From 81fbc5ef9b22df2e2198dd0c530719a263a8d1c5 Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Tue, 21 Dec 2010 19:56:17 -0700 Subject: OMAP2+: wd_timer: separate watchdog disable code from the rest of mach-omap2/devices.c Split the wd_timer disable code out into its own file, mach-omap2/wd_timer.c; it belongs in its own file rather than cluttering up devices.c. Signed-off-by: Paul Walmsley Cc: Charulatha Varadarajan --- arch/arm/mach-omap2/devices.c | 55 ++++--------------------------------------- 1 file changed, 5 insertions(+), 50 deletions(-) (limited to 'arch/arm/mach-omap2/devices.c') diff --git a/arch/arm/mach-omap2/devices.c b/arch/arm/mach-omap2/devices.c index 1bca147ac91d..9221a486b51f 100644 --- a/arch/arm/mach-omap2/devices.c +++ b/arch/arm/mach-omap2/devices.c @@ -33,6 +33,7 @@ #include "mux.h" #include "control.h" +#include "wd_timer.h" #if defined(CONFIG_VIDEO_OMAP2) || defined(CONFIG_VIDEO_OMAP2_MODULE) @@ -955,69 +956,23 @@ static inline void omap_init_vout(void) {} /*-------------------------------------------------------------------------*/ -/* - * Inorder to avoid any assumptions from bootloader regarding WDT - * settings, WDT module is reset during init. This enables the watchdog - * timer. Hence it is required to disable the watchdog after the WDT reset - * during init. Otherwise the system would reboot as per the default - * watchdog timer registers settings. - */ -#define OMAP_WDT_WPS (0x34) -#define OMAP_WDT_SPR (0x48) - static int omap2_disable_wdt(struct omap_hwmod *oh, void *unused) { - void __iomem *base; - int ret; - - if (!oh) { - pr_err("%s: Could not look up wdtimer_hwmod\n", __func__); - return -EINVAL; - } - - base = omap_hwmod_get_mpu_rt_va(oh); - if (!base) { - pr_err("%s: Could not get the base address for %s\n", - oh->name, __func__); - return -EINVAL; - } - - /* Enable the clocks before accessing the WDT registers */ - ret = omap_hwmod_enable(oh); - if (ret) { - pr_err("%s: Could not enable clocks for %s\n", - oh->name, __func__); - return ret; - } - - /* sequence required to disable watchdog */ - __raw_writel(0xAAAA, base + OMAP_WDT_SPR); - while (__raw_readl(base + OMAP_WDT_WPS) & 0x10) - cpu_relax(); - - __raw_writel(0x5555, base + OMAP_WDT_SPR); - while (__raw_readl(base + OMAP_WDT_WPS) & 0x10) - cpu_relax(); - - ret = omap_hwmod_idle(oh); - if (ret) - pr_err("%s: Could not disable clocks for %s\n", - oh->name, __func__); - - return ret; + return omap2_wd_timer_disable(oh); } static void __init omap_disable_wdt(void) { if (cpu_class_is_omap2()) omap_hwmod_for_each_by_class("wd_timer", - omap2_disable_wdt, NULL); + omap2_disable_wdt, NULL); return; } static int __init omap2_init_devices(void) { - /* please keep these calls, and their implementations above, + /* + * please keep these calls, and their implementations above, * in alphabetical order so they're easier to sort through. */ omap_disable_wdt(); -- cgit v1.2.3 From ff2516fbef20ed9edd9cc2fc8b8b48d5cb5a932f Mon Sep 17 00:00:00 2001 From: Paul Walmsley Date: Tue, 21 Dec 2010 15:39:15 -0700 Subject: OMAP2+: wd_timer: disable on boot via hwmod postsetup mechanism MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The OMAP watchdog timer IP blocks require a specific set of register writes to occur before they will be disabled[1], even if the device clocks appear to be disabled in the CM_*CLKEN registers. In the MPU watchdog case, failure to execute this reset sequence will eventually cause the watchdog to reset the OMAP unexpectedly. Previously, the code to disable this watchdog was manually called from mach-omap2/devices.c during device initialization. This causes the watchdog to be unconditionally disabled for a portion of kernel initialization. This should be controllable by the board-*.c files, since some system integrators will want full watchdog coverage of kernel initialization. Also, the watchdog disable code was not connected to the hwmod shutdown code. This means that calling omap_hwmod_shutdown() will not, in fact, disable the watchdog, and the goal of omap_hwmod_shutdown() is to be able to shutdown any on-chip OMAP device. To resolve the latter problem, populate the pre_shutdown pointer in the watchdog timer hwmod classes with a function that executes the watchdog shutdown sequence. This allows the hwmod code to fully disable the watchdog. Then, to allow some board files to support watchdog coverage throughout kernel initialization, add common code to mach-omap2/io.c to cause the MPU watchdog to be disabled on boot unless a board file specifically requests it to remain enabled. Board files can do this by changing the watchdog timer hwmod's postsetup state between the omap2_init_common_infrastructure() and omap2_init_common_devices() function calls. 1. OMAP34xx Multimedia Device Silicon Revision 3.1.x Rev. ZH [SWPU222H], Section 16.4.3.6, "Start/Stop Sequence for WDTs (Using WDTi.WSPR Register)" Signed-off-by: Paul Walmsley Cc: Benoît Cousson Cc: Kevin Hilman Cc: Charulatha Varadarajan --- arch/arm/mach-omap2/devices.c | 15 --------------- 1 file changed, 15 deletions(-) (limited to 'arch/arm/mach-omap2/devices.c') diff --git a/arch/arm/mach-omap2/devices.c b/arch/arm/mach-omap2/devices.c index 9221a486b51f..381f4eb92352 100644 --- a/arch/arm/mach-omap2/devices.c +++ b/arch/arm/mach-omap2/devices.c @@ -33,7 +33,6 @@ #include "mux.h" #include "control.h" -#include "wd_timer.h" #if defined(CONFIG_VIDEO_OMAP2) || defined(CONFIG_VIDEO_OMAP2_MODULE) @@ -956,26 +955,12 @@ static inline void omap_init_vout(void) {} /*-------------------------------------------------------------------------*/ -static int omap2_disable_wdt(struct omap_hwmod *oh, void *unused) -{ - return omap2_wd_timer_disable(oh); -} - -static void __init omap_disable_wdt(void) -{ - if (cpu_class_is_omap2()) - omap_hwmod_for_each_by_class("wd_timer", - omap2_disable_wdt, NULL); - return; -} - static int __init omap2_init_devices(void) { /* * please keep these calls, and their implementations above, * in alphabetical order so they're easier to sort through. */ - omap_disable_wdt(); omap_hsmmc_reset(); omap_init_audio(); omap_init_camera(); -- cgit v1.2.3