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author | Wim Van Sebroeck <wim@iguana.be> | 2007-08-17 10:38:02 +0200 |
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committer | Wim Van Sebroeck <wim@iguana.be> | 2007-10-18 12:39:03 +0200 |
commit | b7e04f8c61a46d742de23af5d7ca2b41b33e40ac (patch) | |
tree | c52a7ea568648e2d8ed0d423098b42298de2058b /drivers/watchdog/mpc5200_wdt.c | |
parent | Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/... (diff) | |
download | linux-b7e04f8c61a46d742de23af5d7ca2b41b33e40ac.tar.xz linux-b7e04f8c61a46d742de23af5d7ca2b41b33e40ac.zip |
mv watchdog tree under drivers
move watchdog tree from drivers/char/watchdog to drivers/watchdog.
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/mpc5200_wdt.c')
-rw-r--r-- | drivers/watchdog/mpc5200_wdt.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/drivers/watchdog/mpc5200_wdt.c b/drivers/watchdog/mpc5200_wdt.c new file mode 100644 index 000000000000..9cfb97576623 --- /dev/null +++ b/drivers/watchdog/mpc5200_wdt.c @@ -0,0 +1,286 @@ +#include <linux/init.h> +#include <linux/module.h> +#include <linux/miscdevice.h> +#include <linux/watchdog.h> +#include <linux/io.h> +#include <linux/spinlock.h> +#include <asm/of_platform.h> +#include <asm/uaccess.h> +#include <asm/mpc52xx.h> + + +#define GPT_MODE_WDT (1<<15) +#define GPT_MODE_CE (1<<12) +#define GPT_MODE_MS_TIMER (0x4) + + +struct mpc5200_wdt { + unsigned count; /* timer ticks before watchdog kicks in */ + long ipb_freq; + struct miscdevice miscdev; + struct resource mem; + struct mpc52xx_gpt __iomem *regs; + spinlock_t io_lock; +}; + +/* is_active stores wether or not the /dev/watchdog device is opened */ +static unsigned long is_active; + +/* misc devices don't provide a way, to get back to 'dev' or 'miscdev' from + * file operations, which sucks. But there can be max 1 watchdog anyway, so... + */ +static struct mpc5200_wdt *wdt_global; + + +/* helper to calculate timeout in timer counts */ +static void mpc5200_wdt_set_timeout(struct mpc5200_wdt *wdt, int timeout) +{ + /* use biggest prescaler of 64k */ + wdt->count = (wdt->ipb_freq + 0xffff) / 0x10000 * timeout; + + if (wdt->count > 0xffff) + wdt->count = 0xffff; +} +/* return timeout in seconds (calculated from timer count) */ +static int mpc5200_wdt_get_timeout(struct mpc5200_wdt *wdt) +{ + return wdt->count * 0x10000 / wdt->ipb_freq; +} + + +/* watchdog operations */ +static int mpc5200_wdt_start(struct mpc5200_wdt *wdt) +{ + spin_lock(&wdt->io_lock); + /* disable */ + out_be32(&wdt->regs->mode, 0); + /* set timeout, with maximum prescaler */ + out_be32(&wdt->regs->count, 0x0 | wdt->count); + /* enable watchdog */ + out_be32(&wdt->regs->mode, GPT_MODE_CE | GPT_MODE_WDT | GPT_MODE_MS_TIMER); + spin_unlock(&wdt->io_lock); + + return 0; +} +static int mpc5200_wdt_ping(struct mpc5200_wdt *wdt) +{ + spin_lock(&wdt->io_lock); + /* writing A5 to OCPW resets the watchdog */ + out_be32(&wdt->regs->mode, 0xA5000000 | (0xffffff & in_be32(&wdt->regs->mode))); + spin_unlock(&wdt->io_lock); + return 0; +} +static int mpc5200_wdt_stop(struct mpc5200_wdt *wdt) +{ + spin_lock(&wdt->io_lock); + /* disable */ + out_be32(&wdt->regs->mode, 0); + spin_unlock(&wdt->io_lock); + return 0; +} + + +/* file operations */ +static ssize_t mpc5200_wdt_write(struct file *file, const char __user *data, + size_t len, loff_t *ppos) +{ + struct mpc5200_wdt *wdt = file->private_data; + mpc5200_wdt_ping(wdt); + return 0; +} +static struct watchdog_info mpc5200_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, + .identity = "mpc5200 watchdog on GPT0", +}; +static int mpc5200_wdt_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) +{ + struct mpc5200_wdt *wdt = file->private_data; + int __user *data = (int __user *)arg; + int timeout; + int ret = 0; + + switch (cmd) { + case WDIOC_GETSUPPORT: + ret = copy_to_user(data, &mpc5200_wdt_info, + sizeof(mpc5200_wdt_info)); + if (ret) + ret = -EFAULT; + break; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + ret = put_user(0, data); + break; + + case