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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 A6E61C433E0 for ; Tue, 30 Jun 2020 14:37:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8B34C206BE for ; Tue, 30 Jun 2020 14:37:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388968AbgF3OhJ (ORCPT ); Tue, 30 Jun 2020 10:37:09 -0400 Received: from mga01.intel.com ([192.55.52.88]:49391 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726672AbgF3OhI (ORCPT ); Tue, 30 Jun 2020 10:37:08 -0400 IronPort-SDR: u/5ngZ9eeHDm0uJ8+9MNY73f65U15CCfGUUgKA/cSn3JCR12S/6hKIBODzXOFxFyjq59Cpvaxt sdYrEzOjPgYA== X-IronPort-AV: E=McAfee;i="6000,8403,9666"; a="164251998" X-IronPort-AV: E=Sophos;i="5.75,297,1589266800"; d="scan'208";a="164251998" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Jun 2020 07:37:08 -0700 IronPort-SDR: TXnmtpuuv8IkPHzCQZ8xil9NFjyMMlIhDaUlHleEi9/3MlNTBqZVvADOI64AV/rGk+FbVBXUaf bDSog2SN/SQw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,297,1589266800"; d="scan'208";a="266488793" Received: from smile.fi.intel.com (HELO smile) ([10.237.68.40]) by fmsmga008.fm.intel.com with ESMTP; 30 Jun 2020 07:37:04 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1jqHNh-00GrcC-2T; Tue, 30 Jun 2020 17:37:05 +0300 Date: Tue, 30 Jun 2020 17:37:05 +0300 From: Andy Shevchenko To: Tomasz Figa Cc: Sakari Ailus , Dongchun Zhu , Linus Walleij , Bartosz Golaszewski , Mauro Carvalho Chehab , Rob Herring , Mark Rutland , Nicolas Boichat , Matthias Brugger , Cao Bing Bu , srv_heupstream , "moderated list:ARM/Mediatek SoC support" , "list@263.net:IOMMU DRIVERS , Joerg Roedel ," , Sj Huang , Linux Media Mailing List , linux-devicetree , Louis Kuo , Shengnan Wang =?utf-8?B?KOeOi+Wco+eUtyk=?= Subject: Re: [PATCH V11 2/2] media: i2c: ov02a10: Add OV02A10 image sensor driver Message-ID: <20200630143705.GW3703480@smile.fi.intel.com> References: <20200630024942.20891-1-dongchun.zhu@mediatek.com> <20200630024942.20891-3-dongchun.zhu@mediatek.com> <20200630095430.GF16711@paasikivi.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, Jun 30, 2020 at 04:21:31PM +0200, Tomasz Figa wrote: > On Tue, Jun 30, 2020 at 4:19 PM Tomasz Figa wrote: > > On Tue, Jun 30, 2020 at 11:54 AM Sakari Ailus > > wrote: ... > > > > + ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); > > > > > > > > > Shouldn't this be GPIOD_OUT_HIGH? That's the state it'll be after powering > > > the sensor off the first time. Alternatively make reset signal high in > > > runtime suspend callback. > > > > We might want to keep the signals low when the regulators are powered > > down, to reduce the leakage. > > Ah, I actually recall that the reset pin was physically active low, so > we would indeed better keep it at HIGH. Sorry for the noise. Here HIGH means "asserted", so in the code above it's LOW, means "deasserted", i.o.w. non-reset state. I dunno what is better, it depends to the firmware / driver expectations of the device configuration (from the power point of view, HIGH makes sense here, and not LOW, i.o.w. asserted reset line). And nice of the logical state that it doesn't depend to the active low / high (the latter just transparent to the user). -- With Best Regards, Andy Shevchenko 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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 183DDC433E0 for ; Tue, 30 Jun 2020 14:37:23 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DA65A206BE for ; Tue, 30 Jun 2020 14:37:22 +0000 (UTC) Authentication-Results: mail.kernel.org; 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30 Jun 2020 07:37:04 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1jqHNh-00GrcC-2T; Tue, 30 Jun 2020 17:37:05 +0300 Date: Tue, 30 Jun 2020 17:37:05 +0300 From: Andy Shevchenko To: Tomasz Figa Subject: Re: [PATCH V11 2/2] media: i2c: ov02a10: Add OV02A10 image sensor driver Message-ID: <20200630143705.GW3703480@smile.fi.intel.com> References: <20200630024942.20891-1-dongchun.zhu@mediatek.com> <20200630024942.20891-3-dongchun.zhu@mediatek.com> <20200630095430.GF16711@paasikivi.fi.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo X-BeenThere: linux-mediatek@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-devicetree , Nicolas Boichat , srv_heupstream , Linus Walleij , Shengnan Wang =?utf-8?B?KOeOi+Wco+eUtyk=?= , Louis Kuo , Bartosz Golaszewski , Sj Huang , Rob Herring , "moderated list:ARM/Mediatek SoC support" , Dongchun Zhu , Sakari Ailus , Matthias Brugger , Cao Bing Bu , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Linux Media Mailing List Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-mediatek" Errors-To: linux-mediatek-bounces+linux-mediatek=archiver.kernel.org@lists.infradead.org On Tue, Jun 30, 2020 at 04:21:31PM +0200, Tomasz Figa wrote: > On Tue, Jun 30, 2020 at 4:19 PM Tomasz Figa wrote: > > On Tue, Jun 30, 2020 at 11:54 AM Sakari Ailus > > wrote: ... > > > > + ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); > > > > > > > > > Shouldn't this be GPIOD_OUT_HIGH? That's the state it'll be after powering > > > the sensor off the first time. Alternatively make reset signal high in > > > runtime suspend callback. > > > > We might want to keep the signals low when the regulators are powered > > down, to reduce the leakage. > > Ah, I actually recall that the reset pin was physically active low, so > we would indeed better keep it at HIGH. Sorry for the noise. Here HIGH means "asserted", so in the code above it's LOW, means "deasserted", i.o.w. non-reset state. I dunno what is better, it depends to the firmware / driver expectations of the device configuration (from the power point of view, HIGH makes sense here, and not LOW, i.o.w. asserted reset line). And nice of the logical state that it doesn't depend to the active low / high (the latter just transparent to the user). -- With Best Regards, Andy Shevchenko _______________________________________________ Linux-mediatek mailing list Linux-mediatek@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-mediatek 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=-1.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 6EE01C433E0 for ; Tue, 30 Jun 2020 14:38:33 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3BBD3206BE for ; 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30 Jun 2020 07:37:04 -0700 Received: from andy by smile with local (Exim 4.94) (envelope-from ) id 1jqHNh-00GrcC-2T; Tue, 30 Jun 2020 17:37:05 +0300 Date: Tue, 30 Jun 2020 17:37:05 +0300 From: Andy Shevchenko To: Tomasz Figa Subject: Re: [PATCH V11 2/2] media: i2c: ov02a10: Add OV02A10 image sensor driver Message-ID: <20200630143705.GW3703480@smile.fi.intel.com> References: <20200630024942.20891-1-dongchun.zhu@mediatek.com> <20200630024942.20891-3-dongchun.zhu@mediatek.com> <20200630095430.GF16711@paasikivi.fi.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-devicetree , Nicolas Boichat , srv_heupstream , Linus Walleij , Shengnan Wang =?utf-8?B?KOeOi+Wco+eUtyk=?= , Louis Kuo , Bartosz Golaszewski , Sj Huang , Rob Herring , "moderated list:ARM/Mediatek SoC support" , Dongchun Zhu , Sakari Ailus , Matthias Brugger , Cao Bing Bu , Mauro Carvalho Chehab , "list@263.net:IOMMU DRIVERS , Joerg Roedel , " , Linux Media Mailing List Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jun 30, 2020 at 04:21:31PM +0200, Tomasz Figa wrote: > On Tue, Jun 30, 2020 at 4:19 PM Tomasz Figa wrote: > > On Tue, Jun 30, 2020 at 11:54 AM Sakari Ailus > > wrote: ... > > > > + ov02a10->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); > > > > > > > > > Shouldn't this be GPIOD_OUT_HIGH? That's the state it'll be after powering > > > the sensor off the first time. Alternatively make reset signal high in > > > runtime suspend callback. > > > > We might want to keep the signals low when the regulators are powered > > down, to reduce the leakage. > > Ah, I actually recall that the reset pin was physically active low, so > we would indeed better keep it at HIGH. Sorry for the noise. Here HIGH means "asserted", so in the code above it's LOW, means "deasserted", i.o.w. non-reset state. I dunno what is better, it depends to the firmware / driver expectations of the device configuration (from the power point of view, HIGH makes sense here, and not LOW, i.o.w. asserted reset line). And nice of the logical state that it doesn't depend to the active low / high (the latter just transparent to the user). -- With Best Regards, Andy Shevchenko _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel