[PATCH v2 1/2] clk: mediatek: clk-mux: Support custom parent indices for muxes

From: AngeloGioacchino Del Regno
Date: Wed Oct 18 2023 - 06:36:05 EST


Add support for customized parent indices for MediaTek muxes: this is
necessary for the case in which we want to exclude some clocks from
a mux's parent clocks list, where the exclusions are not from the
very bottom of the list but either in the middle or the beginning.

Example:
- MUX1 (all parents)
- parent1; idx=0
- parent2; idx=1
- parent3; idx=2

- MUX1 (wanted parents)
- parent1; idx=0
- parent3; idx=2

To achieve that add a `parent_index` array pointer to struct mtk_mux,
then in .set_parent(), .get_parent() callbacks check if this array
was populated and eventually get the index from that.

Also, to avoid updating all clock drivers for all SoCs, rename the
"main" macro to __GATE_CLR_SET_UPD_FLAGS (so, `__` was added) and
add the new member to it; furthermore, GATE_CLK_SET_UPD_FLAGS has
been reintroduced as being fully compatible with the older version.

The new parent_index can be specified with the new `_INDEXED`
variants of the MUX_GATE_CLR_SET_UPD_xxxx macros.

Reviewed-by: Alexandre Mergnat <amergnat@xxxxxxxxxxxx>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
drivers/clk/mediatek/clk-mux.c | 14 +++++++++++
drivers/clk/mediatek/clk-mux.h | 43 ++++++++++++++++++++++++++++++----
2 files changed, 53 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/mediatek/clk-mux.c b/drivers/clk/mediatek/clk-mux.c
index c93bc7f926e5..60990296450b 100644
--- a/drivers/clk/mediatek/clk-mux.c
+++ b/drivers/clk/mediatek/clk-mux.c
@@ -89,6 +89,17 @@ static u8 mtk_clk_mux_get_parent(struct clk_hw *hw)
regmap_read(mux->regmap, mux->data->mux_ofs, &val);
val = (val >> mux->data->mux_shift) & mask;

+ if (mux->data->parent_index) {
+ int i;
+
+ for (i = 0; i < mux->data->num_parents; i++)
+ if (mux->data->parent_index[i] == val)
+ return i;
+
+ /* Not found: return an impossible index to generate error */
+ return mux->data->num_parents + 1;
+ }
+
return val;
}

@@ -104,6 +115,9 @@ static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index)
else
__acquire(mux->lock);

+ if (mux->data->parent_index)
+ index = mux->data->parent_index[index];
+
regmap_read(mux->regmap, mux->data->mux_ofs, &orig);
val = (orig & ~(mask << mux->data->mux_shift))
| (index << mux->data->mux_shift);
diff --git a/drivers/clk/mediatek/clk-mux.h b/drivers/clk/mediatek/clk-mux.h
index 7ecb963b0ec6..943ad1d7ce4b 100644
--- a/drivers/clk/mediatek/clk-mux.h
+++ b/drivers/clk/mediatek/clk-mux.h
@@ -21,6 +21,7 @@ struct mtk_mux {
int id;
const char *name;
const char * const *parent_names;
+ const u8 *parent_index;
unsigned int flags;

u32 mux_ofs;
@@ -37,9 +38,10 @@ struct mtk_mux {
signed char num_parents;
};

-#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) { \
+#define __GATE_CLR_SET_UPD_FLAGS(_id, _name, _parents, _paridx, \
+ _num_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, \
@@ -51,11 +53,28 @@ struct mtk_mux {
.gate_shift = _gate, \
.upd_shift = _upd, \
.parent_names = _parents, \
- .num_parents = ARRAY_SIZE(_parents), \
+ .parent_index = _paridx, \
+ .num_parents = _num_parents, \
.flags = _flags, \
.ops = &_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) \
+ __GATE_CLR_SET_UPD_FLAGS(_id, _name, _parents, \
+ NULL, ARRAY_SIZE(_parents), _mux_ofs, \
+ _mux_set_ofs, _mux_clr_ofs, _shift, _width, \
+ _gate, _upd_ofs, _upd, _flags, _ops) \
+
+#define GATE_CLR_SET_UPD_FLAGS_INDEXED(_id, _name, _parents, _paridx, \
+ _mux_ofs, _mux_set_ofs, _mux_clr_ofs, _shift, \
+ _width, _gate, _upd_ofs, _upd, _flags, _ops) \
+ __GATE_CLR_SET_UPD_FLAGS(_id, _name, _parents, \
+ _paridx, ARRAY_SIZE(_paridx), _mux_ofs, \
+ _mux_set_ofs, _mux_clr_ofs, _shift, _width, \
+ _gate, _upd_ofs, _upd, _flags, _ops) \
+
extern const struct clk_ops mtk_mux_clr_set_upd_ops;
extern const struct clk_ops mtk_mux_gate_clr_set_upd_ops;

@@ -67,6 +86,14 @@ extern const struct clk_ops mtk_mux_gate_clr_set_upd_ops;
_gate, _upd_ofs, _upd, _flags, \
mtk_mux_gate_clr_set_upd_ops)

+#define MUX_GATE_CLR_SET_UPD_FLAGS_INDEXED(_id, _name, _parents, \
+ _paridx, _mux_ofs, _mux_set_ofs, _mux_clr_ofs, \
+ _shift, _width, _gate, _upd_ofs, _upd, _flags) \
+ GATE_CLR_SET_UPD_FLAGS_INDEXED(_id, _name, _parents, \
+ _paridx, _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) \
@@ -75,6 +102,14 @@ extern const struct clk_ops mtk_mux_gate_clr_set_upd_ops;
_width, _gate, _upd_ofs, _upd, \
CLK_SET_RATE_PARENT)

+#define MUX_GATE_CLR_SET_UPD_INDEXED(_id, _name, _parents, _paridx, \
+ _mux_ofs, _mux_set_ofs, _mux_clr_ofs, _shift, \
+ _width, _gate, _upd_ofs, _upd) \
+ MUX_GATE_CLR_SET_UPD_FLAGS_INDEXED(_id, _name, \
+ _parents, _paridx, _mux_ofs, _mux_set_ofs, \
+ _mux_clr_ofs, _shift, _width, _gate, _upd_ofs, \
+ _upd, CLK_SET_RATE_PARENT)
+
#define MUX_CLR_SET_UPD(_id, _name, _parents, _mux_ofs, \
_mux_set_ofs, _mux_clr_ofs, _shift, _width, \
_upd_ofs, _upd) \
--
2.42.0