| /***************************************************************************** |
| * 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 <linux/mutex.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); |
| |
| static DEFINE_MUTEX(open_disc_mutex); |
| |
| |
| 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; |
| struct semaphore limit_sem; /* to stop writes at full throttle from |
| * using up all RAM */ |
| struct usb_anchor submitted; /* URBs to wait for before suspend */ |
| }; |
| #define to_lcd_dev(d) container_of(d, struct usb_lcd, kref) |
| |
| #define USB_LCD_CONCURRENT_WRITES 5 |
| |
| 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, r; |
| |
| subminor = iminor(inode); |
| |
| interface = usb_find_interface(&lcd_driver, subminor); |
| if (!interface) { |
| err ("USBLCD: %s - error, can't find device for minor %d", |
| __func__, subminor); |
| return -ENODEV; |
| } |
| |
| mutex_lock(&open_disc_mutex); |
| dev = usb_get_intfdata(interface); |
| if (!dev) { |
| mutex_unlock(&open_disc_mutex); |
| return -ENODEV; |
| } |
| |
| /* increment our usage count for the device */ |
| kref_get(&dev->kref); |
| mutex_unlock(&open_disc_mutex); |
| |
| /* grab a power reference */ |
| r = usb_autopm_get_interface(interface); |
| if (r < 0) { |
| kref_put(&dev->kref, lcd_delete); |
| return r; |
| } |
| |
| /* save our object in the file's private structure */ |
| file->private_data = dev; |
| |
| return 0; |
| } |
| |
| 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 */ |
| usb_autopm_put_interface(dev->interface); |
| 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 long lcd_ioctl(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: |
| lock_kernel(); |
| 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)); |
| unlock_kernel(); |
| 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; |
| int status = urb->status; |
| |
| dev = urb->context; |
| |
| /* sync/async unlink faults aren't errors */ |
| if (status && |
| !(status == -ENOENT || |
| status == -ECONNRESET || |
| status == -ESHUTDOWN)) { |
| dbg("USBLCD: %s - nonzero write bulk status received: %d", |
| __func__, status); |
| } |
| |
| /* free up our allocated buffer */ |
| usb_buffer_free(urb->dev, urb->transfer_buffer_length, |
| urb->transfer_buffer, urb->transfer_dma); |
| up(&dev->limit_sem); |
| } |
| |
| 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, r; |
| 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; |
| |
| r = down_interruptible(&dev->limit_sem); |
| if (r < 0) |
| return -EINTR; |
| |
| /* create a urb, and a buffer for it, and copy the data to the urb */ |
| urb = usb_alloc_urb(0, GFP_KERNEL); |
| if (!urb) { |
| retval = -ENOMEM; |
| goto err_no_buf; |
| } |
| |
| 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; |
| |
| usb_anchor_urb(urb, &dev->submitted); |
| |
| /* 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", __func__, retval); |
| goto error_unanchor; |
| } |
| |
| /* release our reference to this urb, the USB core will eventually free it entirely */ |
| usb_free_urb(urb); |
| |
| exit: |
| return count; |
| error_unanchor: |
| usb_unanchor_urb(urb); |
| error: |
| usb_buffer_free(dev->udev, count, buf, urb->transfer_dma); |
| usb_free_urb(urb); |
| err_no_buf: |
| up(&dev->limit_sem); |
| return retval; |
| } |
| |
| static const struct file_operations lcd_fops = { |
| .owner = THIS_MODULE, |
| .read = lcd_read, |
| .write = lcd_write, |
| .open = lcd_open, |
| .unlocked_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); |
| sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES); |
| init_usb_anchor(&dev->submitted); |
| |
| 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_draw_down(struct usb_lcd *dev) |
| { |
| int time; |
| |
| time = usb_wait_anchor_empty_timeout(&dev->submitted, 1000); |
| if (!time) |
| usb_kill_anchored_urbs(&dev->submitted); |
| } |
| |
| static int lcd_suspend(struct usb_interface *intf, pm_message_t message) |
| { |
| struct usb_lcd *dev = usb_get_intfdata(intf); |
| |
| if (!dev) |
| return 0; |
| lcd_draw_down(dev); |
| return 0; |
| } |
| |
| static int lcd_resume (struct usb_interface *intf) |
| { |
| return 0; |
| } |
| |
| static void lcd_disconnect(struct usb_interface *interface) |
| { |
| struct usb_lcd *dev; |
| int minor = interface->minor; |
| |
| mutex_lock(&open_disc_mutex); |
| dev = usb_get_intfdata(interface); |
| usb_set_intfdata(interface, NULL); |
| mutex_unlock(&open_disc_mutex); |
| |
| /* give back our minor */ |
| usb_deregister_dev(interface, &lcd_class); |
| |
| /* 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, |
| .suspend = lcd_suspend, |
| .resume = lcd_resume, |
| .id_table = id_table, |
| .supports_autosuspend = 1, |
| }; |
| |
| 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"); |