[PATCH 2/2] powerpc/watchdog: allow the e500 watchdog driver to be compiled as a module
Timur Tabi
timur at freescale.com
Sat Sep 18 08:53:28 EST 2010
Register the __init and __exit functions in the PowerPC e500 watchdog driver
as module entry/exit functions, and modify the Kconfig entry.
Add a .release method for the PowerPC e500 watchdog driver, so that the
watchdog is disabled when the driver is closed.
Loosely based on original code from Jiang Yutang <b14898 at freescale.com>.
Signed-off-by: Timur Tabi <timur at freescale.com>
---
This patch requires:
powerpc: export ppc_tb_freq so that modules can reference it
drivers/watchdog/Kconfig | 5 ++++-
drivers/watchdog/booke_wdt.c | 39 +++++++++++++++++++++++++++++++++++++--
2 files changed, 41 insertions(+), 3 deletions(-)
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 24efd8e..d9cf5a9 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 e500 chips, such as the Freescale
+ MPC85xx SOCs.
+
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 3d49671..a989998 100644
--- a/drivers/watchdog/booke_wdt.c
+++ b/drivers/watchdog/booke_wdt.c
@@ -4,7 +4,7 @@
* Author: Matthew McClintock
* Maintainer: Kumar Gala <galak at kernel.crashing.org>
*
- * 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");
--
1.7.2.3
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