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author | Anton Vorontsov <avorontsov@ru.mvista.com> | 2008-07-03 23:51:34 -0700 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2008-08-06 13:06:25 +0000 |
commit | 28acd02f9f9efe44718de3bbe8be22d6dfb7e47f (patch) | |
tree | a9afe194d2d4cee5d3356f25c790b4486dd2b77a /drivers/watchdog/mpc8xxx_wdt.c | |
parent | 500c919e3d699644cc9d6c1e93022481baafd8e1 (diff) | |
download | linux-stable-28acd02f9f9efe44718de3bbe8be22d6dfb7e47f.tar.gz linux-stable-28acd02f9f9efe44718de3bbe8be22d6dfb7e47f.tar.bz2 linux-stable-28acd02f9f9efe44718de3bbe8be22d6dfb7e47f.zip |
[WATCHDOG] mpc83xx_wdt: rename to mpc8xxx_wdt
Rename the driver because now we support some MPC86xx processors.
There are no changes to the mpc83xx_wdt.c file, yet. When possible, we do
file renames and changes separately (because Linus once asked so, because
it helps git to track the renamed files).
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/watchdog/mpc8xxx_wdt.c')
-rw-r--r-- | drivers/watchdog/mpc8xxx_wdt.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/drivers/watchdog/mpc8xxx_wdt.c b/drivers/watchdog/mpc8xxx_wdt.c new file mode 100644 index 000000000000..fa82ec99ba81 --- /dev/null +++ b/drivers/watchdog/mpc8xxx_wdt.c @@ -0,0 +1,294 @@ +/* + * mpc83xx_wdt.c - MPC83xx/MPC86xx watchdog userspace interface + * + * Authors: Dave Updegraff <dave@cray.org> + * Kumar Gala <galak@kernel.crashing.org> + * Attribution: from 83xx_wst: Florian Schirmer <jolt@tuxbox.org> + * ..and from sc520_wdt + * Copyright (c) 2008 MontaVista Software, Inc. + * Anton Vorontsov <avorontsov@ru.mvista.com> + * + * Note: it appears that you can only actually ENABLE or DISABLE the thing + * once after POR. Once enabled, you cannot disable, and vice versa. + * + * 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 + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/timer.h> +#include <linux/miscdevice.h> +#include <linux/of_platform.h> +#include <linux/module.h> +#include <linux/watchdog.h> +#include <linux/io.h> +#include <linux/uaccess.h> +#include <sysdev/fsl_soc.h> + +struct mpc83xx_wdt { + __be32 res0; + __be32 swcrr; /* System watchdog control register */ +#define SWCRR_SWTC 0xFFFF0000 /* Software Watchdog Time Count. */ +#define SWCRR_SWEN 0x00000004 /* Watchdog Enable bit. */ +#define SWCRR_SWRI 0x00000002 /* Software Watchdog Reset/Interrupt Select bit.*/ +#define SWCRR_SWPR 0x00000001 /* Software Watchdog Counter Prescale bit. */ + __be32 swcnr; /* System watchdog count register */ + u8 res1[2]; + __be16 swsrr; /* System watchdog service register */ + u8 res2[0xF0]; +}; + +struct mpc83xx_wdt_type { + int prescaler; + bool hw_enabled; +}; + +static struct mpc83xx_wdt __iomem *wd_base; + +static u16 timeout = 0xffff; +module_param(timeout, ushort, 0); +MODULE_PARM_DESC(timeout, + "Watchdog timeout in ticks. (0<timeout<65536, default=65535"); + +static int reset = 1; +module_param(reset, bool, 0); +MODULE_PARM_DESC(reset, + "Watchdog Interrupt/Reset Mode. 0 = interrupt, 1 = reset"); + +static int nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " + "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +/* + * We always prescale, but if someone really doesn't want to they can set this + * to 0 + */ +static int prescale = 1; +static unsigned int timeout_sec; + +static unsigned long wdt_is_open; +static DEFINE_SPINLOCK(wdt_spinlock); + +static void mpc83xx_wdt_keepalive(void) +{ + /* Ping the WDT */ + spin_lock(&wdt_spinlock); + out_be16(&wd_base->swsrr, 0x556c); + out_be16(&wd_base->swsrr, 0xaa39); + spin_unlock(&wdt_spinlock); +} + +static void mpc83xx_wdt_timer_ping(unsigned long arg); +static DEFINE_TIMER(wdt_timer, mpc83xx_wdt_timer_ping, 0, 0); + +static void mpc83xx_wdt_timer_ping(unsigned long arg) +{ + mpc83xx_wdt_keepalive(); + /* We're pinging it twice faster than needed, just to be sure. */ + mod_timer(&wdt_timer, jiffies + HZ * timeout_sec / 2); +} + +static void mpc83xx_wdt_pr_warn(const char *msg) +{ + pr_crit("mpc83xx_wdt: %s, expect the %s soon!