From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751488AbeCNTxV (ORCPT ); Wed, 14 Mar 2018 15:53:21 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:59086 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751289AbeCNTxT (ORCPT ); Wed, 14 Mar 2018 15:53:19 -0400 Subject: Re: [PATCH 2/2] watchdog: aspeed: Allow configuring for alternate boot To: Guenter Roeck Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org, joel@jms.id.au, wim@linux-watchdog.org, Milton Miller References: <1520632700-25800-1-git-send-email-eajames@linux.vnet.ibm.com> <1520632700-25800-3-git-send-email-eajames@linux.vnet.ibm.com> <20180309220610.GB32606@roeck-us.net> From: Eddie James Date: Wed, 14 Mar 2018 14:53:13 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <20180309220610.GB32606@roeck-us.net> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-TM-AS-GCONF: 00 x-cbid: 18031419-0004-0000-0000-000013CD68A8 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00008674; HX=3.00000241; KW=3.00000007; PH=3.00000004; SC=3.00000254; SDB=6.01003054; UDB=6.00510441; IPR=6.00782384; MB=3.00020035; MTD=3.00000008; XFM=3.00000015; UTC=2018-03-14 19:53:17 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18031419-0005-0000-0000-00008676D904 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2018-03-14_10:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1803140214 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/09/2018 04:06 PM, Guenter Roeck wrote: > On Fri, Mar 09, 2018 at 03:58:20PM -0600, Eddie James wrote: >> From: Milton Miller >> >> Allow the device tree to specify a watchdog to fallover to >> the alternate boot source. >> >> The aspeeed watchdog can set a latch directing flash chip select 0 to >> chip select 1, allowing boot from an alternate media if the watchdog >> is not reset in time. On the ast2400 bank 1 also goes to flash bank 1, >> while on the ast2500 the chip selects are swapped. >> >> Signed-off-by: Milton Miller >> Signed-off-by: Eddie James > This is already documented in the bindings document, so the property > should be ok. > > Reviewed-by: Guenter Roeck Thanks. On a related note, our system has need of a way to determine if it's currently booted from the alternate chip or not. It seems the only way to tell is to look at the ast2400/2500 watchdog timeout status register. We can add some debugfs to the aspeed driver I guess, but I wonder if this is a common enough situation that the watchdog core could use some debugfs or sysfs for providing that info? Thanks, Eddie > >> --- >> drivers/watchdog/aspeed_wdt.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c >> index d1987d6..f41d246 100644 >> --- a/drivers/watchdog/aspeed_wdt.c >> +++ b/drivers/watchdog/aspeed_wdt.c >> @@ -46,6 +46,7 @@ struct aspeed_wdt_config { >> #define WDT_RELOAD_VALUE 0x04 >> #define WDT_RESTART 0x08 >> #define WDT_CTRL 0x0C >> +#define WDT_CTRL_BOOT_SECONDARY BIT(7) >> #define WDT_CTRL_RESET_MODE_SOC (0x00 << 5) >> #define WDT_CTRL_RESET_MODE_FULL_CHIP (0x01 << 5) >> #define WDT_CTRL_RESET_MODE_ARM_CPU (0x10 << 5) >> @@ -245,6 +246,8 @@ static int aspeed_wdt_probe(struct platform_device *pdev) >> } >> if (of_property_read_bool(np, "aspeed,external-signal")) >> wdt->ctrl |= WDT_CTRL_WDT_EXT; >> + if (of_property_read_bool(np, "aspeed,alt-boot")) >> + wdt->ctrl |= WDT_CTRL_BOOT_SECONDARY; >> >> if (readl(wdt->base + WDT_CTRL) & WDT_CTRL_ENABLE) { >> /* >> -- >> 1.8.3.1 >>