xref: /openbmc/linux/drivers/hid/hid-picolcd_lcd.c (revision 24c9d96d)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /***************************************************************************
3  *   Copyright (C) 2010-2012 by Bruno Prémont <bonbons@linux-vserver.org>  *
4  *                                                                         *
5  *   Based on Logitech G13 driver (v0.4)                                   *
6  *     Copyright (C) 2009 by Rick L. Vinyard, Jr. <rvinyard@cs.nmsu.edu>   *
7  *                                                                         *
8  ***************************************************************************/
9 
10 #include <linux/hid.h>
11 
12 #include <linux/fb.h>
13 #include <linux/lcd.h>
14 
15 #include "hid-picolcd.h"
16 
17 /*
18  * lcd class device
19  */
picolcd_get_contrast(struct lcd_device * ldev)20 static int picolcd_get_contrast(struct lcd_device *ldev)
21 {
22 	struct picolcd_data *data = lcd_get_data(ldev);
23 	return data->lcd_contrast;
24 }
25 
picolcd_set_contrast(struct lcd_device * ldev,int contrast)26 static int picolcd_set_contrast(struct lcd_device *ldev, int contrast)
27 {
28 	struct picolcd_data *data = lcd_get_data(ldev);
29 	struct hid_report *report = picolcd_out_report(REPORT_CONTRAST, data->hdev);
30 	unsigned long flags;
31 
32 	if (!report || report->maxfield != 1 || report->field[0]->report_count != 1)
33 		return -ENODEV;
34 
35 	data->lcd_contrast = contrast & 0x0ff;
36 	spin_lock_irqsave(&data->lock, flags);
37 	hid_set_field(report->field[0], 0, data->lcd_contrast);
38 	if (!(data->status & PICOLCD_FAILED))
39 		hid_hw_request(data->hdev, report, HID_REQ_SET_REPORT);
40 	spin_unlock_irqrestore(&data->lock, flags);
41 	return 0;
42 }
43 
picolcd_check_lcd_fb(struct lcd_device * ldev,struct fb_info * fb)44 static int picolcd_check_lcd_fb(struct lcd_device *ldev, struct fb_info *fb)
45 {
46 	return fb && fb == picolcd_fbinfo((struct picolcd_data *)lcd_get_data(ldev));
47 }
48 
49 static struct lcd_ops picolcd_lcdops = {
50 	.get_contrast   = picolcd_get_contrast,
51 	.set_contrast   = picolcd_set_contrast,
52 	.check_fb       = picolcd_check_lcd_fb,
53 };
54 
picolcd_init_lcd(struct picolcd_data * data,struct hid_report * report)55 int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report)
56 {
57 	struct device *dev = &data->hdev->dev;
58 	struct lcd_device *ldev;
59 
60 	if (!report)
61 		return -ENODEV;
62 	if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
63 			report->field[0]->report_size != 8) {
64 		dev_err(dev, "unsupported CONTRAST report");
65 		return -EINVAL;
66 	}
67 
68 	ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops);
69 	if (IS_ERR(ldev)) {
70 		dev_err(dev, "failed to register LCD\n");
71 		return PTR_ERR(ldev);
72 	}
73 	ldev->props.max_contrast = 0x0ff;
74 	data->lcd_contrast = 0xe5;
75 	data->lcd = ldev;
76 	picolcd_set_contrast(ldev, 0xe5);
77 	return 0;
78 }
79 
picolcd_exit_lcd(struct picolcd_data * data)80 void picolcd_exit_lcd(struct picolcd_data *data)
81 {
82 	struct lcd_device *ldev = data->lcd;
83 
84 	data->lcd = NULL;
85 	lcd_device_unregister(ldev);
86 }
87 
picolcd_resume_lcd(struct picolcd_data * data)88 int picolcd_resume_lcd(struct picolcd_data *data)
89 {
90 	if (!data->lcd)
91 		return 0;
92 	return picolcd_set_contrast(data->lcd, data->lcd_contrast);
93 }
94 
95