From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko Stuebner Subject: Re: [PATCH v2 06/12] mmc: pwrseq: add support for power-on sequencing through DT Date: Sat, 09 Jan 2016 03:42:03 +0100 Message-ID: <6960259.dpUH8KWsNS@phil> References: <1452155155-16232-1-git-send-email-wxt@rock-chips.com> <1452155155-16232-7-git-send-email-wxt@rock-chips.com> <568FAA07.1010509@osg.samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from gloria.sntech.de ([95.129.55.99]:47881 "EHLO gloria.sntech.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754717AbcAICmR (ORCPT ); Fri, 8 Jan 2016 21:42:17 -0500 In-Reply-To: <568FAA07.1010509@osg.samsung.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Javier Martinez Canillas Cc: Caesar Wang , Ulf Hansson , linux-rockchip@lists.infradead.org, leecam@google.com, leozwang@google.com, keescook@google.com, Srinivas Kandagatla , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, Alexandre Courbot , NeilBrown Am Freitag, 8. Januar 2016, 09:22:31 schrieb Javier Martinez Canillas: > > For example: > > we need enable wifi module power to via the WL_REG_ON > > pin, we need enable it as the regulator if this pin is connected to > > the gpio of cpu. > > This part confuses me, so does your chip have an actual regulator that > needs to be enabled or is just a fake regulator whose gpio property is > used not to enable the regulator but to toggle the WL_REG_ON pin of > the WiFi chip? another option would be to use the reset-gpio-handles. rk3288-veyron and I think some Exynos as well use it that way. > > Maybe, someone will say that can pull up/down from dts. > > Unfortunately some SoCs can't support pinctrl pull up/down in > > internal. > > Can you please elaborate on this? AFAIU this limitation is the reason > why you went with the regulator approach so I think it deserve a more > deep explanation. On the rk3036 each pin has an individual unchangable pull direction. So it's either no bias or pulling in the predefined direction (the pin_default bias option). Heiko