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Tue, 27 Nov 2018 10:13:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1543313625; bh=/SbckQH1vgSNT6q2LyWeBCSIEfdsxmfF5Ra2OQo8BVE=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=ms4NlmS7spDqrn+w08AF72/zGg/JS+bXl3dBD2UV75FSu+BOPbhMq+p9UU0mDUhIO /Z2S9rKJtDm8bthPMCRQiZPiEvWx0G5+8G/Ldr0tguEcVeE+Qwxxs1AngpA6t+UmOL IYPAwlYKa99QAiLkfaIeKbWR3uzbvD3kUoGqZhoc= Received: by mail-wm1-f46.google.com with SMTP id k198so21615195wmd.3; Tue, 27 Nov 2018 02:13:45 -0800 (PST) X-Gm-Message-State: AA+aEWbkBXGFaBoch72WvAIKDtVy43PW2N4NZjVULnRf/B201smlds9E CCo377fyBWIwdrXxUqdq6TCEJUjVDycjvF0drQk= X-Received: by 2002:a1c:b406:: with SMTP id d6mr5115290wmf.129.1543313623970; Tue, 27 Nov 2018 02:13:43 -0800 (PST) MIME-Version: 1.0 References: <20181127034254.24721-1-weiyi.lu@mediatek.com> <20181127034254.24721-3-weiyi.lu@mediatek.com> In-Reply-To: <20181127034254.24721-3-weiyi.lu@mediatek.com> From: Sean Wang Date: Tue, 27 Nov 2018 02:13:33 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH v2 01/11] clk: mediatek: add new clkmux register API To: weiyi.lu@mediatek.com Cc: drinkcat@chromium.org, Matthias Brugger , sboyd@codeaurora.org, robh@kernel.org, jamesjj.liao@mediatek.com, srv_heupstream@mediatek.com, linux-kernel@vger.kernel.org, fan.chen@mediatek.com, linux-mediatek@lists.infradead.org, owen.chen@mediatek.com, linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > From: Owen Chen > > 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 > Signed-off-by: Weiyi Lu > --- > drivers/clk/mediatek/Makefile | 2 +- > drivers/clk/mediatek/clk-mux.c | 240 +++++++++++++++++++++++++++++++++ > drivers/clk/mediatek/clk-mux.h | 101 ++++++++++++++ > 3 files changed, 342 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 844b55d2770d..b97980dbb738 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 add a proper words wrap? > 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..8618e5fa2b30 > --- /dev/null > +++ b/drivers/clk/mediatek/clk-mux.c > @@ -0,0 +1,240 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2018 MediaTek Inc. > + * Author: Owen Chen > + */ > + > +#include > +#include > +#include > +#include > + > +#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->gate_shift); > + > + return regmap_update_bits(mux->regmap, mux->mux_ofs, mask, 0); prefer to return regmap_update_bits(mux->regmap, mux->mux_ofs, mask, ~mask); just to align with mtk_clk_mux_disable > +} > + > +static void mtk_clk_mux_disable(struct clk_hw *hw) > +{ > + struct mtk_clk_mux *mux = to_mtk_clk_mux(hw); > + u32 mask = BIT(mux->gate_shift); > + > + regmap_update_bits(mux->regmap, mux->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); > + u32 val; > + > + val = BIT(mux->gate_shift); > + > + return regmap_write(mux->regmap, mux->mux_clr_ofs, val); prefer to return regmap_write(mux->regmap, mux->mux_clr_ofs, BIT(mux->gate_shift)); and drop u32 val declaration > +} > + > +static void mtk_clk_mux_disable_setclr(struct clk_hw *hw) > +{ > + struct mtk_clk_mux *mux = to_mtk_clk_mux(hw); > + u32 val; > + > + val = BIT(mux->gate_shift); > + regmap_write(mux->regmap, mux->mux_set_ofs, val); perfer to regmap_write(mux->regmap, mux->mux_set_ofs, BIT(mux->gate_shift)); and drop u32 val > +} > + > +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->mux_ofs, &val); > + > + return (val & BIT(mux->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->mux_width - 1, 0); > + u32 val; > + > + regmap_read(mux->regmap, mux->mux_ofs, &val); > + val = (val >> mux->mux_shift) & mask; > + > + return val; an u32 to u8 happens here > +} > + > +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->mux_width - 1, 0); > + u32 val; > + unsigned long flags = 0; zero init is unnecessary > + > + if (mux->lock) > + spin_lock_irqsave(mux->lock, flags); > + else > + __acquire(mux->lock); > + > + regmap_read(mux->regmap, mux->mux_ofs, &val); > + val = (val & mask) >> mux->mux_shift; > + > + if (val != index) { > + val = index << mux->mux_shift; > + regmap_update_bits(mux->regmap, mux->mux_ofs, mask, val); > + } regmap_update_bits(mux->regmap, mux->mux_ofs, mask, index << mux->mux_shift); appears to be sufficient. regmap_update_bits would check whether the register write is necessary. > + > + 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->mux_width - 1, 0); > + u32 val, orig; > + unsigned long flags = 0; zero init is unnecessary > + > + if (mux->lock) > + spin_lock_irqsave(mux->lock, flags); > + else > + __acquire(mux->lock); > + > + regmap_read(mux->regmap, mux->mux_ofs, &orig); > + val = (orig & ~(mask << mux->mux_shift)) | (index << mux->mux_shift); > + > + if (val != orig) { > + regmap_write(mux->regmap, mux->mux_clr_ofs, > + mask << mux->mux_shift); > + regmap_write(mux->regmap, mux->mux_set_ofs, > + index << mux->mux_shift); > + > + if (mux->upd_shift >= 0) upd_shift is an u8 > + regmap_write(mux->regmap, mux->upd_ofs, > + BIT(mux->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 *mtk_mux; > + struct clk_init_data init; > + struct clk *clk; > + > + 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)) { > + kfree(mtk_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..ff0276bb771c > --- /dev/null > +++ b/drivers/clk/mediatek/clk-mux.h > @@ -0,0 +1,101 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * Copyright (c) 2018 MediaTek Inc. > + * Author: Owen Chen > + */ > + > +#ifndef __DRV_CLK_MUX_H > +#define __DRV_CLK_MUX_H how about adding a mtk specific prefix? > + > +#include > + > +struct mtk_clk_mux { > + struct clk_hw hw; > + struct regmap *regmap; > + > + const char *name; > + > + u32 mux_set_ofs; > + u32 mux_clr_ofs; > + u32 mux_ofs; > + u32 upd_ofs; > + > + u8 mux_shift; > + u8 mux_width; > + u8 gate_shift; > + u8 upd_shift; > + > + 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; > + u8 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_MUX_H */ > -- > 2.18.0 > > > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek