[PATCH v3 6/9] clk: realtek: Add support for mux clock
From: Yu-Chun Lin <eleanor.lin@realtek.com>
Date: 2026-01-22 11:09:15
Also in:
linux-clk, lkml
Subsystem:
common clk framework, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Linus Torvalds
From: Cheng-Yu Lee <redacted> Add a simple regmap-based clk_ops implementation for Realtek mux clocks. The implementation supports parent selection and rate determination through regmap-backed register access. Signed-off-by: Cheng-Yu Lee <redacted> Co-developed-by: Yu-Chun Lin <eleanor.lin@realtek.com> Signed-off-by: Yu-Chun Lin <eleanor.lin@realtek.com> --- Changes in v3: - Added prefix "rtk_" in operation names to avoid duplicate symbol problem. --- drivers/clk/realtek/Makefile | 1 + drivers/clk/realtek/clk-regmap-mux.c | 46 ++++++++++++++++++++++++++++ drivers/clk/realtek/clk-regmap-mux.h | 43 ++++++++++++++++++++++++++ 3 files changed, 90 insertions(+) create mode 100644 drivers/clk/realtek/clk-regmap-mux.c create mode 100644 drivers/clk/realtek/clk-regmap-mux.h
diff --git a/drivers/clk/realtek/Makefile b/drivers/clk/realtek/Makefile
index 97058d48a176..b40dd5a26653 100644
--- a/drivers/clk/realtek/Makefile
+++ b/drivers/clk/realtek/Makefile@@ -5,5 +5,6 @@ clk-rtk-y += common.o clk-rtk-y += clk-pll.o clk-rtk-y += clk-regmap-gate.o +clk-rtk-y += clk-regmap-mux.o clk-rtk-y += freq_table.o clk-rtk-y += reset.o
diff --git a/drivers/clk/realtek/clk-regmap-mux.c b/drivers/clk/realtek/clk-regmap-mux.c
new file mode 100644
index 000000000000..d1612de2e2bc
--- /dev/null
+++ b/drivers/clk/realtek/clk-regmap-mux.c@@ -0,0 +1,46 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2017 Realtek Semiconductor Corporation + * Author: Cheng-Yu Lee <cylee12@realtek.com> + */ + +#include "clk-regmap-mux.h" + +static u8 clk_regmap_mux_get_parent(struct clk_hw *hw) +{ + struct clk_regmap_mux *clkm = to_clk_regmap_mux(hw); + int num_parents = clk_hw_get_num_parents(hw); + u32 val; + int ret; + + ret = regmap_read(clkm->clkr.regmap, clkm->mux_ofs, &val); + if (ret) + return 0; + + val = val >> clkm->shift & clkm->mask; + + if (val >= num_parents) + return 0; + + return val; +} + +static int clk_regmap_mux_set_parent(struct clk_hw *hw, u8 index) +{ + struct clk_regmap_mux *clkm = to_clk_regmap_mux(hw); + + return regmap_update_bits(clkm->clkr.regmap, clkm->mux_ofs, + clkm->mask << clkm->shift, index << clkm->shift); +} + +const struct clk_ops rtk_clk_regmap_mux_ops = { + .set_parent = clk_regmap_mux_set_parent, + .get_parent = clk_regmap_mux_get_parent, + .determine_rate = __clk_mux_determine_rate, +}; +EXPORT_SYMBOL_GPL(rtk_clk_regmap_mux_ops); + +const struct clk_ops rtk_clk_regmap_mux_ro_ops = { + .get_parent = clk_regmap_mux_get_parent, +}; +EXPORT_SYMBOL_GPL(rtk_clk_regmap_mux_ro_ops);
diff --git a/drivers/clk/realtek/clk-regmap-mux.h b/drivers/clk/realtek/clk-regmap-mux.h
new file mode 100644
index 000000000000..cf7ab6a0604c
--- /dev/null
+++ b/drivers/clk/realtek/clk-regmap-mux.h@@ -0,0 +1,43 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017 Realtek Semiconductor Corporation + * Author: Cheng-Yu Lee <cylee12@realtek.com> + */ + +#ifndef __CLK_REALTEK_CLK_REGMAP_MUX_H +#define __CLK_REALTEK_CLK_REGMAP_MUX_H + +#include "common.h" + +struct clk_regmap_mux { + struct clk_regmap clkr; + int mux_ofs; + unsigned int mask; + unsigned int shift; +}; + +#define __clk_regmap_mux_hw(_p) __clk_regmap_hw(&(_p)->clkr) + +#define __CLK_REGMAP_MUX(_name, _parents, _ops, _flags, _ofs, _sft, _mask) \ + struct clk_regmap_mux _name = { \ + .clkr.hw.init = \ + CLK_HW_INIT_PARENTS(#_name, _parents, _ops, _flags), \ + .mux_ofs = _ofs, \ + .shift = _sft, \ + .mask = _mask, \ + } + +#define CLK_REGMAP_MUX(_name, _parents, _flags, _ofs, _sft, _mask) \ + __CLK_REGMAP_MUX(_name, _parents, &rtk_clk_regmap_mux_ops, _flags, _ofs, \ + _sft, _mask) + +static inline struct clk_regmap_mux *to_clk_regmap_mux(struct clk_hw *hw) +{ + struct clk_regmap *clkr = to_clk_regmap(hw); + + return container_of(clkr, struct clk_regmap_mux, clkr); +} + +extern const struct clk_ops rtk_clk_regmap_mux_ops; + +#endif /* __CLK_REALTEK_CLK_REGMAP_MUX_H */
--
2.34.1