tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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 */
20static 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
26static 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
44static const struct lcd_ops picolcd_lcdops = {
45 .get_contrast = picolcd_get_contrast,
46 .set_contrast = picolcd_set_contrast,
47};
48
49int picolcd_init_lcd(struct picolcd_data *data, struct hid_report *report)
50{
51 struct device *dev = &data->hdev->dev;
52 struct lcd_device *ldev;
53
54 if (!report)
55 return -ENODEV;
56 if (report->maxfield != 1 || report->field[0]->report_count != 1 ||
57 report->field[0]->report_size != 8) {
58 dev_err(dev, "unsupported CONTRAST report");
59 return -EINVAL;
60 }
61
62 ldev = lcd_device_register(dev_name(dev), dev, data, &picolcd_lcdops);
63 if (IS_ERR(ldev)) {
64 dev_err(dev, "failed to register LCD\n");
65 return PTR_ERR(ldev);
66 }
67 ldev->props.max_contrast = 0x0ff;
68 data->lcd_contrast = 0xe5;
69 data->lcd = ldev;
70 picolcd_set_contrast(ldev, 0xe5);
71 return 0;
72}
73
74void picolcd_exit_lcd(struct picolcd_data *data)
75{
76 struct lcd_device *ldev = data->lcd;
77
78 data->lcd = NULL;
79 lcd_device_unregister(ldev);
80}
81
82int picolcd_resume_lcd(struct picolcd_data *data)
83{
84 if (!data->lcd)
85 return 0;
86 return picolcd_set_contrast(data->lcd, data->lcd_contrast);
87}
88