1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Input driver for slidebars on some Lenovo IdeaPad laptops
4  *
5  * Copyright (C) 2013 Andrey Moiseev <o2g.org.ru@gmail.com>
6  *
7  * Reverse-engineered from Lenovo SlideNav software (SBarHook.dll).
8  *
9  * Trademarks are the property of their respective owners.
10  */
11 
12 /*
13  * Currently tested and works on:
14  *	Lenovo IdeaPad Y550
15  *	Lenovo IdeaPad Y550P
16  *
17  * Other models can be added easily. To test,
18  * load with 'force' parameter set 'true'.
19  *
20  * LEDs blinking and input mode are managed via sysfs,
21  * (hex, unsigned byte value):
22  * /sys/devices/platform/ideapad_slidebar/slidebar_mode
23  *
24  * The value is in byte range, however, I only figured out
25  * how bits 0b10011001 work. Some other bits, probably,
26  * are meaningfull too.
27  *
28  * Possible states:
29  *
30  * STD_INT, ONMOV_INT, OFF_INT, LAST_POLL, OFF_POLL
31  *
32  * Meaning:
33  *           released      touched
34  * STD       'heartbeat'   lights follow the finger
35  * ONMOV     no lights     lights follow the finger
36  * LAST      at last pos   lights follow the finger
37  * OFF       no lights     no lights
38  *
39  * INT       all input events are generated, interrupts are used
40  * POLL      no input events by default, to get them,
41  *	     send 0b10000000 (read below)
42  *
43  * Commands: write
44  *
45  * All      |  0b01001 -> STD_INT
46  * possible |  0b10001 -> ONMOV_INT
47  * states   |  0b01000 -> OFF_INT
48  *
49  *                      |  0b0 -> LAST_POLL
50  * STD_INT or ONMOV_INT |
51  *                      |  0b1 -> STD_INT
52  *
53  *                      |  0b0 -> OFF_POLL
54  * OFF_INT or OFF_POLL  |
55  *                      |  0b1 -> OFF_INT
56  *
57  * Any state |   0b10000000 ->  if the slidebar has updated data,
58  *				produce one input event (last position),
59  *				switch to respective POLL mode
60  *				(like 0x0), if not in POLL mode yet.
61  *
62  * Get current state: read
63  *
64  * masked by 0x11 read value means:
65  *
66  * 0x00   LAST
67  * 0x01   STD
68  * 0x10   OFF
69  * 0x11   ONMOV
70  */
71 
72 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
73 
74 #include <linux/module.h>
75 #include <linux/kernel.h>
76 #include <linux/dmi.h>
77 #include <linux/spinlock.h>
78 #include <linux/platform_device.h>
79 #include <linux/input.h>
80 #include <linux/io.h>
81 #include <linux/ioport.h>
82 #include <linux/i8042.h>
83 #include <linux/serio.h>
84 
85 #define IDEAPAD_BASE	0xff29
86 
87 static bool force;
88 module_param(force, bool, 0);
89 MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
90 
91 static DEFINE_SPINLOCK(io_lock);
92 
93 static struct input_dev *slidebar_input_dev;
94 static struct platform_device *slidebar_platform_dev;
95 
96 static u8 slidebar_pos_get(void)
97 {
98 	u8 res;
99 	unsigned long flags;
100 
101 	spin_lock_irqsave(&io_lock, flags);
102 	outb(0xf4, 0xff29);
103 	outb(0xbf, 0xff2a);
104 	res = inb(0xff2b);
105 	spin_unlock_irqrestore(&io_lock, flags);
106 
107 	return res;
108 }
109 
110 static u8 slidebar_mode_get(void)
111 {
112 	u8 res;
113 	unsigned long flags;
