/* * Berkshire USB-PC Watchdog Card Driver * * (c) Copyright 2004-2007 Wim Van Sebroeck <wim@iguana.be>. * * Based on source code of the following authors: * Ken Hollis <kenji@bitgate.com>, * Alan Cox <alan@lxorguk.ukuu.org.uk>, * Matt Domsch <Matt_Domsch@dell.com>, * Rob Radez <rob@osinvestor.com>, * Greg Kroah-Hartman <greg@kroah.com> * * 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. * * Neither Wim Van Sebroeck nor Iguana vzw. admit liability nor * provide warranty for any of this software. This material is * provided "AS-IS" and at no charge. * * Thanks also to Simon Machell at Berkshire Products Inc. for * providing the test hardware. More info is available at * http://www.berkprod.com/ or http://www.pcwatchdog.com/ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> /* For module specific items */ #include <linux/moduleparam.h> /* For new moduleparam's */ #include <linux/types.h> /* For standard types (like size_t) */ #include <linux/errno.h> /* For the -ENODEV/... values */ #include <linux/kernel.h> /* For printk/panic/... */ #include <linux/delay.h> /* For mdelay function */ #include <linux/miscdevice.h> /* For struct miscdevice */ #include <linux/watchdog.h> /* For the watchdog specific items */ #include <linux/notifier.h> /* For notifier support */ #include <linux/reboot.h> /* For reboot_notifier stuff */ #include <linux/init.h> /* For __init/__exit/... */ #include <linux/fs.h> /* For file operations */ #include <linux/usb.h> /* For USB functions */ #include <linux/slab.h> /* For kmalloc, ... */ #include <linux/mutex.h> /* For mutex locking */ #include <linux/hid.h> /* For HID_REQ_SET_REPORT & HID_DT_REPORT */ #include <linux/uaccess.h> /* For copy_to_user/put_user/... */ /* Module and Version Information */ #define DRIVER_VERSION "1.02" #define DRIVER_AUTHOR "Wim Van Sebroeck <wim@iguana.be>" #define DRIVER_DESC "Berkshire USB-PC Watchdog driver" #define DRIVER_LICENSE "GPL" #define DRIVER_NAME "pcwd_usb" MODULE_AUTHOR(DRIVER_AUTHOR); MODULE_DESCRIPTION(DRIVER_DESC); MODULE_LICENSE(DRIVER_LICENSE); #define WATCHDOG_HEARTBEAT 0 /* default heartbeat = delay-time from dip-switches */ static int heartbeat = WATCHDOG_HEARTBEAT; module_param(heartbeat, int, 0); MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds. " "(0<heartbeat<65536 or 0=delay-time from dip-switches, default=" __MODULE_STRING(WATCHDOG_HEARTBEAT) ")"); 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) ")"); /* The vendor and product id's for the USB-PC Watchdog card */ #define USB_PCWD_VENDOR_ID 0x0c98 #define USB_PCWD_PRODUCT_ID 0x1140 /* table of devices that work with this driver */ static struct usb_device_id usb_pcwd_table[] = { { USB_DEVICE(USB_PCWD_VENDOR_ID, USB_PCWD_PRODUCT_ID) }, { } /* Terminating entry */ }; MODULE_DEVICE_TABLE(usb, usb_pcwd_table); /* according to documentation max. time to process a command for the USB * watchdog card is 100 or 200 ms, so we give it 250 ms to do it's job */ #define USB_COMMAND_TIMEOUT 250 /* Watchdog's internal commands */ #define CMD_READ_TEMP 0x02 /* Read Temperature; Re-trigger Watchdog */ #define CMD_TRIGGER CMD_READ_TEMP #define CMD_GET_STATUS 0x04 /* Get Status Information */ #define CMD_GET_FIRMWARE_VERSION 0x08 /* Get Firmware Version */ #define