[PATCH 05/30] clk: mediatek: clk-mux: Add ops for mux gates with HW voter and FENC

Laura Nao
2025-06-23T10:30:34Z

MT8196 use a HW voter for mux gate enable/disable control, along with a
FENC status bit to check the status. Voting is performed using
set/clr/upd registers, with a status bit used to verify the vote state.
Add new set of mux gate clock operations with support for voting via
set/clr/upd regs and FENC status logic.

Signed-off-by: Laura Nao <laura.nao@collabora.com>
---
drivers/clk/mediatek/clk-mtk.h | 1 +
drivers/clk/mediatek/clk-mux.c | 71 +++++++++++++++++++++++++++++++++-
drivers/clk/mediatek/clk-mux.h | 42 ++++++++++++++++++++
3 files changed, 113 insertions(+), 1 deletion(-)

diff --git a/drivers/clk/mediatek/clk-mtk.h b/drivers/clk/mediatek/clk-mtk.h
index 8ed2c9208b1f..e2cefd9bc5b8 100644
--- a/drivers/clk/mediatek/clk-mtk.h
+++ b/drivers/clk/mediatek/clk-mtk.h
@@ -20,6 +20,7 @@

#define MHZ (1000 * 1000)

+#define MTK_WAIT_HWV_DONE_US 30
#define MTK_WAIT_FENC_DONE_US 30

struct platform_device;
diff --git a/drivers/clk/mediatek/clk-mux.c b/drivers/clk/mediatek/clk-mux.c
index b1b8eeb0b501..65889fc6a3e5 100644
--- a/drivers/clk/mediatek/clk-mux.c
+++ b/drivers/clk/mediatek/clk-mux.c
@@ -8,6 +8,7 @@
#include <linux/clk-provider.h>
#include <linux/compiler_types.h>
#include <linux/container_of.h>
+#include <linux/dev_printk.h>
#include <linux/err.h>
#include <linux/mfd/syscon.h>
#include <linux/module.h>
@@ -21,6 +22,7 @@
struct mtk_clk_mux {
struct clk_hw hw;
struct regmap *regmap;
+ struct regmap *regmap_hwv;
const struct mtk_mux *data;
spinlock_t *lock;
bool reparent;
@@ -118,6 +120,41 @@ static int mtk_clk_mux_is_enabled(struct clk_hw *hw)
return (val & BIT(mux->data->gate_shift)) == 0;
}

+static int mtk_clk_mux_hwv_fenc_enable(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 val;
+ int ret;
+
+ regmap_write(mux->regmap_hwv, mux->data->hwv_set_ofs,
+ BIT(mux->data->gate_shift));
+
+ ret = regmap_read_poll_timeout_atomic(mux->regmap_hwv, mux->data->hwv_sta_ofs,
+ val, val & BIT(mux->data->gate_shift), 0,
+ MTK_WAIT_HWV_DONE_US);
+ if (ret)
+ return ret;
+
+ ret = regmap_read_poll_timeout_atomic(mux->regmap, mux->data->fenc_sta_mon_ofs,
+ val, val & BIT(mux->data->fenc_shift), 1,
+ MTK_WAIT_FENC_DONE_US);
+
+ return ret;
+}
+
+static void mtk_clk_mux_hwv_disable(struct clk_hw *hw)
+{
+ struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
+ u32 val;
+
+ regmap_write(mux->regmap_hwv, mux->data->hwv_clr_ofs,
+ BIT(mux->data->gate_shift));
+
+ regmap_read_poll_timeout_atomic(mux->regmap_hwv, mux->data->hwv_sta_ofs,
+ val, (val & BIT(mux->data->gate_shift)),
+ 0, MTK_WAIT_HWV_DONE_US);
+}
+
static u8 mtk_clk_mux_get_parent(struct clk_hw *hw)
{
struct mtk_clk_mux *mux = to_mtk_clk_mux(hw);
@@ -189,6 +226,14 @@ static int mtk_clk_mux_determine_rate(struct clk_hw *hw,
return clk_mux_determine_rate_flags(hw, req, mux->data->flags);
}

+static bool mtk_clk_mux_uses_hwv(const struct clk_ops *ops)
+{
+ if (ops == &mtk_mux_gate_hwv_fenc_clr_set_upd_ops)
+ return true;
+
+ return false;
+}
+
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,
@@ -216,9 +261,20 @@ const struct clk_ops mtk_mux_gate_fenc_clr_set_upd_ops = {
};
EXPORT_SYMBOL_GPL(mtk_mux_gate_fenc_clr_set_upd_ops);

+const struct clk_ops mtk_mux_gate_hwv_fenc_clr_set_upd_ops = {
+ .enable = mtk_clk_mux_hwv_fenc_enable,
+ .disable = mtk_clk_mux_hwv_disable,
+ .is_enabled = mtk_clk_mux_fenc_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_hwv_fenc_clr_set_upd_ops);
+
static struct clk_hw *mtk_clk_register_mux(struct device *dev,
const struct mtk_mux *mux,
struct regmap *regmap,
+ struct regmap *regmap_hwv,
spinlock_t *lock)
{
struct mtk_clk_mux *clk_mux;
@@ -234,8 +290,13 @@ static struct clk_hw *mtk_clk_register_mux(struct device *dev,
init.parent_names = mux->parent_names;
init.num_parents = mux->num_parents;
init.ops = mux->ops;
+ if (mtk_clk_mux_uses_hwv(init.ops) && !regmap_hwv) {
+ dev_err(dev, "regmap not found for hardware voter clocks\n");
+ return ERR_PTR(-ENXIO);
+ }

clk_mux->regmap = regmap;
+ clk_mux->regmap_hwv = regmap_hwv;
clk_mux->data = mux;
clk_mux->lock = lock;
clk_mux->hw.init = &init;
@@ -268,6 +329,7 @@ int mtk_clk_register_muxes(struct device *dev,
struct clk_hw_onecell_data *clk_data)
{
struct regmap *regmap;
+ struct regmap *regmap_hwv;
struct clk_hw *hw;
int i;

