From patchwork Fri Mar 17 01:48:56 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Rivshin X-Patchwork-Id: 9629615 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CED2860244 for ; Fri, 17 Mar 2017 02:21:34 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BF97528653 for ; Fri, 17 Mar 2017 02:21:34 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B40C12868B; Fri, 17 Mar 2017 02:21:34 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 52F3728653 for ; Fri, 17 Mar 2017 02:21:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752781AbdCQCVc (ORCPT ); Thu, 16 Mar 2017 22:21:32 -0400 Received: from out1-smtp.messagingengine.com ([66.111.4.25]:55322 "EHLO out1-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751478AbdCQCV2 (ORCPT ); Thu, 16 Mar 2017 22:21:28 -0400 Received: from compute7.internal (compute7.nyi.internal [10.202.2.47]) by mailout.nyi.internal (Postfix) with ESMTP id 4DB7C209EA; Thu, 16 Mar 2017 21:53:55 -0400 (EDT) Received: from frontend2 ([10.202.2.161]) by compute7.internal (MEProxy); Thu, 16 Mar 2017 21:53:55 -0400 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=awxrd.com; h=cc :date:from:in-reply-to:message-id:references:subject:to :x-me-sender:x-me-sender:x-sasl-enc:x-sasl-enc; s=fm1; bh=oKHu/3 oJFWEJT+8VrOnyPyn4I90=; b=Y3AtHL/WReuWAd5PyhhZspB97goai1eIJpAgBf 49wYTsg4SOVdK9gC3IbOcWxOGApmdxCrdo1H0Ztir3YKa0n6TviIyswqgax+665G RIHSjVUIQI7gQJuwCTkG2OPKnVomEokC3LksyPJGbOFVN9rzwCA6E7AeN6lC8EVo 67Iw6JuyaPIMqlEaFdaTHMxbzaZ5338XsuZZYQqCG2GYqLW5NGnEADHrsrRSk6J3 oGXlO4EqHTz+t5V3ryZTsfHPHbqxAE402f9nWcW48UTik+nzjPVde8OYQqnUdFUK NmiK/fljkzzYY2AbQc0iwDXllqfnJuhp3G7IzijcZTVzddBw== DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d= messagingengine.com; h=cc:date:from:in-reply-to:message-id :references:subject:to:x-me-sender:x-me-sender:x-sasl-enc :x-sasl-enc; s=fm1; bh=oKHu/3oJFWEJT+8VrOnyPyn4I90=; b=H4DOfWyv8 a6J8wFR896oAT/WVaRrrl3+BbG0CYmF1+BdjUTjXDM5awim18u6KXb/uelvrY7sw WH5BOUw8vT8k3/wEl0WrUG/IZs3HCuzdjxceYM1JcgQPxNhjrwxrzgkYpwO4w5d1 FPfv+mCcCGWL3/fJoDrHnFo2ywTuVC4czd9ssCc2WGqRTeyAaycMpfgxPnlbNC7o rH24vv1wZieB9dBDa3XpsNZlnCRDFIXl7Pnaw6/FbhKUJZCIMl8Z0m2ozHDvfk35 QTU+DqSRZvZb38xUm8b8o8qp1eSfKCVExSVf6gzQNZeyZnzXgieymvYpDE+7nRbJ qI3tHnzfIbjIQ== X-ME-Sender: X-Sasl-enc: WeO+t7W5wPecP9/PSrB2KtJQBa3dAGrknmYxNW1IBqPk 1489715635 Received: from drivshin-linux.crosskeys.inscitek.com (unknown [24.213.148.66]) by mail.messagingengine.com (Postfix) with ESMTPA id D1C3F245A4; Thu, 16 Mar 2017 21:53:54 -0400 (EDT) From: David Rivshin To: linux-gpio@vger.kernel.org, linux-omap@vger.kernel.org, Grygorii Strashko Cc: Santosh Shilimkar , Kevin Hilman , Linus Walleij , Alexandre Courbot , linux-arm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 2/2] gpio: omap: compute debounce-time from actual debounce-clock rate Date: Thu, 16 Mar 2017 21:48:56 -0400 Message-Id: <20170317014856.31449-3-drivshin@awxrd.com> X-Mailer: git-send-email 2.9.3 In-Reply-To: <20170317014856.31449-1-drivshin@awxrd.com> References: <20170317014856.31449-1-drivshin@awxrd.com> Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: David Rivshin omap2_set_gpio_debounce() assumes the debounce clock runs at 32768Hz, leading to 31us granularity. In reality the debounce clock (which is provided by other modules) could be at different rate, leading to an incorrect computation of the number of debounce clock cycles for GPIO_DEBOUNCINGTIME[DEBOUNCETIME]. Also, even with a standard 32768Hz input clock, the actual granularity is ~30.5us. This leads to the actual debounce time being ~1.5% too short. Fix both issues by simply querying the dbck rate, rather than hardcoding. Fixes: e85ec6c3047b ("gpio: omap: fix omap2_set_gpio_debounce") Cc: # 4.3+ Signed-off-by: David Rivshin --- This logical bug existed before e85ec6c3047b, but if backporting further it's probably best to just cherry-pick/backport e85ec6c3047b first. drivers/gpio/gpio-omap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c index c40dbdd..66dbe37 100644 --- a/drivers/gpio/gpio-omap.c +++ b/drivers/gpio/gpio-omap.c @@ -205,8 +205,8 @@ static inline void omap_gpio_dbck_disable(struct gpio_bank *bank) * @offset: the gpio number on this @bank * @debounce: debounce time to use * - * OMAP's debounce time is in 31us steps - * = (GPIO_DEBOUNCINGTIME[7:0].DEBOUNCETIME + 1) x 31 + * OMAP's debounce time is in 1/DBCK steps + * = (GPIO_DEBOUNCINGTIME[7:0].DEBOUNCETIME + 1) / DBCK * so we need to convert and round up to the closest unit. * * Return: 0 on success, negative error otherwise. @@ -223,7 +223,9 @@ static int omap2_set_gpio_debounce(struct gpio_bank *bank, unsigned offset, return -ENOTSUPP; if (enable) { - debounce = DIV_ROUND_UP(debounce, 31) - 1; + u64 tmp = (u64)debounce * clk_get_rate(bank->dbck); + + debounce = DIV_ROUND_UP_ULL(tmp, 1000000) - 1; if ((debounce & OMAP4_GPIO_DEBOUNCINGTIME_MASK) != debounce) return -EINVAL; }