CMD_GET_DIP_SWITCH_SETTINGS 0x0c /* Get Dip Switch Settings */ #define CMD_READ_WATCHDOG_TIMEOUT 0x18 /* Read Current Watchdog Time */ #define CMD_WRITE_WATCHDOG_TIMEOUT 0x19 /* Write Current WatchdogTime */ #define CMD_ENABLE_WATCHDOG 0x30 /* Enable / Disable Watchdog */ #define CMD_DISABLE_WATCHDOG CMD_ENABLE_WATCHDOG /* Watchdog's Dip Switch heartbeat values */ static const int heartbeat_tbl[] = { 5, /* OFF-OFF-OFF = 5 Sec */ 10, /* OFF-OFF-ON = 10 Sec */ 30, /* OFF-ON-OFF = 30 Sec */ 60, /* OFF-ON-ON = 1 Min */ 300, /* ON-OFF-OFF = 5 Min */ 600, /* ON-OFF-ON = 10 Min */ 1800, /* ON-ON-OFF = 30 Min */ 3600, /* ON-ON-ON = 1 hour */ }; /* We can only use 1 card due to the /dev/watchdog restriction */ static int cards_found; /* some internal variables */ static unsigned long is_active; static char expect_release; /* Structure to hold all of our device specific stuff */ struct usb_pcwd_private { /* save off the usb device pointer */ struct usb_device *udev; /* the interface for this device */ struct usb_interface *interface; /* the interface number used for cmd's */ unsigned int interface_number; /* the buffer to intr data */ unsigned char *intr_buffer; /* the dma address for the intr buffer */ dma_addr_t intr_dma; /* the size of the intr buffer */ size_t intr_size; /* the urb used for the intr pipe */ struct urb *intr_urb; /* The command that is reported back */ unsigned char cmd_command; /* The data MSB that is reported back */ unsigned char cmd_data_msb; /* The data LSB that is reported back */ unsigned char cmd_data_lsb; /* true if we received a report after a command */ atomic_t cmd_received; /* Wether or not the device exists */ int exists; /* locks this structure */ struct mutex mtx; }; static struct usb_pcwd_private *usb_pcwd_device; /* prevent races between open() and disconnect() */ static DEFINE_MUTEX(disconnect_mutex); /* local function prototypes */ static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id); static void usb_pcwd_disconnect(struct usb_interface *interface); /* usb specific object needed to register this driver with the usb subsystem */ static struct usb_driver usb_pcwd_driver = { .name = DRIVER_NAME, .probe = usb_pcwd_probe, .disconnect = usb_pcwd_disconnect, .id_table = usb_pcwd_table, }; static void usb_pcwd_intr_done(struct urb *urb) { struct usb_pcwd_private *usb_pcwd = (struct usb_pcwd_private *)urb->context; unsigned char *data = usb_pcwd->intr_buffer; struct device *dev = &usb_pcwd->interface->dev; int retval; switch (urb->status) { case 0: /* success */ break; case -ECONNRESET: /* unlink */ case -ENOENT: case -ESHUTDOWN: /* this urb is terminated, clean up */ dev_dbg(dev, "%s - urb shutting down with status: %d", __func__, urb->status); return; /* -EPIPE: should clear the halt */ default: /* error */ dev_dbg(dev, "%s - nonzero urb status received: %d", __func__, urb->status); goto resubmit; } dev_dbg(dev, "received following data cmd=0x%02x msb=0x%02x lsb=0x%02x", data[0], data[1], data[2]); usb_pcwd->cmd_command = data[0]; usb_pcwd->cmd_data_msb = data[1]; usb_pcwd->cmd_data_lsb = data[2]; /* notify anyone waiting that the cmd has finished */ atomic_set(&usb_pcwd->cmd_received, 1); resubmit: retval = usb_submit_urb(urb, GFP_ATOMIC); if (retval) pr_err("can't resubmit intr, usb_submit_urb failed with result %d\n", retval); } static int usb_pcwd_send_command(struct usb_pcwd_private *usb_pcwd, unsigned char cmd, unsigned char *msb, unsigned char *lsb) { int got_response, count; unsigned char *buf; /* We will not send any commands if the USB PCWD device does * not exist */ if ((!usb_pcwd) || (!usb_pcwd->exists)) return -1; buf = kmalloc(6, GFP_KERNEL); if (buf == NULL) return 0; /* The USB PC Watchdog uses a 6 byte report format. * The board currently uses only 3 of the six bytes of the report. */ buf[0] = cmd; /* Byte 0 = CMD */ buf[1] = *msb; /* Byte 1 = Data MSB */ buf[2] = *lsb; /* Byte 2 = Data LSB */ buf[3] = buf[4] = buf[5] = 0; /* All other bytes not used */ dev_dbg(&usb_pcwd->interface->dev, "sending following data cmd=0x%02x msb=0x%02x lsb=0x%02x", buf[0], buf[1], buf[2]); atomic_set(&usb_pcwd->cmd_received, 0); if (usb_control_msg(usb_pcwd->udev, usb_sndctrlpipe(usb_pcwd->udev, 0), HID_REQ_SET_REPORT, HID_DT_REPORT, 0x0200, usb_pcwd->interface_number, buf, 6, USB_COMMAND_TIMEOUT) != 6) { dev_dbg(&usb_pcwd->interface->dev, "usb_pcwd_send_command: error in usb_control_msg for cmd 0x%x 0x%x 0x%x\n", cmd, *msb, *lsb); } /* wait till the usb card processed the command, * with a max. timeout of USB_COMMAND_TIMEOUT */ got_response = 0; for (count = 0; (count < USB_COMMAND_TIMEOUT) && (!got_response); count++) { mdelay(1); if (atomic_read(&usb_pcwd->cmd_received)) got_response = 1; } if ((got_response) && (cmd == usb_pcwd->cmd_command)) { /* read back response */ *msb = usb_pcwd->cmd_data_msb; *lsb = usb_pcwd->cmd_data_lsb; } kfree(buf); return got_response; } static int usb_pcwd_start(struct usb_pcwd_private *usb_pcwd) { unsigned char msb = 0x00; unsigned char lsb = 0x00; int retval; /* Enable Watchdog */ retval = usb_pcwd_send_command(usb_pcwd, CMD_ENABLE_WATCHDOG, &msb, &lsb); if ((retval == 0) || (lsb == 0)) { pr_err("Card did not acknowledge enable attempt\n"); return -1; } return 0; } static int usb_pcwd_stop(struct usb_pcwd_private *usb_pcwd) { unsigned char msb = 0xA5; unsigned char lsb = 0xC3; int retval; /* Disable Watchdog */ retval = usb_pcwd_send_command(usb_pcwd, CMD_DISABLE_WATCHDOG, &msb, &lsb); if ((retval == 0) || (lsb != 0)) { pr_err("Card did not acknowledge disable attempt\n"); return -1; } return 0; } static int usb_pcwd_keepalive(struct usb_pcwd_private *usb_pcwd) { unsigned char dummy; /* Re-trigger Watchdog */ usb_pcwd_send_command(usb_pcwd, CMD_TRIGGER, &dummy, &dummy); return 0; } static int usb_pcwd_set_heartbeat(struct usb_pcwd_private *usb_pcwd, int t) { unsigned char msb = t / 256; unsigned char lsb = t % 256; if ((t < 0x0001) || (t > 0xFFFF)) return -EINVAL; /* Write new heartbeat to watchdog */ usb_pcwd_send_command(usb_pcwd, CMD_WRITE_WATCHDOG_TIMEOUT, &msb, &lsb); heartbeat = t; return 0; } static int usb_pcwd_get_temperature(struct usb_pcwd_private *usb_pcwd, int *temperature) { unsigned char msb, lsb; usb_pcwd_send_command(usb_pcwd, CMD_READ_TEMP, &msb, &lsb); /* * Convert celsius to fahrenheit, since this was * the decided 'standard' for this return value. */ *temperature = (lsb * 9 / 5) + 32; return 0; } static int usb_pcwd_get_timeleft(struct usb_pcwd_private *usb_pcwd, int *time_left) { unsigned char