From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:43239 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751035AbbECS4H (ORCPT ); Sun, 3 May 2015 14:56:07 -0400 Date: Sun, 3 May 2015 20:56:01 +0200 From: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= To: Timo Kokkonen Cc: linux-arm-kernel@lists.infradead.org, linux-watchdog@vger.kernel.org, boris.brezillon@free-electrons.com, nicolas.ferre@atmel.com, alexandre.belloni@free-electrons.com, Wenyou.Yang@atmel.com Subject: Re: [PATCHv7 8/8] watchdog: omap_wdt: Convert to use new core extensions Message-ID: <20150503185601.GD25193@pengutronix.de> References: <1429701102-22320-1-git-send-email-timo.kokkonen@offcode.fi> <1429701102-22320-9-git-send-email-timo.kokkonen@offcode.fi> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1429701102-22320-9-git-send-email-timo.kokkonen@offcode.fi> Sender: linux-watchdog-owner@vger.kernel.org List-Id: linux-watchdog@vger.kernel.org Hello, On Wed, Apr 22, 2015 at 02:11:42PM +0300, Timo Kokkonen wrote: > Use the new watchdog core extensions to let watchdog core take over > boot time watchdog behavior. The difference is that early-timeout-sec > device tree property becomes available for this driver and a running > watchdog is not stopped unless the core decides to stop it. > > Omap watchdog is running by default in the boot up but bootloader > might have stopped it. Therefore we fill the WDOG_HW_RUNNING_AT_BOOT > bit depending on the actual watchdog state so that the watchdog core > can act properly. > > Signed-off-by: Timo Kokkonen > --- > drivers/watchdog/omap_wdt.c | 28 +++++++++++++++++++++++++++- > 1 file changed, 27 insertions(+), 1 deletion(-) > > diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c > index bbaf39a..7164f2e 100644 > --- a/drivers/watchdog/omap_wdt.c > +++ b/drivers/watchdog/omap_wdt.c > @@ -78,6 +78,13 @@ static void omap_wdt_reload(struct omap_wdt_dev *wdev) > /* reloaded WCRR from WLDR */ > } > > +static int omap_wdt_is_running(struct omap_wdt_dev *wdev) > +{ > + void __iomem *base = wdev->base; > + > + return readl_relaxed(base + OMAP_WATCHDOG_SPR) == 0x4444; > +} This isn't reliable. The sequence needed to enable the watchdog is writel(0xbbbb, base + OMAP_WATCHDOG_SPR); writel(0x4444, base + OMAP_WATCHDOG_SPR); The sequence to stop is: writel(0xaaaa, base + OMAP_WATCHDOG_SPR); writel(0x5555, base + OMAP_WATCHDOG_SPR); But: barebox@TI AM335x BeagleBone black:/ md 0x44e35048+4 44e35048: 00005555 UU.. barebox@TI AM335x BeagleBone black:/ mw 0x44e35048 0x4444 barebox@TI AM335x BeagleBone black:/ md 0x44e35048+4 44e35048: 00004444 DD.. So the register contains 0x4444 but the timer doesn't run. So at best testing for 0x4444 is a good heuristic. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | http://www.pengutronix.de/ | From mboxrd@z Thu Jan 1 00:00:00 1970 From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=) Date: Sun, 3 May 2015 20:56:01 +0200 Subject: [PATCHv7 8/8] watchdog: omap_wdt: Convert to use new core extensions In-Reply-To: <1429701102-22320-9-git-send-email-timo.kokkonen@offcode.fi> References: <1429701102-22320-1-git-send-email-timo.kokkonen@offcode.fi> <1429701102-22320-9-git-send-email-timo.kokkonen@offcode.fi> Message-ID: <20150503185601.GD25193@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello, On Wed, Apr 22, 2015 at 02:11:42PM +0300, Timo Kokkonen wrote: > Use the new watchdog core extensions to let watchdog core take over > boot time watchdog behavior. The difference is that early-timeout-sec > device tree property becomes available for this driver and a running > watchdog is not stopped unless the core decides to stop it. > > Omap watchdog is running by default in the boot up but bootloader > might have stopped it. Therefore we fill the WDOG_HW_RUNNING_AT_BOOT > bit depending on the actual watchdog state so that the watchdog core > can act properly. > > Signed-off-by: Timo Kokkonen > --- > drivers/watchdog/omap_wdt.c | 28 +++++++++++++++++++++++++++- > 1 file changed, 27 insertions(+), 1 deletion(-) > > diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c > index bbaf39a..7164f2e 100644 > --- a/drivers/watchdog/omap_wdt.c > +++ b/drivers/watchdog/omap_wdt.c > @@ -78,6 +78,13 @@ static void omap_wdt_reload(struct omap_wdt_dev *wdev) > /* reloaded WCRR from WLDR */ > } > > +static int omap_wdt_is_running(struct omap_wdt_dev *wdev) > +{ > + void __iomem *base = wdev->base; > + > + return readl_relaxed(base + OMAP_WATCHDOG_SPR) == 0x4444; > +} This isn't reliable. The sequence needed to enable the watchdog is writel(0xbbbb, base + OMAP_WATCHDOG_SPR); writel(0x4444, base + OMAP_WATCHDOG_SPR); The sequence to stop is: writel(0xaaaa, base + OMAP_WATCHDOG_SPR); writel(0x5555, base + OMAP_WATCHDOG_SPR); But: barebox at TI AM335x BeagleBone black:/ md 0x44e35048+4 44e35048: 00005555 UU.. barebox at TI AM335x BeagleBone black:/ mw 0x44e35048 0x4444 barebox at TI AM335x BeagleBone black:/ md 0x44e35048+4 44e35048: 00004444 DD.. So the register contains 0x4444 but the timer doesn't run. So at best testing for 0x4444 is a good heuristic. Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |