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
slidebar_pos_get(void)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
slidebar_mode_get(void)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
slidebar_mode_set(u8 mode)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
slidebar_i8042_filter(unsigned char data,unsigned char str,struct serio * port)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
show_slidebar_mode(struct device * dev,struct device_attribute * attr,char * buf)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
store_slidebar_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)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
ideapad_probe(struct platform_device * pdev)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
ideapad_remove(struct platform_device * pdev)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
ideapad_dmi_check(const struct dmi_system_id * id)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
slidebar_init(void)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
slidebar_exit(void)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