X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fusb%2Fusb-skeleton.c;h=296b091cf168c7e460ec70db19ac7dcc18a777c1;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=4de9fb56ebfc02294636e65b1ca92303286e2b4e;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/drivers/usb/usb-skeleton.c b/drivers/usb/usb-skeleton.c index 4de9fb56e..296b091cf 100644 --- a/drivers/usb/usb-skeleton.c +++ b/drivers/usb/usb-skeleton.c @@ -1,5 +1,5 @@ /* - * USB Skeleton driver - 2.0 + * USB Skeleton driver - 2.2 * * Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com) * @@ -7,13 +7,11 @@ * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation, version 2. * - * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c - * but has been rewritten to be easy to read and use, as no locks are now - * needed anymore. + * This driver is based on the 2.6.3 version of drivers/usb/usb-skeleton.c + * but has been rewritten to be easier to read and use. * */ -#include #include #include #include @@ -22,6 +20,7 @@ #include #include #include +#include /* Define these values to match your devices */ @@ -33,38 +32,39 @@ static struct usb_device_id skel_table [] = { { USB_DEVICE(USB_SKEL_VENDOR_ID, USB_SKEL_PRODUCT_ID) }, { } /* Terminating entry */ }; -MODULE_DEVICE_TABLE (usb, skel_table); +MODULE_DEVICE_TABLE(usb, skel_table); /* Get a minor range for your devices from the usb maintainer */ #define USB_SKEL_MINOR_BASE 192 /* our private defines. if this grows any larger, use your own .h file */ -#define MAX_TRANSFER ( PAGE_SIZE - 512 ) +#define MAX_TRANSFER (PAGE_SIZE - 512) #define WRITES_IN_FLIGHT 8 /* Structure to hold all of our device specific stuff */ struct usb_skel { - struct usb_device * udev; /* the usb device for this device */ - struct usb_interface * interface; /* the interface for this device */ + struct usb_device *dev; /* the usb device for this device */ + struct usb_interface *interface; /* the interface for this device */ struct semaphore limit_sem; /* limiting the number of writes in progress */ - unsigned char * bulk_in_buffer; /* the buffer to receive data */ + unsigned char *bulk_in_buffer; /* the buffer to receive data */ size_t bulk_in_size; /* the size of the receive buffer */ __u8 bulk_in_endpointAddr; /* the address of the bulk in endpoint */ __u8 bulk_out_endpointAddr; /* the address of the bulk out endpoint */ struct kref kref; + struct mutex io_mutex; /* synchronize I/O with disconnect */ }; #define to_skel_dev(d) container_of(d, struct usb_skel, kref) static struct usb_driver skel_driver; static void skel_delete(struct kref *kref) -{ +{ struct usb_skel *dev = to_skel_dev(kref); usb_put_dev(dev->udev); - kfree (dev->bulk_in_buffer); - kfree (dev); + kfree(dev->bulk_in_buffer); + kfree(dev); } static int skel_open(struct inode *inode, struct file *file) @@ -90,6 +90,11 @@ static int skel_open(struct inode *inode, struct file *file) goto exit; } + /* prevent the device from being autosuspended */ + retval = usb_autopm_get_interface(interface); + if (retval) + goto exit; + /* increment our usage count for the device */ kref_get(&dev->kref); @@ -108,6 +113,12 @@ static int skel_release(struct inode *inode, struct file *file) if (dev == NULL) return -ENODEV; + /* allow the device to be autosuspended */ + mutex_lock(&dev->io_mutex); + if (dev->interface) + usb_autopm_put_interface(dev->interface); + mutex_unlock(&dev->io_mutex); + /* decrement the count on our device */ kref_put(&dev->kref, skel_delete); return 0; @@ -116,11 +127,17 @@ static int skel_release(struct inode *inode, struct file *file) static ssize_t skel_read(struct file *file, char *buffer, size_t count, loff_t *ppos) { struct usb_skel *dev; - int retval = 0; + int retval; int bytes_read; dev = (struct usb_skel *)file->private_data; - + + mutex_lock(&dev->io_mutex); + if (!dev->interface) { /* disconnect() was called */ + retval = -ENODEV; + goto exit; + } + /* do a blocking bulk read to get data from the device */ retval = usb_bulk_msg(dev->udev, usb_rcvbulkpipe(dev->udev, dev->bulk_in_endpointAddr), @@ -136,26 +153,28 @@ static ssize_t skel_read(struct file *file, char *buffer, size_t count, loff_t * retval = bytes_read; } +exit: + mutex_unlock(&dev->io_mutex); return retval; } -static void skel_write_bulk_callback(struct urb *urb, struct pt_regs *regs) +static void skel_write_bulk_callback(struct urb *urb) { struct usb_skel *dev; dev = (struct usb_skel *)urb->context; /* sync/async unlink faults aren't errors */ - if (urb->status && - !