From patchwork Mon Oct 13 19:14:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Felipe Balbi X-Patchwork-Id: 399264 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 28F651400F4 for ; Tue, 14 Oct 2014 06:14:23 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754501AbaJMTOT (ORCPT ); Mon, 13 Oct 2014 15:14:19 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:47637 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754236AbaJMTOS (ORCPT ); Mon, 13 Oct 2014 15:14:18 -0400 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id s9DJEBVT018850; Mon, 13 Oct 2014 14:14:11 -0500 Received: from DFLE72.ent.ti.com (dfle72.ent.ti.com [128.247.5.109]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id s9DJEBo3017609; Mon, 13 Oct 2014 14:14:11 -0500 Received: from dflp32.itg.ti.com (10.64.6.15) by DFLE72.ent.ti.com (128.247.5.109) with Microsoft SMTP Server id 14.3.174.1; Mon, 13 Oct 2014 14:14:11 -0500 Received: from localhost (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id s9DJEAqP014702; Mon, 13 Oct 2014 14:14:11 -0500 Date: Mon, 13 Oct 2014 14:14:05 -0500 From: Felipe Balbi To: David Cohen CC: , , , Subject: Re: [PATCH] pinctrl: baytrail: show output gpio state correctly on Intel Baytrail Message-ID: <20141013191405.GB29810@saruman> Reply-To: References: <1412355319-18946-1-git-send-email-david.a.cohen@linux.intel.com> <1413224639-21552-1-git-send-email-david.a.cohen@linux.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1413224639-21552-1-git-send-email-david.a.cohen@linux.intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Mon, Oct 13, 2014 at 11:23:59AM -0700, David Cohen wrote: > Even if a gpio pin is set to output, we still need to set INPUT_EN bit here you say you're setting that bit. > to be able to read its value. Without this change, we'll always read low > level state. > > Cc: # v3.14+ > Signed-off-by: David Cohen > --- > > Hi, > > I'm resending same v1 patch but now copying linux stable and linux gpio. > This patch is meant for all linux stable trees >= v3.14. > > Br, David > --- > > drivers/pinctrl/pinctrl-baytrail.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-baytrail.c > index e12e5b07f6d7..c23d8ded936d 100644 > --- a/drivers/pinctrl/pinctrl-baytrail.c > +++ b/drivers/pinctrl/pinctrl-baytrail.c > @@ -318,7 +318,7 @@ static int byt_gpio_direction_output(struct gpio_chip *chip, > "Potential Error: Setting GPIO with direct_irq_en to output"); > > reg_val = readl(reg) | BYT_DIR_MASK; > - reg_val &= ~BYT_OUTPUT_EN; > + reg_val &= ~(BYT_OUTPUT_EN | BYT_INPUT_EN); but code is clearing it. Also, you're not patching byt_gpio_get(), so you can't be 'reading its value' either. Quite frankly, this looks very fishy to me. Comments on BYT_OUTPUT_EN and BYT_INPUT_EN states that those bits are active low, meaning that clearing them enables that particular feature. How can you enable a pin to be both OUTPUT and INPUT ? Look like what you really want is: completely untested however. Care to further explain why clearing both bits - thus enabling both INPUT and OUTPUT - is correct ? diff --git a/drivers/pinctrl/pinctrl-baytrail.c b/drivers/pinctrl/pinctrl-baytrail.c index e12e5b0..69f882d 100644 --- a/drivers/pinctrl/pinctrl-baytrail.c +++ b/drivers/pinctrl/pinctrl-baytrail.c @@ -290,6 +290,7 @@ static int byt_gpio_direction_input(struct gpio_chip *chip, unsigned offset) value = readl(reg) | BYT_DIR_MASK; value &= ~BYT_INPUT_EN; /* active low */ + value |= BYT_OUTPUT_EN; /* disable output */ writel(value, reg); spin_unlock_irqrestore(&vg->lock, flags); @@ -319,6 +320,7 @@ static int byt_gpio_direction_output(struct gpio_chip *chip, reg_val = readl(reg) | BYT_DIR_MASK; reg_val &= ~BYT_OUTPUT_EN; + value |= BYT_INPUT_EN; /* disable input */ if (value) writel(reg_val | BYT_LEVEL, reg);