1 /*
2  * Input driver for slidebars on some Lenovo IdeaPad laptops
3  *
4  * Copyright (C) 2013 Andrey Moiseev <o2g.org.ru@gmail.com>
5  *
6  * Reverse-engineered from Lenovo SlideNav software (SBarHook.dll).
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the Free
10  * Software Foundation; either version 2 of the License, or (at your option)
11  * any later version.
12  *
13  * Trademarks are the property of their respective owners.
14  */
15 
16 /*
17  * Currently tested and works on:
18  *	Lenovo IdeaPad Y550
19  *	Lenovo IdeaPad Y550P
20  *
21  * Other models can be added easily. To test,
22  * load with 'force' parameter set 'true'.
23  *
24  * LEDs blinking and input mode are managed via sysfs,
25  * (hex, unsigned byte value):
26  * /sys/devices/platform/ideapad_slidebar/slidebar_mode
27  *
28  * The value is in byte range, however, I only figured out
29  * how bits 0b10011001 work. Some other bits, probably,
30  * are meaningfull too.
31  *
32  * Possible states:
33  *
34  * STD_INT, ONMOV_INT, OFF_INT, LAST_POLL, OFF_POLL
35  *
36  * Meaning:
37  *           released      touched
38  * STD       'heartbeat'   lights follow the finger
39  * ONMOV     no lights     lights follow the finger
40  * LAST      at last pos   lights follow the finger
41  * OFF       no lights     no lights
42  *
43  * INT       all input events are generated, interrupts are used
44  * POLL      no input events by default, to get them,
45  *	     send 0b10000000 (read below)
46  *
47  * Commands: write
48  *
49  * All      |  0b01001 -> STD_INT
50  * possible |  0b10001 -> ONMOV_INT
51  * states   |  0b01000 -> OFF_INT
52  *
53  *                      |  0b0 -> LAST_POLL
54  * STD_INT or ONMOV_INT |
55  *                      |  0b1 -> STD_INT
56  *
57  *                      |  0b0 -> OFF_POLL
58  * OFF_INT or OFF_POLL  |
59  *                      |  0b1 -> OFF_INT
60  *
61  * Any state |   0b10000000 ->  if the slidebar has updated data,
62  *				produce one input event (last position),
63  *				switch to respective POLL mode
64  *				(like 0x0), if not in POLL mode yet.
65  *
66  * Get current state: read
67  *
68  * masked by 0x11 read value means:
69  *
70  * 0x00   LAST
71  * 0x01   STD
72  * 0x10   OFF
73  * 0x11   ONMOV
74  */
75 
76 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
77 
78 #include <linux/module.h>
79 #include <linux/kernel.h>
80 #include <linux/dmi.h>
81 #include <linux/spinlock.h>
82 #include <linux/platform_device.h>
83 #include <linux/input.h>
84 #include <linux/io.h>
85 #include <linux/ioport.h>
86 #include <linux/i8042.h>
87 #include <linux/serio.h>
88 
89 #define IDEAPAD_BASE	0xff29
90 
91 static bool force;
92 module_param(force, bool, 0);
93 MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
94 
95 static DEFINE_SPINLOCK(io_lock);
96 
97 static struct input_dev *slidebar_input_dev;
98 static struct platform_device *slidebar_platform_dev;
99 
100 static u8 slidebar_pos_get(void)
101 {
102 	u8 res;
103 	unsigned long flags;
104 
105 	spin_lock_irqsave(&io_lock, flags);
106 	outb(0xf4, 0xff29);
107 	outb(0xbf, 0xff2a);
108 	res = inb(0xff2b);
109 	spin_unlock_irqrestore(&io_lock, flags);
110 
111 	return res;
112 }
