Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754029AbcDZU2v (ORCPT ); Tue, 26 Apr 2016 16:28:51 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:58539 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753845AbcDZU0R (ORCPT ); Tue, 26 Apr 2016 16:26:17 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Stephen Boyd , Dmitry Torokhov , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 63/66] Input: pmic8xxx-pwrkey - fix algorithm for converting trigger delay Date: Tue, 26 Apr 2016 13:24:54 -0700 Message-Id: <1461702297-7792-64-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1461702297-7792-1-git-send-email-kamal@canonical.com> References: <1461702297-7792-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2470 Lines: 65 3.19.8-ckt20 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Stephen Boyd commit eda5ecc0a6b865561997e177c393f0b0136fe3b7 upstream. The trigger delay algorithm that converts from microseconds to the register value looks incorrect. According to most of the PMIC documentation, the equation is delay (Seconds) = (1 / 1024) * 2 ^ (x + 4) except for one case where the documentation looks to have a formatting issue and the equation looks like delay (Seconds) = (1 / 1024) * 2 x + 4 Most likely this driver was written with the improper documentation to begin with. According to the downstream sources the valid delays are from 2 seconds to 1/64 second, and the latter equation just doesn't make sense for that. Let's fix the algorithm and the range check to match the documentation and the downstream sources. Reported-by: Bjorn Andersson Fixes: 92d57a73e410 ("input: Add support for Qualcomm PMIC8XXX power key") Signed-off-by: Stephen Boyd Tested-by: John Stultz Acked-by: Bjorn Andersson Signed-off-by: Dmitry Torokhov Signed-off-by: Kamal Mostafa --- drivers/input/misc/pmic8xxx-pwrkey.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/input/misc/pmic8xxx-pwrkey.c b/drivers/input/misc/pmic8xxx-pwrkey.c index c4ca20e..b6d14bb 100644 --- a/drivers/input/misc/pmic8xxx-pwrkey.c +++ b/drivers/input/misc/pmic8xxx-pwrkey.c @@ -92,7 +92,8 @@ static int pmic8xxx_pwrkey_probe(struct platform_device *pdev) if (of_property_read_u32(pdev->dev.of_node, "debounce", &kpd_delay)) kpd_delay = 15625; - if (kpd_delay > 62500 || kpd_delay == 0) { + /* Valid range of pwr key trigger delay is 1/64 sec to 2 seconds. */ + if (kpd_delay > USEC_PER_SEC * 2 || kpd_delay < USEC_PER_SEC / 64) { dev_err(&pdev->dev, "invalid power key trigger delay\n"); return -EINVAL; } @@ -122,8 +123,8 @@ static int pmic8xxx_pwrkey_probe(struct platform_device *pdev) pwr->name = "pmic8xxx_pwrkey"; pwr->phys = "pmic8xxx_pwrkey/input0"; - delay = (kpd_delay << 10) / USEC_PER_SEC; - delay = 1 + ilog2(delay); + delay = (kpd_delay << 6) / USEC_PER_SEC; + delay = ilog2(delay); err = regmap_read(regmap, PON_CNTL_1, &pon_cntl); if (err < 0) { -- 2.7.4