114 
115 	spin_lock_irqsave(&io_lock, flags);
116 	outb(0xf7, 0xff29);
117 	outb(0x8b, 0xff2a);
118 	res = inb(0xff2b);
119 	spin_unlock_irqrestore(&io_lock, flags);
120 
121 	return res;
122 }
123 
124 static void slidebar_mode_set(u8 mode)
125 {
126 	unsigned long flags;
127 
128 	spin_lock_irqsave(&io_lock, flags);
129 	outb(0xf7, 0xff29);
130 	outb(0x8b, 0xff2a);
131 	outb(mode, 0xff2b);
132 	spin_unlock_irqrestore(&io_lock, flags);
133 }
134 
135 static bool slidebar_i8042_filter(unsigned char data, unsigned char str,
136 				  struct serio *port)
137 {
138 	static bool extended = false;
139 
140 	/* We are only interested in data coming form KBC port */
141 	if (str & I8042_STR_AUXDATA)
142 		return false;
143 
144 	/* Scancodes: e03b on move, e0bb on release. */
145 	if (data == 0xe0) {
146 		extended = true;
147 		return true;
148 	}
149 
150 	if (!extended)
151 		return false;
152 
153 	extended = false;
154 
155 	if (likely((data & 0x7f) != 0x3b)) {
156 		serio_interrupt(port, 0xe0, 0);
157 		return false;
158 	}
159 
160 	if (data & 0x80) {
161 		input_report_key(slidebar_input_dev, BTN_TOUCH, 0);
162 	} else {
163 		input_report_key(slidebar_input_dev, BTN_TOUCH, 1);
164 		input_report_abs(slidebar_input_dev, ABS_X, slidebar_pos_get());
165 	}
166 	input_sync(slidebar_input_dev);
167 
168 	return true;
169 }
170 
171 static ssize_t show_slidebar_mode(struct device *dev,
172 				  struct device_attribute *attr,
173 				  char *buf)
174 {
175 	return sprintf(buf, "%x\n", slidebar_mode_get());
176 }
177 
178 static ssize_t store_slidebar_mode(struct device *dev,
179 				   struct device_attribute *attr,
180 				   const char *buf, size_t count)
181 {
182 	u8 mode;
183 	int error;
184 
185 	error = kstrtou8(buf, 0, &mode);
186 	if (error)
187 		return error;
188 
189 	slidebar_mode_set(mode);
190 
191 	return count;
192 }
193 
194 static DEVICE_ATTR(slidebar_mode, S_IWUSR | S_IRUGO,
195 		   show_slidebar_mode, store_slidebar_mode);
196 
197 static struct attribute *ideapad_attrs[] = {
198 	&dev_attr_slidebar_mode.attr,
199 	NULL
200 };
201 
202 static struct attribute_group ideapad_attr_group = {
203 	.attrs = ideapad_attrs
204 };
205 
206 static const struct attribute_group *ideapad_attr_groups[] = {
207 	&ideapad_attr_group,
208 	NULL
209 };
210 
211 static int __init ideapad_probe(struct platform_device* pdev)
212 {
213 	int err;
214 
215 	if (!request_region(IDEAPAD_BASE, 3, "ideapad_slidebar")) {
216 		dev_err(&pdev->dev, "IO ports are busy\n");
217 		return -EBUSY;
218 	}
219 
220 	slidebar_input_dev = input_allocate_device();
221 	if (!slidebar_input_dev) {
222 		dev_err(&pdev->dev, "Failed to allocate input device\n");
223 		err = -ENOMEM;
224 		goto err_release_ports;
225 	}
226 
227 	slidebar_input_dev->name = "IdeaPad Slidebar";
228 	slidebar_input_dev->id.bustype = BUS_HOST;
229 	slidebar_input_dev->dev.parent = &pdev->dev;
230 	input_set_capability(slidebar_input_dev, EV_KEY, BTN_TOUCH);
231 	input_set_capability(slidebar_input_dev, EV_ABS, ABS_X);
232 	input_set_abs_params(slidebar_input_dev, ABS_X, 0, 0xff, 0, 0);
233 
234 	err = i8042_install_filter(slidebar_i8042_filter);
