diff options
author | Priyanka Gupta <priyankag@google.com> | 2010-10-25 17:58:04 -0700 |
---|---|---|
committer | Wim Van Sebroeck <wim@iguana.be> | 2011-01-12 13:51:16 +0000 |
commit | 15e28bf130081a574192fb934b832ac7d07739f7 (patch) | |
tree | b4aeef95f06f6c60697ae078e589034c8b198ff5 /drivers/watchdog/sp5100_tco.c | |
parent | e13752a1de02044bfda352cbc834e3c9541f148b (diff) | |
download | linux-stable-15e28bf130081a574192fb934b832ac7d07739f7.tar.gz linux-stable-15e28bf130081a574192fb934b832ac7d07739f7.tar.bz2 linux-stable-15e28bf130081a574192fb934b832ac7d07739f7.zip |
watchdog: Add support for sp5100 chipset TCO
This driver adds /dev/watchdog support for the AMD sp5100 aka SB7x0 chipsets.
It follows the same conventions found in other /dev/watchdog drivers.
Signed-off-by: Priyanka Gupta <priyankag@google.com>
Signed-off-by: Mike Waychison <mikew@google.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Diffstat (limited to 'drivers/watchdog/sp5100_tco.c')
-rw-r--r-- | drivers/watchdog/sp5100_tco.c | 480 |
1 files changed, 480 insertions, 0 deletions
diff --git a/drivers/watchdog/sp5100_tco.c b/drivers/watchdog/sp5100_tco.c new file mode 100644 index 000000000000..808372883e88 --- /dev/null +++ b/drivers/watchdog/sp5100_tco.c @@ -0,0 +1,480 @@ +/* + * 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 struct pci_device_id 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); |