1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  Driver for Samsung Q10 and related laptops: controls the backlight
4 *
5 *  Copyright (c) 2011 Frederick van der Wyck <fvanderwyck@gmail.com>
6 */
7
8#include <linux/module.h>
9#include <linux/kernel.h>
10#include <linux/init.h>
11#include <linux/platform_device.h>
12#include <linux/backlight.h>
13#include <linux/dmi.h>
14#include <linux/acpi.h>
15
16#define SAMSUNGQ10_BL_MAX_INTENSITY 7
17
18static acpi_handle ec_handle;
19
20static bool force;
21module_param(force, bool, 0);
22MODULE_PARM_DESC(force,
23		"Disable the DMI check and force the driver to be loaded");
24
25static int samsungq10_bl_set_intensity(struct backlight_device *bd)
26{
27
28	acpi_status status;
29	int i;
30
31	for (i = 0; i < SAMSUNGQ10_BL_MAX_INTENSITY; i++) {
32		status = acpi_evaluate_object(ec_handle, "_Q63", NULL, NULL);
33		if (ACPI_FAILURE(status))
34			return -EIO;
35	}
36	for (i = 0; i < bd->props.brightness; i++) {
37		status = acpi_evaluate_object(ec_handle, "_Q64", NULL, NULL);
38		if (ACPI_FAILURE(status))
39			return -EIO;
40	}
41
42	return 0;
43}
44
45static const struct backlight_ops samsungq10_bl_ops = {
46	.update_status	= samsungq10_bl_set_intensity,
47};
48
49static int samsungq10_probe(struct platform_device *pdev)
50{
51
52	struct backlight_properties props;
53	struct backlight_device *bd;
54
55	memset(&props, 0, sizeof(struct backlight_properties));
56	props.type = BACKLIGHT_PLATFORM;
57	props.max_brightness = SAMSUNGQ10_BL_MAX_INTENSITY;
58	bd = backlight_device_register("samsung", &pdev->dev, NULL,
59				       &samsungq10_bl_ops, &props);
60	if (IS_ERR(bd))
61		return PTR_ERR(bd);
62
63	platform_set_drvdata(pdev, bd);
64
65	return 0;
66}
67
68static void samsungq10_remove(struct platform_device *pdev)
69{
70
71	struct backlight_device *bd = platform_get_drvdata(pdev);
72
73	backlight_device_unregister(bd);
74}
75
76static struct platform_driver samsungq10_driver = {
77	.driver		= {
78		.name	= KBUILD_MODNAME,
79	},
80	.probe		= samsungq10_probe,
81	.remove_new	= samsungq10_remove,
82};
83
84static struct platform_device *samsungq10_device;
85
86static int __init dmi_check_callback(const struct dmi_system_id *id)
87{
88	printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
89	return 1;
90}
91
92static const struct dmi_system_id samsungq10_dmi_table[] __initconst = {
93	{
94		.ident = "Samsung Q10",
95		.matches = {
96			DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
97			DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
98		},
99		.callback = dmi_check_callback,
100	},
101	{
102		.ident = "Samsung Q20",
103		.matches = {
104			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
105			DMI_MATCH(DMI_PRODUCT_NAME, "SENS Q20"),
106		},
107		.callback = dmi_check_callback,
108	},
109	{
110		.ident = "Samsung Q25",
111		.matches = {
112			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
113			DMI_MATCH(DMI_PRODUCT_NAME, "NQ25"),
114		},
115		.callback = dmi_check_callback,
116	},
117	{
118		.ident = "Dell Latitude X200",
119		.matches = {
120			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
121			DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
122		},
123		.callback = dmi_check_callback,
124	},
125	{ },
126};
127MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
128
129static int __init samsungq10_init(void)
130{
131	if (!force && !dmi_check_system(samsungq10_dmi_table))
132		return -ENODEV;
133
134	ec_handle = ec_get_handle();
135
136	if (!ec_handle)
137		return -ENODEV;
138
139	samsungq10_device = platform_create_bundle(&samsungq10_driver,
140						   samsungq10_probe,
141						   NULL, 0, NULL, 0);
142
143	return PTR_ERR_OR_ZERO(samsungq10_device);
144}
145
146static void __exit samsungq10_exit(void)
147{
148	platform_device_unregister(samsungq10_device);
149	platform_driver_unregister(&samsungq10_driver);
150}
151
152module_init(samsungq10_init);
153module_exit(samsungq10_exit);
154
155MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
156MODULE_DESCRIPTION("Samsung Q10 Driver");
157MODULE_LICENSE("GPL");
158