From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/watchdog/alim7101_wdt.c | 449 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 449 insertions(+) create mode 100644 drivers/watchdog/alim7101_wdt.c (limited to 'drivers/watchdog/alim7101_wdt.c') diff --git a/drivers/watchdog/alim7101_wdt.c b/drivers/watchdog/alim7101_wdt.c new file mode 100644 index 000000000..665e0e7df --- /dev/null +++ b/drivers/watchdog/alim7101_wdt.c @@ -0,0 +1,449 @@ +/* + * ALi M7101 PMU Computer Watchdog Timer driver + * + * Based on w83877f_wdt.c by Scott Jennings + * and the Cobalt kernel WDT timer driver by Tim Hockin + * + * + * (c)2002 Steve Hill + * + * This WDT driver is different from most other Linux WDT + * drivers in that the driver will ping the watchdog by itself, + * because this particular WDT has a very short timeout (1.6 + * seconds) and it would be insane to count on any userspace + * daemon always getting scheduled within that time frame. + * + * Additions: + * Aug 23, 2004 - Added use_gpio module parameter for use on revision a1d PMUs + * found on very old cobalt hardware. + * -- Mike Waychison + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +#define WDT_ENABLE 0x9C +#define WDT_DISABLE 0x8C + +#define ALI_7101_WDT 0x92 +#define ALI_7101_GPIO 0x7D +#define ALI_7101_GPIO_O 0x7E +#define ALI_WDT_ARM 0x01 + +/* + * We're going to use a 1 second timeout. + * If we reset the watchdog every ~250ms we should be safe. */ + +#define WDT_INTERVAL (HZ/4+1) + +/* + * We must not require too good response from the userspace daemon. + * Here we require the userspace daemon to send us a heartbeat + * char to /dev/watchdog every 30 seconds. + */ + +#define WATCHDOG_TIMEOUT 30 /* 30 sec default timeout */ +/* in seconds, will be multiplied by HZ to get seconds to wait for a ping */ +static int timeout = WATCHDOG_TIMEOUT; +module_param(timeout, int, 0); +MODULE_PARM_DESC(timeout, + "Watchdog timeout in seconds. (1<=timeout<=3600, default=" + __MODULE_STRING(WATCHDOG_TIMEOUT) ")"); + +static int use_gpio; /* Use the pic (for a1d revision alim7101) */ +module_param(use_gpio, int, 0); +MODULE_PARM_DESC(use_gpio, + "Use the gpio watchdog (required by old cobalt boards)."); + +static void wdt_timer_ping(unsigned long); +static DEFINE_TIMER(timer, wdt_timer_ping, 0, 1); +static unsigned long next_heartbeat; +static unsigned long wdt_is_open; +static char wdt_expect_close; +static struct pci_dev *alim7101_pmu; + +static bool nowayout = WATCHDOG_NOWAYOUT; +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, + "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +/* + * Whack the dog + */ + +static void wdt_timer_ping(unsigned long data) +{ + /* If we got a heartbeat pulse within the WDT_US_INTERVAL + * we agree to ping the WDT + */ + char tmp; + + if (time_before(jiffies, next_heartbeat)) { + /* Ping the WDT (this is actually a disarm/arm sequence) */ + pci_read_config_byte(alim7101_pmu, 0x92, &tmp); + pci_write_config_byte(alim7101_pmu, + ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); + pci_write_config_byte(alim7101_pmu, + ALI_7101_WDT, (tmp | ALI_WDT_ARM)); + if (use_gpio) { + pci_read_config_byte(alim7101_pmu, + ALI_7101_GPIO_O, &tmp); + pci_write_config_byte(alim7101_pmu, + ALI_7101_GPIO_O, tmp | 0x20); + pci_write_config_byte(alim7101_pmu, + ALI_7101_GPIO_O, tmp & ~0x20); + } + } else { + pr_warn("Heartbeat lost! Will not ping the watchdog\n"); + } + /* Re-set the timer interval */ + mod_timer(&timer, jiffies + WDT_INTERVAL); +} + +/* + * Utility routines + */ + +static void wdt_change(int writeval) +{ + char tmp; + + pci_read_config_byte(alim7101_pmu, ALI_7101_WDT, &tmp); + if (writeval == WDT_ENABLE) { + pci_write_config_byte(alim7101_pmu, + ALI_7101_WDT, (tmp | ALI_WDT_ARM)); + if (use_gpio) { + pci_read_config_byte(alim7101_pmu, + ALI_7101_GPIO_O, &tmp); + pci_write_config_byte(alim7101_pmu, + ALI_7101_GPIO_O, tmp & ~0x20); + } + + } else { + pci_write_config_byte(alim7101_pmu, + ALI_7101_WDT, (tmp & ~ALI_WDT_ARM)); + if (use_gpio) { + pci_read_config_byte(alim7101_pmu, + ALI_7101_GPIO_O, &tmp); + pci_write_config_byte(alim7101_pmu, + ALI_7101_GPIO_O, tmp | 0x20); + } + } +} + +static void wdt_startup(void) +{ + next_heartbeat = jiffies + (timeout * HZ); + + /* We must enable before we kick off the timer in case the timer + occurs as we ping it */ + + wdt_change(WDT_ENABLE); + + /* Start the timer */ + mod_timer(&timer, jiffies + WDT_INTERVAL); + + pr_info("Watchdog timer is now enabled\n"); +} + +static void wdt_turnoff(void) +{ + /* Stop the timer */ + del_timer_sync(&timer); + wdt_change(WDT_DISABLE); + pr_info("Watchdog timer is now disabled...\n"); +} + +static void wdt_keepalive(void) +{ + /* user land ping */ + next_heartbeat = jiffies + (timeout * HZ); +} + +/* + * /dev/watchdog handling + */ + +static ssize_t fop_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppos) +{ + /* See if we got the magic character 'V' and reload the timer */ + if (count) { + if (!nowayout) { + size_t ofs; + + /* note: just in case someone wrote the magic character + * five months ago... */ + wdt_expect_close = 0; + + /* now scan */ + for (ofs = 0; ofs != count; ofs++) { + char c; + if (get_user(c, buf + ofs)) + return -EFAULT; + if (c == 'V') + wdt_expect_close = 42; + } + } + /* someone wrote to us, we should restart timer */ + wdt_keepalive(); + } + return count; +} + +static int fop_open(struct inode *inode, struct file *file) +{ + /* Just in case we're already talking to someone... */ + if (test_and_set_bit(0, &wdt_is_open)) + return -EBUSY; + /* Good, fire up the show */ + wdt_startup(); + return nonseekable_open(inode, file); +} + +static int fop_close(struct inode *inode, struct file *file) +{ + if (wdt_expect_close == 42) + wdt_turnoff(); + else { + /* wim: shouldn't there be a: del_timer(&timer); */ + pr_crit("device file closed unexpectedly. Will not stop the WDT!\n"); + } + clear_bit(0, &wdt_is_open); + wdt_expect_close = 0; + return 0; +} + +static long fop_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + int __user *p = argp; + static const struct watchdog_info ident = { + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT + | WDIOF_MAGICCLOSE, + .firmware_version = 1, + .identity = "ALiM7101", + }; + + 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: + { + int new_options, retval = -EINVAL; + + if (get_user(new_options, p)) + return -EFAULT; + if (new_options & WDIOS_DISABLECARD) { + wdt_turnoff(); + retval = 0; + } + if (new_options & WDIOS_ENABLECARD) { + wdt_startup(); + retval = 0; + } + return retval; + } + case WDIOC_KEEPALIVE: + wdt_keepalive(); + return 0; + case WDIOC_SETTIMEOUT: + { + int new_timeout; + + if (get_user(new_timeout, p)) + return -EFAULT; + /* arbitrary upper limit */ + if (new_timeout < 1 || new_timeout > 3600) + return -EINVAL; + timeout = new_timeout; + wdt_keepalive(); + /* Fall through */ + } + case WDIOC_GETTIMEOUT: + return put_user(timeout, p); + default: + return -ENOTTY; + } +} + +static const struct file_operations wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .write = fop_write, + .open = fop_open, + .release = fop_close, + .unlocked_ioctl = fop_ioctl, +}; + +static struct miscdevice wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &wdt_fops, +}; + +static int wdt_restart_handle(struct notifier_block *this, unsigned long mode, + void *cmd) +{ + /* + * Cobalt devices have no way of rebooting themselves other + * than getting the watchdog to pull reset, so we restart the + * watchdog on reboot with no heartbeat. + */ + wdt_change(WDT_ENABLE); + + /* loop until the watchdog fires */ + while (true) + ; + + return NOTIFY_DONE; +} + +static struct notifier_block wdt_restart_handler = { + .notifier_call = wdt_restart_handle, + .priority = 128, +}; + +/* + * Notifier for system down + */ + +static int wdt_notify_sys(struct notifier_block *this, + unsigned long code, void *unused) +{ + if (code == SYS_DOWN || code == SYS_HALT) + wdt_turnoff(); + + return NOTIFY_DONE; +} + +/* + * The WDT needs to learn about soft shutdowns in order to + * turn the timebomb registers off. + */ + +static struct notifier_block wdt_notifier = { + .notifier_call = wdt_notify_sys, +}; + +static void __exit alim7101_wdt_unload(void) +{ + wdt_turnoff(); + /* Deregister */ + misc_deregister(&wdt_miscdev); + unregister_reboot_notifier(&wdt_notifier); + unregister_restart_handler(&wdt_restart_handler); + pci_dev_put(alim7101_pmu); +} + +static int __init alim7101_wdt_init(void) +{ + int rc = -EBUSY; + struct pci_dev *ali1543_south; + char tmp; + + pr_info("Steve Hill \n"); + alim7101_pmu = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101, + NULL); + if (!alim7101_pmu) { + pr_info("ALi M7101 PMU not present - WDT not set\n"); + return -EBUSY; + } + + /* Set the WDT in the PMU to 1 second */ + pci_write_config_byte(alim7101_pmu, ALI_7101_WDT, 0x02); + + ali1543_south = pci_get_device(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533, + NULL); + if (!ali1543_south) { + pr_info("ALi 1543 South-Bridge not present - WDT not set\n"); + goto err_out; + } + pci_read_config_byte(ali1543_south, 0x5e, &tmp); + pci_dev_put(ali1543_south); + if ((tmp & 0x1e) == 0x00) { + if (!use_gpio) { + pr_info("Detected old alim7101 revision 'a1d'. If this is a cobalt board, set the 'use_gpio' module parameter.\n"); + goto err_out; + } + nowayout = 1; + } else if ((tmp & 0x1e) != 0x12 && (tmp & 0x1e) != 0x00) { + pr_info("ALi 1543 South-Bridge does not have the correct revision number (???1001?) - WDT not set\n"); + goto err_out; + } + + if (timeout < 1 || timeout > 3600) { + /* arbitrary upper limit */ + timeout = WATCHDOG_TIMEOUT; + pr_info("timeout value must be 1 <= x <= 3600, using %d\n", + timeout); + } + + rc = register_reboot_notifier(&wdt_notifier); + if (rc) { + pr_err("cannot register reboot notifier (err=%d)\n", rc); + goto err_out; + } + + rc = register_restart_handler(&wdt_restart_handler); + if (rc) { + pr_err("cannot register restart handler (err=%d)\n", rc); + goto err_out_reboot; + } + + rc = misc_register(&wdt_miscdev); + if (rc) { + pr_err("cannot register miscdev on minor=%d (err=%d)\n", + wdt_miscdev.minor, rc); + goto err_out_restart; + } + + if (nowayout) + __module_get(THIS_MODULE); + + pr_info("WDT driver for ALi M7101 initialised. timeout=%d sec (nowayout=%d)\n", + timeout, nowayout); + return 0; + +err_out_restart: + unregister_restart_handler(&wdt_restart_handler); +err_out_reboot: + unregister_reboot_notifier(&wdt_notifier); +err_out: + pci_dev_put(alim7101_pmu); + return rc; +} + +module_init(alim7101_wdt_init); +module_exit(alim7101_wdt_unload); + +static const struct pci_device_id alim7101_pci_tbl[] __used = { + { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M1533) }, + { PCI_DEVICE(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M7101) }, + { } +}; + +MODULE_DEVICE_TABLE(pci, alim7101_pci_tbl); + +MODULE_AUTHOR("Steve Hill"); +MODULE_DESCRIPTION("ALi M7101 PMU Computer Watchdog Timer driver"); +MODULE_LICENSE("GPL"); -- cgit v1.2.3-54-g00ecf