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
18 static acpi_handle ec_handle;
19
20 static bool force;
21 module_param(force, bool, 0);
22 MODULE_PARM_DESC(force,
23 "Disable the DMI check and force the driver to be loaded");
24
samsungq10_bl_set_intensity(struct backlight_device * bd)25 static 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
45 static const struct backlight_ops samsungq10_bl_ops = {
46 .update_status = samsungq10_bl_set_intensity,
47 };
48
samsungq10_probe(struct platform_device * pdev)49 static 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
samsungq10_remove(struct platform_device * pdev)68 static 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
76 static struct platform_driver samsungq10_driver = {
77 .driver = {
78 .name = KBUILD_MODNAME,
79 },
80 .probe = samsungq10_probe,
81 .remove_new = samsungq10_remove,
82 };
83
84 static struct platform_device *samsungq10_device;
85
dmi_check_callback(const struct dmi_system_id * id)86 static 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
92 static 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 };
127 MODULE_DEVICE_TABLE(dmi, samsungq10_dmi_table);
128
samsungq10_init(void)129 static 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
samsungq10_exit(void)146 static void __exit samsungq10_exit(void)
147 {
148 platform_device_unregister(samsungq10_device);
149 platform_driver_unregister(&samsungq10_driver);
150 }
151
152 module_init(samsungq10_init);
153 module_exit(samsungq10_exit);
154
155 MODULE_AUTHOR("Frederick van der Wyck <fvanderwyck@gmail.com>");
156 MODULE_DESCRIPTION("Samsung Q10 Driver");
157 MODULE_LICENSE("GPL");
158