113 
114 static u8 slidebar_mode_get(void)
115 {
116 	u8 res;
117 	unsigned long flags;
118 
119 	spin_lock_irqsave(&io_lock, flags);
120 	outb(0xf7, 0xff29);
121 	outb(0x8b, 0xff2a);
122 	res = inb(0xff2b);
123 	spin_unlock_irqrestore(&io_lock, flags);
124 
125 	return res;
126 }
127 
128 static void slidebar_mode_set(u8 mode)
129 {
130 	unsigned long flags;
131 
132 	spin_lock_irqsave(&io_lock, flags);
133 	outb(0xf7, 0xff29);
134 	outb(0x8b, 0xff2a);
135 	outb(mode, 0xff2b);
136 	spin_unlock_irqrestore(&io_lock, flags);
137 }
138 
139 static bool slidebar_i8042_filter(unsigned char data, unsigned char str,
140 				  struct serio *port)
141 {
142 	static bool extended = false;
143 
144 	/* We are only interested in data coming form KBC port */
145 	if (str & I8042_STR_AUXDATA)
146 		return false;
147 
148 	/* Scancodes: e03b on move, e0bb on release. */
149 	if (data == 0xe0) {
150 		extended = true;
151 		return true;
152 	}
153 
154 	if (!extended)
155 		return false;
156 
157 	extended = false;
158 
159 	if (likely((data & 0x7f) != 0x3b)) {
160 		serio_interrupt(port, 0xe0, 0);
161 		return false;
162 	}
163 
164 	if (data & 0x80) {
165 		input_report_key(slidebar_input_dev, BTN_TOUCH, 0);
166 	} else {
167 		input_report_key(slidebar_input_dev, BTN_TOUCH, 1);
168 		input_report_abs(slidebar_input_dev, ABS_X, slidebar_pos_get());
169 	}
170 	input_sync(slidebar_input_dev);
171 
172 	return true;
173 }
174 
175 static ssize_t show_slidebar_mode(struct device *dev,
176 				  struct device_attribute *attr,
177 				  char *buf)
178 {
179 	return sprintf(buf, "%x\n", slidebar_mode_get());
180 }
181 
182 static ssize_t store_slidebar_mode(struct device *dev,
183 				   struct device_attribute *attr,
184 				   const char *buf, size_t count)
185 {
186 	u8 mode;
187 	int error;
188 
189 	error = kstrtou8(buf, 0, &mode);
190 	if (error)
191 		return error;
192 
193 	slidebar_mode_set(mode);
194 
195 	return count;
196 }
197 
198 static DEVICE_ATTR(slidebar_mode, S_IWUSR | S_IRUGO,
199 		   show_slidebar_mode, store_slidebar_mode);
200 
201 static struct attribute *ideapad_attrs[] = {
202 	&dev_attr_slidebar_mode.attr,
203 	NULL
204 };
205 
206 static struct attribute_group ideapad_attr_group = {
207 	.attrs = ideapad_attrs
208 };
209 
210 static const struct attribute_group *ideapad_attr_groups[] = {
211 	&ideapad_attr_group,
212 	NULL
213 };
214 
215 static int __init ideapad_probe(struct platform_device* pdev)
216 {
217 	int err;
218 
219 	if (!request_region(IDEAPAD_BASE, 3, "ideapad_slidebar")) {
220 		dev_err(&pdev->dev, "IO ports are busy\n");
221 		return -EBUSY;
222 	}
223 
224 	slidebar_input_dev = input_allocate_device();
225 	if (!slidebar_input_dev) {
226 		dev_err(&pdev->dev, "Failed to allocate input device\n");
227 		err = -ENOMEM;
228 		goto err_release_ports;
229 	}
230 
231 	slidebar_input_dev->name = "IdeaPad Slidebar";
232 	slidebar_input_dev->id.bustype = BUS_HOST;
233 	slidebar_input_dev->dev.parent = &pdev->dev;
234 	input_set_capability(slidebar_input_dev, EV_KEY, BTN_TOUCH);
235 	input_set_capability(slidebar_input_dev, EV_ABS, ABS_X);
236 	input_set_abs_params(slidebar_input_dev, ABS_X, 0, 0xff, 0, 0);
237 
