diff options
Diffstat (limited to 'drivers/sbus')
| -rw-r--r-- | drivers/sbus/char/cpwatchdog.c | 1035 |
1 files changed, 436 insertions, 599 deletions
diff --git a/drivers/sbus/char/cpwatchdog.c b/drivers/sbus/char/cpwatchdog.c index 23abfdfb44f..c88df62e705 100644 --- a/drivers/sbus/char/cpwatchdog.c +++ b/drivers/sbus/char/cpwatchdog.c @@ -11,6 +11,7 @@ * reset 'stopped' watchdogs on affected platforms. * * Copyright (c) 2000 Eric Brower (ebrower@usa.net) + * Copyright (C) 2008 David S. Miller <davem@davemloft.net> */ #include <linux/kernel.h> @@ -25,36 +26,34 @@ #include <linux/timer.h> #include <linux/smp_lock.h> #include <linux/io.h> +#include <linux/of.h> +#include <linux/of_device.h> + #include <asm/irq.h> -#include <asm/ebus.h> -#include <asm/oplib.h> #include <asm/uaccess.h> #include <asm/watchdog.h> +#define DRIVER_NAME "cpwd" +#define PFX DRIVER_NAME ": " + #define WD_OBPNAME "watchdog" -#define WD_BADMODEL "SUNW,501-5336" +#define WD_BADMODEL "SUNW,501-5336" #define WD_BTIMEOUT (jiffies + (HZ * 1000)) #define WD_BLIMIT 0xFFFF -#define WD0_DEVNAME "watchdog0" -#define WD1_DEVNAME "watchdog1" -#define WD2_DEVNAME "watchdog2" - #define WD0_MINOR 212 #define WD1_MINOR 213 #define WD2_MINOR 214 +/* Internal driver definitions. */ +#define WD0_ID 0 +#define WD1_ID 1 +#define WD2_ID 2 +#define WD_NUMDEVS 3 -/* Internal driver definitions - */ -#define WD0_ID 0 /* Watchdog0 */ -#define WD1_ID 1 /* Watchdog1 */ -#define WD2_ID 2 /* Watchdog2 */ -#define WD_NUMDEVS 3 /* Device contains 3 timers */ - -#define WD_INTR_OFF 0 /* Interrupt disable value */ -#define WD_INTR_ON 1 /* Interrupt enable value */ +#define WD_INTR_OFF 0 +#define WD_INTR_ON 1 #define WD_STAT_INIT 0x01 /* Watchdog timer is initialized */ #define WD_STAT_BSTOP 0x02 /* Watchdog timer is brokenstopped */ @@ -69,6 +68,29 @@ #define WD_S_RUNNING 0x01 /* Watchdog device status running */ #define WD_S_EXPIRED 0x02 /* Watchdog device status expired */ +struct cpwd { + void __iomem *regs; + spinlock_t lock; + + unsigned int irq; + + unsigned long timeout; + bool enabled; + bool reboot; + bool broken; + bool initialized; + + struct { + struct miscdevice misc; + void __iomem *regs; + u8 intr_mask; + u8 runstatus; + u16 timeout; + } devs[WD_NUMDEVS]; +}; + +static struct cpwd *cpwd_device; + /* Sun uses Altera PLD EPF8820ATC144-4 * providing three hardware watchdogs: * @@ -130,40 +152,12 @@ #define PLD_IMASK (PLD_OFF + 0x00) #define PLD_STATUS (PLD_OFF + 0x04) -/* Individual timer structure - */ -struct wd_timer { - __u16 timeout; - __u8 intr_mask; - unsigned char runstatus; - void __iomem *regs; -}; - -/* Device structure - */ -struct wd_device { - int irq; - spinlock_t lock; - unsigned char isbaddoggie; /* defective PLD */ - unsigned char opt_enable; - unsigned char opt_reboot; - unsigned short opt_timeout; - unsigned char initialized; - struct wd_timer watchdog[WD_NUMDEVS]; - void __iomem *regs; -}; - -static struct wd_device wd_dev = { - 0, __SPIN_LOCK_UNLOCKED(wd_dev.lock), 0, 0, 0, 0, -}; - -static struct timer_list wd_timer; +static struct timer_list cpwd_timer; static int wd0_timeout = 0; static int wd1_timeout = 0; static int wd2_timeout = 0; -#ifdef MODULE module_param (wd0_timeout, int, 0); MODULE_PARM_DESC(wd0_timeout, "Default watchdog0 timeout in 1/10secs"); module_param (wd1_timeout, int, 0); @@ -171,234 +165,313 @@ MODULE_PARM_DESC(wd1_timeout, "Default watchdog1 timeout in 1/10secs"); module_param (wd2_timeout, int, 0); MODULE_PARM_DESC(wd2_timeout, "Default watchdog2 timeout in 1/10secs"); -MODULE_AUTHOR - ("Eric Brower <ebrower@usa.net>"); -MODULE_DESCRIPTION - ("Hardware watchdog driver for Sun Microsystems CP1400/1500"); +MODULE_AUTHOR("Eric Brower <ebrower@usa.net>"); +MODULE_DESCRIPTION("Hardware watchdog driver for Sun Microsystems CP1400/1500"); MODULE_LICENSE("GPL"); -MODULE_SUPPORTED_DEVICE - ("watchdog"); -#endif /* ifdef MODULE */ +MODULE_SUPPORTED_DEVICE("watchdog"); + +static