msb, lsb; /* Read the time that's left before rebooting */ /* Note: if the board is not yet armed then we will read 0xFFFF */ usb_pcwd_send_command(usb_pcwd, CMD_READ_WATCHDOG_TIMEOUT, &msb, &lsb); *time_left = (msb << 8) + lsb; return 0; } /* * /dev/watchdog handling */ static ssize_t usb_pcwd_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... */ expect_release = 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') expect_release = 42; } } /* someone wrote to us, we should reload the timer */ usb_pcwd_keepalive(usb_pcwd_device); } return len; } static long usb_pcwd_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 = DRIVER_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_GETTEMP: { int temperature; if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature)) return -EFAULT; return put_user(temperature, p); } case WDIOC_SETOPTIONS: { int new_options, retval = -EINVAL; if (get_user(new_options, p)) return -EFAULT; if (new_options & WDIOS_DISABLECARD) { usb_pcwd_stop(usb_pcwd_device); retval = 0; } if (new_options & WDIOS_ENABLECARD) { usb_pcwd_start(usb_pcwd_device); retval = 0; } return retval; } case WDIOC_KEEPALIVE: usb_pcwd_keepalive(usb_pcwd_device); return 0; case WDIOC_SETTIMEOUT: { int new_heartbeat; if (get_user(new_heartbeat, p)) return -EFAULT; if (usb_pcwd_set_heartbeat(usb_pcwd_device, new_heartbeat)) return -EINVAL; usb_pcwd_keepalive(usb_pcwd_device); /* Fall */ } case WDIOC_GETTIMEOUT: return put_user(heartbeat, p); case WDIOC_GETTIMELEFT: { int time_left; if (usb_pcwd_get_timeleft(usb_pcwd_device, &time_left)) return -EFAULT; return put_user(time_left, p); } default: return -ENOTTY; } } static int usb_pcwd_open(struct inode *inode, struct file *file) { /* /dev/watchdog can only be opened once */ if (test_and_set_bit(0, &is_active)) return -EBUSY; /* Activate */ usb_pcwd_start(usb_pcwd_device); usb_pcwd_keepalive(usb_pcwd_device); return nonseekable_open(inode, file); } static int usb_pcwd_release(struct inode *inode, struct file *file) { /* * Shut off the timer. */ if (expect_release == 42) { usb_pcwd_stop(usb_pcwd_device); } else { pr_crit("Unexpected close, not stopping watchdog!\n"); usb_pcwd_keepalive(usb_pcwd_device); } expect_release = 0; clear_bit(0, &is_active); return 0; } /* * /dev/temperature handling */ static ssize_t usb_pcwd_temperature_read(struct file *file, char __user *data, size_t len, loff_t *ppos) { int temperature; if (usb_pcwd_get_temperature(usb_pcwd_device, &temperature)) return -EFAULT; if (copy_to_user(data, &temperature, 1)) return -EFAULT; return 1; } static int usb_pcwd_temperature_open(struct inode *inode, struct file *file) { return nonseekable_open(inode, file); } static int usb_pcwd_temperature_release(struct inode *inode, struct file *file) { return 0; } /* * Notify system */ static int usb_pcwd_notify_sys(struct notifier_block *this, unsigned long code, void *unused) { if (code == SYS_DOWN || code == SYS_HALT) usb_pcwd_stop(usb_pcwd_device); /* Turn the WDT off */ return NOTIFY_DONE; } /* * Kernel Interfaces */ static const struct file_operations usb_pcwd_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .write = usb_pcwd_write, .unlocked_ioctl = usb_pcwd_ioctl, .open = usb_pcwd_open, .release = usb_pcwd_release, }; static struct miscdevice usb_pcwd_miscdev = { .minor = WATCHDOG_MINOR, .name = "watchdog", .fops = &usb_pcwd_fops, }; static const struct file_operations usb_pcwd_temperature_fops = { .owner = THIS_MODULE, .llseek = no_llseek, .read = usb_pcwd_temperature_read, .open = usb_pcwd_temperature_open, .release = usb_pcwd_temperature_release, }; static struct miscdevice usb_pcwd_temperature_miscdev = { .minor = TEMP_MINOR, .name = "temperature", .fops = &usb_pcwd_temperature_fops, }; static struct notifier_block usb_pcwd_notifier = { .notifier_call = usb_pcwd_notify_sys, }; /** * usb_pcwd_delete */ static inline void usb_pcwd_delete(struct usb_pcwd_private *usb_pcwd) { usb_free_urb(usb_pcwd->intr_urb); if (usb_pcwd->intr_buffer != NULL) usb_free_coherent(usb_pcwd->udev, usb_pcwd->intr_size, usb_pcwd->intr_buffer, usb_pcwd->intr_dma); kfree(usb_pcwd); } /** * usb_pcwd_probe * * Called by the usb core when a new device is connected that it thinks * this driver might be interested in. */ static int usb_pcwd_probe(struct usb_interface *interface, const struct usb_device_id *id) { struct usb_device *udev = interface_to_usbdev(interface); struct usb_host_interface *iface_desc; struct usb_endpoint_descriptor *endpoint; struct usb_pcwd_private *usb_pcwd = NULL; int pipe; int retval = -ENOMEM; int got_fw_rev; unsigned char fw_rev_major, fw_rev_minor; char fw_ver_str[20]; unsigned char option_switches, dummy; cards_found++; if (cards_found > 1) { pr_err("This driver only supports 1 device\n"); return -ENODEV; } /* get the active interface descriptor */ iface_desc = interface->cur_altsetting; /* check out that we have a HID device */ if (!(iface_desc->desc.bInterfaceClass == USB_CLASS_HID)) { pr_err("The device isn't a Human Interface Device\n"); return -ENODEV; } /* check out the endpoint: it has to be Interrupt & IN */ endpoint = &iface_desc->endpoint[0].desc; if (!usb_endpoint_is_int_in(endpoint)) { /* we didn't find a Interrupt endpoint with direction IN */ pr_err("Couldn't find an INTR & IN endpoint\n"); return -ENODEV; } /* get a handle to the interrupt data pipe */ pipe = usb_rcvintpipe(udev, endpoint->bEndpointAddress); /* allocate memory for our device and initialize it */ usb_pcwd = kzalloc(sizeof(struct usb_pcwd_private), GFP_KERNEL); if (usb_pcwd == NULL) goto error; usb_pcwd_device = usb_pcwd; mutex_init(&usb_pcwd->mtx); usb_pcwd->udev = udev; usb_pcwd->interface = interface; usb_pcwd->interface_number = iface_desc->desc.bInterfaceNumber; usb_pcwd->intr_size = (le16_to_cpu(endpoint->wMaxPacketSize) > 8 ? le16_to_cpu(endpoint->wMaxPacketSize) : 8); /* set up the memory buffer's */ usb_pcwd->intr_buffer = usb_alloc_coherent(udev, usb_pcwd->intr_size, GFP_ATOMIC, &usb_pcwd->intr_dma); if (!usb_pcwd->intr_buffer) { pr_err("Out of memory\n"); goto error; } /* allocate the urb's */ usb_pcwd->intr_urb = usb_alloc_urb(0, GFP_KERNEL); if (!usb_pcwd->intr_urb) goto error; /* initialise the intr urb's */ usb_fill_int_urb(usb_pcwd->intr_urb, udev, pipe, usb_pcwd->intr_buffer, usb_pcwd->intr_size, usb_pcwd_intr_done, usb_pcwd, endpoint->bInterval); usb_pcwd->intr_urb->transfer_dma = usb_pcwd->intr_dma; usb_pcwd->intr_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; /* register our interrupt URB with the USB system */ if (usb_submit_urb(usb_pcwd->intr_urb, GFP_KERNEL)) { pr_err("Problem registering interrupt URB\n"); retval = -EIO; /* failure */ goto error; } /* The device exists and can be communicated with */ usb_pcwd->exists = 1; /* disable card */ usb_pcwd_stop(usb_pcwd); /* Get the Firmware Version */ got_fw_rev = usb_pcwd_send_command(usb_pcwd, CMD_GET_FIRMWARE_VERSION, &fw_rev_major, &fw_rev_minor); if (got_fw_rev) sprintf(fw_ver_str, "%u.