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(0xf4, 0xff29);
103	outb(0xbf, 0xff2a);
104	res = inb(0xff2b);
105	spin_unlock_irqrestore(&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(0xf7, 0xff29);
117	outb(0x8b, 0xff2a);
118	res = inb(0xff2b);
119	spin_unlock_irqrestore(&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(0xf7, 0xff29);
130	outb(0x8b, 0xff2a);
131	outb(mode, 0xff2b);
132	spin_unlock_irqrestore(&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(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
171static 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
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(buf, 0, &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(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
250err_remove_filter:
251	i8042_remove_filter(slidebar_i8042_filter);
252err_free_dev:
253	input_free_device(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(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(ideapad_dmi)) {
307		pr_err("DMI does not match\n");
308		return -ENODEV;
309	}
310
311	slidebar_platform_dev = platform_device_alloc("ideapad_slidebar", -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(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(slidebar_platform_dev);
335err_free_dev:
336	platform_device_put(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