From fbdd7144ceadd578bc2a875af1dabd67e80ba0d0 Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Mon, 20 Sep 2010 11:23:42 -0500 Subject: powerpc/watchdog: Allow the Book-E driver to be compiled as a module Register the __init and __exit functions in the PowerPC Book-E Watchdog driver as module entry/exit functions, and modify the Kconfig entry. Add a .release method for the PowerPC Book-E Watchdog driver, so that the watchdog is disabled when the driver is closed. Loosely based on original code from Jiang Yutang . Signed-off-by: Timur Tabi Signed-off-by: Kumar Gala --- drivers/watchdog/Kconfig | 5 ++++- drivers/watchdog/booke_wdt.c | 39 +++++++++++++++++++++++++++++++++++++-- 2 files changed, 41 insertions(+), 3 deletions(-) (limited to 'drivers/watchdog') diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 24efd8ea41bb..a6812eb31fa1 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -957,9 +957,12 @@ config PIKA_WDT the Warp platform. config BOOKE_WDT - bool "PowerPC Book-E Watchdog Timer" + tristate "PowerPC Book-E Watchdog Timer" depends on BOOKE || 4xx ---help--- + Watchdog driver for PowerPC Book-E chips, such as the Freescale + MPC85xx SOCs and the IBM PowerPC 440. + Please see Documentation/watchdog/watchdog-api.txt for more information. diff --git a/drivers/watchdog/booke_wdt.c b/drivers/watchdog/booke_wdt.c index 3d49671cdf5a..a9899981fd97 100644 --- a/drivers/watchdog/booke_wdt.c +++ b/drivers/watchdog/booke_wdt.c @@ -4,7 +4,7 @@ * Author: Matthew McClintock * Maintainer: Kumar Gala * - * Copyright 2005, 2008 Freescale Semiconductor Inc. + * Copyright 2005, 2008, 2010 Freescale Semiconductor Inc. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the @@ -114,6 +114,27 @@ static void __booke_wdt_enable(void *data) mtspr(SPRN_TCR, val); } +/** + * booke_wdt_disable - disable the watchdog on the given CPU + * + * This function is called on each CPU. It disables the watchdog on that CPU. + * + * TCR[WRC] cannot be changed once it has been set to non-zero, but we can + * effectively disable the watchdog by setting its period to the maximum value. + */ +static void __booke_wdt_disable(void *data) +{ + u32 val; + + val = mfspr(SPRN_TCR); + val &= ~(TCR_WIE | WDTP_MASK); + mtspr(SPRN_TCR, val); + + /* clear status to make sure nothing is pending */ + __booke_wdt_ping(NULL); + +} + static ssize_t booke_wdt_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { @@ -193,12 +214,21 @@ static int booke_wdt_open(struct inode *inode, struct file *file) return nonseekable_open(inode, file); } +static int booke_wdt_release(struct inode *inode, struct file *file) +{ + on_each_cpu(__booke_wdt_disable, NULL, 0); + booke_wdt_enabled = 0; + + return 0; +} + static const struct file_operations booke_wdt_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = booke_wdt_write, .unlocked_ioctl = booke_wdt_ioctl, .open = booke_wdt_open, + .release = booke_wdt_release, }; static struct miscdevice booke_wdt_miscdev = { @@ -237,4 +267,9 @@ static int __init booke_wdt_init(void) return ret; } -device_initcall(booke_wdt_init); + +module_init(booke_wdt_init); +module_exit(booke_wdt_exit); + +MODULE_DESCRIPTION("PowerPC Book-E watchdog driver"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3 From e0dc09ff9a28f37441c5e92a14de6abda8db49d6 Mon Sep 17 00:00:00 2001 From: Timur Tabi Date: Wed, 13 Oct 2010 14:19:36 -0500 Subject: powerpc/watchdog: Make default timeout for Book-E watchdog a Kconfig option The PowerPC Book-E watchdog driver (booke_wdt.c) defines a default timeout value in the code based on whether it's a Freescale Book-E part of not. Instead of having hard-coded values in the driver, make it a Kconfig option. As newer chips gets faster, the current default values become less appropriate, since the timeout sometimes occurs before the kernel finishes booting. Making the value a Kconfig option allows BSPs to configure a new value without requiring the wdt_period command-line parameter to be set. Signed-off-by: Timur Tabi Signed-off-by: Kumar Gala --- drivers/watchdog/Kconfig | 17 +++++++++++++++++ drivers/watchdog/booke_wdt.c | 8 +------- 2 files changed, 18 insertions(+), 7 deletions(-) (limited to 'drivers/watchdog') diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index a6812eb31fa1..c356146bd712 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -966,6 +966,23 @@ config BOOKE_WDT Please see Documentation/watchdog/watchdog-api.txt for more information. +config BOOKE_WDT_DEFAULT_TIMEOUT + int "PowerPC Book-E Watchdog Timer Default Timeout" + depends on BOOKE_WDT + default 38 if FSL_BOOKE + range 0 63 if FSL_BOOKE + default 3 if !FSL_BOOKE + range 0 3 if !FSL_BOOKE + help + Select the default watchdog timer period to be used by the PowerPC + Book-E watchdog driver. A watchdog "event" occurs when the bit + position represented by this number transitions from zero to one. + + For Freescale Book-E processors, this is a number between 0 and 63. + For other Book-E processors, this is a number between 0 and 3. + + The value can be overidden by the wdt_period command-line parameter. + # PPC64 Architecture config WATCHDOG_RTAS diff --git a/drivers/watchdog/booke_wdt.c b/drivers/watchdog/booke_wdt.c index a9899981fd97..d11ffb091b0d 100644 --- a/drivers/watchdog/booke_wdt.c +++ b/drivers/watchdog/booke_wdt.c @@ -33,14 +33,8 @@ * occur, and the final time the board will reset. */ -#ifdef CONFIG_FSL_BOOKE -#define WDT_PERIOD_DEFAULT 38 /* Ex. wdt_period=28 bus=333Mhz,reset=~40sec */ -#else -#define WDT_PERIOD_DEFAULT 3 /* Refer to the PPC40x and PPC4xx manuals */ -#endif /* for timing information */ - u32 booke_wdt_enabled; -u32 booke_wdt_period = WDT_PERIOD_DEFAULT; +u32 booke_wdt_period = CONFIG_BOOKE_WDT_DEFAULT_TIMEOUT; #ifdef CONFIG_FSL_BOOKE #define WDTP(x) ((((x)&0x3)<<30)|(((x)&0x3c)<<15)) -- cgit v1.2.3