/***************************************************************************** * USBLCD Kernel Driver * * Version 1.05 * * (C) 2005 Georges Toth <g.toth@e-biz.lu> * * * * This file is licensed under the GPL. See COPYING in the package. * * Based on usb-skeleton.c 2.0 by Greg Kroah-Hartman (greg@kroah.com) * * * * * * 28.02.05 Complete rewrite of the original usblcd.c driver, * * based on usb_skeleton.c. * * This new driver allows more than one USB-LCD to be connected * * and controlled, at once * *****************************************************************************/ #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/errno.h> #include <asm/uaccess.h> #include <linux/usb.h> #define DRIVER_VERSION "USBLCD Driver Version 1.05" #define USBLCD_MINOR 144 #define IOCTL_GET_HARD_VERSION 1 #define IOCTL_GET_DRV_VERSION 2 static struct usb_device_id id_table [] = { { .idVendor = 0x10D2, .match_flags = USB_DEVICE_ID_MATCH_VENDOR, }, { }, }; MODULE_DEVICE_TABLE (usb, id_table); struct usb_lcd { struct usb_device * udev; /* init: probe_lcd */ struct usb_interface * interface; /* the interface for this device */ 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; }; #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) static struct usb_driver lcd_driver; static void lcd_delete(struct kref *kref) { struct usb_lcd *dev = to_lcd_dev(kref); usb_put_dev(dev->udev); kfree (dev->bulk_in_buffer); kfree (dev); } static int lcd_open(struct inode *inode, struct file *file) { struct usb_lcd *dev; struct usb_interface *interface; int subminor; int retval = 0; subminor = iminor(inode); interface = usb_find_interface(&lcd_driver, subminor); if (!interface) { err ("USBLCD: %s - error, can't find device for minor %d", __FUNCTION__, subminor); retval = -ENODEV; goto exit; } dev = usb_get_intfdata(interface); if (!dev) { retval = -ENODEV; goto exit; } /* increment our usage count for the device */ kref_get(&dev->kref); /* save our object in the file's private structure */ file->private_data = dev; exit: return retval; } static int lcd_release(struct inode *inode, struct file *file) { struct usb_lcd *dev; dev = (struct usb_lcd *)file->private_data; if (dev == NULL) return -ENODEV; /* decrement the count on our device */ kref_put(&dev->kref, lcd_delete); return 0; } static ssize_t lcd_read(struct file *file, char __user * buffer, size_t count, loff_t *ppos) { struct usb_lcd *dev; int retval = 0; int bytes_read; dev = (struct usb_lcd *)file->private_data; /* 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), dev->bulk_in_buffer, min(dev->bulk_in_size, count), &bytes_read, 10000); /* if the read was successful, copy the data to userspace */ if (!retval) { if (copy_to_user(buffer, dev->bulk_in_buffer, bytes_read)) retval = -EFAULT; else retval = bytes_read; } return retval; } static int lcd_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg) { struct usb_lcd *dev; u16 bcdDevice; char buf[30]; dev = (struct usb_lcd *)file->private_data; if (dev == NULL) return -ENODEV; switch (cmd) { case IOCTL_GET_HARD_VERSION: bcdDevice = le16_to_cpu((dev->udev)->descriptor.bcdDevice); sprintf(buf,"%1d%1d.%1d%1d", (bcdDevice & 0xF000)>>12, (bcdDevice & 0xF00)>>8, (bcdDevice & 0xF0)>>4, (bcdDevice & 0xF)); if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) return -EFAULT; break; case IOCTL_GET_DRV_VERSION: sprintf(buf,DRIVER_VERSION); if (copy_to_user((void __user *)arg,buf,strlen(buf))!=0) return -EFAULT; break; default: return -ENOTTY; break; } return 0; } static void lcd_write_bulk_callback(struct urb *urb) { struct usb_lcd *dev; dev = (struct usb_lcd *)urb->context; /* sync/async unlink faults aren't errors */ if (urb->status && !(urb->status == -ENOENT || urb->status == -ECONNRESET || urb->status == -ESHUTDOWN)) { dbg("USBLCD: %s - nonzero write bulk status received: %d", __FUNCTION__, urb->status); } /* free up our allocated buffer */ usb_buffer_free(urb->dev, urb->transfer_buffer_length, urb->transfer_buffer, urb->transfer_dma); } static ssize_t lcd_write(struct file *file, const char __user * user_buffer, size_t count, loff_t *ppos) { struct usb_lcd *dev; int retval = 0; struct urb *urb = NULL; char *buf = NULL; dev = (struct usb_lcd *)file->private_data; /* verify that we actually have some data to write */ if (count == 0) goto exit; /* create a urb, and a buffer for it, and copy the data to the urb */ urb = usb_alloc_urb(0, GFP_KERNEL); if (!urb) return -ENOMEM; buf = usb_buffer_alloc(dev->udev, count, GFP_KERNEL, &urb->transfer_dma); if (!buf) { retval = -ENOMEM; goto error; } if (copy_from_user(buf, user_buffer, count)) { retval = -EFAULT; goto error; } /* initialize the urb properly */ usb_fill_bulk_urb(urb, dev->udev, usb_sndbulkpipe(dev->udev, dev->bulk_out_endpointAddr), buf, count, lcd_write_bulk_callback, dev); urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; /* send the data out the bulk port */ retval = usb_submit_urb(urb, GFP_KERNEL); if (retval) { err("USBLCD: %s - failed submitting write urb, error %d", __FUNCTION__, retval); goto error; } /* release our reference to this urb, the USB core will eventually free it entirely */ usb_free_urb(urb); exit: return count; error: usb_buffer_free(dev->udev, count, buf, urb->transfer_dma); usb_free_urb(urb); return retval; } static const struct file_operations lcd_fops = { .owner = THIS_MODULE, .read = lcd_read, .write = lcd_write, .open = lcd_open, .ioctl = lcd_ioctl, .release = lcd_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 */ static struct usb_class_driver lcd_class = { .name = "lcd%d", .fops = &lcd_fops, .minor_base = USBLCD_MINOR, }; static int lcd_probe(struct usb_interface *interface, const struct usb_device_id *id) { struct usb_lcd *dev = NULL; struct usb_host_interface *iface_desc; struct usb_endpoint_descriptor *endpoint; size_t buffer_size; int i; int retval = -ENOMEM; /* allocate memory for our device state and initialize it */ dev = kzalloc(sizeof(*dev), GFP_KERNEL); if (dev == NULL) { err("Out of memory"); goto error; } kref_init(&dev->kref); dev->udev = usb_get_dev(interface_to_usbdev(interface)); dev->interface = interface; if (le16_to_cpu(dev->udev->descriptor.idProduct) != 0x0001) { warn(KERN_INFO "USBLCD model not supported."); return -ENODEV; } /* set up the endpoint information */ /* use only the first bulk-in and bulk-out endpoints */ iface_desc = interface->cur_altsetting; for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) { endpoint = &iface_desc->endpoint[i].desc; if (!dev->bulk_in_endpointAddr && 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; dev->bulk_in_endpointAddr = endpoint->bEndpointAddress; dev->bulk_in_buffer = kmalloc(buffer_size, GFP_KERNEL); if (!dev->bulk_in_buffer) { err("Could not allocate bulk_in_buffer"); goto error; } } if (!dev->bulk_out_endpointAddr && usb_endpoint_is_bulk_out(endpoint)) { /* we found a bulk out endpoint */ dev->bulk_out_endpointAddr = endpoint->bEndpointAddress; } } if (!(dev->bulk_in_endpointAddr && dev->bulk_out_endpointAddr)) { err("Could not find both bulk-in and bulk-out endpoints"); goto error; } /* save our data pointer in this interface device */ usb_set_intfdata(interface, dev); /* we can register the device now, as it is ready */ retval = usb_register_dev(interface, &lcd_class); if (retval) { /* something prevented us from registering this driver */ err("Not able to get a minor for this device."); usb_set_intfdata(interface, NULL); goto error; } i = le16_to_cpu(dev->udev->descriptor.bcdDevice); info("USBLCD Version %1d%1d.%1d%1d found at address %d", (i & 0xF000)>>12,(i & 0xF00)>>8,(i & 0xF0)>>4,(i & 0xF), dev->udev->devnum); /* let the user know what node this device is now attached to */ info("USB LCD device now attached to USBLCD-%d", interface->minor); return 0; error: if (dev) kref_put(&dev->kref, lcd_delete); return retval; } static void lcd_disconnect(struct usb_interface *interface) { struct usb_lcd *dev; int minor = interface->minor; /* prevent skel_open() from racing skel_disconnect() */ lock_kernel(); dev = usb_get_intfdata(interface); usb_set_intfdata(interface, NULL); /* give back our minor */ usb_deregister_dev(interface, &lcd_class); unlock_kernel(); /* decrement our usage count */ kref_put(&dev->kref, lcd_delete); info("USB LCD #%d now disconnected", minor); } static struct usb_driver lcd_driver = { .name = "usblcd", .probe = lcd_probe, .disconnect = lcd_disconnect, .id_table = id_table, }; static int __init usb_lcd_init(void) { int result; result = usb_register(&lcd_driver); if (result) err("usb_register failed. Error number %d", result); return result; } static void __exit usb_lcd_exit(void) { usb_deregister(&lcd_driver); } module_init(usb_lcd_init); module_exit(usb_lcd_exit); MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>"); MODULE_DESCRIPTION(DRIVER_VERSION); MODULE_LICENSE("GPL");