diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/watchdog/pcwd_usb.c | 807 |
1 files changed, 807 insertions, 0 deletions
diff --git a/drivers/watchdog/pcwd_usb.c b/drivers/watchdog/pcwd_usb.c new file mode 100644 index 000000000..8202f0a6b --- /dev/null +++ b/drivers/watchdog/pcwd_usb.c @@ -0,0 +1,807 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * 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> + * + * 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_NAME "pcwd_usb" + +MODULE_AUTHOR(DRIVER_AUTHOR); +MODULE_DESCRIPTION(DRIVER_DESC); +MODULE_LICENSE("GPL"); + +#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 const 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 = 0x00; + unsigned char lsb = 0x00; + + 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 = 0x00; + unsigned char lsb = 0x00; + + /* 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); + } + fallthrough; + + 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 stream_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 stream_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, + .compat_ioctl = compat_ptr_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); + 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; + } + + if (iface_desc->desc.bNumEndpoints < 1) + 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_KERNEL, &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); |