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![Markus Elfring](/assets/img/avatar_default.png)
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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#include <linux/hid.h>
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#include <linux/fb.h>
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#include <linux/lcd.h>
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#include "hid-picolcd.h"
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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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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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if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
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return -ENODEV;
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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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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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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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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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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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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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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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data->lcd = NULL;
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lcd_device_unregister(ldev);
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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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