From patchwork Thu Oct 25 20:29:26 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Walmsley X-Patchwork-Id: 1647371 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 848D9DF2AB for ; Thu, 25 Oct 2012 20:29:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935967Ab2JYU32 (ORCPT ); Thu, 25 Oct 2012 16:29:28 -0400 Received: from utopia.booyaka.com ([74.50.51.50]:38015 "EHLO utopia.booyaka.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935981Ab2JYU31 (ORCPT ); Thu, 25 Oct 2012 16:29:27 -0400 Received: (qmail 3586 invoked by uid 1019); 25 Oct 2012 20:29:26 -0000 Date: Thu, 25 Oct 2012 20:29:26 +0000 (UTC) From: Paul Walmsley To: Jon Hunter cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Wim Van Sebroeck , linux-watchdog@vger.kernel.org Subject: Re: [PATCH 6/7] watchdog: OMAP: use standard GETBOOTSTATUS interface; use platform_data fn ptr In-Reply-To: Message-ID: References: <20121016012448.21844.92339.stgit@dusk.lan> <20121016013233.21844.1279.stgit@dusk.lan> <50899DB9.8050308@ti.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org On Thu, 25 Oct 2012, Paul Walmsley wrote: > On Thu, 25 Oct 2012, Jon Hunter wrote: > > > In the case of booting with device-tree, pdata could be null and so > > should we check for this too? In other words ... > > > > + if (!pdata || !pdata->read_reset_sources) > > + return put_user(0, (int __user *)arg); > > Thanks, good catch, will integrate that fix. Here's the updated patch. - Paul From: Paul Walmsley Date: Sun, 7 Oct 2012 20:13:26 -0600 Subject: [PATCH] watchdog: OMAP: use standard GETBOOTSTATUS interface; use platform_data fn ptr Previously the OMAP watchdog driver used a non-standard way to report the chip reset source via the GETBOOTSTATUS ioctl. This patch converts the driver to use the standard WDIOF_* flags for this purpose. This patch may break existing userspace code that uses the existing non-standard data format returned by the OMAP watchdog driver's GETBOOTSTATUS ioctl. To fetch detailed reset source information, userspace code will need to retrieve it directly from the CGRM or PRM drivers when those are completed. Previously, to fetch the reset source, the driver either read a register outside the watchdog IP block (OMAP1), or called a function exported directly from arch/arm/mach-omap2. Both approaches are broken. This patch also converts the driver to use a platform_data function pointer. This approach is temporary, and is due to the lack of drivers for the OMAP16xx+ Clock Generation and Reset Management IP block and the OMAP2+ Power and Reset Management IP block. Once drivers are available for those IP blocks, the watchdog driver can be converted to call exported drivers from those functions directly. At that point, the platform_data function pointer can be removed. In the short term, this patch is needed to allow the PRM code to be removed from arch/arm/mach-omap2 (it is being moved to a driver). This version integrates a fix from Jon Hunter that avoids a NULL pointer dereference in a DT-only boot. Signed-off-by: Paul Walmsley Cc: Wim Van Sebroeck Cc: Jon Hunter --- drivers/watchdog/omap_wdt.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c index f5db18db..477a1d4 100644 --- a/drivers/watchdog/omap_wdt.c +++ b/drivers/watchdog/omap_wdt.c @@ -46,8 +46,8 @@ #include #include #include -#include -#include + +#include #include "omap_wdt.h" @@ -202,8 +202,10 @@ static ssize_t omap_wdt_write(struct file *file, const char __user *data, static long omap_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { + struct omap_wd_timer_platform_data *pdata; struct omap_wdt_dev *wdev; - int new_margin; + u32 rs; + int new_margin, bs; static const struct watchdog_info ident = { .identity = "OMAP Watchdog", .options = WDIOF_SETTIMEOUT, @@ -211,6 +213,7 @@ static long omap_wdt_ioctl(struct file *file, unsigned int cmd, }; wdev = file->private_data; + pdata = wdev->dev->platform_data; switch (cmd) { case WDIOC_GETSUPPORT: @@ -219,17 +222,12 @@ static long omap_wdt_ioctl(struct file *file, unsigned int cmd, case WDIOC_GETSTATUS: return put_user(0, (int __user *)arg); case WDIOC_GETBOOTSTATUS: -#ifdef CONFIG_ARCH_OMAP1 - if (cpu_is_omap16xx()) - return put_user(__raw_readw(ARM_SYSST), - (int __user *)arg); -#endif -#ifdef CONFIG_ARCH_OMAP2PLUS - if (cpu_is_omap24xx()) - return put_user(omap_prcm_get_reset_sources(), - (int __user *)arg); -#endif - return put_user(0, (int __user *)arg); + if (!pdata || !pdata->read_reset_sources) + return put_user(0, (int __user *)arg); + rs = pdata->read_reset_sources(); + bs = (rs & (1 << OMAP_MPU_WD_RST_SRC_ID_SHIFT)) ? + WDIOF_CARDRESET : 0; + return put_user(bs, (int __user *)arg); case WDIOC_KEEPALIVE: spin_lock(&wdt_lock); omap_wdt_ping(wdev);