From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754497Ab3B1Ixs (ORCPT ); Thu, 28 Feb 2013 03:53:48 -0500 Received: from pegase2.c-s.fr ([93.17.235.10]:46631 "EHLO mailhub2.si.c-s.fr" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754173Ab3B1Ixn (ORCPT ); Thu, 28 Feb 2013 03:53:43 -0500 Date: Thu, 28 Feb 2013 09:52:22 +0100 Message-Id: <201302280852.r1S8qMYu003742@localhost.localdomain> From: Christophe Leroy To: Wim Van Sebroeck CC: linux-kernel@vger.kernel.org, linux-watchdog@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Subject: [PATCH v2] Enhanced support for MPC8xx/8xxx watchdog Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch modifies the behaviour of the MPC8xx/8xxx watchdog. On the MPC8xx, at 133Mhz, the maximum timeout of the watchdog timer is 1s, which means it must be pinged twice a second. This is not in line with the Linux watchdog concept which is based on a default watchdog timeout around 60s. This patch introduces an intermediate layer between the CPU and the userspace. The kernel pings the watchdog at the required frequency at the condition that userspace tools refresh it regularly. Existing parameter 'timeout' is renamed 'hw_time'. The new parameter 'timeout' allows to set up the userspace timeout. The driver also implements the WDIOC_SETTIMEOUT ioctl. Signed-off-by: Christophe Leroy diff -ur linux-3.7.9/drivers/watchdog/mpc8xxx_wdt.c linux/drivers/watchdog/mpc8xxx_wdt.c --- linux-3.7.9/drivers/watchdog/mpc8xxx_wdt.c 2013-02-17 19:53:32.000000000 +0100 +++ linux/drivers/watchdog/mpc8xxx_wdt.c 2013-02-27 16:00:07.000000000 +0100 @@ -52,10 +52,17 @@ static struct mpc8xxx_wdt __iomem *wd_base; static int mpc8xxx_wdt_init_late(void); -static u16 timeout = 0xffff; -module_param(timeout, ushort, 0); +#define WD_TIMO 10 /* Default timeout = 10 seconds */ + +static uint timeout = WD_TIMO; +module_param(timeout, uint, 0); MODULE_PARM_DESC(timeout, - "Watchdog timeout in ticks. (0swcrr, tmp); - del_timer_sync(&wdt_timer); + wdt_auto = 0; return nonseekable_open(inode, file); } @@ -138,7 +158,8 @@ static int mpc8xxx_wdt_release(struct inode *inode, struct file *file) { if (!nowayout) - mpc8xxx_wdt_timer_ping(0); + wdt_auto = 1; + else mpc8xxx_wdt_pr_warn("watchdog closed"); clear_bit(0, &wdt_is_open); @@ -163,10 +184,12 @@ case WDIOC_GETBOOTSTATUS: return put_user(0, p); case WDIOC_KEEPALIVE: - mpc8xxx_wdt_keepalive(); + mpc8xxx_wdt_sw_keepalive(); return 0; case WDIOC_GETTIMEOUT: - return put_user(timeout_sec, p); + return put_user(timeout, p); + case WDIOC_SETTIMEOUT: + return get_user(timeout, p); default: return -ENOTTY; } @@ -215,12 +238,14 @@ ret = -ENOSYS; goto err_unmap; } + if (enabled) + hw_timo = in_be32(&wd_base->swcrr) >> 16; /* Calculate the timeout in seconds */ if (prescale) - timeout_sec = (timeout * wdt_type->prescaler) / freq; + hw_timo_sec = (hw_timo * wdt_type->prescaler) / freq; else - timeout_sec = timeout / freq; + hw_timo_sec = hw_timo / freq; #ifdef MODULE ret = mpc8xxx_wdt_init_late(); @@ -228,8 +253,8 @@ goto err_unmap; #endif - pr_info("WDT driver for MPC8xxx initialized. mode:%s timeout=%d (%d seconds)\n", - reset ? "reset" : "interrupt", timeout, timeout_sec); + pr_info("WDT driver for MPC8xxx initialized. mode:%s timeout = %d (%d seconds)\n", + reset ? "reset" : "interrupt", hw_timo, hw_timo_sec); /* * If the watchdog was previously enabled or we're running on @@ -273,6 +298,7 @@ .compatible = "fsl,mpc823-wdt", .data = &(struct mpc8xxx_wdt_type) { .prescaler = 0x800, + .hw_enabled = true, }, }, {},