ideapad_slidebar.c

  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
 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	guard(spinlock_irqsave)(&io_lock);
 99
100	outb(0xf4, 0xff29);
101	outb(0xbf, 0xff2a);
102	return inb(0xff2b);
103}
104
105static 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
114static 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
123static bool slidebar_i8042_filter(unsigned char data, unsigned char str,
124				  struct serio *port, void *context)
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
159static 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
166static 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
182static DEVICE_ATTR(slidebar_mode, S_IWUSR | S_IRUGO,
183		   show_slidebar_mode, store_slidebar_mode);
184
185static struct attribute *ideapad_attrs[] = {
186	&dev_attr_slidebar_mode.attr,
187	NULL
188};
189
190static struct attribute_group ideapad_attr_group = {
191	.attrs = ideapad_attrs
192};
193
194static const struct attribute_group *ideapad_attr_groups[] = {
195	&ideapad_attr_group,
196	NULL
197};
198
199static 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, NULL);
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
238err_remove_filter:
239	i8042_remove_filter(slidebar_i8042_filter);
240err_free_dev:
241	input_free_device(slidebar_input_dev);
242err_release_ports:
243	release_region(IDEAPAD_BASE, 3);
244	return err;
245}
246
247static 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
254static struct platform_driver slidebar_drv = {
255	.driver = {
256		.name = "ideapad_slidebar",
257	},
258	.remove = ideapad_remove,
259};
260
261static 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
267static 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};
288MODULE_DEVICE_TABLE(dmi, ideapad_dmi);
289
290static 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
321err_delete_dev:
322	platform_device_del(slidebar_platform_dev);
323err_free_dev:
324	platform_device_put(slidebar_platform_dev);
325	return err;
326}
327
328static void __exit slidebar_exit(void)
329{
330	platform_device_unregister(slidebar_platform_dev);
331	platform_driver_unregister(&slidebar_drv);
332}
333
334module_init(slidebar_init);
335module_exit(slidebar_exit);
336
337MODULE_AUTHOR("Andrey Moiseev <o2g.org.ru@gmail.com>");
338MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
339MODULE_LICENSE("GPL");