void cpwd_writew(u16 val, void __iomem *addr) +{ + writew(cpu_to_le16(val), addr); +} +static u16 cpwd_readw(void __iomem *addr) +{ + u16 val = readw(addr); + + return le16_to_cpu(val); +} + +static void cpwd_writeb(u8 val, void __iomem *addr) +{ + writeb(val, addr); +} + +static u8 cpwd_readb(void __iomem *addr) +{ + return readb(addr); +} -/* Forward declarations of internal methods +/* Enable or disable watchdog interrupts + * Because of the CP1400 defect this should only be + * called during initialzation or by wd_[start|stop]timer() + * + * index - sub-device index, or -1 for 'all' + * enable - non-zero to enable interrupts, zero to disable */ -#ifdef WD_DEBUG -static void wd_dumpregs(void); -#endif -static irqreturn_t wd_interrupt(int irq, void *dev_id); -static void wd_toggleintr(struct wd_timer* pTimer, int enable); -static void wd_pingtimer(struct wd_timer* pTimer); -static void wd_starttimer(struct wd_timer* pTimer); -static void wd_resetbrokentimer(struct wd_timer* pTimer); -static void wd_stoptimer(struct wd_timer* pTimer); -static void wd_brokentimer(unsigned long data); -static int wd_getstatus(struct wd_timer* pTimer); - -/* PLD expects words to be written in LSB format, - * so we must flip all words prior to writing them to regs +static void cpwd_toggleintr(struct cpwd *p, int index, int enable) +{ + unsigned char curregs = cpwd_readb(p->regs + PLD_IMASK); + unsigned char setregs = + (index == -1) ? + (WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) : + (p->devs[index].intr_mask); + + if (enable == WD_INTR_ON) + curregs &= ~setregs; + else + curregs |= setregs; + + cpwd_writeb(curregs, p->regs + PLD_IMASK); +} + +/* Restarts timer with maximum limit value and + * does not unset 'brokenstop' value. */ -static inline unsigned short flip_word(unsigned short word) +static void cpwd_resetbrokentimer(struct cpwd *p, int index) { - return ((word & 0xff) << 8) | ((word >> 8) & 0xff); + cpwd_toggleintr(p, index, WD_INTR_ON); + cpwd_writew(WD_BLIMIT, p->devs[index].regs + WD_LIMIT); } -#define wd_writew(val, addr) (writew(flip_word(val), addr)) -#define wd_readw(addr) (flip_word(readw(addr))) -#define wd_writeb(val, addr) (writeb(val, addr)) -#define wd_readb(addr) (readb(addr)) +/* Timer method called to reset stopped watchdogs-- + * because of the PLD bug on CP1400, we cannot mask + * interrupts within the PLD so me must continually + * reset the timers ad infinitum. + */ +static void cpwd_brokentimer(unsigned long data) +{ + struct cpwd *p = (struct cpwd *) data; + int id, tripped = 0; + + /* kill a running timer instance, in case we + * were called directly instead of by kernel timer + */ + if (timer_pending(&cpwd_timer)) + del_timer(&cpwd_timer); + for (id = 0; id < WD_NUMDEVS; id++) { + if (p->devs[id].runstatus & WD_STAT_BSTOP) { + ++tripped; + cpwd_resetbrokentimer(p, id); + } + } -/* CP1400s seem to have broken PLD implementations-- - * the interrupt_mask register cannot be written, so - * no timer interrupts can be masked within the PLD. + if (tripped) { + /* there is at least one timer brokenstopped-- reschedule */ + cpwd_timer.expires = WD_BTIMEOUT; + add_timer(&cpwd_timer); + } +} + +/* Reset countdown timer with 'limit' value and continue countdown. + * This will not start a stopped timer. */ -static inline int wd_isbroken(void) +static void cpwd_pingtimer(struct cpwd *p, int index) { - /* we could test this by read/write/read/restore - * on the interrupt mask register only if OBP - * 'watchdog-enable?' == FALSE, but it seems - * ubiquitous on CP1400s - */ - char val[32]; - prom_getproperty(prom_root_node, "model", val, sizeof(val)); - return((!strcmp(val, WD_BADMODEL)) ? 1 : 0); + if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING) + cpwd_readw(p->devs[index].regs + WD_DCNTR); } - -/* Retrieve watchdog-enable? option from OBP - * Returns 0 if false, 1 if true + +/* Stop a running watchdog timer-- the timer actually keeps + * running, but the interrupt is masked so that no action is + * taken upon expiration. */ -static inline int wd_opt_enable(void) +static void cpwd_stoptimer(struct cpwd *p, int index) { - int opt_node; + if (cpwd_readb(p->devs[index].regs + WD_STATUS) & WD_S_RUNNING) { + cpwd_toggleintr(p, index, WD_INTR_OFF); - opt_node = prom_getchild(prom_root_node); - opt_node = prom_searchsiblings(opt_node, "options"); - return((-1 == prom_getint(opt_node, "watchdog-enable?")) ? 0 : 1); + if (p->broken) { + p->devs[index].runstatus |= WD_STAT_BSTOP; + cpwd_brokentimer((unsigned long) p); + } + } } -/* Retrieve watchdog-reboot? option from OBP - * Returns 0 if false, 1 if true +/* Start a watchdog timer with the specified limit value + * If the watchdog is running, it will be restarted with + * the provided limit value. + * + * This function will enable interrupts on the specified + * watchdog. */ -static inline int wd_opt_reboot(void) +static void cpwd_starttimer(struct cpwd *p, int index) { - int opt_node; + if (p->broken) + p->devs[index].runstatus &= ~WD_STAT_BSTOP; + + p->devs[index].runstatus &= ~WD_STAT_SVCD; - opt_node = prom_getchild(prom_root_node); - opt_node = prom_searchsiblings(opt_node, "options"); - return((-1 == prom_getint(opt_node, "watchdog-reboot?")) ? 0 : 1); + cpwd_writew(p->devs[index].timeout, p->devs[index].regs + WD_LIMIT); + cpwd_toggleintr(p, index, WD_INTR_ON); } -/* Retrieve watchdog-timeout option from OBP - * Returns OBP value, or 0 if not located - */ -static inline int wd_opt_timeout(void) +static int cpwd_getstatus(struct cpwd *p, int index) { - int opt_node; - char value[32]; - char *p = value; - - opt_node = prom_getchild(prom_root_node); - opt_node = prom_searchsiblings(opt_node, "options"); - opt_node = prom_getproperty(opt_node, - "watchdog-timeout", - value, - sizeof(value)); - if(-1 != opt_node) { - /* atoi implementation */ - for(opt_node = 0; /* nop */; p++) { - if(*p >= '0' && *p <= '9') { - opt_node = (10*opt_node)+(*p-'0'); - } - else { - break; + unsigned char stat = cpwd_readb(p->devs[index].regs + WD_STATUS); + unsigned char intr = cpwd_readb(p->devs[index].regs + PLD_IMASK); + unsigned char ret = WD_STOPPED; + + /* determine STOPPED */ + if (!stat) + return ret; + + /* determine EXPIRED vs FREERUN vs RUNNING */ + else if (WD_S_EXPIRED & stat) { + ret = WD_EXPIRED; + } else if(WD_S_RUNNING & stat) { + if (intr & p->devs[index].intr_mask) { + ret = WD_FREERUN; + } else { + /* Fudge WD_EXPIRED status for defective CP1400-- + * IF timer is running + * AND brokenstop is set + * AND an interrupt has been serviced + * we are WD_EXPIRED. + * + * IF timer is running + * AND brokenstop is set + * AND no interrupt has been serviced + * we are WD_FREERUN. + */ + if (p->broken && + (p->devs[index].runstatus & WD_STAT_BSTOP)) { + if (p->devs[index].runstatus & WD_STAT_SVCD) { + ret = WD_EXPIRED; + } else { + /* we could as well pretend we are expired */ + ret = WD_FREERUN; + } + } else { + ret = WD_RUNNING; } } } - return((-1 == opt_node) ? (0) : (opt_node)); + + /* determine SERVICED */ + if (p->devs[index].runstatus & WD_STAT_SVCD) + ret |= WD_SERVICED; + + return(ret); +} + +static irqreturn_t cpwd_interrupt(int irq, void *dev_id) +{ + struct cpwd *p = dev_id; + + /* Only WD0 will interrupt-- others are NMI and we won't + * see them here.... + */ + spin_lock_irq(&p->lock); + + cpwd_stoptimer(p, WD0_ID); + p->devs[WD0_ID].runstatus |= WD_STAT_SVCD; + + spin_unlock_irq(&p->lock); + + return IRQ_HANDLED; } -static int wd_open(struct inode *inode, struct file *f) +static int cpwd_open(struct inode *inode, struct file *f) { + struct cpwd *p = cpwd_device; + lock_kernel(); - switch(iminor(inode)) - { + switch(iminor(inode)) { case WD0_MINOR: - f->private_data = &wd_dev.watchdog[WD0_ID]; - break; case WD1_MINOR: - f->private_data = &wd_dev.watchdog[WD1_ID]; - break; case WD2_MINOR: - f->private_data = &wd_dev.watchdog[WD2_ID]; break; + default: unlock_kernel(); - return(-ENODEV); + return -ENODEV; } /* Register IRQ on first open of device */ - if(0 == wd_dev.initialized) - { - if (request_irq(wd_dev.irq, - &wd_interrupt, - IRQF_SHARED, - WD_OBPNAME, - (void *)wd_dev.regs)) { - printk("%s: Cannot register IRQ %d\n", - WD_OBPNAME, wd_dev.irq); + if (!p->initialized) { + if (request_irq(p->irq, &cpwd_interrupt, + IRQF_SHARED, DRIVER_NAME, p)) { + printk(KERN_ERR PFX "Cannot register IRQ %d\n", + p->irq); unlock_kernel(); - return(-EBUSY); + return -EBUSY; } - wd_dev.initialized = 1; + p->initialized = true; } unlock_kernel(); - return(nonseekable_open(inode, f)); + + return nonseekable_open(inode, f); } -static int wd_release(struct inode *inode, struct file *file) +static int cpwd_release(struct inode *inode, struct file *file) { return 0; } -static int wd_ioctl(struct inode *inode, struct file *file, - unsigned int cmd, unsigned long arg) +static int cpwd_ioctl(struct inode *inode, struct file *file, + unsigned int cmd, unsigned long arg) { - int setopt = 0; - struct wd_timer* pTimer = (struct wd_timer*)file->private_data; - void __user *argp = (void __user *)arg; - struct watchdog_info info = { - 0, - 0, - "Altera EPF8820ATC144-4" + static struct watchdog_info info = { + .options = WDIOF_SETTIMEOUT, + .firmware_version = 1, + .identity = DRIVER_NAME, }; + void __user *argp = (void __user *)arg; + int index = iminor(inode) - WD0_MINOR; + struct cpwd *p = cpwd_device; + int setopt = 0; - if(NULL == pTimer) { - return(-EINVAL); - } + switch (cmd) { + /* Generic Linux IOCTLs */ + case WDIOC_GETSUPPORT: + if (copy_to_user(argp, &info, sizeof(struct watchdog_info))) + return -EFAULT; + break; - switch(cmd) - { - /* Generic Linux IOCTLs */ - case WDIOC_GETSUPPORT: - if(copy_to_user(argp, &info, sizeof(struct watchdog_info))) { - return(-EFAULT); - } - break; - case WDIOC_GETSTATUS: - case WDIOC_GETBOOTSTATUS: - if (put_user(0, (int __user *)argp)) - return -EFAULT; - break; - case WDIOC_KEEPALIVE: - wd_pingtimer(pTimer); - break; - case WDIOC_SETOPTIONS: - if(copy_from_user(&setopt, argp, sizeof(unsigned int))) { - return -EFAULT; - } - if(setopt & WDIOS_DISABLECARD) { - if(wd_dev.opt_enable) { - printk( - "%s: cannot disable watchdog in ENABLED mode\n", - WD_OBPNAME); - return(-EINVAL); - } - wd_stoptimer(pTimer); - } - else if(setopt & WDIOS_ENABLECARD) { - wd_starttimer(pTimer); - } - else { - return(-EINVAL); - } - break; - /* Solaris-compatible IOCTLs */ - case WIOCGSTAT: - setopt = wd_getstatus(pTimer); - if(copy_to_user(argp, &setopt, sizeof(unsigned int))) { - return(-EFAULT); - } - break; - case WIOCSTART: - wd_starttimer(pTimer); - break; - case WIOCSTOP: - if(wd_dev.opt_enable) { - printk("%s: cannot disable watchdog in ENABLED mode\n", - WD_OBPNAME); - return(-EINVAL); - } - wd_stoptimer(pTimer); - break; - default: + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + if (put_user(0, (int __user *)argp)) + return -EFAULT; + break; + + case WDIOC_KEEPALIVE: + cpwd_pingtimer(p, index); + break; + + case WDIOC_SETOPTIONS: + if (copy_from_user(&setopt, argp, sizeof(unsigned int))) + return -EFAULT; + + if (setopt & WDIOS_DISABLECARD) { + if (p->enabled) + return -EINVAL; + cpwd_stoptimer(p, index); + } else if (setopt & WDIOS_ENABLECARD) { + cpwd_starttimer(p, index); + } else { + return -EINVAL; + } + break; + + /* Solaris-compatible IOCTLs */ + case WIOCGSTAT: + setopt = cpwd_getstatus(p, index); + if (copy_to_user(argp, &setopt, sizeof(unsigned int))) + return -EFAULT; + break; + + case WIOCSTART: + cpwd_starttimer(p, index); + break; + + case WIOCSTOP: + if (p->enabled) return(-EINVAL); + + cpwd_stoptimer(p, index); + break; + + default: + return -EINVAL; } - return(0); + + return 0; } -static long wd_compat_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) +static long cpwd_compat_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) { int rval = -ENOIOCTLCMD; @@ -408,9 +481,10 @@ static long wd_compat_ioctl(struct file *file, unsigned int cmd, case WIOCSTOP: case WIOCGSTAT: lock_kernel(); - rval = wd_ioctl(file->f_path.dentry->d_inode, file, cmd, arg); + rval = cpwd_ioctl(file->f_path.dentry->d_inode, file, cmd, arg); unlock_kernel(); break; + /* everything else is handled by the generic compat layer */ default: break; @@ -419,440 +493,203 @@ static long wd_compat_ioctl(struct file *file, unsigned int cmd, return rval; } -static ssize_t wd_write(struct file *file, - const char __user *buf, - size_t count, - loff_t *ppos) +static ssize_t cpwd_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) { - struct wd_timer* pTimer = (struct wd_timer*)file->private_data; - - if(NULL == pTimer) { - return(-EINVAL); - } + struct inode *inode = file->f_path.dentry->d_inode; + struct cpwd *p = cpwd_device; + int index = iminor(inode); if (count) { - wd_pingtimer(pTimer); + cpwd_pingtimer(p, index); return 1; } - return 0; -} -static ssize_t wd_read(struct file * file, char __user *buffer, - size_t count, loff_t *ppos) -{ -#ifdef WD_DEBUG - wd_dumpregs(); - return(0); -#else - return(-EINVAL); -#endif /* ifdef WD_DEBUG */ + return 0; } -static irqreturn_t wd_interrupt(int irq, void *dev_id) +static ssize_t cpwd_read(struct file * file, char __user *buffer, + size_t count, loff_t *ppos) { - /* Only WD0 will interrupt-- others are NMI and we won't - * see them here.... - */ - spin_lock_irq(&wd_dev.lock); - if((unsigned long)wd_dev.regs == (unsigned long)dev_id) - { - wd_stoptimer(&wd_dev.watchdog[WD0_ID]); - wd_dev.watchdog[WD0_ID].runstatus |= WD_STAT_SVCD; - } - spin_unlock_irq(&wd_dev.lock); - return IRQ_HANDLED; + return -EINVAL; } -static const struct file_operations wd_fops = { +static const struct file_operations cpwd_fops = { .owner = THIS_MODULE, - .ioctl = wd_ioctl, - .compat_ioctl = wd_compat_ioctl, - .open = wd_open, - .write = wd_write, - .read = wd_read, - .release = wd_release, + .ioctl = cpwd_ioctl, + .compat_ioctl = cpwd_compat_ioctl, + .open = cpwd_open, + .write = cpwd_write, + .read = cpwd_read, + .release = cpwd_release, }; -static struct miscdevice wd0_miscdev = { WD0_MINOR, WD0_DEVNAME, &wd_fops }; -static struct miscdevice wd1_miscdev = { WD1_MINOR, WD1_DEVNAME, &wd_fops }; -static struct miscdevice wd2_miscdev = { WD2_MINOR, WD2_DEVNAME, &wd_fops }; - -#ifdef WD_DEBUG -static void wd_dumpregs(void) +static int __devinit cpwd_probe(struct of_device *op, + const struct of_device_id *match) { - /* Reading from downcounters initiates watchdog countdown-- - * Example is included below for illustration purposes. - */ - int i; - printk("%s: dumping register values\n", WD_OBPNAME); - for(i = WD0_ID; i < WD_NUMDEVS; ++i) { - /* printk("\t%s%i: dcntr at 0x%lx: 0x%x\n", - * WD_OBPNAME, - * i, - * (unsigned long)(&wd_dev.watchdog[i].regs->dcntr), - * readw(&wd_dev.watchdog[i].regs->dcntr)); - */ - printk("\t%s%i: limit at 0x%lx: 0x%x\n", - WD_OBPNAME, - i, - (unsigned long)(&wd_dev.watchdog[i].regs->limit), - readw(&wd_dev.watchdog[i].regs->limit)); - printk("\t%s%i: status at 0x%lx: 0x%x\n", - WD_OBPNAME, - i, - (unsigned long)(&wd_dev.watchdog[i].regs->status), - readb(&wd_dev.watchdog[i].regs->status)); - printk("\t%s%i: driver status: 0x%x\n", - WD_OBPNAME, - i, - wd_getstatus(&wd_dev.watchdog[i])); - } - printk("\tintr_mask at %p: 0x%x\n", - wd_dev.regs + PLD_IMASK, - readb(wd_dev.regs + PLD_IMASK)); - printk("\tpld_status at %p: 0x%x\n", - wd_dev.regs + PLD_STATUS, - readb(wd_dev.regs + PLD_STATUS)); -} -#endif - -/* Enable or disable watchdog interrupts - * Because of the CP1400 defect this should only be - * called during initialzation or by wd_[start|stop]timer() - * - * pTimer - pointer to timer device, or NULL to indicate all timers - * enable - non-zero to enable interrupts, zero to disable - */ -static void wd_toggleintr(struct wd_timer* pTimer, int enable) -{ - unsigned char curregs = wd_readb(wd_dev.regs + PLD_IMASK); - unsigned char setregs = - (NULL == pTimer) ? - (WD0_INTR_MASK | WD1_INTR_MASK | WD2_INTR_MASK) : - (pTimer->intr_mask); - - (WD_INTR_ON == enable) ? - (curregs &= ~setregs): - (curregs |= setregs); + struct device_node *options; + const char *str_prop; + const void *prop_val; + int i, err = -EINVAL; + struct cpwd *p; - wd_writeb(curregs, wd_dev.regs + PLD_IMASK); - return; -} + if (cpwd_device) + return -EINVAL; -/* Reset countdown timer with 'limit' value and continue countdown. - * This will not start a stopped timer. - * - * pTimer - pointer to timer device - */ -static void wd_pingtimer(struct wd_timer* pTimer) -{ - if (wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) { - wd_readw(pTimer->regs + WD_DCNTR); + p = kzalloc(sizeof(*p), GFP_KERNEL); + err = -ENOMEM; + if (!p) { + printk(KERN_ERR PFX "Unable to allocate struct cpwd.\n"); + goto out; } -} -/* Stop a running watchdog timer-- the timer actually keeps - * running, but the interrupt is masked so that no action is - * taken upon expiration. - * - * pTimer - pointer to timer device - */ -static void wd_stoptimer(struct wd_timer* pTimer) -{ - if(wd_readb(pTimer->regs + WD_STATUS) & WD_S_RUNNING) { - wd_toggleintr(pTimer, WD_INTR_OFF); + p->irq = op->irqs[0]; - if(wd_dev.isbaddoggie) { - pTimer->runstatus |= WD_STAT_BSTOP; - wd_brokentimer((unsigned long)&wd_dev); - } - } -} + spin_lock_init(&p->lock); -/* Start a watchdog timer with the specified limit value - * If the watchdog is running, it will be restarted with - * the provided limit value. - * - * This function will enable interrupts on the specified - * watchdog. - * - * pTimer - pointer to timer device - * limit - limit (countdown) value in 1/10th seconds - */ -static void wd_starttimer(struct wd_timer* pTimer) -{ - if(wd_dev.isbaddoggie) { - pTimer->runstatus &= ~WD_STAT_BSTOP; + p->regs = of_ioremap(&op->resource[0], 0, + 4 * WD_TIMER_REGSZ, DRIVER_NAME); + if (!p->regs) { + printk(KERN_ERR PFX "Unable to map registers.\n"); + goto out_free; } - pTimer->runstatus &= ~WD_STAT_SVCD; - wd_writew(pTimer->timeout, pTimer->regs + WD_LIMIT); - wd_toggleintr(pTimer, WD_INTR_ON); -} + options = of_find_node_by_path("/options"); + err = -ENODEV; + if (!options) { + printk(KERN_ERR PFX "Unable to find /options node.\n"); + goto out_iounmap; + } -/* Restarts timer with maximum limit value and - * does not unset 'brokenstop' value. - */ -static void wd_resetbrokentimer(struct wd_timer* pTimer) -{ - wd_toggleintr(pTimer, WD_INTR_ON); - wd_writew(WD_BLIMIT, pTimer->regs + WD_LIMIT); -} + prop_val = of_get_property(options, "watchdog-enable?", NULL); + p->enabled = (prop_val ? true : false); -/* Timer device initialization helper. - * Returns 0 on success, other on failure - */ -static int wd_inittimer(int whichdog) -{ - struct miscdevice *whichmisc; - void __iomem *whichregs; - char whichident[8]; - int whichmask; - __u16 whichlimit; + prop_val = of_get_property(options, "watchdog-reboot?", NULL); + p->reboot = (prop_val ? true : false); - switch(whichdog) - { - case WD0_ID: - whichmisc = &wd0_miscdev; - strcpy(whichident, "RIC"); - whichregs = wd_dev.regs + WD0_OFF; - whichmask = WD0_INTR_MASK; - whichlimit= (0 == wd0_timeout) ? - (wd_dev.opt_timeout): - (wd0_timeout); - break; - case WD1_ID: - whichmisc = &wd1_miscdev; - strcpy(whichident, "XIR"); - whichregs = wd_dev.regs + WD1_OFF; - whichmask = WD1_INTR_MASK; - whichlimit= (0 == wd1_timeout) ? - (wd_dev.opt_timeout): - (wd1_timeout); - break; - case WD2_ID: - whichmisc = &wd2_miscdev; - strcpy(whichident, "POR"); - whichregs = wd_dev.regs + WD2_OFF; - whichmask = WD2_INTR_MASK; - whichlimit= (0 == wd2_timeout) ? - (wd_dev.opt_timeout): - (wd2_timeout); - break; - default: - printk("%s: %s: invalid watchdog id: %i\n", - WD_OBPNAME, __func__, whichdog); - return(1); - } - if(0 != misc_register(whichmisc)) - { - return(1); - } - wd_dev.watchdog[whichdog].regs = whichregs; - wd_dev.watchdog[whichdog].timeout = whichlimit; - wd_dev.watchdog[whichdog].intr_mask = whichmask; - wd_dev.watchdog[whichdog].runstatus &= ~WD_STAT_BSTOP; - wd_dev.watchdog[whichdog].runstatus |= WD_STAT_INIT; - - printk("%s%i: %s hardware watchdog [%01i.