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
87static bool force;
88module_param(force, bool, 0);
89MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
90
91static DEFINE_SPINLOCK(io_lock);
92
93static struct input_dev *slidebar_input_dev;
94static struct platform_device *slidebar_platform_dev;
95
96static u8 slidebar_pos_get(void)
97{
98 u8 res;
99 unsigned long flags;
100
101 spin_lock_irqsave(&io_lock, flags);
102 outb(value: 0xf4, port: 0xff29);
103 outb(value: 0xbf, port: 0xff2a);
104 res = inb(port: 0xff2b);
105 spin_unlock_irqrestore(lock: &io_lock, flags);
106
107 return res;
108}
109
110static u8 slidebar_mode_get(void)
111{
112 u8 res;
113 unsigned long flags;
114
115 spin_lock_irqsave(&io_lock, flags);
116 outb(value: 0xf7, port: 0xff29);
117 outb(value: 0x8b, port: 0xff2a);
118 res = inb(port: 0xff2b);
119 spin_unlock_irqrestore(lock: &io_lock, flags);
120
121 return res;
122}
123
124static void slidebar_mode_set(u8 mode)
125{
126 unsigned long flags;
127
128 spin_lock_irqsave(&io_lock, flags);
129 outb(value: 0xf7, port: 0xff29);
130 outb(value: 0x8b, port: 0xff2a);
131 outb(value: mode, port: 0xff2b);
132 spin_unlock_irqrestore(lock: &io_lock, flags);
133}
134
135static 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(serio: port, data: 0xe0, flags: 0);
157 return false;
158 }
159
160 if (data & 0x80) {
161 input_report_key(dev: slidebar_input_dev, BTN_TOUCH, value: 0);
162 } else {
163 input_report_key(dev: slidebar_input_dev, BTN_TOUCH, value: 1);
164 input_report_abs(dev: slidebar_input_dev, ABS_X, value: slidebar_pos_get());
165 }
166 input_sync(dev: slidebar_input_dev);
167
168 return true;
169}
170
171static ssize_t show_slidebar_mode(struct device *dev,
172 struct device_attribute *attr,
173 char *buf)
174{
175 return sprintf(buf, fmt: "%x\n", slidebar_mode_get());
176}
177
178static 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(s: buf, base: 0, res: &mode);
186 if (error)
187 return error;
188
189 slidebar_mode_set(mode);
190
191 return count;
192}
193
194static DEVICE_ATTR(slidebar_mode, S_IWUSR | S_IRUGO,
195 show_slidebar_mode, store_slidebar_mode);
196
197static struct attribute *ideapad_attrs[] = {
198 &dev_attr_slidebar_mode.attr,
199 NULL
200};
201
202static struct attribute_group ideapad_attr_group = {
203 .attrs = ideapad_attrs
204};
205
206static const struct attribute_group *ideapad_attr_groups[] = {
207 &ideapad_attr_group,
208 NULL
209};
210
211static 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(dev: slidebar_input_dev, EV_KEY, BTN_TOUCH);
231 input_set_capability(dev: slidebar_input_dev, EV_ABS, ABS_X);
232 input_set_abs_params(dev: slidebar_input_dev, ABS_X, min: 0, max: 0xff, fuzz: 0, flat: 0);
233
234 err = i8042_install_filter(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
250err_remove_filter:
251 i8042_remove_filter(filter: slidebar_i8042_filter);
252err_free_dev:
253 input_free_device(dev: slidebar_input_dev);
254err_release_ports:
255 release_region(IDEAPAD_BASE, 3);
256 return err;
257}
258
259static void ideapad_remove(struct platform_device *pdev)
260{
261 i8042_remove_filter(filter: slidebar_i8042_filter);
262 input_unregister_device(slidebar_input_dev);
263 release_region(IDEAPAD_BASE, 3);
264}
265
266static struct platform_driver slidebar_drv = {
267 .driver = {
268 .name = "ideapad_slidebar",
269 },
270 .remove_new = ideapad_remove,
271};
272
273static int __init ideapad_dmi_check(const struct dmi_system_id *id)
274{
275 pr_info("Laptop model '%s'\n", id->ident);
276 return 1;
277}
278
279static const struct dmi_system_id ideapad_dmi[] __initconst = {
280 {
281 .ident = "Lenovo IdeaPad Y550",
282 .matches = {
283 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
284 DMI_MATCH(DMI_PRODUCT_NAME, "20017"),
285 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550")
286 },
287 .callback = ideapad_dmi_check
288 },
289 {
290 .ident = "Lenovo IdeaPad Y550P",
291 .matches = {
292 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
293 DMI_MATCH(DMI_PRODUCT_NAME, "20035"),
294 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550P")
295 },
296 .callback = ideapad_dmi_check
297 },
298 { NULL, }
299};
300MODULE_DEVICE_TABLE(dmi, ideapad_dmi);
301
302static int __init slidebar_init(void)
303{
304 int err;
305
306 if (!force && !dmi_check_system(list: ideapad_dmi)) {
307 pr_err("DMI does not match\n");
308 return -ENODEV;
309 }
310
311 slidebar_platform_dev = platform_device_alloc(name: "ideapad_slidebar", id: -1);
312 if (!slidebar_platform_dev) {
313 pr_err("Not enough memory\n");
314 return -ENOMEM;
315 }
316
317 slidebar_platform_dev->dev.groups = ideapad_attr_groups;
318
319 err = platform_device_add(pdev: slidebar_platform_dev);
320 if (err) {
321 pr_err("Failed to register platform device\n");
322 goto err_free_dev;
323 }
324
325 err = platform_driver_probe(&slidebar_drv, ideapad_probe);
326 if (err) {
327 pr_err("Failed to register platform driver\n");
328 goto err_delete_dev;
329 }
330
331 return 0;
332
333err_delete_dev:
334 platform_device_del(pdev: slidebar_platform_dev);
335err_free_dev:
336 platform_device_put(pdev: slidebar_platform_dev);
337 return err;
338}
339
340static void __exit slidebar_exit(void)
341{
342 platform_device_unregister(slidebar_platform_dev);
343 platform_driver_unregister(&slidebar_drv);
344}
345
346module_init(slidebar_init);
347module_exit(slidebar_exit);
348
349MODULE_AUTHOR("Andrey Moiseev <o2g.org.ru@gmail.com>");
350MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
351MODULE_LICENSE("GPL");
352

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source code of linux/drivers/input/misc/ideapad_slidebar.c