Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756908AbcJXAxe (ORCPT ); Sun, 23 Oct 2016 20:53:34 -0400 Received: from mail-qk0-f178.google.com ([209.85.220.178]:32848 "EHLO mail-qk0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756728AbcJXAxc (ORCPT ); Sun, 23 Oct 2016 20:53:32 -0400 MIME-Version: 1.0 In-Reply-To: <1477062035-30825-1-git-send-email-enric.balletbo@collabora.com> References: <1477062035-30825-1-git-send-email-enric.balletbo@collabora.com> From: Linus Walleij Date: Mon, 24 Oct 2016 02:53:31 +0200 Message-ID: Subject: Re: [PATCH] gpio: mcp23s08: Add option to configure pullups. To: Enric Balletbo i Serra Cc: "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-gpio@vger.kernel.org" , Rob Herring Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 752 Lines: 24 On Fri, Oct 21, 2016 at 5:00 PM, Enric Balletbo i Serra wrote: > Default is without pullups, but if property is specified in DT and the bit > is set, set a pullup on GPIO-n. > > Signed-off-by: Enric Balletbo i Serra I don't generally like this. In device tree it is the consumer that specifies how the line is used, not the producer (gpiochip). We currently only specify polarity, open drain and open source for consumers though. And the entire pin control system came into being *exactly* because Grant didn't like me adding these things to the GPIO drivers. So how many other things does the MCP support? Drive strength? Schmitt trigger? Is there a datasheet? Yours, Linus Walleij