View difference between Paste ID: ihzBfkPE and SGNjWUd5

 #include <linux/init.h>
 
 #include <linux/module.h>
 #include <linux/backlight.h>
 #include <linux/usb.h>
 
 #include <linux/kernel.h>
 #include <linux/slab.h>
 
 #include "usb-pkk-backlight.h"
 static void urb_out_complete(struct urb *urb)
 {
 	return;
 }
 
 static int pkk_bl_get_brightness(struct backlight_device *bdev)
 {
 	struct pkk_bl_data *data = bl_get_data(bdev);
 
 	//uint8_t *brightness = &bdev->props.brightness; //Not sure, that this is right
 	uint8_t *brightness = &data->brightness;
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Brightness get function called. Current brightness: %d.\n", *brightness);
 	return *brightness;
 }
 
 static int pkk_bl_set_brightness(struct backlight_device *bdev)
 {
 	struct pkk_bl_data *data = bl_get_data(bdev);
 
 	//uint8_t *brightness = &bdev->props.brightness; //Not sure, that this is right
 	uint8_t *brightness = &data->brightness;
 	unsigned char *transfer_buffer_out = data->transfer_buffer_out;
 	int error;
 	printk("%s(): data->transfer_buffer_out = %p\n", __FUNCTION__, data->transfer_buffer_out);
 	*brightness = bdev->props.brightness;
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Brightness set function called. New brightness: %d.\n", *brightness);
 	*transfer_buffer_out = PKK_BL_CMD_SET_BRIGHTNESS;
 	transfer_buffer_out++;
 	*transfer_buffer_out = *brightness;
 	error = usb_submit_urb(data->urb, GFP_KERNEL);
 	if (data->urb->status != 0 || error != 0) {
 		printk(KERN_ERR PKK_BL_DRIVER_NAME "Urb submit failled. Urb status: %d. Usb_submit_urb returned:%d.\n",
 		       data->urb->status, error);
 	}
 	return 0;
 }
 
 static const struct backlight_ops pkk_bl_blops = {
 	.update_status = pkk_bl_set_brightness,
 	.get_brightness = pkk_bl_get_brightness,
 };
 
 static int pkk_bl_init_backlight(struct pkk_bl_data *data)	// I'm not sure that it should be static
 {
 	struct device *dev = &data->intf->dev;
 	struct backlight_device *bdev;
 	struct backlight_properties props;
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Backlight device initialization...\n");
 	if (data->intf == 0) {
 		printk(KERN_ERR PKK_BL_DRIVER_NAME "%s(): no such interface\n", __FUNCTION__);
 		return -ENODEV;
 	}
 	/* PicoLCD - There was sommething for hid_report */
 	memset(&props, 0, sizeof(props));
 	props.type = BACKLIGHT_RAW;	//I don't know what is it
 	props.max_brightness = PKK_BL_MAX_BRIGHTNESS;
 	printk("%s(): data->intf = %p\ndev = %p\ndata = %p\n", __FUNCTION__, data->intf, (void *)dev, data);
 	printk("%s(): dev_name(dev) = %s\ndev = %p\ndata = %p\n", __FUNCTION__, dev_name(dev), (void *)dev, data);
 	bdev = backlight_device_register(dev_name(dev), dev, data, &pkk_bl_blops, &props);
 	if (IS_ERR(bdev)) {
 		printk(KERN_ERR PKK_BL_DRIVER_NAME "Failed to register backlight.\n");
 		return PTR_ERR(bdev);
 	}
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "%s():%d", __FUNCTION__, __LINE__);
 	bdev->props.brightness = PKK_BL_DEFAULT_BRIGHTNESS;
 	data->bdev = bdev;
 	pkk_bl_set_brightness(bdev);
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Backlight device initialized.\n");
 	return 0;
 }
 
 static void pkk_bl_exit_backlight(struct pkk_bl_data *data)	// I'm not sure that it should be static
 {
 	struct backlight_device *bdev = data->bdev;
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Backlight device unregistering...\n");
 	data->bdev = NULL;
 	if (bdev)
 		backlight_device_unregister(bdev);
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Backlight device unregistered successfully.\n");
 }
 
 static int pkk_bl_probe(struct usb_interface *intf, const struct usb_device_id *id)
 {
 	struct pkk_bl_data *data;
 	int error = 0;
 	struct urb *urb;
 	unsigned char *transfer_buffer_out;
 	struct usb_device *udev = interface_to_usbdev(intf);
 
 	if (intf == NULL) {
 		printk(KERN_ERR "%s(): no such interface\n", __FUNCTION__);
 		error = -ENODEV;
 		goto err_nodev;
 	}
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Hardware probe...\n");
 