238 	err = i8042_install_filter(slidebar_i8042_filter);
239 	if (err) {
240 		dev_err(&pdev->dev,
241 			"Failed to install i8042 filter: %d\n", err);
242 		goto err_free_dev;
243 	}
244 
245 	err = input_register_device(slidebar_input_dev);
246 	if (err) {
247 		dev_err(&pdev->dev,
248 			"Failed to register input device: %d\n", err);
249 		goto err_remove_filter;
250 	}
251 
252 	return 0;
253 
254 err_remove_filter:
255 	i8042_remove_filter(slidebar_i8042_filter);
256 err_free_dev:
257 	input_free_device(slidebar_input_dev);
258 err_release_ports:
259 	release_region(IDEAPAD_BASE, 3);
260 	return err;
261 }
262 
263 static int ideapad_remove(struct platform_device *pdev)
264 {
265 	i8042_remove_filter(slidebar_i8042_filter);
266 	input_unregister_device(slidebar_input_dev);
267 	release_region(IDEAPAD_BASE, 3);
268 
269 	return 0;
270 }
271 
272 static struct platform_driver slidebar_drv = {
273 	.driver = {
274 		.name = "ideapad_slidebar",
275 	},
276 	.remove = ideapad_remove,
277 };
278 
279 static int __init ideapad_dmi_check(const struct dmi_system_id *id)
280 {
281 	pr_info("Laptop model '%s'\n", id->ident);
282 	return 1;
283 }
284 
285 static const struct dmi_system_id ideapad_dmi[] __initconst = {
286 	{
287 		.ident = "Lenovo IdeaPad Y550",
288 		.matches = {
289 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
290 			DMI_MATCH(DMI_PRODUCT_NAME, "20017"),
291 			DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550")
292 		},
293 		.callback = ideapad_dmi_check
294 	},
295 	{
296 		.ident = "Lenovo IdeaPad Y550P",
297 		.matches = {
298 			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
299 			DMI_MATCH(DMI_PRODUCT_NAME, "20035"),
300 			DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550P")
301 		},
302 		.callback = ideapad_dmi_check
303 	},
304 	{ NULL, }
305 };
306 MODULE_DEVICE_TABLE(dmi, ideapad_dmi);
307 
308 static int __init slidebar_init(void)
309 {
310 	int err;
311 
312 	if (!force && !dmi_check_system(ideapad_dmi)) {
313 		pr_err("DMI does not match\n");
314 		return -ENODEV;
315 	}
316 
317 	slidebar_platform_dev = platform_device_alloc("ideapad_slidebar", -1);
318 	if (!slidebar_platform_dev) {
319 		pr_err("Not enough memory\n");
320 		return -ENOMEM;
321 	}
322 
323 	slidebar_platform_dev->dev.groups = ideapad_attr_groups;
324 
325 	err = platform_device_add(slidebar_platform_dev);
326 	if (err) {
327 		pr_err("Failed to register platform device\n");
328 		goto err_free_dev;
329 	}
330 
331 	err = platform_driver_probe(&slidebar_drv, ideapad_probe);
332 	if (err) {
333 		pr_err("Failed to register platform driver\n");
334 		goto err_delete_dev;
335 	}
336 
337 	return 0;
338 
339 err_delete_dev:
340 	platform_device_del(slidebar_platform_dev);
341 err_free_dev:
342 	platform_device_put(slidebar_platform_dev);
343 	return err;
344 }
345 
346 static void __exit slidebar_exit(void)
347 {
348 	platform_device_unregister(slidebar_platform_dev);
349 	platform_driver_unregister(&slidebar_drv);
350 }
351 
352 module_init(slidebar_init);
353 module_exit(slidebar_exit);
354 
355 MODULE_AUTHOR("Andrey Moiseev <o2g.org.ru@gmail.com>");
356 MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
357 MODULE_LICENSE("GPL");
358