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 int 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	return 0;
76}
77
78static struct platform_driver samsungq10_driver = {
79	.driver		= {
80		.name	= KBUILD_MODNAME,
81	},
82	.probe		= samsungq10_probe,
83	.remove		= samsungq10_remove,
84};
85
86static struct platform_device *samsungq10_device;
87
88static int __init dmi_check_callback(const struct dmi_system_id *id)
89{
90	printk(KERN_INFO KBUILD_MODNAME ": found model '%s'\n", id->ident);
91	return 1;
92}
93
94static const struct dmi_system_id samsungq10_dmi_table[] __initconst = {
95	{
96		.ident = "Samsung Q10",
97		.matches = {
98			DMI_MATCH(DMI_SYS_VENDOR, "Samsung"),
99			DMI_MATCH(DMI_PRODUCT_NAME, "SQ10"),
100		},
101		.callback = dmi_check_callback,
102	},
103	{
104		.ident = "Samsung Q20",
105		.matches = {
106			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
107			DMI_MATCH(DMI_PRODUCT_NAME, "SENS Q20"),
108		},
109		.callback = dmi_check_callback,
110	},
111	{
112		.ident = "Samsung Q25",
113		.matches = {
114			DMI_MATCH(DMI_SYS_VENDOR, "SAMSUNG Electronics"),
115			DMI_MATCH(DMI_PRODUCT_NAME, "NQ25"),
116		},
117		.callback = dmi_check_callback,
118	},
119	{
120		.ident = "Dell Latitude X200",
121		.matches = {
122			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
123			DMI_MATCH(DMI_PRODUCT_NAME, "X200"),
124		},
125		.callback = dmi_check_callback,
126	},
127	{ },
128};
129MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
130
131static int __init samsungq10_init(void)
132{
133	if (!force && !dmi_check_system(samsungq10_dmi_table))
134		return -ENODEV;
135
136	ec_handle = ec_get_handle();
137
138	if (!ec_handle)
139		return -ENODEV;
140
141	samsungq10_device = platform_create_bundle(&samsungq10_driver,
142						   samsungq10_probe,
143						   NULL, 0, NULL, 0);
144
145	return PTR_ERR_OR_ZERO(samsungq10_device);
146}
147
148static void __exit samsungq10_exit(void)
149{
150	platform_device_unregister(samsungq10_device);
151	platform_driver_unregister(&samsungq10_driver);
152}
153
154module_init(samsungq10_init);
155module_exit(samsungq10_exit);
156
157MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
158MODULE_DESCRIPTION("Samsung Q10 Driver");
159MODULE_LICENSE("GPL");
160