@@ -277,6 +339,13 @@ int mtk_clk_register_muxes(struct device *dev,
return PTR_ERR(regmap);
}

+ regmap_hwv = mtk_clk_get_hwv_regmap(node);
+ if (IS_ERR(regmap_hwv)) {
+ pr_err("Cannot find hardware voter regmap for %pOF: %pe\n",
+ node, regmap_hwv);
+ return PTR_ERR(regmap_hwv);
+ }
+
for (i = 0; i < num; i++) {
const struct mtk_mux *mux = &muxes[i];

@@ -286,7 +355,7 @@ int mtk_clk_register_muxes(struct device *dev,
continue;
}

- hw = mtk_clk_register_mux(dev, mux, regmap, lock);
+ hw = mtk_clk_register_mux(dev, mux, regmap, regmap_hwv, lock);

if (IS_ERR(hw)) {
pr_err("Failed to register clk %s: %pe\n", mux->name,
diff --git a/drivers/clk/mediatek/clk-mux.h b/drivers/clk/mediatek/clk-mux.h
index ba390b579e6c..6b47c44f11ed 100644
--- a/drivers/clk/mediatek/clk-mux.h
+++ b/drivers/clk/mediatek/clk-mux.h
@@ -28,6 +28,10 @@ struct mtk_mux {
u32 set_ofs;
u32 clr_ofs;
u32 upd_ofs;
+
+ u32 hwv_set_ofs;
+ u32 hwv_clr_ofs;
+ u32 hwv_sta_ofs;
u32 fenc_sta_mon_ofs;

u8 mux_shift;
@@ -80,6 +84,7 @@ struct mtk_mux {
extern const struct clk_ops mtk_mux_clr_set_upd_ops;
extern const struct clk_ops mtk_mux_gate_clr_set_upd_ops;
extern const struct clk_ops mtk_mux_gate_fenc_clr_set_upd_ops;
+extern const struct clk_ops mtk_mux_gate_hwv_fenc_clr_set_upd_ops;

#define MUX_GATE_CLR_SET_UPD_FLAGS(_id, _name, _parents, _mux_ofs, \
_mux_set_ofs, _mux_clr_ofs, _shift, _width, \
@@ -121,6 +126,43 @@ extern const struct clk_ops mtk_mux_gate_fenc_clr_set_upd_ops;
0, _upd_ofs, _upd, CLK_SET_RATE_PARENT, \
mtk_mux_clr_set_upd_ops)

+#define MUX_GATE_HWV_FENC_CLR_SET_UPD_FLAGS(_id, _name, _parents, \
+ _mux_ofs, _mux_set_ofs, _mux_clr_ofs, \
+ _hwv_sta_ofs, _hwv_set_ofs, _hwv_clr_ofs, \
+ _shift, _width, _gate, _upd_ofs, _upd, \
+ _fenc_sta_mon_ofs, _fenc, _flags) { \
+ .id = _id, \
+ .name = _name, \
+ .mux_ofs = _mux_ofs, \
+ .set_ofs = _mux_set_ofs, \
+ .clr_ofs = _mux_clr_ofs, \
+ .hwv_sta_ofs = _hwv_sta_ofs, \
+ .hwv_set_ofs = _hwv_set_ofs, \
+ .hwv_clr_ofs = _hwv_clr_ofs, \
+ .upd_ofs = _upd_ofs, \
+ .fenc_sta_mon_ofs = _fenc_sta_mon_ofs, \
+ .mux_shift = _shift, \
+ .mux_width = _width, \
+ .gate_shift = _gate, \
+ .upd_shift = _upd, \
+ .fenc_shift = _fenc, \
+ .parent_names = _parents, \
+ .num_parents = ARRAY_SIZE(_parents), \
+ .flags = _flags, \
+ .ops = &mtk_mux_gate_hwv_fenc_clr_set_upd_ops, \
+ }
+
+#define MUX_GATE_HWV_FENC_CLR_SET_UPD(_id, _name, _parents, \
+ _mux_ofs, _mux_set_ofs, _mux_clr_ofs, \
+ _hwv_sta_ofs, _hwv_set_ofs, _hwv_clr_ofs, \
+ _shift, _width, _gate, _upd_ofs, _upd, \
+ _fenc_sta_mon_ofs, _fenc) \
+ MUX_GATE_HWV_FENC_CLR_SET_UPD_FLAGS(_id, _name, _parents, \
+ _mux_ofs, _mux_set_ofs, _mux_clr_ofs, \
+ _hwv_sta_ofs, _hwv_set_ofs, _hwv_clr_ofs, \
+ _shift, _width, _gate, _upd_ofs, _upd, \
+ _fenc_sta_mon_ofs, _fenc, 0)
+
#define MUX_GATE_FENC_CLR_SET_UPD_FLAGS(_id, _name, _parents, \
_mux_ofs, _mux_set_ofs, _mux_clr_ofs, \
_shift, _width, _gate, _upd_ofs, _upd, \
--
2.39.5