485 lines
12 KiB
C
485 lines
12 KiB
C
/*****************************************************************************
|
|
* 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/rwsem.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 */
|
|
struct rw_semaphore io_rwsem;
|
|
unsigned long disconnected:1;
|
|
};
|
|
#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;
|
|
|
|
down_read(&dev->io_rwsem);
|
|
|
|
if (dev->disconnected) {
|
|
retval = -ENODEV;
|
|
goto out_up_io;
|
|
}
|
|
|
|
/* 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;
|
|
}
|
|
|
|
out_up_io:
|
|
up_read(&dev->io_rwsem);
|
|
|
|
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;
|
|
|
|
down_read(&dev->io_rwsem);
|
|
|
|
if (dev->disconnected) {
|
|
retval = -ENODEV;
|
|
goto err_up_io;
|
|
}
|
|
|
|
/* 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_up_io;
|
|
}
|
|
|
|
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);
|
|
|
|
up_read(&dev->io_rwsem);
|
|
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_up_io:
|
|
up_read(&dev->io_rwsem);
|
|
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)
|
|
goto error;
|
|
kref_init(&dev->kref);
|
|
sema_init(&dev->limit_sem, USB_LCD_CONCURRENT_WRITES);
|
|
init_rwsem(&dev->io_rwsem);
|
|
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)
|
|
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);
|
|
|
|
down_write(&dev->io_rwsem);
|
|
dev->disconnected = 1;
|
|
up_write(&dev->io_rwsem);
|
|
|
|
usb_kill_anchored_urbs(&dev->submitted);
|
|
|
|
/* 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");
|