--- /dev/null
+/*****************************************************************************
+ * 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/slab.h>
+#include <linux/errno.h>
+#include <linux/mutex.h>
+#include <linux/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 DEFINE_MUTEX(lcd_mutex);
+static const 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;
+
+ mutex_lock(&lcd_mutex);
+ subminor = iminor(inode);
+
+ interface = usb_find_interface(&lcd_driver, subminor);
+ if (!interface) {
+ mutex_unlock(&lcd_mutex);
+ printk(KERN_ERR "USBLCD: %s - error, can't find device for minor %d\n",
+ __func__, subminor);
+ return -ENODEV;
+ }
+
+ mutex_lock(&open_disc_mutex);
+ dev = usb_get_intfdata(interface);
+ if (!dev) {
+ mutex_unlock(&open_disc_mutex);
+ mutex_unlock(&lcd_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);
+ mutex_unlock(&lcd_mutex);
+ return r;
+ }
+
+ /* save our object in the file's private structure */
+ file->private_data = dev;
+ mutex_unlock(&lcd_mutex);
+
+ return 0;
+}
+
+static int lcd_release(struct inode *inode, struct file *file)
+{
+ struct usb_lcd *dev;
+
+ dev = 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 = 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 = file->private_data;
+ if (dev == NULL)
+ return -ENODEV;
+
+ switch (cmd) {
+ case IOCTL_GET_HARD_VERSION:
+ mutex_lock(&lcd_mutex);
+ 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));
+ mutex_unlock(&lcd_mutex);
+ 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)) {
+ dev_dbg(&dev->interface->dev,
+ "nonzero write bulk status received: %d\n", status);
+ }
+
+ /* free up our allocated buffer */
+ usb_free_coherent(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 = 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_alloc_coherent(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) {
+ dev_err(&dev->udev->dev,
+ "%s - failed submitting write urb, error %d\n",
+ __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_free_coherent(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,
+ .llseek = noop_llseek,
+};
+
+/*
+ * 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) {
+ dev_err(&interface->dev, "Out of memory\n");
+ 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) {
+ dev_warn(&interface->dev, "USBLCD model not supported.\n");
+ retval = -ENODEV;
+ goto error;
+ }
+
+ /* 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 = usb_endpoint_maxp(endpoint);
+ 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) {
+ dev_err(&interface->dev,
+ "Could not allocate bulk_in_buffer\n");
+ 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)) {
+ dev_err(&interface->dev,
+ "Could not find both bulk-in and bulk-out endpoints\n");
+ 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 */
+ dev_err(&interface->dev,
+ "Not able to get a minor for this device.\n");
+ usb_set_intfdata(interface, NULL);
+ goto error;
+ }
+
+ i = le16_to_cpu(dev->udev->descriptor.bcdDevice);
+
+ dev_info(&interface->dev, "USBLCD Version %1d%1d.%1d%1d found "
+ "at address %d\n", (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 */
+ dev_info(&interface->dev, "USB LCD device now attached to USBLCD-%d\n",
+ 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);
+
+ dev_info(&interface->dev, "USB LCD #%d now disconnected\n", 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,
+};
+
+module_usb_driver(lcd_driver);
+
+MODULE_AUTHOR("Georges Toth <g.toth@e-biz.lu>");
+MODULE_DESCRIPTION(DRIVER_VERSION);
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff