk_mux *mux,
+ struct regmap *regmap,
+ spinlock_t *lock)
+{
+ struct clk *clk;
+ struct clk_init_data init;
+ struct mtk_clk_mux *mtk_mux = NULL;
+ int ret;
+
+ mtk_mux = kzalloc(sizeof(*mtk_mux), GFP_KERNEL);
+ if (!mtk_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;
+
+ mtk_mux->regmap = regmap;
+ mtk_mux->name = mux->name;
+ mtk_mux->mux_ofs = mux->mux_ofs;
+ mtk_mux->mux_set_ofs = mux->set_ofs;
+ mtk_mux->mux_clr_ofs = mux->clr_ofs;
+ mtk_mux->upd_ofs = mux->upd_ofs;
+ mtk_mux->mux_shift = mux->mux_shift;
+ mtk_mux->mux_width = mux->mux_width;
+ mtk_mux->gate_shift = mux->gate_shift;
+ mtk_mux->upd_shift = mux->upd_shift;
+
+ mtk_mux->lock = lock;
+ mtk_mux->hw.init = &init;
+
+ clk = clk_register(NULL, &mtk_mux->hw);
+ if (IS_ERR(clk)) {
+ ret = PTR_ERR(clk);
+ goto err_out;
+ }
+
+ return clk;
+err_out:
+ kfree(mtk_mux);
+
+ return ERR_PTR(ret);
+}
diff --git a/drivers/clk/mediatek/clk-mux.h b/drivers/clk/mediatek/clk-mux.h
new file mode 100644
index 0000000..64f8e7c
--- /dev/null
+++ b/drivers/clk/mediatek/clk-mux.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2018 MediaTek Inc.
+ * Author: Owen Chen <owen.chen@mediatek.com>
+ */
+
+#ifndef __DRV_CLK_MUX_H
+#define __DRV_CLK_MUX_H
+
+#include <linux/clk-provider.h>
+
+struct mtk_clk_mux {
+ struct clk_hw hw;
+ struct regmap *regmap;
+
+ const char *name;
+
+ int mux_set_ofs;
+ int mux_clr_ofs;
+ int mux_ofs;
+ int upd_ofs;
+
+ s8 mux_shift;
+ s8 mux_width;
+ s8 gate_shift;
+ s8 upd_shift;
+
+ spinlock_t *lock;
+};
+
+extern const struct clk_ops mtk_mux_upd_ops;
+extern const struct clk_ops mtk_mux_clr_set_upd_ops;
+
+struct clk *mtk_clk_register_mux(const struct mtk_mux *mux,
+ struct regmap *regmap,
+ spinlock_t *lock);
+
+#endif /* __DRV_CLK_MUX_H */
--
1.7.9.5