| /* |
| * sp5100_tco : TCO timer driver for sp5100 chipsets |
| * |
| * (c) Copyright 2009 Google Inc., All Rights Reserved. |
| * |
| * Based on i8xx_tco.c: |
| * (c) Copyright 2000 kernel concepts <nils@kernelconcepts.de>, All Rights |
| * Reserved. |
| * http://www.kernelconcepts.de |
| * |
| * 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. |
| * |
| * See AMD Publication 43009 "AMD SB700/710/750 Register Reference Guide" |
| */ |
| |
| /* |
| * Includes, defines, variables, module parameters, ... |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/moduleparam.h> |
| #include <linux/types.h> |
| #include <linux/miscdevice.h> |
| #include <linux/watchdog.h> |
| #include <linux/init.h> |
| #include <linux/fs.h> |
| #include <linux/pci.h> |
| #include <linux/ioport.h> |
| #include <linux/platform_device.h> |
| #include <linux/uaccess.h> |
| #include <linux/io.h> |
| |
| #include "sp5100_tco.h" |
| |
| /* Module and version information */ |
| #define TCO_VERSION "0.01" |
| #define TCO_MODULE_NAME "SP5100 TCO timer" |
| #define TCO_DRIVER_NAME TCO_MODULE_NAME ", v" TCO_VERSION |
| #define PFX TCO_MODULE_NAME ": " |
| |
| /* internal variables */ |
| static void __iomem *tcobase; |
| static unsigned int pm_iobase; |
| static DEFINE_SPINLOCK(tco_lock); /* Guards the hardware */ |
| static unsigned long timer_alive; |
| static char tco_expect_close; |
| static struct pci_dev *sp5100_tco_pci; |
| |
| /* the watchdog platform device */ |
| static struct platform_device *sp5100_tco_platform_device; |
| |
| /* module parameters */ |
| |
| #define WATCHDOG_HEARTBEAT 60 /* 60 sec default heartbeat. */ |
| static int heartbeat = WATCHDOG_HEARTBEAT; /* in seconds */ |
| module_param(heartbeat, int, 0); |
| MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. (default=" |
| __MODULE_STRING(WATCHDOG_HEARTBEAT) ")"); |
| |
| 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) ")"); |
| |
| /* |
| * Some TCO specific functions |
| */ |
| static void tco_timer_start(void) |
| { |
| u32 val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&tco_lock, flags); |
| val = readl(SP5100_WDT_CONTROL(tcobase)); |
| val |= SP5100_WDT_START_STOP_BIT; |
| writel(val, SP5100_WDT_CONTROL(tcobase)); |
| spin_unlock_irqrestore(&tco_lock, flags); |
| } |
| |
| static void tco_timer_stop(void) |
| { |
| u32 val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&tco_lock, flags); |
| val = readl(SP5100_WDT_CONTROL(tcobase)); |
| val &= ~SP5100_WDT_START_STOP_BIT; |
| writel(val, SP5100_WDT_CONTROL(tcobase)); |
| spin_unlock_irqrestore(&tco_lock, flags); |
| } |
| |
| static void tco_timer_keepalive(void) |
| { |
| u32 val; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&tco_lock, flags); |
| val = readl(SP5100_WDT_CONTROL(tcobase)); |
| val |= SP5100_WDT_TRIGGER_BIT; |
| writel(val, SP5100_WDT_CONTROL(tcobase)); |
| spin_unlock_irqrestore(&tco_lock, flags); |
| } |
| |
| static int tco_timer_set_heartbeat(int t) |
| { |
| unsigned long flags; |
| |
| if (t < 0 || t > 0xffff) |
| return -EINVAL; |
| |
| /* Write new heartbeat to watchdog */ |
| spin_lock_irqsave(&tco_lock, flags); |
| writel(t, SP5100_WDT_COUNT(tcobase)); |
