GNU Linux-libre 4.4.289-gnu1
[releases.git] / drivers / hid / hid-picolcd_lcd.c
1 /***************************************************************************
2  *   Copyright (C) 2010-2012 by Bruno PrĂ©mont <bonbons@linux-vserver.org>  *
3  *                                                                         *
4  *   Based on Logitech G13 driver (v0.4)                                   *
5  *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
6  *                                                                         *
7  *   This program is free software: you can redistribute it and/or modify  *
8  *   it under the terms of the GNU General Public License as published by  *
9  *   the Free Software Foundation, version 2 of the License.               *
10  *                                                                         *
11  *   This driver is distributed in the hope that it will be useful, but    *
12  *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
13  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU      *
14  *   General Public License for more details.                              *
15  *                                                                         *
16  *   You should have received a copy of the GNU General Public License     *
17  *   along with this software. If not see <http://www.gnu.org/licenses/>.  *
18  ***************************************************************************/
19
20 #include <linux/hid.h>
21
22 #include <linux/fb.h>
23 #include <linux/lcd.h>
24
25 #include "hid-picolcd.h"
26
27 /*
28  * lcd class device
29  */
30 static int picolcd_get_contrast(struct lcd_device *ldev)
31 {
32         struct picolcd_data *data = lcd_get_data(ldev);
33         return data->lcd_contrast;
34 }
35
36 static int picolcd_set_contrast(struct lcd_device *ldev, int contrast)
37 {
38         struct picolcd_data *data = lcd_get_data(ldev);
39         struct hid_report *report = picolcd_out_report(REPORT_CONTRAST, data->hdev);
40         unsigned long flags;
41
42         if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
43                 return -ENODEV;
44
45         data->lcd_contrast = contrast & 0x0ff;
46         spin_lock_irqsave(&data->lock, flags);
47         hid_set_field(report->field[0], 0, data->lcd_contrast);
48         if (!(data->status & PICOLCD_FAILED))
49                 hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
50         spin_unlock_irqrestore(&data->lock, flags);
51         return 0;
52 }
53
54 static int picolcd_check_lcd_fb(struct lcd_device *ldev, struct fb_info *fb)
55 {
56         return fb && fb == picolcd_fbinfo((struct picolcd_data *)lcd_get_data(ldev));
57 }
58
59 static struct lcd_ops picolcd_lcdops = {
60         .get_contrast   = picolcd_get_contrast,
61         .set_contrast   = picolcd_set_contrast,
62         .check_fb       = picolcd_check_lcd_fb,
63 };
64
65 int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report)
66 {
67         struct device *dev = &data->hdev->dev;
68         struct lcd_device *ldev;
69
70         if (!report)
71                 return -ENODEV;
72         if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
73                         report->field[0]->report_size != 8) {
74                 dev_err(dev, "unsupported CONTRAST report");
75                 return -EINVAL;
76         }
77
78         ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops);
79         if (IS_ERR(ldev)) {
80                 dev_err(dev, "failed to register LCD\n");
81                 return PTR_ERR(ldev);
82         }
83         ldev->props.max_contrast = 0x0ff;
84         data->lcd_contrast = 0xe5;
85         data->lcd = ldev;
86         picolcd_set_contrast(ldev, 0xe5);
87         return 0;
88 }
89
90 void picolcd_exit_lcd(struct picolcd_data *data)
91 {
92         struct lcd_device *ldev = data->lcd;
93
94         data->lcd = NULL;
95         lcd_device_unregister(ldev);
96 }
97
98 int picolcd_resume_lcd(struct picolcd_data *data)
99 {
100         if (!data->lcd)
101                 return 0;
102         return picolcd_set_contrast(data->lcd, data->lcd_contrast);
103 }
104