diff options
Diffstat (limited to 'drivers/watchdog')
| -rw-r--r-- | drivers/watchdog/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/watchdog/shwdt.c | 365 |
2 files changed, 170 insertions, 203 deletions
diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 31649b7b672f..908160e938dc 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1083,14 +1083,6 @@ config SH_WDT To compile this driver as a module, choose M here: the module will be called shwdt. -config SH_WDT_MMAP - bool "Allow mmap of SH WDT" - default n - depends on SH_WDT - help - If you say Y here, user applications will be able to mmap the - WDT/CPG registers. - # SPARC Architecture # SPARC64 Architecture diff --git a/drivers/watchdog/shwdt.c b/drivers/watchdog/shwdt.c index 6fc74065abee..4e3e7eb5919c 100644 --- a/drivers/watchdog/shwdt.c +++ b/drivers/watchdog/shwdt.c @@ -1,9 +1,9 @@ /* - * drivers/char/watchdog/shwdt.c + * drivers/watchdog/shwdt.c * * Watchdog driver for integrated watchdog in the SuperH processors. * - * Copyright (C) 2001, 2002, 2003 Paul Mundt <lethal@linux-sh.org> + * Copyright (C) 2001 - 2010 Paul Mundt <lethal@linux-sh.org> * * 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 @@ -19,6 +19,7 @@ */ #include <linux/module.h> #include <linux/moduleparam.h> +#include <linux/platform_device.h> #include <linux/init.h> #include <linux/types.h> #include <linux/miscdevice.h> @@ -28,11 +29,12 @@ #include <linux/ioport.h> #include <linux/fs.h> #include <linux/mm.h> +#include <linux/slab.h> #include <linux/io.h> #include <linux/uaccess.h> #include <asm/watchdog.h> -#define PFX "shwdt: " +#define DRV_NAME "sh-wdt" /* * Default clock division ratio is 5.25 msecs. For an additional table of @@ -62,37 +64,36 @@ * misses its deadline, the kernel timer will allow the WDT to overflow. */ static int clock_division_ratio = WTCSR_CKS_4096; - #define next_ping_period(cks) msecs_to_jiffies(cks - 4) -static void sh_wdt_ping(unsigned long data); - -static unsigned long shwdt_is_open; static const struct watchdog_info sh_wdt_info; -static char shwdt_expect_close; -static DEFINE_TIMER(timer, sh_wdt_ping, 0, 0); -static unsigned long next_heartbeat; +static struct platform_device *sh_wdt_dev; static DEFINE_SPINLOCK(shwdt_lock); #define WATCHDOG_HEARTBEAT 30 /* 30 sec default heartbeat */ static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */ - static int nowayout = WATCHDOG_NOWAYOUT; +static unsigned long next_heartbeat; -/** - * sh_wdt_start - Start the Watchdog - * - * Starts the watchdog. - */ -static void sh_wdt_start(void) +struct sh_wdt { + void __iomem *base; + struct device *dev; + + struct timer_list timer; + + unsigned long enabled; + char expect_close; +}; + +static void sh_wdt_start(struct sh_wdt *wdt) { - __u8 csr; unsigned long flags; + u8 csr; spin_lock_irqsave(&shwdt_lock, flags); next_heartbeat = jiffies + (heartbeat * HZ); - mod_timer(&timer, next_ping_period(clock_division_ratio)); + mod_timer(&wdt->timer, next_ping_period(clock_division_ratio)); csr = sh_wdt_read_csr(); csr |= WTCSR_WT | clock_division_ratio; @@ -114,15 +115,6 @@ static void sh_wdt_start(void) sh_wdt_write_csr(csr); #ifdef CONFIG_CPU_SH2 - /* - * Whoever came up with the RSTCSR semantics must've been smoking - * some of the good stuff, since in addition to the WTCSR/WTCNT write - * brain-damage, it's managed to fuck things up one step further.. - * - * If we need to clear the WOVF bit, the upper byte has to be 0xa5.. - * but if we want to touch RSTE or RSTS, the upper byte has to be - * 0x5a.. - */ csr = sh_wdt_read_rstcsr(); csr &= ~RSTCSR_RSTS; sh_wdt_write_rstcsr(csr); @@ -130,30 +122,23 @@ static void sh_wdt_start(void) spin_unlock_irqrestore(&shwdt_lock, flags); } -/** - * sh_wdt_stop - Stop the Watchdog - * Stops the watchdog. - */ -static void sh_wdt_stop(void) +static void sh_wdt_stop(struct sh_wdt *wdt) { - __u8 