From patchwork Mon Jan 13 09:15:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marco Felsch X-Patchwork-Id: 11329807 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1BBD8138D for ; Mon, 13 Jan 2020 09:15:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 040E52082E for ; Mon, 13 Jan 2020 09:15:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725954AbgAMJPe (ORCPT ); Mon, 13 Jan 2020 04:15:34 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:50273 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725878AbgAMJPe (ORCPT ); Mon, 13 Jan 2020 04:15:34 -0500 Received: from dude02.hi.pengutronix.de ([2001:67c:670:100:1d::28] helo=dude02.lab.pengutronix.de) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1iqvop-0000XT-6m; Mon, 13 Jan 2020 10:15:31 +0100 Received: from mfe by dude02.lab.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1iqvoo-0001dm-4X; Mon, 13 Jan 2020 10:15:30 +0100 From: Marco Felsch To: support.opensource@diasemi.com, linux@roeck-us.net, contact@stefanchrist.eu, Adam.Thomson.Opensource@diasemi.com Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de Subject: [PATCH] watchdog: da9062: make restart handler atomic safe Date: Mon, 13 Jan 2020 10:15:21 +0100 Message-Id: <20200113091521.5754-1-m.felsch@pengutronix.de> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::28 X-SA-Exim-Mail-From: mfe@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-watchdog@vger.kernel.org Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org The restart handler is executed during the shutdown phase which is atomic/irq-less. The i2c framework supports atomic transfers since commit 63b96983a5dd ("i2c: core: introduce callbacks for atomic transfers") but unfortunately the regmap framework doesn't support it yet. Hard coding the i2c stuff can be done without worries since the DA9062 is an i2c-only device. Signed-off-by: Marco Felsch Reviewed-by: Stefan Lengfeld --- Hi, This patch is based on Stefan Lengfeld's RFC Patch [1]. [1] https://patchwork.ozlabs.org/patch/1085942/ --- drivers/watchdog/da9062_wdt.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/drivers/watchdog/da9062_wdt.c b/drivers/watchdog/da9062_wdt.c index c9b9d6394525..84c5a0a455b2 100644 --- a/drivers/watchdog/da9062_wdt.c +++ b/drivers/watchdog/da9062_wdt.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -149,12 +150,18 @@ static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action, void *data) { struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); + struct i2c_client *client = to_i2c_client(wdt->hw->dev); + u8 buf[] = {DA9062AA_CONTROL_F, DA9062AA_SHUTDOWN_MASK}; + struct i2c_msg msg = { + .addr = client->addr, + .flags = 0, + .len = sizeof(buf), + .buf = buf, + }; int ret; - ret = regmap_write(wdt->hw->regmap, - DA9062AA_CONTROL_F, - DA9062AA_SHUTDOWN_MASK); - if (ret) + ret = i2c_transfer(client->adapter, &msg, 1); + if (ret < 0) dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n", ret);