(urb->status == -ENOENT || + if (urb->status && + !(urb->status == -ENOENT || urb->status == -ECONNRESET || urb->status == -ESHUTDOWN)) { - dbg("%s - nonzero write bulk status received: %d", + err("%s - nonzero write bulk status received: %d", __FUNCTION__, urb->status); } /* free up our allocated buffer */ - usb_buffer_free(urb->dev, urb->transfer_buffer_length, + usb_buffer_free(urb->dev, urb->transfer_buffer_length, urb->transfer_buffer, urb->transfer_dma); up(&dev->limit_sem); } @@ -180,6 +199,12 @@ static ssize_t skel_write(struct file *file, const char *user_buffer, size_t cou goto exit; } + mutex_lock(&dev->io_mutex); + if (!dev->interface) { /* disconnect() was called */ + retval = -ENODEV; + goto error; + } + /* create a urb, and a buffer for it, and copy the data to the urb */ urb = usb_alloc_urb(0, GFP_KERNEL); if (!urb) { @@ -214,17 +239,22 @@ static ssize_t skel_write(struct file *file, const char *user_buffer, size_t cou /* release our reference to this urb, the USB core will eventually free it entirely */ usb_free_urb(urb); -exit: + mutex_unlock(&dev->io_mutex); return writesize; error: - usb_buffer_free(dev->udev, writesize, buf, urb->transfer_dma); - usb_free_urb(urb); + if (urb) { + usb_buffer_free(dev->udev, writesize, buf, urb->transfer_dma); + usb_free_urb(urb); + } + mutex_unlock(&dev->io_mutex); up(&dev->limit_sem); + +exit: return retval; } -static struct file_operations skel_fops = { +static const struct file_operations skel_fops = { .owner = THIS_MODULE, .read = skel_read, .write = skel_write, @@ -232,7 +262,7 @@ static struct file_operations skel_fops = { .release = skel_release, }; -/* +/* * usb class driver info in order to get a minor number from the usb core, * and to have the device registered with the driver core */ @@ -244,7 +274,7 @@ static struct usb_class_driver skel_class = { static int skel_probe(struct usb_interface *interface, const struct usb_device_id *id) { - struct usb_skel *dev = NULL; + struct usb_skel *dev; struct usb_host_interface *iface_desc; struct usb_endpoint_descriptor *endpoint; size_t buffer_size; @@ -253,12 +283,13 @@ static int skel_probe(struct usb_interface *interface, const struct usb_device_i /* allocate memory for our device state and initialize it */ dev = kzalloc(sizeof(*dev), GFP_KERNEL); - if (dev == NULL) { + if (!dev) { err("Out of memory"); goto error; } kref_init(&dev->kref); sema_init(&dev->limit_sem, WRITES_IN_FLIGHT); + mutex_init(&dev->io_mutex); dev->udev = usb_get_dev(interface_to_usbdev(interface)); dev->interface = interface; @@ -270,10 +301,7 @@ static int skel_probe(struct usb_interface *interface, const struct usb_device_i endpoint = &iface_desc->endpoint[i].desc; if (!dev->bulk_in_endpointAddr && - ((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) - == USB_DIR_IN) && - ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) - == USB_ENDPOINT_XFER_BULK)) { + usb_endpoint_is_bulk_in(endpoint)) { /* we found a bulk in endpoint */ buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); dev->bulk_in_size = buffer_size; @@ -286,10 +314,7 @@ static int skel_probe(struct usb_interface *interface, const struct usb_device_i } if (!dev->bulk_out_endpointAddr && - ((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) - == USB_DIR_OUT) && - ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) - == USB_ENDPOINT_XFER_BULK)) { + usb_endpoint_is_bulk_out(endpoint)) { /* we found a bulk out endpoint */ dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; } @@ -335,6 +360,11 @@ static void skel_disconnect(struct usb_interface *interface) /* give back our minor */ usb_deregister_dev(interface, &skel_class); + /* prevent more I/O from starting */ + mutex_lock(&dev->io_mutex); + dev->interface = NULL; + mutex_unlock(&dev->io_mutex); + unlock_kernel(); /* decrement our usage count */ @@ -368,7 +398,7 @@ static void __exit usb_skel_exit(void) usb_deregister(&skel_driver); } -module_init (usb_skel_init); -module_exit (usb_skel_exit); +module_init(usb_skel_init); +module_exit(usb_skel_exit); MODULE_LICENSE("GPL");