X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fchar%2Fwatchdog%2Fsc520_wdt.c;h=8b68721f9a0d74a6f94ed3ec5d9ad4d2a9fe3a99;hb=9bf4aaab3e101692164d49b7ca357651eb691cb6;hp=ce99e3664142f2d4bda2af1158108f3fe4c135ce;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git diff --git a/drivers/char/watchdog/sc520_wdt.c b/drivers/char/watchdog/sc520_wdt.c index ce99e3664..8b68721f9 100644 --- a/drivers/char/watchdog/sc520_wdt.c +++ b/drivers/char/watchdog/sc520_wdt.c @@ -23,22 +23,25 @@ * - Switched to private locks not lock_kernel * - Used ioremap/writew/readw * - Added NOWAYOUT support - * - * 4/12 - 2002 Changes by Rob Radez - * - Change comments - * - Eliminate fop_llseek - * - Change CONFIG_WATCHDOG_NOWAYOUT semantics - * - Add KERN_* tags to printks - * - fix possible wdt_is_open race - * - Report proper capabilities in watchdog_info - * - Add WDIOC_{GETSTATUS, GETBOOTSTATUS, SETTIMEOUT, - * GETTIMEOUT, SETOPTIONS} ioctls - * 09/8 - 2003 Changes by Wim Van Sebroeck - * - cleanup of trailing spaces - * - added extra printk's for startup problems - * - use module_param - * - made timeout (the emulated heartbeat) a module_param - * - made the keepalive ping an internal subroutine + * 4/12 - 2002 Changes by Rob Radez + * - Change comments + * - Eliminate fop_llseek + * - Change CONFIG_WATCHDOG_NOWAYOUT semantics + * - Add KERN_* tags to printks + * - fix possible wdt_is_open race + * - Report proper capabilities in watchdog_info + * - Add WDIOC_{GETSTATUS, GETBOOTSTATUS, SETTIMEOUT, + * GETTIMEOUT, SETOPTIONS} ioctls + * 09/8 - 2003 Changes by Wim Van Sebroeck + * - cleanup of trailing spaces + * - added extra printk's for startup problems + * - use module_param + * - made timeout (the emulated heartbeat) a module_param + * - made the keepalive ping an internal subroutine + * 3/27 - 2004 Changes by Sean Young + * - set MMCR_BASE to 0xfffef000 + * - CBAR does not need to be read + * - removed debugging printks * * This WDT driver is different from most other Linux WDT * drivers in that the driver will ping the watchdog by itself, @@ -65,8 +68,16 @@ #include #include +#define OUR_NAME "sc520_wdt" +#define PFX OUR_NAME ": " + /* - * The SC520 can timeout anywhere from 492us to 32.21s. + * The AMD Elan SC520 timeout value is 492us times a power of 2 (0-7) + * + * 0: 492us 2: 1.01s 4: 4.03s 6: 16.22s + * 1: 503ms 3: 2.01s 5: 8.05s 7: 32.21s + * + * We will program the SC520 watchdog for a timeout of 2.01s. * If we reset the watchdog every ~250ms we should be safe. */ @@ -83,25 +94,33 @@ static int timeout = WATCHDOG_TIMEOUT; /* in seconds, will be multiplied by HZ t module_param(timeout, int, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); -/* - * AMD Elan SC520 timeout value is 492us times a power of 2 (0-7) - * - * 0: 492us 2: 1.01s 4: 4.03s 6: 16.22s - * 1: 503ms 3: 2.01s 5: 8.05s 7: 32.21s - */ - -#define TIMEOUT_EXPONENT ( 1 << 3 ) /* 0x08 = 2.01s */ - -/* #define MMCR_BASE_DEFAULT 0xfffef000 */ -#define MMCR_BASE_DEFAULT ((__u16 *)0xffffe) -#define OFFS_WDTMRCTL ((unsigned int)0xcb0) -#define WDT_ENB 0x8000 /* [15] Watchdog Timer Enable */ -#define WDT_WRST_ENB 0x4000 /* [14] Watchdog