Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756679AbbHZHth (ORCPT ); Wed, 26 Aug 2015 03:49:37 -0400 Received: from mail-ob0-f174.google.com ([209.85.214.174]:35431 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756364AbbHZHtf convert rfc822-to-8bit (ORCPT ); Wed, 26 Aug 2015 03:49:35 -0400 MIME-Version: 1.0 In-Reply-To: <1439896258-26449-4-git-send-email-grygorii.strashko@ti.com> References: <1439896258-26449-1-git-send-email-grygorii.strashko@ti.com> <1439896258-26449-4-git-send-email-grygorii.strashko@ti.com> Date: Wed, 26 Aug 2015 09:49:34 +0200 Message-ID: Subject: Re: [PATCH 3/7] gpio: omap: fix omap2_set_gpio_debounce From: Linus Walleij To: Grygorii Strashko Cc: Alexandre Courbot , Santosh Shilimkar , Kevin Hilman , Tony Lindgren , Javier Martinez Canillas , Linux-OMAP , "linux-gpio@vger.kernel.org" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1565 Lines: 40 On Tue, Aug 18, 2015 at 1:10 PM, Grygorii Strashko wrote: > According to TRMs: > > Required input line stable = > (the value of the GPIO_DEBOUNCINGTIME[7:0].DEBOUNCETIME + 1) × 31, > where the value of the GPIO_DEBOUNCINGTIME[7:0].DEBOUNCETIME bit field > is from 0 to 255. > > But now omap2_set_gpio_debounce() will calculate debounce time and > behave incorrectly in the following cases: > 1) requested debounce time is !0 and <32 > calculated DEBOUNCETIME = 0x1 == 62 us; > expected value of DEBOUNCETIME = 0x0 == 31us > 2) requested debounce time is 0 > calculated DEBOUNCETIME = 0x1 == 62 us; > expected: disable debounce and DEBOUNCETIME = 0x0 > 3) requested debounce time is >32 and <63 > calculated DEBOUNCETIME = 0x0 and debounce will be disabled; > expected: enable debounce and DEBOUNCETIME = 0x1 == 62 us > > Hence, rework omap2_set_gpio_debounce() to fix above cases: > 1) introduce local variable "enable" and use it to identify > when debounce need to be enabled or disabled. Disable debounce > if requested debounce time is 0. > 2) use below formula for debounce time calculation: > debounce = (DIV_ROUND_UP(debounce, 31) - 1) & 0xFF; > > Signed-off-by: Grygorii Strashko Very hightech. Patch applied. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/