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	 4b8a826208
			
		
	
	
		4b8a826208
		
	
	
	
	
		
			
			The functions backlight_device_unregister(), lcd_device_unregister() and rc_unregister_device() test whether their argument is NULL and then return immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Reviewed-by: Bruno Prémont <bonbons@linux-vserver.org> Signed-off-by: Jiri Kosina <jkosina@suse.com>
		
			
				
	
	
		
			104 lines
		
	
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			104 lines
		
	
	
	
		
			3.4 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /***************************************************************************
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|  *   Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org>  *
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|  *                                                                         *
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|  *   Based on Logitech G13 driver (v0.4)                                   *
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|  *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
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|  *                                                                         *
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|  *   This program is free software: you can redistribute it and/or modify  *
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|  *   it under the terms of the GNU General Public License as published by  *
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|  *   the Free Software Foundation, version 2 of the License.               *
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|  *                                                                         *
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|  *   This driver is distributed in the hope that it will be useful, but    *
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|  *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
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|  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      *
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|  *   General Public License for more details.                              *
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|  *                                                                         *
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|  *   You should have received a copy of the GNU General Public License     *
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|  *   along with this software. If not see <http://www.gnu.org/licenses/>.  *
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|  ***************************************************************************/
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| 
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| #include <linux/hid.h>
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| 
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| #include <linux/fb.h>
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| #include <linux/lcd.h>
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| 
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| #include "hid-picolcd.h"
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| 
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| /*
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|  * lcd class device
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|  */
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| static int picolcd_get_contrast(struct lcd_device *ldev)
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| {
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| 	struct picolcd_data *data = lcd_get_data(ldev);
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| 	return data->lcd_contrast;
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| }
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| 
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| static int picolcd_set_contrast(struct lcd_device *ldev, int contrast)
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| {
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| 	struct picolcd_data *data = lcd_get_data(ldev);
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| 	struct hid_report *report = picolcd_out_report(REPORT_CONTRAST, data->hdev);
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| 	unsigned long flags;
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| 
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| 	if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
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| 		return -ENODEV;
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| 
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| 	data->lcd_contrast = contrast & 0x0ff;
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| 	spin_lock_irqsave(&data->lock, flags);
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| 	hid_set_field(report->field[0], 0, data->lcd_contrast);
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| 	if (!(data->status & PICOLCD_FAILED))
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| 		hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
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| 	spin_unlock_irqrestore(&data->lock, flags);
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| 	return 0;
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| }
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| 
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| static int picolcd_check_lcd_fb(struct lcd_device *ldev, struct fb_info *fb)
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| {
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| 	return fb && fb == picolcd_fbinfo((struct picolcd_data *)lcd_get_data(ldev));
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| }
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| 
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| static struct lcd_ops picolcd_lcdops = {
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| 	.get_contrast   = picolcd_get_contrast,
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| 	.set_contrast   = picolcd_set_contrast,
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| 	.check_fb       = picolcd_check_lcd_fb,
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| };
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| 
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| int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report)
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| {
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| 	struct device *dev = &data->hdev->dev;
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| 	struct lcd_device *ldev;
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| 
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| 	if (!report)
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| 		return -ENODEV;
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| 	if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
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| 			report->field[0]->report_size != 8) {
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| 		dev_err(dev, "unsupported CONTRAST report");
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| 		return -EINVAL;
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| 	}
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| 
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| 	ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops);
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| 	if (IS_ERR(ldev)) {
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| 		dev_err(dev, "failed to register LCD\n");
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| 		return PTR_ERR(ldev);
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| 	}
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| 	ldev->props.max_contrast = 0x0ff;
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| 	data->lcd_contrast = 0xe5;
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| 	data->lcd = ldev;
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| 	picolcd_set_contrast(ldev, 0xe5);
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| 	return 0;
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| }
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| 
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| void picolcd_exit_lcd(struct picolcd_data *data)
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| {
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| 	struct lcd_device *ldev = data->lcd;
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| 
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| 	data->lcd = NULL;
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| 	lcd_device_unregister(ldev);
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| }
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| 
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| int picolcd_resume_lcd(struct picolcd_data *data)
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| {
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| 	if (!data->lcd)
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| 		return 0;
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| 	return picolcd_set_contrast(data->lcd, data->lcd_contrast);
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| }
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| 
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