1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  Backlight Driver for the KB3886 Backlight
4  *
5  *  Copyright (c) 2007-2008 Claudio Nieder
6  *
7  *  Based on corgi_bl.c by Richard Purdie and kb3886 driver by Robert Woerle
8  */
9 
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/platform_device.h>
14 #include <linux/mutex.h>
15 #include <linux/fb.h>
16 #include <linux/backlight.h>
17 #include <linux/delay.h>
18 #include <linux/dmi.h>
19 
20 #define KB3886_PARENT 0x64
21 #define KB3886_IO 0x60
22 #define KB3886_ADC_DAC_PWM 0xC4
23 #define KB3886_PWM0_WRITE 0x81
24 #define KB3886_PWM0_READ 0x41
25 
26 static DEFINE_MUTEX(bl_mutex);
27 
28 static void kb3886_bl_set_intensity(int intensity)
29 {
30 	mutex_lock(&bl_mutex);
31 	intensity = intensity&0xff;
32 	outb(KB3886_ADC_DAC_PWM, KB3886_PARENT);
33 	usleep_range(10000, 11000);
34 	outb(KB3886_PWM0_WRITE, KB3886_IO);
35 	usleep_range(10000, 11000);
36 	outb(intensity, KB3886_IO);
37 	mutex_unlock(&bl_mutex);
38 }
39 
40 struct kb3886bl_machinfo {
41 	int max_intensity;
42 	int default_intensity;
43 	int limit_mask;
44 	void (*set_bl_intensity)(int intensity);
45 };
46 
47 static struct kb3886bl_machinfo kb3886_bl_machinfo = {
48 	.max_intensity = 0xff,
49 	.default_intensity = 0xa0,
50 	.limit_mask = 0x7f,
51 	.set_bl_intensity = kb3886_bl_set_intensity,
52 };
53 
54 static struct platform_device kb3886bl_device = {
55 	.name		= "kb3886-bl",
56 	.dev		= {
57 		.platform_data	= &kb3886_bl_machinfo,
58 	},
59 	.id		= -1,
60 };
61 
62 static struct platform_device *devices[] __initdata = {
63 	&kb3886bl_device,
64 };
65 
66 /*
67  * Back to driver
68  */
69 
70 static int kb3886bl_intensity;
71 static struct backlight_device *kb3886_backlight_device;
72 static struct kb3886bl_machinfo *bl_machinfo;
73 
74 static unsigned long kb3886bl_flags;
75 #define KB3886BL_SUSPENDED     0x01
76 
77 static const struct dmi_system_id kb3886bl_device_table[] __initconst = {
78 	{
79 		.ident = "Sahara Touch-iT",
80 		.matches = {
81 			DMI_MATCH(DMI_SYS_VENDOR, "SDV"),
82 			DMI_MATCH(DMI_PRODUCT_NAME, "iTouch T201"),
83 		},
84 	},
85 	{ }
86 };
87 
88 static int kb3886bl_send_intensity(struct backlight_device *bd)
89 {
90 	int intensity = backlight_get_brightness(bd);
91 
92 	if (kb3886bl_flags & KB3886BL_SUSPENDED)
93 		intensity = 0;
94 
95 	bl_machinfo->set_bl_intensity(intensity);
96 
97 	kb3886bl_intensity = intensity;
98 	return 0;
99 }
100 
101 #ifdef CONFIG_PM_SLEEP
102 static int kb3886bl_suspend(struct device *dev)
103 {
104 	struct backlight_device *bd = dev_get_drvdata(dev);
105 
106 	kb3886bl_flags |= KB3886BL_SUSPENDED;
107 	backlight_update_status(bd);
108 	return 0;
109 }
110 
111 static int kb3886bl_resume(struct device *dev)
112 {
113 	struct backlight_device *bd = dev_get_drvdata(dev);
114 
115 	kb3886bl_flags &= ~KB3886BL_SUSPENDED;
116 	backlight_update_status(bd);
117 	return 0;
118 }
119 #endif
120 
121 static SIMPLE_DEV_PM_OPS(kb3886bl_pm_ops, kb3886bl_suspend, kb3886bl_resume);
122 
123 static int kb3886bl_get_intensity(struct backlight_device *bd)
124 {
125 	return kb3886bl_intensity;
126 }
127 
128 static const struct backlight_ops kb3886bl_ops = {
129 	.get_brightness = kb3886bl_get_intensity,
130 	.update_status  = kb3886bl_send_intensity,
131 };
132 
133 static int kb3886bl_probe(struct platform_device *pdev)
134 {
135 	struct backlight_properties props;
136 	struct kb3886bl_machinfo *machinfo = dev_get_platdata(&pdev->dev);
137 
138 	bl_machinfo = machinfo;
139 	if (!machinfo->limit_mask)
140 		machinfo->limit_mask = -1;
141 
142 	memset(&props, 0, sizeof(struct backlight_properties));
143 	props.type = BACKLIGHT_RAW;
144 	props.max_brightness = machinfo->max_intensity;
145 	kb3886_backlight_device = devm_backlight_device_register(&pdev->dev,
146 							"kb3886-bl", &pdev->dev,
147 							NULL, &kb3886bl_ops,
148 							&props);
149 	if (IS_ERR(kb3886_backlight_device))
150 		return PTR_ERR(kb3886_backlight_device);
151 
152 	platform_set_drvdata(pdev, kb3886_backlight_device);
153 
154 	kb3886_backlight_device->props.power = FB_BLANK_UNBLANK;
155 	kb3886_backlight_device->props.brightness = machinfo->default_intensity;
156 	backlight_update_status(kb3886_backlight_device);
157 
158 	return 0;
159 }
160 
161 static struct platform_driver kb3886bl_driver = {
162 	.probe		= kb3886bl_probe,
163 	.driver		= {
164 		.name	= "kb3886-bl",
165 		.pm	= &kb3886bl_pm_ops,
166 	},
167 };
168 
169 static int __init kb3886_init(void)
170 {
171 	if (!dmi_check_system(kb3886bl_device_table))
172 		return -ENODEV;
173 
174 	platform_add_devices(devices, ARRAY_SIZE(devices));
175 	return platform_driver_register(&kb3886bl_driver);
176 }
177 
178 static void __exit kb3886_exit(void)
179 {
180 	platform_driver_unregister(&kb3886bl_driver);
181 }
182 
183 module_init(kb3886_init);
184 module_exit(kb3886_exit);
185 
186 MODULE_AUTHOR("Claudio Nieder <private@claudio.ch>");
187 MODULE_DESCRIPTION("Tabletkiosk Sahara Touch-iT Backlight Driver");
188 MODULE_LICENSE("GPL");
189 MODULE_ALIAS("dmi:*:svnSDV:pniTouchT201:*");
190