 	/* Varibles initialization and assigments */
 	data = kzalloc(sizeof(struct pkk_bl_data), GFP_KERNEL);
 	if (data == NULL) {
 		printk(KERN_ERR PKK_BL_DRIVER_NAME "Can't allocate space for device data.\n");
 		error = -ENOMEM;
 		goto err_no_cleanup;
 	}
 
 	/* PicoLCD - There was synchronization elements (initialization & using) */
 	dev_set_drvdata(&intf->dev, data);
 	printk("pkk_bl_probe: intf = %p\n", (void *)intf);
 	printk("pkk_bl_probe: &intf->dev = %p\n", (void *)&intf->dev);
 
 	/* Filling data structure */
 	data->udev_id = (struct usb_device_id *)id;
 	data->udev = udev;
 	data->intf = intf;
 
 	/* Modules initialization */
 	urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (urb == NULL) {
 		printk(KERN_ERR PKK_BL_DRIVER_NAME "Can't initializate urb.\n");
 		goto err_exit_backlight;
 	}
 	data->urb = urb;
 	transfer_buffer_out = kzalloc(sizeof(unsigned char) * PKK_BL_TRANSFER_BUFFER_OUT_SIZE, GFP_KERNEL);
 	if (transfer_buffer_out == NULL) {
 		printk(KERN_ERR PKK_BL_DRIVER_NAME "Can't allocate space for transfer buffer (out).\n");
 		error = -ENOMEM;
 		goto err_urb_cleanup;
 	}
 
 	data->transfer_buffer_out = transfer_buffer_out;
 	error = pkk_bl_init_backlight(data);
 	if (error) {
 		pkk_bl_exit_backlight(data);
 		printk(KERN_ERR PKK_BL_DRIVER_NAME "Can't initializate backlight device.\n");
 		goto err_cleanup_data;
 	}
 
     usb_fill_int_urb(urb, udev, usb_rcvintpipe(to_usb_device(&intf->dev), PKK_BL_OUT_ENDPOINT), transfer_buffer_out, PKK_BL_TRANSFER_BUFFER_OUT_SIZE, urb_out_complete, data, PKK_BL_OUT_INTERVAL);
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Device activated and initialized.\n");
 	return 0;
  err_cleanup_data:kfree(data);
  err_urb_cleanup:usb_free_urb(urb);
  err_exit_backlight:pkk_bl_exit_backlight(data);
  err_no_cleanup:
 	//dev_set_drvdata(&intf->dev, NULL); - intf->dev->data Wasn't assigned in this step(dev_setdrvdata wasn't called
  err_nodev:
 	return error;
 }
 
 static void pkk_bl_disconnect(struct usb_interface *intf)
 {
 	struct pkk_bl_data *data = dev_get_drvdata(&intf->dev);
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Hardware remove...\n");
 
 	/* PicoLCD - There was synchronization elements (removing & using) */
 	pkk_bl_exit_backlight(data);
 	dev_set_drvdata(&intf->dev, NULL);
 	usb_free_urb(data->urb);
 	kfree(data->transfer_buffer_out);
 	kfree(data);
 	printk(KERN_INFO PKK_BL_DRIVER_NAME "Device disconnected successfully.\n");
 }
 
 static struct usb_device_id pkk_bl_devices[] = {
 	{ USB_DEVICE(USB_VENDOR_ID_PKK_BL, USB_DEVICE_ID_PKK_BL) },
 	{}
 };
 
 MODULE_DEVICE_TABLE(usb, pkk_bl_devices);
 static struct usb_driver pkk_bl_driver = {
 	.name = "usb_pkk_backlight",
 	.id_table = pkk_bl_devices,
 	.probe = pkk_bl_probe,
 	.disconnect = pkk_bl_disconnect,
 };
 
 module_usb_driver(pkk_bl_driver);
 MODULE_DESCRIPTION("PKK USB backlight driver");
 MODULE_LICENSE("GPL v2");
 MODULE_AUTHOR("Dmitry Chepurovskiy <dm3chip@gmail.com>");