Timer Reset Enable */ +#ifdef CONFIG_WATCHDOG_NOWAYOUT +static int nowayout = 1; +#else +static int nowayout = 0; +#endif -#define OUR_NAME "sc520_wdt" -#define PFX OUR_NAME ": " +module_param(nowayout, int, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); -#define WRT_DOG(data) *wdtmrctl=data +/* + * AMD Elan SC520 - Watchdog Timer Registers + */ +#define MMCR_BASE 0xfffef000 /* The default base address */ +#define OFFS_WDTMRCTL 0xCB0 /* Watchdog Timer Control Register */ + +/* WDT Control Register bit definitions */ +#define WDT_EXP_SEL_01 0x0001 /* [01] Time-out = 496 us (with 33 Mhz clk). */ +#define WDT_EXP_SEL_02 0x0002 /* [02] Time-out = 508 ms (with 33 Mhz clk). */ +#define WDT_EXP_SEL_03 0x0004 /* [03] Time-out = 1.02 s (with 33 Mhz clk). */ +#define WDT_EXP_SEL_04 0x0008 /* [04] Time-out = 2.03 s (with 33 Mhz clk). */ +#define WDT_EXP_SEL_05 0x0010 /* [05] Time-out = 4.07 s (with 33 Mhz clk). */ +#define WDT_EXP_SEL_06 0x0020 /* [06] Time-out = 8.13 s (with 33 Mhz clk). */ +#define WDT_EXP_SEL_07 0x0040 /* [07] Time-out = 16.27s (with 33 Mhz clk). */ +#define WDT_EXP_SEL_08 0x0080 /* [08] Time-out = 32.54s (with 33 Mhz clk). */ +#define WDT_IRQ_FLG 0x1000 /* [12] Interrupt Request Flag */ +#define WDT_WRST_ENB 0x4000 /* [14] Watchdog Timer Reset Enable */ +#define WDT_ENB 0x8000 /* [15] Watchdog Timer Enable */ static __u16 *wdtmrctl; @@ -112,15 +131,6 @@ static unsigned long wdt_is_open; static char wdt_expect_close; static spinlock_t wdt_spinlock; -#ifdef CONFIG_WATCHDOG_NOWAYOUT -static int nowayout = 1; -#else -static int nowayout = 0; -#endif - -module_param(nowayout, int, 0); -MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=CONFIG_WATCHDOG_NOWAYOUT)"); - /* * Whack the dog */ @@ -147,7 +157,7 @@ static void wdt_timer_ping(unsigned long data) } /* - * Utility routines + * Utility routines */ static void wdt_config(int writeval) @@ -157,10 +167,10 @@ static void wdt_config(int writeval) /* buy some time (ping) */ spin_lock_irqsave(&wdt_spinlock, flags); - dummy=readw(wdtmrctl); /* ensure write synchronization */ + dummy=readw(wdtmrctl); /* ensure write synchronization */ writew(0xAAAA, wdtmrctl); writew(0x5555, wdtmrctl); - /* make WDT configuration register writable one time */ + /* unlock WDT = make WDT configuration register writable one time */ writew(0x3333, wdtmrctl); writew(0xCCCC, wdtmrctl); /* write WDT configuration register */ @@ -168,7 +178,7 @@ static void wdt_config(int writeval) spin_unlock_irqrestore(&wdt_spinlock, flags); } -static void wdt_startup(void) +static int wdt_startup(void) { next_heartbeat = jiffies + (timeout * HZ); @@ -176,41 +186,50 @@ static void wdt_startup(void) timer.expires = jiffies + WDT_INTERVAL; add_timer(&timer); - wdt_config(WDT_ENB | WDT_WRST_ENB | TIMEOUT_EXPONENT); + /* Start the watchdog */ + wdt_config(WDT_ENB | WDT_WRST_ENB | WDT_EXP_SEL_04); + printk(KERN_INFO PFX "Watchdog timer is now enabled.\n"); + return 0; } -static void wdt_turnoff(void) +static int wdt_turnoff(void) { - if (!nowayout) { - /* Stop the timer */ - del_timer(&timer); - wdt_config(0); - printk(KERN_INFO PFX "Watchdog timer is now disabled...