csr; unsigned long flags; + u8 csr; spin_lock_irqsave(&shwdt_lock, flags); - del_timer(&timer); + del_timer(&wdt->timer); csr = sh_wdt_read_csr(); csr &= ~WTCSR_TME; sh_wdt_write_csr(csr); + spin_unlock_irqrestore(&shwdt_lock, flags); } -/** - * sh_wdt_keepalive - Keep the Userspace Watchdog Alive - * The Userspace watchdog got a KeepAlive: schedule the next heartbeat. - */ -static inline void sh_wdt_keepalive(void) +static inline void sh_wdt_keepalive(struct sh_wdt *wdt) { unsigned long flags; @@ -162,10 +147,6 @@ static inline void sh_wdt_keepalive(void) spin_unlock_irqrestore(&shwdt_lock, flags); } -/** - * sh_wdt_set_heartbeat - Set the Userspace Watchdog heartbeat - * Set the Userspace Watchdog heartbeat - */ static int sh_wdt_set_heartbeat(int t) { unsigned long flags; @@ -179,19 +160,14 @@ static int sh_wdt_set_heartbeat(int t) return 0; } -/** - * sh_wdt_ping - Ping the Watchdog - * @data: Unused - * - * Clears overflow bit, resets timer counter. - */ static void sh_wdt_ping(unsigned long data) { + struct sh_wdt *wdt = (struct sh_wdt *)data; unsigned long flags; spin_lock_irqsave(&shwdt_lock, flags); if (time_before(jiffies, next_heartbeat)) { - __u8 csr; + u8 csr; csr = sh_wdt_read_csr(); csr &= ~WTCSR_IOVF; @@ -199,148 +175,76 @@ static void sh_wdt_ping(unsigned long data) sh_wdt_write_cnt(0); - mod_timer(&timer, next_ping_period(clock_division_ratio)); + mod_timer(&wdt->timer, next_ping_period(clock_division_ratio)); } else - printk(KERN_WARNING PFX "Heartbeat lost! Will not ping " - "the watchdog\n"); + dev_warn(wdt->dev, "Heartbeat lost! Will not ping " + "the watchdog\n"); spin_unlock_irqrestore(&shwdt_lock, flags); } -/** - * sh_wdt_open - Open the Device - * @inode: inode of device - * @file: file handle of device - * - * Watchdog device is opened and started. - */ static int sh_wdt_open(struct inode *inode, struct file *file) { - if (test_and_set_bit(0, &shwdt_is_open)) + struct sh_wdt *wdt = platform_get_drvdata(sh_wdt_dev); + + if (test_and_set_bit(0, &wdt->enabled)) return -EBUSY; if (nowayout) __module_get(THIS_MODULE); - sh_wdt_start(); + file->private_data = wdt; + + sh_wdt_start(wdt); return nonseekable_open(inode, file); } -/** - * sh_wdt_close - Close the Device - * @inode: inode of device - * @file: file handle of device - * - * Watchdog device is closed and stopped. - */ static int sh_wdt_close(struct inode *inode, struct file *file) { - if (shwdt_expect_close == 42) { - sh_wdt_stop(); + struct sh_wdt *wdt = file->private_data; + + if (wdt->expect_close == 42) { + sh_wdt_stop(wdt); } else { - printk(KERN_CRIT PFX "Unexpected close, not " - "stopping watchdog!\n"); - sh_wdt_keepalive(); + dev_crit(wdt->dev, "Unexpected close, not " + "stopping watchdog!\n"); + sh_wdt_keepalive(wdt); } - clear_bit(0, &shwdt_is_open); - shwdt_expect_close = 0; + clear_bit(0, &wdt->enabled); + wdt->expect_close = 0; return 0; } -/** - * sh_wdt_write - Write to Device - * @file: file handle of device - * @buf: buffer to write - * @count: length of buffer - * @ppos: offset - * - * Pings the watchdog on write. - */ static ssize_t sh_wdt_write(struct file *file, const char *buf, size_t count, loff_t *ppos) { + struct sh_wdt *wdt = file->private_data; + if (count) { if (!nowayout) { size_t i; - shwdt_expect_close = 0; + wdt->expect_close = 0; for (i = 0; i != count; i++) { char c; if (get_user(c, buf + i)) return -EFAULT; if (c == 'V') - shwdt_expect_close = 42; + wdt->expect_close = 42; } } - sh_wdt_keepalive(); + sh_wdt_keepalive(wdt); } return count; } -/** - * sh_wdt_mmap - map WDT/CPG registers into userspace - * @file: file structure for the device - * @vma: VMA to map the registers into - * - * A simple mmap() implementation for the corner cases where the counter - * needs to be mapped in userspace directly. Due to the relatively small - * size of the area, neighbouring registers not necessarily tied to the - * CPG will also be accessible through the register page, so this remains - * configurable for users that really know what they're doing. - * - * Additionaly, the register page maps in the CPG register base relative - * to the nearest page-aligned boundary, which requires that userspace do - * the appropriate CPU subtype math for calculating the page offset for - * the counter value. - */ -static int sh_wdt_mmap(struct file *file, struct vm_area_struct *vma) -{ - int ret = -ENOSYS; - -#ifdef CONFIG_SH_WDT_MMAP - unsigned long addr; - - /* Only support the simple cases where we map in a register page. */ - if (((vma->vm_end - vma->vm_start) != PAGE_SIZE) || vma->vm_pgoff) - return -EINVAL; - - /* - * Pick WTCNT as the start, it's usually the first register after the - * FRQCR, and neither one are generally page-aligned out of the box. - */ - addr = WTCNT & ~(PAGE_SIZE - 1); - - vma->vm_flags |= VM_IO; - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); - - if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT, - PAGE_SIZE, vma->vm_page_prot)) { - printk(KERN_ERR PFX "%s: io_remap_pfn_range failed\n", - __func__); - return -EAGAIN; - } - - ret = 0; -#endif - - return ret; -} - -/** - * sh_wdt_ioctl - Query Device - * @file: file handle of device - * @cmd: watchdog command - * @arg: argument - * - * Query basic information from the device or ping it, as outlined by the - * watchdog API. - */ static long sh_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { + struct sh_wdt *wdt = file->private_data; int new_heartbeat; int options, retval = -EINVAL; @@ -356,18 +260,18 @@ static long sh_wdt_ioctl(struct file *file, unsigned int cmd, return -EFAULT; if (options & WDIOS_DISABLECARD) { - sh_wdt_stop(); + sh_wdt_stop(wdt); retval = 0; } if (options & WDIOS_ENABLECARD) { - sh_wdt_start(); + sh_wdt_start(wdt); retval = 0; } return retval; case WDIOC_KEEPALIVE: - sh_wdt_keepalive(); + sh_wdt_keepalive(wdt); return 0; case WDIOC_SETTIMEOUT: if (get_user(new_heartbeat, (int *)arg)) @@ -376,7 +280,7 @@ static long sh_wdt_ioctl(struct file *file, unsigned int cmd, if (sh_wdt_set_heartbeat(new_heartbeat)) return -EINVAL; - sh_wdt_keepalive(); + sh_wdt_keepalive(wdt); /* Fall */ case WDIOC_GETTIMEOUT: return put_user(heartbeat, (int *)arg); @@ -386,20 +290,13 @@ static long sh_wdt_ioctl(struct file *file, unsigned int cmd, return 0; } -/** - * sh_wdt_notify_sys - Notifier Handler - * @this: notifier block - * @code: notifier event - * @unused: unused - * - * Handles specific events, such as turning off the watchdog during a - * shutdown event. - */ static int sh_wdt_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { + struct sh_wdt *wdt = platform_get_drvdata(sh_wdt_dev); + if (code == SYS_DOWN || code == SYS_HALT) - sh_wdt_stop(); + sh_wdt_stop(wdt); return NOTIFY_DONE; } @@ -411,7 +308,6 @@ static const struct file_operations sh_wdt_fops = { .unlocked_ioctl = sh_wdt_ioctl, .open = sh_wdt_open, .release = sh_wdt_close, - .mmap = sh_wdt_mmap, }; static const struct watchdog_info sh_wdt_info = { @@ -431,66 +327,148 @@ static struct miscdevice sh_wdt_miscdev = { .fops = &sh_wdt_fops, }; -/** - * sh_wdt_init - Initialize module - * Registers the device and notifier handler. Actual device - * initialization is handled by sh_wdt_open(). - */ -static int __init sh_wdt_init(void) +static int __devinit sh_wdt_probe(struct platform_device *pdev) { + struct sh_wdt *wdt; + struct resource *res; int rc; - if (clock_division_ratio < 0x5 || clock_division_ratio > 0x7) { - clock_division_ratio = WTCSR_CKS_4096; - printk(KERN_INFO PFX - "clock_division_ratio value must be 0x5<=x<=0x7, using %d\n", - clock_division_ratio); + /* + * As this driver only covers the global watchdog case, reject + * any attempts to register per-CPU watchdogs. + */ + if (pdev->id != -1) + return -EINVAL; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (unlikely(!res)) + return -EINVAL; + + if (!devm_request_mem_region(&pdev->dev, res->start, + resource_size(res), DRV_NAME)) + return -EBUSY; + + wdt = devm_kzalloc(&pdev->dev, sizeof(struct sh_wdt), GFP_KERNEL); + if (unlikely(!wdt)) { + rc = -ENOMEM; + goto out_release; } - rc = sh_wdt_set_heartbeat(heartbeat); - if (unlikely(rc)) { - heartbeat = WATCHDOG_HEARTBEAT; - printk(KERN_INFO PFX - "heartbeat value must be 1<=x<=3600, using %d\n", - heartbeat); + wdt->dev = &pdev->dev; + + wdt->base = devm_ioremap(&pdev->dev, res->start, resource_size(res)); + if (unlikely(!wdt->base)) { + rc = -ENXIO; + goto out_err; } rc = register_reboot_notifier(&sh_wdt_notifier); if (unlikely(rc)) { - printk(KERN_ERR PFX + dev_err(&pdev->dev, "Can't register reboot notifier (err=%d)\n", rc); - return rc; + goto out_unmap; } + sh_wdt_miscdev.parent = wdt->dev; + rc = misc_register(&sh_wdt_miscdev); if (unlikely(rc)) { - printk(KERN_ERR PFX + dev_err(&pdev->dev, "Can't register miscdev on minor=%d (err=%d)\n", sh_wdt_miscdev.minor, rc); - unregister_reboot_notifier(&sh_wdt_notifier); - return rc; + goto out_unreg; } - printk(KERN_INFO PFX "initialized. heartbeat=%d sec (nowayout=%d)\n", - heartbeat, nowayout); + init_timer(&wdt->timer); + wdt->timer.function = sh_wdt_ping; + wdt->timer.data = (unsigned long)wdt; + wdt->timer.expires = next_ping_period(clock_division_ratio); + + platform_set_drvdata(pdev, wdt); + sh_wdt_dev = pdev; + + dev_info(&pdev->dev, "initialized.\n"); return 0; + +out_unreg: + unregister_reboot_notifier(&sh_wdt_notifier); +out_unmap: + devm_iounmap(&pdev->dev, wdt->base); +out_err: + devm_kfree(&pdev->dev, wdt); +out_release: + devm_release_mem_region(&pdev->dev, res->start, resource_size(res)); + + return rc; } -/** - * sh_wdt_exit - Deinitialize module - * Unregisters the device and notifier handler. Actual device - * deinitialization is handled by sh_wdt_close(). - */ -static void __exit sh_wdt_exit(void) +static int __devexit sh_wdt_remove(struct platform_device *pdev) { + struct sh_wdt *wdt = platform_get_drvdata(pdev); + struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + platform_set_drvdata(pdev, NULL); + misc_deregister(&sh_wdt_miscdev); + + sh_wdt_dev = NULL; + unregister_reboot_notifier(&sh_wdt_notifier); + devm_release_mem_region(&pdev->dev, res->start, resource_size(res)); + devm_iounmap(&pdev->dev, wdt->base); + devm_kfree(&pdev->dev, wdt); + + return 0; } +static struct platform_driver sh_wdt_driver = { + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + }, + + .probe = sh_wdt_probe, + .remove = __devexit_p(sh_wdt_remove), +}; + +static int __init sh_wdt_init(void) +{ + int rc; + + if (unlikely(clock_division_ratio < 0x5 || + clock_division_ratio > 0x7)) { + clock_division_ratio = WTCSR_CKS_4096; + + pr_info("%s: divisor must be 0x5<=x<=0x7, using %d\n", + DRV_NAME, clock_division_ratio); + } + + rc = sh_wdt_set_heartbeat(heartbeat); + if (unlikely(rc)) { + heartbeat = WATCHDOG_HEARTBEAT; + + pr_info("%s: heartbeat value must be 1<=x<=3600, using %d\n", + DRV_NAME, heartbeat); + } + + pr_info("%s: configured with heartbeat=%d sec (nowayout=%d)\n", + DRV_NAME, heartbeat, nowayout); + + return platform_driver_register(&sh_wdt_driver); +} + +static void __exit sh_wdt_exit(void) +{ + platform_driver_unregister(&sh_wdt_driver); +} +module_init(sh_wdt_init); +module_exit(sh_wdt_exit); + MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>"); MODULE_DESCRIPTION("SuperH watchdog driver"); MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRV_NAME); MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); module_param(clock_division_ratio, int, 0); @@ -507,6 +485,3 @@ module_param(nowayout, int, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); - -module_init(sh_wdt_init); -module_exit(sh_wdt_exit); |