\n", msg, + reset ? "reset" : "machine check exception"); +} + +static ssize_t mpc83xx_wdt_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + if (count) + mpc83xx_wdt_keepalive(); + return count; +} + +static int mpc83xx_wdt_open(struct inode *inode, struct file *file) +{ + u32 tmp = SWCRR_SWEN; + if (test_and_set_bit(0, &wdt_is_open)) + return -EBUSY; + + /* Once we start the watchdog we can't stop it */ + if (nowayout) + __module_get(THIS_MODULE); + + /* Good, fire up the show */ + if (prescale) + tmp |= SWCRR_SWPR; + if (reset) + tmp |= SWCRR_SWRI; + + tmp |= timeout << 16; + + out_be32(&wd_base->swcrr, tmp); + + del_timer_sync(&wdt_timer); + + return nonseekable_open(inode, file); +} + +static int mpc83xx_wdt_release(struct inode *inode, struct file *file) +{ + if (!nowayout) + mpc83xx_wdt_timer_ping(0); + else + mpc83xx_wdt_pr_warn("watchdog closed"); + clear_bit(0, &wdt_is_open); + return 0; +} + +static long mpc83xx_wdt_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + static struct watchdog_info ident = { + .options = WDIOF_KEEPALIVEPING, + .firmware_version = 1, + .identity = "MPC83xx", + }; + + switch (cmd) { + case WDIOC_GETSUPPORT: + return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0; + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0, p); + case WDIOC_KEEPALIVE: + mpc83xx_wdt_keepalive(); + return 0; + case WDIOC_GETTIMEOUT: + return put_user(timeout_sec, p); + default: + return -ENOTTY; + } +} + +static const struct file_operations mpc83xx_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = mpc83xx_wdt_write, + .unlocked_ioctl = mpc83xx_wdt_ioctl, + .open = mpc83xx_wdt_open, + .release = mpc83xx_wdt_release, +}; + +static struct miscdevice mpc83xx_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &mpc83xx_wdt_fops, +}; + +static int __devinit mpc83xx_wdt_probe(struct of_device *ofdev, + const struct of_device_id *match) +{ + int ret; + struct device_node *np = ofdev->node; + struct mpc83xx_wdt_type *wdt_type = match->data; + u32 freq = fsl_get_sys_freq(); + bool enabled; + + if (!freq || freq == -1) + return -EINVAL; + + wd_base = of_iomap(np, 0); + if (!wd_base) + return -ENOMEM; + + enabled = in_be32(&wd_base->swcrr) & SWCRR_SWEN; + if (!enabled && wdt_type->hw_enabled) { + pr_info("mpc83xx_wdt: could not be enabled in software\n"); + ret = -ENOSYS; + goto err_unmap; + } + + ret = misc_register(&mpc83xx_wdt_miscdev); + if (ret) { + pr_err("cannot register miscdev on minor=%d (err=%d)\n", + WATCHDOG_MINOR, ret); + goto err_unmap; + } + + /* Calculate the timeout in seconds */ + if (prescale) + timeout_sec = (timeout * wdt_type->prescaler) / freq; + else + timeout_sec = timeout / freq; + + pr_info("WDT driver for MPC83xx initialized. mode:%s timeout=%d " + "(%d seconds)\n", reset ? "reset" : "interrupt", timeout, + timeout_sec); + + /* + * If the watchdog was previously enabled or we're running on + * MPC86xx, we should ping the wdt from the kernel until the + * userspace handles it. + */ + if (enabled) + mpc83xx_wdt_timer_ping(0); + return 0; +err_unmap: + iounmap(wd_base); + return ret; +} + +static int __devexit mpc83xx_wdt_remove(struct of_device *ofdev) +{ + mpc83xx_wdt_pr_warn("watchdog removed"); + del_timer_sync(&wdt_timer); + misc_deregister(&mpc83xx_wdt_miscdev); + iounmap(wd_base); + + return 0; +} + +static const struct of_device_id mpc83xx_wdt_match[] = { + { + .compatible = "mpc83xx_wdt", + .data = &(struct mpc83xx_wdt_type) { + .prescaler = 0x10000, + }, + }, + { + .compatible = "fsl,mpc8610-wdt", + .data = &(struct mpc83xx_wdt_type) { + .prescaler = 0x10000, + .hw_enabled = true, + }, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, mpc83xx_wdt_match); + +static struct of_platform_driver mpc83xx_wdt_driver = { + .match_table = mpc83xx_wdt_match, + .probe = mpc83xx_wdt_probe, + .remove = __devexit_p(mpc83xx_wdt_remove), + .driver = { + .name = "mpc83xx_wdt", + .owner = THIS_MODULE, + }, +}; + +static int __init mpc83xx_wdt_init(void) +{ + return of_register_platform_driver(&mpc83xx_wdt_driver); +} + +static void __exit mpc83xx_wdt_exit(void) +{ + of_unregister_platform_driver(&mpc83xx_wdt_driver); +} + +subsys_initcall(mpc83xx_wdt_init); +module_exit(mpc83xx_wdt_exit); + +MODULE_AUTHOR("Dave Updegraff, Kumar Gala"); +MODULE_DESCRIPTION("Driver for watchdog timer in MPC83xx/MPC86xx uProcessors"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |