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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D38AC433F5 for ; Wed, 23 Mar 2022 03:38:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241601AbiCWDkN (ORCPT ); Tue, 22 Mar 2022 23:40:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58006 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241596AbiCWDkJ (ORCPT ); Tue, 22 Mar 2022 23:40:09 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C92F61CB00; Tue, 22 Mar 2022 20:38:39 -0700 (PDT) X-UUID: 7823b751e6424cafa6dfa4eb38cc0079-20220323 X-UUID: 7823b751e6424cafa6dfa4eb38cc0079-20220323 Received: from mtkcas10.mediatek.inc [(172.21.101.39)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 1788832817; Wed, 23 Mar 2022 11:38:34 +0800 Received: from mtkexhb01.mediatek.inc (172.21.101.102) by mtkmbs07n1.mediatek.inc (172.21.101.16) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 23 Mar 2022 11:38:33 +0800 Received: from mtkcas11.mediatek.inc (172.21.101.40) by mtkexhb01.mediatek.inc (172.21.101.102) with Microsoft SMTP Server (TLS) id 15.0.1497.2; Wed, 23 Mar 2022 11:38:33 +0800 Received: from mhfsdcap04 (10.17.3.154) by mtkcas11.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Wed, 23 Mar 2022 11:38:31 +0800 Message-ID: <9415f00e4f2012adc14592c684fa5b670e382ee8.camel@mediatek.com> Subject: Re: [PATCH v8 1/3] dt-bindings: mmc: mtk-sd: extend interrupts and pinctrls properties From: Axe Yang To: Rob Herring CC: AngeloGioacchino Del Regno , "Ulf Hansson" , Chaotian Jing , Matthias Brugger , Adrian Hunter , Yoshihiro Shimoda , Satya Tangirala , "Andy Shevchenko" , Wolfram Sang , Lucas Stach , "Eric Biggers" , Andrew Jeffery , "Stephen Boyd" , Kiwoong Kim , Yue Hu , Tian Tao , , , , , Date: Wed, 23 Mar 2022 11:38:31 +0800 In-Reply-To: References: <20220321115133.32121-1-axe.yang@mediatek.com> <20220321115133.32121-2-axe.yang@mediatek.com> <5d9c7655-b05e-aa77-d405-c1ec971daa77@collabora.com> <4e7a532814510b03b74455f5a924b50a70699ca1.camel@mediatek.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5-0ubuntu0.18.04.2 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-MTK: N Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rob, Sorry, my last mail may mislead your understanding. Let me explain more about this. On Tue, 2022-03-22 at 11:42 -0500, Rob Herring wrote: > On Tue, Mar 22, 2022 at 05:33:55PM +0800, Axe Yang wrote: > > Hello AngeloGioacchino, > > > > On Tue, 2022-03-22 at 09:42 +0100, AngeloGioacchino Del Regno > > wrote: > > > Il 22/03/22 02:35, Axe Yang ha scritto: > > > > On Mon, 2022-03-21 at 18:29 -0500, Rob Herring wrote: > > > > > On Mon, Mar 21, 2022 at 07:51:32PM +0800, Axe Yang wrote: > > > > > > Extend interrupts and pinctrls for SDIO wakeup interrupt > > > > > > feature. > > > > > > This feature allow SDIO devices alarm asynchronous > > > > > > interrupt to > > > > > > host > > > > > > even when host stop providing clock to SDIO card. An extra > > > > > > wakeup > > > > > > interrupt and pinctrl states for SDIO DAT1 pin state > > > > > > switching > > > > > > are > > > > > > required in this scenario. > > > > > > > > > > > > Signed-off-by: Axe Yang > > > > > > --- > > > > > > .../devicetree/bindings/mmc/mtk-sd.yaml | 23 > > > > > > ++++++++++++++++++- > > > > > > 1 file changed, 22 insertions(+), 1 deletion(-) > > > > > > > > > > > > diff --git a/Documentation/devicetree/bindings/mmc/mtk- > > > > > > sd.yaml > > > > > > b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml > > > > > > index 297ada03e3de..f57774535a1d 100644 > > > > > > --- a/Documentation/devicetree/bindings/mmc/mtk-sd.yaml > > > > > > +++ b/Documentation/devicetree/bindings/mmc/mtk-sd.yaml > > > > > > @@ -69,12 +69,23 @@ properties: > > > > > > - const: ahb_cg > > > > > > > > > > > > interrupts: > > > > > > - maxItems: 1 > > > > > > + description: > > > > > > + Should at least contain MSDC GIC interrupt. To > > > > > > support > > > > > > SDIO > > > > > > in-band wakeup, an extended > > > > > > + interrupt is required and be configured as wakeup > > > > > > source > > > > > > irq. > > > > > > + minItems: 1 > > > > > > + maxItems: 2 > > > > > > > > > > > > pinctrl-names: > > > > > > + description: > > > > > > + Should at least contain default and state_uhs. To > > > > > > support > > > > > > SDIO in-band wakeup, dat1 pin > > > > > > + will be switched between GPIO mode and SDIO DAT1 > > > > > > mode, > > > > > > state_eint and state_dat1 are > > > > > > + mandatory in this scenarios. > > > > > > + minItems: 2 > > > > > > items: > > > > > > - const: default > > > > > > - const: state_uhs > > > > > > + - const: state_eint > > > > > > + - const: state_dat1 > > > > > > > > > > > > pinctrl-0: > > > > > > description: > > > > > > @@ -86,6 +97,16 @@ properties: > > > > > > should contain uhs mode pin ctrl. > > > > > > maxItems: 1 > > > > > > > > > > > > + pinctrl-2: > > > > > > + description: > > > > > > + should switch dat1 pin to GPIO mode. > > > > > > + maxItems: 1 > > > > > > + > > > > > > + pinctrl-3: > > > > > > + description: > > > > > > + should switch SDIO dat1 pin from GPIO mode back to > > > > > > SDIO > > > > > > mode. > > > > > > > > > > How is this different than pinctrl-0? > > > > > > > > pinctrl-0 contains default settings for all IO > > > > pins(CLK/CMD/DAT). > > > > pinctrl-1 contains settings for all IO pins(CLK/CMD/DAT) in UHS > > > > mode. > > > > pinctrl-3 is lightweight pinctrl-1, only keep SDIO DAT1 pin > > > > function > > > > switch part. > > > > > > > > > > Is there any particular reason why we cannot simply select > > > pinctrl-1 > > > again > > > instead of pinctrl-3, apart from the virtually not existent > > > overhead > > > of one more mmio write? > > > > No, there is no particular reason. > > I just want to do the pin function switch quick and clean. > > > > The intention of pinctrl-1 is to set the most initial state of IO > > pins > > in UHS mode. If I don't need to adjust IO settings any longer, it > > is > > okay to select pinctrl-1 state instead of pinctrl-3. > > But think about this scenarios: after initial SDIO IO pins to UHS > > mode, > > I want to adjust some IO related properties, such as driving > > strength. > > And I want to keep these settings because with new driving > > strength, > > the signal is better. I'd rather to choose pinctrl-3 but not > > pinctrl-1, > > because I do not want the change be restored after next runtime > > resume. > > The pinctrl-X properties set modes, they aren't supposed to be a > state > machine I do use the pinctl-x properties to set modes, but not judge state from pin state. I need to time-multiplex SDIO DAT1 pin, shift it between GPIO mode and SDIO IO mode, for example: mmc2_pins_default { ... }; mmc2_pins_uhs { pins_clk { pinmux = ; drive-strength = ; bias-pull-down = ; }; pins_cmd_dat { pinmux = , , , , ; input-enable; drive-strength = ; bias-pull-up = ; }; }; mmc2_pins_eint { pins_dat1 { pinmux = ; input-enable; bias-pull-up = ; }; }; mmc2_pins_dat1 { pins_dat1 { pinmux = ; input-enable; bias-pull-up = ; }; }; The pinctrl-1(mmc2_pin_uhs) here contain all SDIO IO pins, for the most early initialize. I SELECT pinctrl-1 when I change SDIO to SDR104 mode, before calibration. And when SDIO bus is idle, I SELECT pinctrl-2(mmc2_pins_eint), use DAT1 as a interrupt line when steping into runtime suspend. After resume, I SELECT pinctrl-3(mmc2_pins_dat1) to set DAT1 pin back to SDIO IO mode. I need all the pinctrl-x properties, and take the initiative to set pin mode according to needs. Best Regard, Axe