From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758221AbcG0Amg (ORCPT ); Tue, 26 Jul 2016 20:42:36 -0400 Received: from regular1.263xmail.com ([211.150.99.131]:48574 "EHLO regular1.263xmail.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756476AbcG0Am1 (ORCPT ); Tue, 26 Jul 2016 20:42:27 -0400 X-263anti-spam: KSV:0; X-MAIL-GRAY: 0 X-MAIL-DELIVERY: 1 X-KSVirus-check: 0 X-ABS-CHECKED: 4 X-ADDR-CHECKED: 0 X-RL-SENDER: wxt@rock-chips.com X-FST-TO: linux@roeck-us.net X-SENDER-IP: 103.29.142.67 X-LOGIN-NAME: wxt@rock-chips.com X-UNIQUE-TAG: X-ATTACHMENT-NUM: 0 X-DNS-TYPE: 0 Message-ID: <57980362.3000406@rock-chips.com> Date: Wed, 27 Jul 2016 08:42:10 +0800 From: Caesar Wang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Guenter Roeck CC: Caesar Wang , devicetree@vger.kernel.org, heiko@sntech.de, linux-iio@vger.kernel.org, dianders@chromium.org, linux-kernel@vger.kernel.org, linux-rockchip@lists.infradead.org, robh+dt@kernel.org, john@metanate.com, linux-arm-kernel@lists.infradead.org, jic23@kernel.org Subject: Re: [PATCH v2 1/4] iio: adc: rockchip_saradc: reset saradc controller before programming it References: <1469535195-5227-1-git-send-email-wxt@rock-chips.com> <57976814.3040605@roeck-us.net> <579777F4.2090002@rock-chips.com> <20160726170023.GA6590@roeck-us.net> In-Reply-To: <20160726170023.GA6590@roeck-us.net> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2016年07月27日 01:00, Guenter Roeck wrote: > On Tue, Jul 26, 2016 at 10:47:16PM +0800, Caesar Wang wrote: >> On 2016年07月26日 21:39, Guenter Roeck wrote: >>>> static int rockchip_saradc_probe(struct platform_device *pdev) >>>> { >>>> struct rockchip_saradc *info = NULL; >>>> @@ -218,6 +231,21 @@ static int rockchip_saradc_probe(struct >>>> platform_device *pdev) >>>> if (IS_ERR(info->regs)) >>>> return PTR_ERR(info->regs); >>>> >>>> + /* >>>> + * The reset should be an optional property, as it should work >>>> + * with old devicetrees as well >>>> + */ >>>> + info->reset = devm_reset_control_get_optional(&pdev->dev, >>>> + "saradc-apb"); >>> Does anyone know what the _optional API is for ? It seems to be exactly >>> the same >>> as devm_reset_control_get(). >> “ >> As far as I see, the difference is WARN_ON(1) >> when CONFIG_RESET_CONTROLLER is not defined. >> >> >> The _optional functions were introduced by the following commit: >> >> ----------------->8----------------- >> commit b424080a9e086e683ad5fdc624a7cf3c024e0c0f >> Author: Philipp Zabel >> Date: Fri Mar 7 15:18:47 2014 +0100 >> >> reset: Add optional resets and stubs >> >> This patch adds device_reset_optional and (devm_)reset_control_get_optional >> variants that drivers can use to indicate they can function without control >> over the reset line. For those functions, stubs are added so the drivers can >> be compiled with CONFIG_RESET_CONTROLLER disabled. >> Also, device_reset is annotated with __must_check. Drivers >> ignoring the return >> value should use device_reset_optional instead. >> > Is that really what we are looking for here ? CONFIG_RESET_CONTROLLER > is required for other functions of rk3399, isn't it ? Right, as the DRM and thermal are depend on the CONFIG_RESET_CONTROLLER ..... > > Guenter > >> Signed-off-by: Philipp Zabel >> ------------------8<----------------------------- >> ” >> >> for more information on http://www.spinics.net/lists/kernel/msg2306677.html >> :-) >> >>> Guenter >>> >>>> + if (IS_ERR(info->reset)) { >>>> + ret = PTR_ERR(info->reset); >>>> + if (ret != -ENOENT) >>>> + return ret; >>>> + >>>> + dev_dbg(&pdev->dev, "no reset control found\n"); >>>> + info->reset = NULL; >>>> + } >>>> + >>>> init_completion(&info->completion); >>>> >>>> irq = platform_get_irq(pdev, 0); >>>> @@ -252,6 +280,9 @@ static int rockchip_saradc_probe(struct >>>> platform_device *pdev) >>>> return PTR_ERR(info->vref); >>>> } >>>> >>>> + if (info->reset) >>>> + rockchip_saradc_reset_controller(info->reset); >>>> + >>>> /* >>>> * Use a default value for the converter clock. >>>> * This may become user-configurable in the future. >>>> >>> >>> _______________________________________________ >>> Linux-rockchip mailing list >>> Linux-rockchip@lists.infradead.org >>> http://lists.infradead.org/mailman/listinfo/linux-rockchip >> >> -- >> caesar wang | software engineer | wxt@rock-chip.com >> >> > _______________________________________________ > Linux-rockchip mailing list > Linux-rockchip@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-rockchip -- caesar wang | software engineer | wxt@rock-chip.com