From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH 2/2 v3] net: smsc911x: request and deassert optional RESET GPIO Date: Wed, 07 Sep 2016 21:06:17 -0700 (PDT) Message-ID: <20160907.210617.685340162025675932.davem@davemloft.net> References: <1473256422-14012-1-git-send-email-linus.walleij@linaro.org> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, steve.glendinning@shawell.net, linux@roeck-us.net, jeremy.linton@arm.com, kamlakant.patel@broadcom.com, p.fedin@samsung.com To: linus.walleij@linaro.org Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:53002 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751332AbcIHEGS (ORCPT ); Thu, 8 Sep 2016 00:06:18 -0400 In-Reply-To: <1473256422-14012-1-git-send-email-linus.walleij@linaro.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Linus Walleij Date: Wed, 7 Sep 2016 15:53:42 +0200 > On some systems (such as the Qualcomm APQ8060 Dragonboard) the > RESET signal of the SMSC911x is not pulled up by a resistor (or > the internal pull-up that will pull it up if the pin is not > even connected) but instead connected to a GPIO line, so that > the operating system must explicitly deassert RESET before use. > > Support this in the SMSC911x driver so this ethernet connector > can be used on such targets. > > Notice that we request the line to go logical low (deassert) > whilst the line on the actual component is active low. This > is managed in the respective hardware description when > specifying the GPIO line with e.g. device tree or ACPI. With > device tree it looks like this in one case: > > reset-gpios = <&tlmm 30 GPIO_ACTIVE_LOW>; > > Which means that logically requesting the RESET line to be > deasserted will result in the line being driven high, taking > the device out of reset. > > Cc: Jeremy Linton > Signed-off-by: Linus Walleij Applied.