WDIOC_KEEPALIVE: + mpc5200_wdt_ping(wdt); + break; + + case WDIOC_SETTIMEOUT: + ret = get_user(timeout, data); + if (ret) + break; + mpc5200_wdt_set_timeout(wdt, timeout); + mpc5200_wdt_start(wdt); + /* fall through and return the timeout */ + + case WDIOC_GETTIMEOUT: + timeout = mpc5200_wdt_get_timeout(wdt); + ret = put_user(timeout, data); + break; + + default: + ret = -ENOTTY; + } + return ret; +} +static int mpc5200_wdt_open(struct inode *inode, struct file *file) +{ + /* /dev/watchdog can only be opened once */ + if (test_and_set_bit(0, &is_active)) + return -EBUSY; + + /* Set and activate the watchdog */ + mpc5200_wdt_set_timeout(wdt_global, 30); + mpc5200_wdt_start(wdt_global); + file->private_data = wdt_global; + return nonseekable_open(inode, file); +} +static int mpc5200_wdt_release(struct inode *inode, struct file *file) +{ +#if WATCHDOG_NOWAYOUT == 0 + struct mpc5200_wdt *wdt = file->private_data; + mpc5200_wdt_stop(wdt); + wdt->count = 0; /* == disabled */ +#endif + clear_bit(0, &is_active); + return 0; +} + +static struct file_operations mpc5200_wdt_fops = { + .owner = THIS_MODULE, + .write = mpc5200_wdt_write, + .ioctl = mpc5200_wdt_ioctl, + .open = mpc5200_wdt_open, + .release = mpc5200_wdt_release, +}; + +/* module operations */ +static int mpc5200_wdt_probe(struct of_device *op, const struct of_device_id *match) +{ + struct mpc5200_wdt *wdt; + int err; + const void *has_wdt; + int size; + + has_wdt = of_get_property(op->node, "has-wdt", NULL); + if (!has_wdt) + return -ENODEV; + + wdt = kzalloc(sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->ipb_freq = mpc52xx_find_ipb_freq(op->node); + + err = of_address_to_resource(op->node, 0, &wdt->mem); + if (err) + goto out_free; + size = wdt->mem.end - wdt->mem.start + 1; + if (!request_mem_region(wdt->mem.start, size, "mpc5200_wdt")) { + err = -ENODEV; + goto out_free; + } + wdt->regs = ioremap(wdt->mem.start, size); + if (!wdt->regs) { + err = -ENODEV; + goto out_release; + } + + dev_set_drvdata(&op->dev, wdt); + spin_lock_init(&wdt->io_lock); + + wdt->miscdev = (struct miscdevice) { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &mpc5200_wdt_fops, + .parent = &op->dev, + }; + wdt_global = wdt; + err = misc_register(&wdt->miscdev); + if (!err) + return 0; + + iounmap(wdt->regs); + out_release: + release_mem_region(wdt->mem.start, size); + out_free: + kfree(wdt); + return err; +} + +static int mpc5200_wdt_remove(struct of_device *op) +{ + struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev); + + mpc5200_wdt_stop(wdt); + misc_deregister(&wdt->miscdev); + iounmap(wdt->regs); + release_mem_region(wdt->mem.start, wdt->mem.end - wdt->mem.start + 1); + kfree(wdt); + + return 0; +} +static int mpc5200_wdt_suspend(struct of_device *op, pm_message_t state) +{ + struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev); + mpc5200_wdt_stop(wdt); + return 0; +} +static int mpc5200_wdt_resume(struct of_device *op) +{ + struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev); + if (wdt->count) + mpc5200_wdt_start(wdt); + return 0; +} +static int mpc5200_wdt_shutdown(struct of_device *op) +{ + struct mpc5200_wdt *wdt = dev_get_drvdata(&op->dev); + mpc5200_wdt_stop(wdt); + return 0; +} + +static struct of_device_id mpc5200_wdt_match[] = { + { .compatible = "mpc5200-gpt", }, + {}, +}; +static struct of_platform_driver mpc5200_wdt_driver = { + .owner = THIS_MODULE, + .name = "mpc5200-gpt-wdt", + .match_table = mpc5200_wdt_match, + .probe = mpc5200_wdt_probe, + .remove = mpc5200_wdt_remove, + .suspend = mpc5200_wdt_suspend, + .resume = mpc5200_wdt_resume, + .shutdown = mpc5200_wdt_shutdown, +}; + + +static int __init mpc5200_wdt_init(void) +{ + return of_register_platform_driver(&mpc5200_wdt_driver); +} + +static void __exit mpc5200_wdt_exit(void) +{ + of_unregister_platform_driver(&mpc5200_wdt_driver); +} + +module_init(mpc5200_wdt_init); +module_exit(mpc5200_wdt_exit); + +MODULE_AUTHOR("Domen Puncer <domen.puncer@telargo.com>"); +MODULE_LICENSE("Dual BSD/GPL"); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |