cregit-Linux how code gets into the kernel

Release 4.11 drivers/usb/misc/usblcd.c

Directory: drivers/usb/misc
/*****************************************************************************
 *                          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); }

Contributors

PersonTokensPropCommitsCommitProp
Georges Toth40100.00%1100.00%
Total40100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Georges Toth6133.33%111.11%
Oliver Neukum5630.60%333.33%
Greg Kroah-Hartman3519.13%222.22%
Arnd Bergmann2513.66%111.11%
Alan Stern52.73%111.11%
Harvey Harrison10.55%111.11%
Total183100.00%9100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman2644.83%133.33%
Georges Toth2543.10%133.33%
Oliver Neukum712.07%133.33%
Total58100.00%3100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Georges Toth9481.74%133.33%
Greg Kroah-Hartman1513.04%133.33%
Al Viro65.22%133.33%
Total115100.00%3100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman13569.95%342.86%
Georges Toth4422.80%114.29%
Arnd Bergmann105.18%114.29%
Alan Cox31.55%114.29%
Oliver Neukum10.52%114.29%
Total193100.00%7100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman4850.00%350.00%
Georges Toth3940.62%116.67%
Oliver Neukum88.33%116.67%
Daniel Mack11.04%116.67%
Total96100.00%6100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Georges Toth13846.46%111.11%
Greg Kroah-Hartman9732.66%333.33%
Oliver Neukum5819.53%222.22%
Daniel Mack20.67%111.11%
Zack Parsons10.34%111.11%
Harvey Harrison10.34%111.11%
Total297100.00%9100.00%

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_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; }

Contributors

PersonTokensPropCommitsCommitProp
Georges Toth25357.89%16.67%
Greg Kroah-Hartman14633.41%640.00%
Oliver Neukum235.26%320.00%
Luiz Fernando N. Capitulino61.37%16.67%
Jiri Slaby61.37%16.67%
Wolfram Sang10.23%16.67%
Eric Sesterhenn / Snakebyte10.23%16.67%
Kuninori Morimoto10.23%16.67%
Total437100.00%15100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Oliver Neukum39100.00%1100.00%
Total39100.00%1100.00%


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; }

Contributors

PersonTokensPropCommitsCommitProp
Oliver Neukum40100.00%1100.00%
Total40100.00%1100.00%


static int lcd_resume(struct usb_interface *intf) { return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Oliver Neukum14100.00%1100.00%
Total14100.00%1100.00%


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); }

Contributors

PersonTokensPropCommitsCommitProp
Greg Kroah-Hartman4150.62%571.43%
Georges Toth2834.57%114.29%
Oliver Neukum1214.81%114.29%
Total81100.00%7100.00%

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");

Overall Contributors

PersonTokensPropCommitsCommitProp
Georges Toth79342.47%12.78%
Greg Kroah-Hartman68836.85%1438.89%
Oliver Neukum29415.75%616.67%
Arnd Bergmann462.46%25.56%
Zack Parsons90.48%12.78%
Luiz Fernando N. Capitulino70.37%25.56%
Al Viro60.32%12.78%
Jiri Slaby60.32%12.78%
Alan Stern50.27%12.78%
Alan Cox40.21%12.78%
Daniel Mack30.16%12.78%
Harvey Harrison20.11%12.78%
Eric Sesterhenn / Snakebyte10.05%12.78%
Wolfram Sang10.05%12.78%
Márton Németh10.05%12.78%
Kuninori Morimoto10.05%12.78%
Arnaldo Carvalho de Melo0.00%00.00%
Total1867100.00%36100.00%
Directory: drivers/usb/misc
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