%i sec] %s\n", - WD_OBPNAME, - whichdog, - whichident, - wd_dev.watchdog[whichdog].timeout / 10, - wd_dev.watchdog[whichdog].timeout % 10, - (0 != wd_dev.opt_enable) ? "in ENABLED mode" : ""); - return(0); -} + str_prop = of_get_property(options, "watchdog-timeout", NULL); + if (str_prop) + p->timeout = simple_strtoul(str_prop, NULL, 10); -/* Timer method called to reset stopped watchdogs-- - * because of the PLD bug on CP1400, we cannot mask - * interrupts within the PLD so me must continually - * reset the timers ad infinitum. - */ -static void wd_brokentimer(unsigned long data) -{ - struct wd_device* pDev = (struct wd_device*)data; - int id, tripped = 0; - - /* kill a running timer instance, in case we - * were called directly instead of by kernel timer + /* CP1400s seem to have broken PLD implementations-- the + * interrupt_mask register cannot be written, so no timer + * interrupts can be masked within the PLD. */ - if(timer_pending(&wd_timer)) { - del_timer(&wd_timer); - } - - for(id = WD0_ID; id < WD_NUMDEVS; ++id) { - if(pDev->watchdog[id].runstatus & WD_STAT_BSTOP) { - ++tripped; - wd_resetbrokentimer(&pDev->watchdog[id]); + str_prop = of_get_property(op->node, "model", NULL); + p->broken = (str_prop && !strcmp(str_prop, WD_BADMODEL)); + + if (!p->enabled) + cpwd_toggleintr(p, -1, WD_INTR_OFF); + + for (i = 0; i < WD_NUMDEVS; i++) { + static const char *cpwd_names[] = { "RIC", "XIR", "POR" }; + static int *parms[] = { &wd0_timeout, + &wd1_timeout, + &wd2_timeout }; + struct miscdevice *mp = &p->devs[i].misc; + + mp->minor = WD0_MINOR + i; + mp->name = cpwd_names[i]; + mp->fops = &cpwd_fops; + + p->devs[i].regs = p->regs + (i * WD_TIMER_REGSZ); + p->devs[i].intr_mask = (WD0_INTR_MASK << i); + p->devs[i].runstatus &= ~WD_STAT_BSTOP; + p->devs[i].runstatus |= WD_STAT_INIT; + p->devs[i].timeout = p->timeout; + if (*parms[i]) + p->devs[i].timeout = *parms[i]; + + err = misc_register(&p->devs[i].misc); + if (err) { + printk(KERN_ERR "Could not register misc device for " + "dev %d\n", i); + goto out_unregister; } } - if(tripped) { - /* there is at least one timer brokenstopped-- reschedule */ - init_timer(&wd_timer); - wd_timer.expires = WD_BTIMEOUT; - add_timer(&wd_timer); + if (p->broken) { + init_timer(&cpwd_timer); + cpwd_timer.function = cpwd_brokentimer; + cpwd_timer.data = (unsigned long) p; + cpwd_timer.expires = WD_BTIMEOUT; + + printk(KERN_INFO PFX "PLD defect workaround enabled for " + "model " WD_BADMODEL ".\n"); } -} -static int wd_getstatus(struct wd_timer* pTimer) -{ - unsigned char stat = wd_readb(pTimer->regs + WD_STATUS); - unsigned char intr = wd_readb(wd_dev.regs + PLD_IMASK); - unsigned char ret = WD_STOPPED; + dev_set_drvdata(&op->dev, p); + cpwd_device = p; + err = 0; - /* determine STOPPED */ - if(0 == stat ) { - return(ret); - } - /* determine EXPIRED vs FREERUN vs RUNNING */ - else if(WD_S_EXPIRED & stat) { - ret = WD_EXPIRED; - } - else if(WD_S_RUNNING & stat) { - if(intr & pTimer->intr_mask) { - ret = WD_FREERUN; - } - else { - /* Fudge WD_EXPIRED status for defective CP1400-- - * IF timer is running - * AND brokenstop is set - * AND an interrupt has been serviced - * we are WD_EXPIRED. - * - * IF timer is running - * AND brokenstop is set - * AND no interrupt has been serviced - * we are WD_FREERUN. - */ - if(wd_dev.isbaddoggie && (pTimer->runstatus & WD_STAT_BSTOP)) { - if(pTimer->runstatus & WD_STAT_SVCD) { - ret = WD_EXPIRED; - } - else { - /* we could as well pretend we are expired */ - ret = WD_FREERUN; - } - } - else { - ret = WD_RUNNING; - } - } - } +out: + return err; - /* determine SERVICED */ - if(pTimer->runstatus & WD_STAT_SVCD) { - ret |= WD_SERVICED; - } +out_unregister: + for (i--; i >= 0; i--) + misc_deregister(&p->devs[i].misc); - return(ret); +out_iounmap: + of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ); + +out_free: + kfree(p); + goto out; } -static int __init wd_init(void) +static int __devexit cpwd_remove(struct of_device *op) { - int id; - struct linux_ebus *ebus = NULL; - struct linux_ebus_device *edev = NULL; - - for_each_ebus(ebus) { - for_each_ebusdev(edev, ebus) { - if (!strcmp(edev->ofdev.node->name, WD_OBPNAME)) - goto ebus_done; + struct cpwd *p = dev_get_drvdata(&op->dev); + int i; + + for (i = 0; i < 4; i++) { + misc_deregister(&p->devs[i].misc); + + if (!p->enabled) { + cpwd_stoptimer(p, i); + if (p->devs[i].runstatus & WD_STAT_BSTOP) + cpwd_resetbrokentimer(p, i); } } -ebus_done: - if(!edev) { - printk("%s: unable to locate device\n", WD_OBPNAME); - return -ENODEV; - } + if (p->broken) + del_timer_sync(&cpwd_timer); - wd_dev.regs = - ioremap(edev->resource[0].start, 4 * WD_TIMER_REGSZ); /* ? */ + if (p->initialized) + free_irq(p->irq, p); - if(NULL == wd_dev.regs) { - printk("%s: unable to map registers\n", WD_OBPNAME); - return(-ENODEV); - } + of_iounmap(&op->resource[0], p->regs, 4 * WD_TIMER_REGSZ); + kfree(p); - /* initialize device structure from OBP parameters */ - wd_dev.irq = edev->irqs[0]; - wd_dev.opt_enable = wd_opt_enable(); - wd_dev.opt_reboot = wd_opt_reboot(); - wd_dev.opt_timeout = wd_opt_timeout(); - wd_dev.isbaddoggie = wd_isbroken(); + cpwd_device = NULL; - /* disable all interrupts unless watchdog-enabled? == true */ - if(! wd_dev.opt_enable) { - wd_toggleintr(NULL, WD_INTR_OFF); - } + return 0; +} - /* register miscellaneous devices */ - for(id = WD0_ID; id < WD_NUMDEVS; ++id) { - if(0 != wd_inittimer(id)) { - printk("%s%i: unable to initialize\n", WD_OBPNAME, id); - } - } +static struct of_device_id cpwd_match[] = { + { + .name = "watchdog", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, cpwd_match); - /* warn about possible defective PLD */ - if(wd_dev.isbaddoggie) { - init_timer(&wd_timer); - wd_timer.function = wd_brokentimer; - wd_timer.data = (unsigned long)&wd_dev; - wd_timer.expires = WD_BTIMEOUT; +static struct of_platform_driver cpwd_driver = { + .name = DRIVER_NAME, + .match_table = cpwd_match, + .probe = cpwd_probe, + .remove = __devexit_p(cpwd_remove), +}; - printk("%s: PLD defect workaround enabled for model %s\n", - WD_OBPNAME, WD_BADMODEL); - } - return(0); +static int __init cpwd_init(void) +{ + return of_register_driver(&cpwd_driver, &of_bus_type); } -static void __exit wd_cleanup(void) +static void __exit cpwd_exit(void) { - int id; - - /* if 'watchdog-enable?' == TRUE, timers are not stopped - * when module is unloaded. All brokenstopped timers will - * also now eventually trip. - */ - for(id = WD0_ID; id < WD_NUMDEVS; ++id) { - if(WD_S_RUNNING == wd_readb(wd_dev.watchdog[id].regs + WD_STATUS)) { - if(wd_dev.opt_enable) { - printk(KERN_WARNING "%s%i: timer not stopped at release\n", - WD_OBPNAME, id); - } - else { - wd_stoptimer(&wd_dev.watchdog[id]); - if(wd_dev.watchdog[id].runstatus & WD_STAT_BSTOP) { - wd_resetbrokentimer(&wd_dev.watchdog[id]); - printk(KERN_WARNING - "%s%i: defect workaround disabled at release, "\ - "timer expires in ~%01i sec\n", - WD_OBPNAME, id, - wd_readw(wd_dev.watchdog[id].regs + WD_LIMIT) / 10); - } - } - } - } - - if(wd_dev.isbaddoggie && timer_pending(&wd_timer)) { - del_timer(&wd_timer); - } - if(0 != (wd_dev.watchdog[WD0_ID].runstatus & WD_STAT_INIT)) { - misc_deregister(&wd0_miscdev); - } - if(0 != (wd_dev.watchdog[WD1_ID].runstatus & WD_STAT_INIT)) { - misc_deregister(&wd1_miscdev); - } - if(0 != (wd_dev.watchdog[WD2_ID].runstatus & WD_STAT_INIT)) { - misc_deregister(&wd2_miscdev); - } - if(0 != wd_dev.initialized) { - free_irq(wd_dev.irq, (void *)wd_dev.regs); - } - iounmap(wd_dev.regs); + of_unregister_driver(&cpwd_driver); } -module_init(wd_init); -module_exit(wd_cleanup); +module_init(cpwd_init); +module_exit(cpwd_exit); |