\n"); - } + /* Stop the timer */ + del_timer(&timer); + + /* Stop the watchdog */ + wdt_config(0); + + printk(KERN_INFO PFX "Watchdog timer is now disabled...\n"); + return 0; } -static void wdt_keepalive(void) +static int wdt_keepalive(void) { /* user land ping */ next_heartbeat = jiffies + (timeout * HZ); + return 0; +} + +static int wdt_set_heartbeat(int t) +{ + if ((t < 1) || (t > 3600)) /* arbitrary upper limit */ + return -EINVAL; + + timeout = t; + return 0; } /* - * /dev/watchdog handling + * /dev/watchdog handling */ -static ssize_t fop_write(struct file * file, const char * buf, size_t count, loff_t * ppos) +static ssize_t fop_write(struct file * file, const char __user * buf, size_t count, loff_t * ppos) { - /* We can't seek */ - if(ppos != &file->f_pos) - return -ESPIPE; - /* See if we got the magic character 'V' and reload the timer */ - if(count) - { - if (!nowayout) - { + if(count) { + if (!nowayout) { size_t ofs; /* note: just in case someone wrote the magic character @@ -235,6 +254,8 @@ static ssize_t fop_write(struct file * file, const char * buf, size_t count, lof static int fop_open(struct inode * inode, struct file * file) { + nonseekable_open(inode, file); + /* Just in case we're already talking to someone... */ if(test_and_set_bit(0, &wdt_is_open)) return -EBUSY; @@ -248,11 +269,11 @@ static int fop_open(struct inode * inode, struct file * file) static int fop_close(struct inode * inode, struct file * file) { - if(wdt_expect_close == 42) + if(wdt_expect_close == 42) { wdt_turnoff(); - else { - del_timer(&timer); - printk(KERN_CRIT PFX "device file closed unexpectedly. Will not stop the WDT!\n"); + } else { + printk(KERN_CRIT PFX "Unexpected close, not stopping watchdog!\n"); + wdt_keepalive(); } clear_bit(0, &wdt_is_open); wdt_expect_close = 0; @@ -262,8 +283,9 @@ static int fop_close(struct inode * inode, struct file * file) static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { - static struct watchdog_info ident= - { + void __user *argp = (void __user *)arg; + int __user *p = argp; + static struct watchdog_info ident = { .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE, .firmware_version = 1, .identity = "SC520", @@ -274,10 +296,10 @@ static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, default: return -ENOIOCTLCMD; case WDIOC_GETSUPPORT: - return copy_to_user((struct watchdog_info *)arg, &ident, sizeof(ident))?-EFAULT:0; + return copy_to_user(argp, &ident, sizeof(ident))?-EFAULT:0; case WDIOC_GETSTATUS: case WDIOC_GETBOOTSTATUS: - return put_user(0, (int *)arg); + return put_user(0, p); case WDIOC_KEEPALIVE: wdt_keepalive(); return 0; @@ -285,7 +307,7 @@ static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, { int new_options, retval = -EINVAL; - if(get_user(new_options, (int *)arg)) + if(get_user(new_options, p)) return -EFAULT; if(new_options & WDIOS_DISABLECARD) { @@ -304,18 +326,17 @@ static int fop_ioctl(struct inode *inode, struct file *file, unsigned int cmd, { int new_timeout; - if(get_user(new_timeout, (int *)arg)) + if(get_user(new_timeout, p)) return -EFAULT; - if(new_timeout < 1 || new_timeout > 3600) /* arbitrary upper limit */ + if(wdt_set_heartbeat(new_timeout)) return -EINVAL; - timeout = new_timeout; wdt_keepalive(); /* Fall through */ } case WDIOC_GETTIMEOUT: - return put_user(timeout, (int *)arg); + return put_user(timeout, p); } } @@ -351,81 +372,59 @@ static int wdt_notify_sys(struct notifier_block *this, unsigned long code, * turn the timebomb registers off. */ -static struct notifier_block wdt_notifier= -{ +static struct notifier_block wdt_notifier = { .notifier_call = wdt_notify_sys, }; static void __exit sc520_wdt_unload(void) { - wdt_turnoff(); + if (!nowayout) + wdt_turnoff(); /* Deregister */ misc_deregister(&wdt_miscdev); - iounmap(wdtmrctl); unregister_reboot_notifier(&wdt_notifier); + iounmap(wdtmrctl); } static int __init sc520_wdt_init(void) { int rc = -EBUSY; - unsigned long cbar; spin_lock_init(&wdt_spinlock); - if(timeout < 1 || timeout > 3600) /* arbitrary upper limit */ - { - timeout = WATCHDOG_TIMEOUT; - printk(KERN_INFO PFX "timeout value must be 1<=x<=3600, using %d\n", - timeout); - } - init_timer(&timer); timer.function = wdt_timer_ping; timer.data = 0; - rc = misc_register(&wdt_miscdev); - if (rc) - { - printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", - wdt_miscdev.minor, rc); + /* Check that the timeout value is within it's range ; if not reset to the default */ + if (wdt_set_heartbeat(timeout)) { + wdt_set_heartbeat(WATCHDOG_TIMEOUT); + printk(KERN_INFO PFX "timeout value must be 1<=timeout<=3600, using %d\n", + WATCHDOG_TIMEOUT); + } + + wdtmrctl = ioremap((unsigned long)(MMCR_BASE + OFFS_WDTMRCTL), 2); + if (!wdtmrctl) { + printk(KERN_ERR PFX "Unable to remap memory\n"); + rc = -ENOMEM; goto err_out_region2; } rc = register_reboot_notifier(&wdt_notifier); - if (rc) - { + if (rc) { printk(KERN_ERR PFX "cannot register reboot notifier (err=%d)\n", rc); - goto err_out_miscdev; + goto err_out_ioremap; } - /* get the Base Address Register */ - cbar = inl_p(0xfffc); - printk(KERN_INFO PFX "CBAR: 0x%08lx\n", cbar); - /* check if MMCR aliasing bit is set */ - if (cbar & 0x80000000) { - printk(KERN_INFO PFX "MMCR Aliasing enabled.\n"); - wdtmrctl = (__u16 *)(cbar & 0x3fffffff); - } else { - printk(KERN_INFO PFX "!!! WARNING !!!\n" - "\t MMCR Aliasing found NOT enabled!\n" - "\t Using default value of: %p\n" - "\t This has not been tested!\n" - "\t Please email Scott Jennings \n" - "\t and Bill Jennings if it works!\n" - , MMCR_BASE_DEFAULT - ); - wdtmrctl = MMCR_BASE_DEFAULT; - } - - wdtmrctl = (__u16 *)((char *)wdtmrctl + OFFS_WDTMRCTL); - wdtmrctl = ioremap((unsigned long)wdtmrctl, 2); - if (!wdtmrctl) { - printk (KERN_ERR PFX "Unable to remap memory.\n"); - rc = -ENOMEM; + rc = misc_register(&wdt_miscdev); + if (rc) { + printk(KERN_ERR PFX "cannot register miscdev on minor=%d (err=%d)\n", + WATCHDOG_MINOR, rc); goto err_out_notifier; } + printk(KERN_INFO PFX "WDT driver for SC520 initialised. timeout=%d sec (nowayout=%d)\n", timeout,nowayout); @@ -433,8 +432,8 @@ static int __init sc520_wdt_init(void) err_out_notifier: unregister_reboot_notifier(&wdt_notifier); -err_out_miscdev: - misc_deregister(&wdt_miscdev); +err_out_ioremap: + iounmap(wdtmrctl); err_out_region2: return rc; }