From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dong Aisheng Subject: Re: [PATCH v2 2/2] net: flexcan: add transceiver switch gpios support Date: Thu, 28 Jun 2012 20:18:18 +0800 Message-ID: <20120628121817.GA5755@shlinux2.ap.freescale.net> References: <1340853701-4488-1-git-send-email-shawn.guo@linaro.org> <1340853701-4488-3-git-send-email-shawn.guo@linaro.org> <20120628113327.GJ6406@shlinux2.ap.freescale.net> <20120628114559.GE22990@S2101-09.ap.freescale.net> <4FEC487A.2050901@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Received: from ch1ehsobe002.messaging.microsoft.com ([216.32.181.182]:8357 "EHLO ch1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752726Ab2F1MXz (ORCPT ); Thu, 28 Jun 2012 08:23:55 -0400 Content-Disposition: inline In-Reply-To: <4FEC487A.2050901@pengutronix.de> Sender: linux-can-owner@vger.kernel.org List-ID: To: Marc Kleine-Budde Cc: Shawn Guo , Dong Aisheng-B29396 , Hui Wang , "David S. Miller" , "linux-arm-kernel@lists.infradead.org" , "linux-can@vger.kernel.org" On Thu, Jun 28, 2012 at 08:05:14PM +0800, Marc Kleine-Budde wrote: > On 06/28/2012 01:46 PM, Shawn Guo wrote: > > On Thu, Jun 28, 2012 at 07:33:28PM +0800, Dong Aisheng wrote: > >>> + phy_stby_gpio = of_get_named_gpio_flags(pdev->dev.of_node, > >>> + "phy-standby-gpios", > >>> + 0, &flags); > >>> + if (gpio_is_valid(phy_stby_gpio)) { > >>> + if (flags == OF_GPIO_ACTIVE_LOW) > >>> + phy_stby_high = false; > >>> + err = devm_gpio_request_one(&pdev->dev, phy_stby_gpio, > >>> + GPIOF_DIR_OUT, > >>> + "phy-standby"); > >>> + if (err) { > >>> + dev_err(&pdev->dev, > >>> + "failed to request gpio %d: %d\n", > >>> + phy_stby_gpio, err); > >>> + goto failed_gpio; > >> I checked mx28 evk, it seems the phy only has a STB gpio and shared by both CAN0&CAN1. > >> I wonder the CAN1 probe may fail here. > >> > > It can be managed by dts. Here is what I have in imx28-evk.dts, where > > only can0 has phy-enable-gpios property. > > > > > > can0: can@80032000 { > > pinctrl-names = "default"; > > pinctrl-0 = <&can0_pins_a>; > > phy-enable-gpios = <&gpio2 13 0>; > > status = "okay"; > > }; > > > > can1: can@80034000 { > > pinctrl-names = "default"; > > pinctrl-0 = <&can1_pins_a>; > > status = "okay"; > > }; > > Will this work if can0 is down and can1 is up? > > Can we abstract the transceiver power as a regulator? Or a clock? :P > Hmm, it may not be a power. For mx28evk, it's a STBY pin. So it may hard to abstract it as a regulator or clock. Regards Dong Aisheng From mboxrd@z Thu Jan 1 00:00:00 1970 From: aisheng.dong@freescale.com (Dong Aisheng) Date: Thu, 28 Jun 2012 20:18:18 +0800 Subject: [PATCH v2 2/2] net: flexcan: add transceiver switch gpios support In-Reply-To: <4FEC487A.2050901@pengutronix.de> References: <1340853701-4488-1-git-send-email-shawn.guo@linaro.org> <1340853701-4488-3-git-send-email-shawn.guo@linaro.org> <20120628113327.GJ6406@shlinux2.ap.freescale.net> <20120628114559.GE22990@S2101-09.ap.freescale.net> <4FEC487A.2050901@pengutronix.de> Message-ID: <20120628121817.GA5755@shlinux2.ap.freescale.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Jun 28, 2012 at 08:05:14PM +0800, Marc Kleine-Budde wrote: > On 06/28/2012 01:46 PM, Shawn Guo wrote: > > On Thu, Jun 28, 2012 at 07:33:28PM +0800, Dong Aisheng wrote: > >>> + phy_stby_gpio = of_get_named_gpio_flags(pdev->dev.of_node, > >>> + "phy-standby-gpios", > >>> + 0, &flags); > >>> + if (gpio_is_valid(phy_stby_gpio)) { > >>> + if (flags == OF_GPIO_ACTIVE_LOW) > >>> + phy_stby_high = false; > >>> + err = devm_gpio_request_one(&pdev->dev, phy_stby_gpio, > >>> + GPIOF_DIR_OUT, > >>> + "phy-standby"); > >>> + if (err) { > >>> + dev_err(&pdev->dev, > >>> + "failed to request gpio %d: %d\n", > >>> + phy_stby_gpio, err); > >>> + goto failed_gpio; > >> I checked mx28 evk, it seems the phy only has a STB gpio and shared by both CAN0&CAN1. > >> I wonder the CAN1 probe may fail here. > >> > > It can be managed by dts. Here is what I have in imx28-evk.dts, where > > only can0 has phy-enable-gpios property. > > > > > > can0: can at 80032000 { > > pinctrl-names = "default"; > > pinctrl-0 = <&can0_pins_a>; > > phy-enable-gpios = <&gpio2 13 0>; > > status = "okay"; > > }; > > > > can1: can at 80034000 { > > pinctrl-names = "default"; > > pinctrl-0 = <&can1_pins_a>; > > status = "okay"; > > }; > > Will this work if can0 is down and can1 is up? > > Can we abstract the transceiver power as a regulator? Or a clock? :P > Hmm, it may not be a power. For mx28evk, it's a STBY pin. So it may hard to abstract it as a regulator or clock. Regards Dong Aisheng