| spin_unlock_irqrestore(&tco_lock, flags); |
| |
| heartbeat = t; |
| return 0; |
| } |
| |
| /* |
| * /dev/watchdog handling |
| */ |
| |
| static int sp5100_tco_open(struct inode *inode, struct file *file) |
| { |
| /* /dev/watchdog can only be opened once */ |
| if (test_and_set_bit(0, &timer_alive)) |
| return -EBUSY; |
| |
| /* Reload and activate timer */ |
| tco_timer_start(); |
| tco_timer_keepalive(); |
| return nonseekable_open(inode, file); |
| } |
| |
| static int sp5100_tco_release(struct inode *inode, struct file *file) |
| { |
| /* Shut off the timer. */ |
| if (tco_expect_close == 42) { |
| tco_timer_stop(); |
| } else { |
| printk(KERN_CRIT PFX |
| "Unexpected close, not stopping watchdog!\n"); |
| tco_timer_keepalive(); |
| } |
| clear_bit(0, &timer_alive); |
| tco_expect_close = 0; |
| return 0; |
| } |
| |
| static ssize_t sp5100_tco_write(struct file *file, const char __user *data, |
| size_t len, loff_t *ppos) |
| { |
| /* See if we got the magic character 'V' and reload the timer */ |
| if (len) { |
| if (!nowayout) { |
| size_t i; |
| |
| /* note: just in case someone wrote the magic character |
| * five months ago... */ |
| tco_expect_close = 0; |
| |
| /* scan to see whether or not we got the magic character |
| */ |
| for (i = 0; i != len; i++) { |
| char c; |
| if (get_user(c, data + i)) |
| return -EFAULT; |
| if (c == 'V') |
| tco_expect_close = 42; |
| } |
| } |
| |
| /* someone wrote to us, we should reload the timer */ |
| tco_timer_keepalive(); |
| } |
| return len; |
| } |
| |
| static long sp5100_tco_ioctl(struct file *file, unsigned int cmd, |
| unsigned long arg) |
| { |
| int new_options, retval = -EINVAL; |
| int new_heartbeat; |
| void __user *argp = (void __user *)arg; |
| int __user *p = argp; |
| static const struct watchdog_info ident = { |
| .options = WDIOF_SETTIMEOUT | |
| WDIOF_KEEPALIVEPING | |
| WDIOF_MAGICCLOSE, |
| .firmware_version = 0, |
| .identity = TCO_MODULE_NAME, |
| }; |
| |
| 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_SETOPTIONS: |
| if (get_user(new_options, p)) |
| return -EFAULT; |
| if (new_options & WDIOS_DISABLECARD) { |
| tco_timer_stop(); |
| retval = 0; |
| } |
| if (new_options & WDIOS_ENABLECARD) { |
| tco_timer_start(); |
| tco_timer_keepalive(); |
| retval = 0; |
| } |
| return retval; |
| case WDIOC_KEEPALIVE: |
| tco_timer_keepalive(); |
| return 0; |
| case WDIOC_SETTIMEOUT: |
| if (get_user(new_heartbeat, p)) |
| return -EFAULT; |
| if (tco_timer_set_heartbeat(new_heartbeat)) |
| return -EINVAL; |
| tco_timer_keepalive(); |
| /* Fall through */ |
| case WDIOC_GETTIMEOUT: |
| return put_user(heartbeat, p); |
| default: |
| return -ENOTTY; |
| } |
| } |
| |
| /* |
| * Kernel Interfaces |
| */ |
| |
| static const struct file_operations sp5100_tco_fops = { |
| .owner = THIS_MODULE, |
| .llseek = no_llseek, |
| .write = sp5100_tco_write, |
| .unlocked_ioctl = sp5100_tco_ioctl, |
| .open = sp5100_tco_open, |
| .release = sp5100_tco_release, |
| }; |
| |
| static struct miscdevice sp5100_tco_miscdev = { |
| .minor = WATCHDOG_MINOR, |
| .name = "watchdog", |
| .fops = &sp5100_tco_fops, |
| }; |
| |
| /* |
| * Data for PCI driver interface |
| * |
| * This data only exists for exporting the supported |
| * PCI ids via MODULE_DEVICE_TABLE. We do not actually |
| * register a pci_driver, because someone else might |
| * want to register another driver on the same PCI id. |
| */ |
| static DEFINE_PCI_DEVICE_TABLE(sp5100_tco_pci_tbl) = { |
| { PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, PCI_ANY_ID, |
| PCI_ANY_ID, }, |
| { 0, }, /* End of list */ |
| }; |
| MODULE_DEVICE_TABLE(pci, sp5100_tco_pci_tbl); |
| |
| /* |
| * Init & exit routines |
| */ |
| |
| static unsigned char __devinit sp5100_tco_setupdevice(void) |
| { |
| struct pci_dev *dev = NULL; |
| u32 val; |
| |
| /* Match the PCI device */ |
| for_each_pci_dev(dev) { |
| if (pci_match_id(sp5100_tco_pci_tbl, dev) != NULL) { |
| sp5100_tco_pci = dev; |
| break; |
| } |
| } |
| |
| if (!sp5100_tco_pci) |
| return 0; |
| |
| /* Request the IO ports used by this driver */ |
| pm_iobase = SP5100_IO_PM_INDEX_REG; |
| if (!request_region(pm_iobase, SP5100_PM_IOPORTS_SIZE, "SP5100 TCO")) { |
| printk(KERN_ERR PFX "I/O address 0x%04x already in use\n", |
| pm_iobase); |
| goto exit; |
| } |
| |
| /* Find the watchdog base address. */ |
| outb(SP5100_PM_WATCHDOG_BASE3, SP5100_IO_PM_INDEX_REG); |
| val = inb(SP5100_IO_PM_DATA_REG); |
| outb(SP5100_PM_WATCHDOG_BASE2, SP5100_IO_PM_INDEX_REG); |
| val = val << 8 | inb(SP5100_IO_PM_DATA_REG); |
| outb(SP5100_PM_WATCHDOG_BASE1, SP5100_IO_PM_INDEX_REG); |
| val = val << 8 | inb(SP5100_IO_PM_DATA_REG); |
| outb(SP5100_PM_WATCHDOG_BASE0, SP5100_IO_PM_INDEX_REG); |
| /* Low three bits of BASE0 are reserved. */ |
| val = val << 8 | (inb(SP5100_IO_PM_DATA_REG) & 0xf8); |
| |
| tcobase = ioremap(val, SP5100_WDT_MEM_MAP_SIZE); |
| if (tcobase == 0) { |
| printk(KERN_ERR PFX "failed to get tcobase address\n"); |
| goto unreg_region; |
| } |
| |
| /* Enable watchdog decode bit */ |
| pci_read_config_dword(sp5100_tco_pci, |
| SP5100_PCI_WATCHDOG_MISC_REG, |
| &val); |
| |
| val |= SP5100_PCI_WATCHDOG_DECODE_EN; |
| |
| pci_write_config_dword(sp5100_tco_pci, |
| SP5100_PCI_WATCHDOG_MISC_REG, |
| val); |
| |
| /* Enable Watchdog timer and set the resolution to 1 sec. */ |
| outb(SP5100_PM_WATCHDOG_CONTROL, SP5100_IO_PM_INDEX_REG); |
| val = inb(SP5100_IO_PM_DATA_REG); |
| val |= SP5100_PM_WATCHDOG_SECOND_RES; |
| val &= ~SP5100_PM_WATCHDOG_DISABLE; |
| outb(val, SP5100_IO_PM_DATA_REG); |
| |
| /* Check that the watchdog action is set to reset the system. */ |
| val = readl(SP5100_WDT_CONTROL(tcobase)); |
| val &= ~SP5100_PM_WATCHDOG_ACTION_RESET; |
| writel(val, SP5100_WDT_CONTROL(tcobase)); |
| |
| /* Set a reasonable heartbeat before we stop the timer */ |
| tco_timer_set_heartbeat(heartbeat); |
| |
| /* |
| * Stop the TCO before we change anything so we don't race with |
| * a zeroed timer. |
| */ |
| tco_timer_stop(); |
| |
| /* Done */ |
| return 1; |
| |
| iounmap(tcobase); |
| unreg_region: |
| release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE); |
| exit: |
| return 0; |
| } |
| |
| static int __devinit sp5100_tco_init(struct platform_device *dev) |
| { |
| int ret; |
| u32 val; |
| |
