From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,UNPARSEABLE_RELAY autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 048AEC04EBB for ; Tue, 20 Nov 2018 06:35:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AAE9A20685 for ; Tue, 20 Nov 2018 06:35:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AAE9A20685 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mediatek.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732336AbeKTRCh (ORCPT ); Tue, 20 Nov 2018 12:02:37 -0500 Received: from mailgw01.mediatek.com ([210.61.82.183]:64291 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726979AbeKTRCh (ORCPT ); Tue, 20 Nov 2018 12:02:37 -0500 X-UUID: b45b2d7710a94ef6b9542dbbb10b03ba-20181120 X-UUID: b45b2d7710a94ef6b9542dbbb10b03ba-20181120 Received: from mtkcas09.mediatek.inc [(172.21.101.178)] by mailgw01.mediatek.com (envelope-from ) (mhqrelay.mediatek.com ESMTP with TLS) with ESMTP id 1220410853; Tue, 20 Nov 2018 14:34:59 +0800 Received: from mtkcas08.mediatek.inc (172.21.101.126) by mtkmbs03n1.mediatek.inc (172.21.101.181) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 20 Nov 2018 14:34:57 +0800 Received: from [172.21.77.4] (172.21.77.4) by mtkcas08.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1395.4 via Frontend Transport; Tue, 20 Nov 2018 14:34:57 +0800 Message-ID: <1542695697.5132.24.camel@mtksdaap41> Subject: Re: [PATCH v1 01/11] clk: mediatek: add new clkmux register API From: Weiyi Lu To: Nicolas Boichat CC: Rob Herring , , , , lkml , , , Matthias Brugger , , , linux-arm Mailing List Date: Tue, 20 Nov 2018 14:34:57 +0800 In-Reply-To: References: <20181106064206.17535-1-weiyi.lu@mediatek.com> <20181106064206.17535-3-weiyi.lu@mediatek.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.10.4-0ubuntu2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2018-11-13 at 08:00 -0800, Nicolas Boichat wrote: > On Mon, Nov 5, 2018 at 10:42 PM Weiyi Lu wrote: > > > > 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 | 252 +++++++++++++++++++++++++++++++++ > > drivers/clk/mediatek/clk-mux.h | 101 +++++++++++++ > > 3 files changed, 354 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 > > 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..18bc9a146be0 > > --- /dev/null > > +++ b/drivers/clk/mediatek/clk-mux.c > > @@ -0,0 +1,252 @@ > > +// 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); > > + > > + regmap_update_bits(mux->regmap, mux->mux_ofs, mask, 0); > > + > > + return 0; > > Might as well return regmap_update_bits(...). > OK, will fix in next version > > +} > > + > > +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); > > + regmap_write(mux->regmap, mux->mux_clr_ofs, val); > > + > > + return 0; > > ditto: return regmap_write(...) . > will fix in next version > > +} > > + > > +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); > > +} > > + > > +static int mtk_clk_mux_is_enabled(struct clk_hw *hw) > > +{ > > + struct mtk_clk_mux *mux = to_mtk_clk_mux(hw); > > + u32 val = 0; > > No need to init to 0. > will fix in next version > > + > > + regmap_read(mux->regmap, mux->mux_ofs, &val); > > + > > + return ((val & BIT(mux->gate_shift)) == 0) ? 1 : 0; > > Just (val & BIT(mux->gate_shift)) != 0. Or more simply val & > BIT(mux->gate_shift). > will fix in next version > > +} > > + > > +static u8 mtk_clk_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 || val >= U8_MAX) > > val > U8_MAX, technically. > > > + return -ERANGE; > > This looks wrong, -34 will be cast to an u8 and appear to be valid... > will fix in next version > > + > > + return val; > > +} > > + > > +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; > > No need to init to 0. > will fix in next version. > > + > > + 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); > > + } > > What's the point of doing read/compare/update? Are there side effects > if you just write the value unconditionally? > Actually writing the value directly has no side effects. We just want to reduce unnecessary operations if the target parent of mux is already selected. > > + > > + 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; > > + > > + if (mux->lock) > > + spin_lock_irqsave(mux->lock, flags); > > + else > > + __acquire(mux->lock); > > + > > + regmap_read(mux->regmap, mux->mux_ofs, &val); > > + orig = val; > > Just read into &orig above. > will fix in next version > > + val &= ~(mask << mux->mux_shift); > > + val |= index << mux->mux_shift; > > Maybe this is more readable? > val = orig & ~(mask << mux->mux_shift) | (index << mux->mux_shift) > will fix in next version > > + > > + if (val != orig) { > > + val = (mask << mux->mux_shift); > > + regmap_write(mux->regmap, mux->mux_clr_ofs, val); > > I'd just regmap_write(..., mask << mux->mux_shift), instead if overriding val. > will fix in next version > > + 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); > > + 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 = NULL; > > Not necessary to init to NULL. > will fix in next version > > + 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; > > mux->flags | CLK_SET_RATE_PARENT > will fix in next version > > + 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; > > + > > + if (!clk_data) > > + return -ENOMEM; > > Is this check necessary? After all you know who the callers are and > maybe you need to be careful not to call this with NULL clk_data? > You're right. it's unnecessary. will fix in next version > > + > > + 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])) { > > A NULL check seems enough, as you'll never assign a PTR_ERR(..) value > into 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; > > Are we ok with returning 0 even though some of these calls failed? > We'd like to skip the failed one first and keep registering the remainings. > > + } > > + > > + 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 > > + > > +#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