235 	if (err) {
236 		dev_err(&pdev->dev,
237 			"Failed to install i8042 filter: %d\n", err);
238 		goto err_free_dev;
239 	}
240 
241 	err = input_register_device(slidebar_input_dev);
242 	if (err) {
243 		dev_err(&pdev->dev,
244 			"Failed to register input device: %d\n", err);
245 		goto err_remove_filter;
246 	}
247 
248 	return 0;
249 
250 err_remove_filter:
251 	i8042_remove_filter(slidebar_i8042_filter);
252 err_free_dev:
253 	input_free_device(slidebar_input_dev);
254 err_release_ports:
255 	release_region(IDEAPAD_BASE, 3);
256 	return err;
257 }
258 
259 static int ideapad_remove(struct platform_device *pdev)
260 {
261 	i8042_remove_filter(slidebar_i8042_filter);
262 	input_unregister_device(slidebar_input_dev);
263 	release_region(IDEAPAD_BASE, 3);
264 
265 	return 0;
266 }
267 
268 static struct platform_driver slidebar_drv = {
269 	.driver = {
270 		.name = "ideapad_slidebar",
271 	},
272 	.remove = ideapad_remove,
273 };
274 
275 static int __init ideapad_dmi_check(const struct dmi_system_id *id)
276 {
277 	pr_info("Laptop model '%s'\n", id->ident);
278 	return 1;
279 }
280 
281 static const struct dmi_system_id ideapad_dmi[] __initconst = {
282 	{
283 		.ident = "Lenovo IdeaPad Y550",
284 		.matches = {
285 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
286 			DMI_MATCH(DMI_PRODUCT_NAME, "20017"),
287 			DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550")
288 		},
289 		.callback = ideapad_dmi_check
290 	},
291 	{
292 		.ident = "Lenovo IdeaPad Y550P",
293 		.matches = {
294 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
295 			DMI_MATCH(DMI_PRODUCT_NAME, "20035"),
296 			DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550P")
297 		},
298 		.callback = ideapad_dmi_check
299 	},
300 	{ NULL, }
301 };
302 MODULE_DEVICE_TABLE(dmi, ideapad_dmi);
303 
304 static int __init slidebar_init(void)
305 {
306 	int err;
307 
308 	if (!force && !dmi_check_system(ideapad_dmi)) {
309 		pr_err("DMI does not match\n");
310 		return -ENODEV;
311 	}
312 
313 	slidebar_platform_dev = platform_device_alloc("ideapad_slidebar", -1);
314 	if (!slidebar_platform_dev) {
315 		pr_err("Not enough memory\n");
316 		return -ENOMEM;
317 	}
318 
319 	slidebar_platform_dev->dev.groups = ideapad_attr_groups;
320 
321 	err = platform_device_add(slidebar_platform_dev);
322 	if (err) {
323 		pr_err("Failed to register platform device\n");
324 		goto err_free_dev;
325 	}
326 
327 	err = platform_driver_probe(&slidebar_drv, ideapad_probe);
328 	if (err) {
329 		pr_err("Failed to register platform driver\n");
330 		goto err_delete_dev;
331 	}
332 
333 	return 0;
334 
335 err_delete_dev:
336 	platform_device_del(slidebar_platform_dev);
337 err_free_dev:
338 	platform_device_put(slidebar_platform_dev);
339 	return err;
340 }
341 
342 static void __exit slidebar_exit(void)
343 {
344 	platform_device_unregister(slidebar_platform_dev);
345 	platform_driver_unregister(&slidebar_drv);
346 }
347 
348 module_init(slidebar_init);
349 module_exit(slidebar_exit);
350 
351 MODULE_AUTHOR("Andrey Moiseev <o2g.org.ru@gmail.com>");
352 MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
353 MODULE_LICENSE("GPL");
354