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 meaningful 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 guard(spinlock_irqsave)(&io_lock);
99
100 outb(0xf4, 0xff29);
101 outb(0xbf, 0xff2a);
102 return inb(0xff2b);
103 }
104
slidebar_mode_get(void)105 static u8 slidebar_mode_get(void)
106 {
107 guard(spinlock_irqsave)(&io_lock);
108
109 outb(0xf7, 0xff29);
110 outb(0x8b, 0xff2a);
111 return inb(0xff2b);
112 }
113
slidebar_mode_set(u8 mode)114 static void slidebar_mode_set(u8 mode)
115 {
116 guard(spinlock_irqsave)(&io_lock);
117
118 outb(0xf7, 0xff29);
119 outb(0x8b, 0xff2a);
120 outb(mode, 0xff2b);
121 }
122
slidebar_i8042_filter(unsigned char data,unsigned char str,struct serio * port)123 static bool slidebar_i8042_filter(unsigned char data, unsigned char str,
124 struct serio *port)
125 {
126 static bool extended = false;
127
128 /* We are only interested in data coming form KBC port */
129 if (str & I8042_STR_AUXDATA)
130 return false;
131
132 /* Scancodes: e03b on move, e0bb on release. */
133 if (data == 0xe0) {
134 extended = true;
135 return true;
136 }
137
138 if (!extended)
139 return false;
140
141 extended = false;
142
143 if (likely((data & 0x7f) != 0x3b)) {
144 serio_interrupt(port, 0xe0, 0);
145 return false;
146 }
147
148 if (data & 0x80) {
149 input_report_key(slidebar_input_dev, BTN_TOUCH, 0);
150 } else {
151 input_report_key(slidebar_input_dev, BTN_TOUCH, 1);
152 input_report_abs(slidebar_input_dev, ABS_X, slidebar_pos_get());
153 }
154 input_sync(slidebar_input_dev);
155
156 return true;
157 }
158
show_slidebar_mode(struct device * dev,struct device_attribute * attr,char * buf)159 static ssize_t show_slidebar_mode(struct device *dev,
160 struct device_attribute *attr,
161 char *buf)
162 {
163 return sprintf(buf, "%x\n", slidebar_mode_get());
164 }
165
store_slidebar_mode(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)166 static ssize_t store_slidebar_mode(struct device *dev,
167 struct device_attribute *attr,
168 const char *buf, size_t count)
169 {
170 u8 mode;
171 int error;
172
173 error = kstrtou8(buf, 0, &mode);
174 if (error)
175 return error;
176
177 slidebar_mode_set(mode);
178
179 return count;
180 }
181
182 static DEVICE_ATTR(slidebar_mode, S_IWUSR | S_IRUGO,
183 show_slidebar_mode, store_slidebar_mode);
184
185 static struct attribute *ideapad_attrs[] = {
186 &dev_attr_slidebar_mode.attr,
187 NULL
188 };
189
190 static struct attribute_group ideapad_attr_group = {
191 .attrs = ideapad_attrs
192 };
193
194 static const struct attribute_group *ideapad_attr_groups[] = {
195 &ideapad_attr_group,
196 NULL
197 };
198
ideapad_probe(struct platform_device * pdev)199 static int __init ideapad_probe(struct platform_device* pdev)
200 {
201 int err;
202
203 if (!request_region(IDEAPAD_BASE, 3, "ideapad_slidebar")) {
204 dev_err(&pdev->dev, "IO ports are busy\n");
205 return -EBUSY;
206 }
207
208 slidebar_input_dev = input_allocate_device();
209 if (!slidebar_input_dev) {
210 dev_err(&pdev->dev, "Failed to allocate input device\n");
211 err = -ENOMEM;
212 goto err_release_ports;
213 }
214
215 slidebar_input_dev->name = "IdeaPad Slidebar";
216 slidebar_input_dev->id.bustype = BUS_HOST;
217 slidebar_input_dev->dev.parent = &pdev->dev;
218 input_set_capability(slidebar_input_dev, EV_KEY, BTN_TOUCH);
219 input_set_capability(slidebar_input_dev, EV_ABS, ABS_X);
220 input_set_abs_params(slidebar_input_dev, ABS_X, 0, 0xff, 0, 0);
221
222 err = i8042_install_filter(slidebar_i8042_filter);
223 if (err) {
224 dev_err(&pdev->dev,
225 "Failed to install i8042 filter: %d\n", err);
226 goto err_free_dev;
227 }
228
229 err = input_register_device(slidebar_input_dev);
230 if (err) {
231 dev_err(&pdev->dev,
232 "Failed to register input device: %d\n", err);
233 goto err_remove_filter;
234 }
235
236 return 0;
237
238 err_remove_filter:
239 i8042_remove_filter(slidebar_i8042_filter);
240 err_free_dev:
241 input_free_device(slidebar_input_dev);
242 err_release_ports:
243 release_region(IDEAPAD_BASE, 3);
244 return err;
245 }
246
ideapad_remove(struct platform_device * pdev)247 static void ideapad_remove(struct platform_device *pdev)
248 {
249 i8042_remove_filter(slidebar_i8042_filter);
250 input_unregister_device(slidebar_input_dev);
251 release_region(IDEAPAD_BASE, 3);
252 }
253
254 static struct platform_driver slidebar_drv = {
255 .driver = {
256 .name = "ideapad_slidebar",
257 },
258 .remove = ideapad_remove,
259 };
260
ideapad_dmi_check(const struct dmi_system_id * id)261 static int __init ideapad_dmi_check(const struct dmi_system_id *id)
262 {
263 pr_info("Laptop model '%s'\n", id->ident);
264 return 1;
265 }
266
267 static const struct dmi_system_id ideapad_dmi[] __initconst = {
268 {
269 .ident = "Lenovo IdeaPad Y550",
270 .matches = {
271 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
272 DMI_MATCH(DMI_PRODUCT_NAME, "20017"),
273 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550")
274 },
275 .callback = ideapad_dmi_check
276 },
277 {
278 .ident = "Lenovo IdeaPad Y550P",
279 .matches = {
280 DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
281 DMI_MATCH(DMI_PRODUCT_NAME, "20035"),
282 DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550P")
283 },
284 .callback = ideapad_dmi_check
285 },
286 { NULL, }
287 };
288 MODULE_DEVICE_TABLE(dmi, ideapad_dmi);
289
slidebar_init(void)290 static int __init slidebar_init(void)
291 {
292 int err;
293
294 if (!force && !dmi_check_system(ideapad_dmi)) {
295 pr_err("DMI does not match\n");
296 return -ENODEV;
297 }
298
299 slidebar_platform_dev = platform_device_alloc("ideapad_slidebar", -1);
300 if (!slidebar_platform_dev) {
301 pr_err("Not enough memory\n");
302 return -ENOMEM;
303 }
304
305 slidebar_platform_dev->dev.groups = ideapad_attr_groups;
306
307 err = platform_device_add(slidebar_platform_dev);
308 if (err) {
309 pr_err("Failed to register platform device\n");
310 goto err_free_dev;
311 }
312
313 err = platform_driver_probe(&slidebar_drv, ideapad_probe);
314 if (err) {
315 pr_err("Failed to register platform driver\n");
316 goto err_delete_dev;
317 }
318
319 return 0;
320
321 err_delete_dev:
322 platform_device_del(slidebar_platform_dev);
323 err_free_dev:
324 platform_device_put(slidebar_platform_dev);
325 return err;
326 }
327
slidebar_exit(void)328 static void __exit slidebar_exit(void)
329 {
330 platform_device_unregister(slidebar_platform_dev);
331 platform_driver_unregister(&slidebar_drv);
332 }
333
334 module_init(slidebar_init);
335 module_exit(slidebar_exit);
336
337 MODULE_AUTHOR("Andrey Moiseev <o2g.org.ru@gmail.com>");
338 MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
339 MODULE_LICENSE("GPL");
340