| /* Check whether or not the hardware watchdog is there. If found, then |
| * set it up. |
| */ |
| if (!sp5100_tco_setupdevice()) |
| return -ENODEV; |
| |
| /* Check to see if last reboot was due to watchdog timeout */ |
| printk(KERN_INFO PFX "Watchdog reboot %sdetected.\n", |
| readl(SP5100_WDT_CONTROL(tcobase)) & SP5100_PM_WATCHDOG_FIRED ? |
| "" : "not "); |
| |
| /* Clear out the old status */ |
| val = readl(SP5100_WDT_CONTROL(tcobase)); |
| val &= ~SP5100_PM_WATCHDOG_FIRED; |
| writel(val, SP5100_WDT_CONTROL(tcobase)); |
| |
| /* |
| * Check that the heartbeat value is within it's range. |
| * If not, reset to the default. |
| */ |
| if (tco_timer_set_heartbeat(heartbeat)) { |
| heartbeat = WATCHDOG_HEARTBEAT; |
| tco_timer_set_heartbeat(heartbeat); |
| } |
| |
| ret = misc_register(&sp5100_tco_miscdev); |
| if (ret != 0) { |
| printk(KERN_ERR PFX "cannot register miscdev on minor=" |
| "%d (err=%d)\n", |
| WATCHDOG_MINOR, ret); |
| goto exit; |
| } |
| |
| clear_bit(0, &timer_alive); |
| |
| printk(KERN_INFO PFX "initialized (0x%p). heartbeat=%d sec" |
| " (nowayout=%d)\n", |
| tcobase, heartbeat, nowayout); |
| |
| return 0; |
| |
| exit: |
| iounmap(tcobase); |
| release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE); |
| return ret; |
| } |
| |
| static void __devexit sp5100_tco_cleanup(void) |
| { |
| /* Stop the timer before we leave */ |
| if (!nowayout) |
| tco_timer_stop(); |
| |
| /* Deregister */ |
| misc_deregister(&sp5100_tco_miscdev); |
| iounmap(tcobase); |
| release_region(pm_iobase, SP5100_PM_IOPORTS_SIZE); |
| } |
| |
| static int __devexit sp5100_tco_remove(struct platform_device *dev) |
| { |
| if (tcobase) |
| sp5100_tco_cleanup(); |
| return 0; |
| } |
| |
| static void sp5100_tco_shutdown(struct platform_device *dev) |
| { |
| tco_timer_stop(); |
| } |
| |
| static struct platform_driver sp5100_tco_driver = { |
| .probe = sp5100_tco_init, |
| .remove = __devexit_p(sp5100_tco_remove), |
| .shutdown = sp5100_tco_shutdown, |
| .driver = { |
| .owner = THIS_MODULE, |
| .name = TCO_MODULE_NAME, |
| }, |
| }; |
| |
| static int __init sp5100_tco_init_module(void) |
| { |
| int err; |
| |
| printk(KERN_INFO PFX "SP5100 TCO WatchDog Timer Driver v%s\n", |
| TCO_VERSION); |
| |
| err = platform_driver_register(&sp5100_tco_driver); |
| if (err) |
| return err; |
| |
| sp5100_tco_platform_device = platform_device_register_simple( |
| TCO_MODULE_NAME, -1, NULL, 0); |
| if (IS_ERR(sp5100_tco_platform_device)) { |
| err = PTR_ERR(sp5100_tco_platform_device); |
| goto unreg_platform_driver; |
| } |
| |
| return 0; |
| |
| unreg_platform_driver: |
| platform_driver_unregister(&sp5100_tco_driver); |
| return err; |
| } |
| |
| static void __exit sp5100_tco_cleanup_module(void) |
| { |
| platform_device_unregister(sp5100_tco_platform_device); |
| platform_driver_unregister(&sp5100_tco_driver); |
| printk(KERN_INFO PFX "SP5100 TCO Watchdog Module Unloaded.\n"); |
| } |
| |
| module_init(sp5100_tco_init_module); |
| module_exit(sp5100_tco_cleanup_module); |
| |
| MODULE_AUTHOR("Priyanka Gupta"); |
| MODULE_DESCRIPTION("TCO timer driver for SP5100 chipset"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); |