%02u", fw_rev_major, fw_rev_minor); else sprintf(fw_ver_str, "<card no answer>"); pr_info("Found card (Firmware: %s) with temp option\n", fw_ver_str); /* Get switch settings */ usb_pcwd_send_command(usb_pcwd, CMD_GET_DIP_SWITCH_SETTINGS, &dummy, &option_switches); pr_info("Option switches (0x%02x): Temperature Reset Enable=%s, Power On Delay=%s\n", option_switches, ((option_switches & 0x10) ? "ON" : "OFF"), ((option_switches & 0x08) ? "ON" : "OFF")); /* If heartbeat = 0 then we use the heartbeat from the dip-switches */ if (heartbeat == 0) heartbeat = heartbeat_tbl[(option_switches & 0x07)]; /* Check that the heartbeat value is within it's range ; * if not reset to the default */ if (usb_pcwd_set_heartbeat(usb_pcwd, heartbeat)) { usb_pcwd_set_heartbeat(usb_pcwd, WATCHDOG_HEARTBEAT); pr_info("heartbeat value must be 0<heartbeat<65536, using %d\n", WATCHDOG_HEARTBEAT); } retval = register_reboot_notifier(&usb_pcwd_notifier); if (retval != 0) { pr_err("cannot register reboot notifier (err=%d)\n", retval); goto error; } retval = misc_register(&usb_pcwd_temperature_miscdev); if (retval != 0) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", TEMP_MINOR, retval); goto err_out_unregister_reboot; } retval = misc_register(&usb_pcwd_miscdev); if (retval != 0) { pr_err("cannot register miscdev on minor=%d (err=%d)\n", WATCHDOG_MINOR, retval); goto err_out_misc_deregister; } /* we can register the device now, as it is ready */ usb_set_intfdata(interface, usb_pcwd); pr_info("initialized. heartbeat=%d sec (nowayout=%d)\n", heartbeat, nowayout); return 0; err_out_misc_deregister: misc_deregister(&usb_pcwd_temperature_miscdev); err_out_unregister_reboot: unregister_reboot_notifier(&usb_pcwd_notifier); error: if (usb_pcwd) usb_pcwd_delete(usb_pcwd); usb_pcwd_device = NULL; return retval; } /** * usb_pcwd_disconnect * * Called by the usb core when the device is removed from the system. * * This routine guarantees that the driver will not submit any more urbs * by clearing dev->udev. */ static void usb_pcwd_disconnect(struct usb_interface *interface) { struct usb_pcwd_private *usb_pcwd; /* prevent races with open() */ mutex_lock(&disconnect_mutex); usb_pcwd = usb_get_intfdata(interface); usb_set_intfdata(interface, NULL); mutex_lock(&usb_pcwd->mtx); /* Stop the timer before we leave */ if (!nowayout) usb_pcwd_stop(usb_pcwd); /* We should now stop communicating with the USB PCWD device */ usb_pcwd->exists = 0; /* Deregister */ misc_deregister(&usb_pcwd_miscdev); misc_deregister(&usb_pcwd_temperature_miscdev); unregister_reboot_notifier(&usb_pcwd_notifier); mutex_unlock(&usb_pcwd->mtx); /* Delete the USB PCWD device */ usb_pcwd_delete(usb_pcwd); cards_found--; mutex_unlock(&disconnect_mutex); pr_info("USB PC Watchdog disconnected\n"); } module_usb_driver(usb_pcwd_driver);