1/*
  2 * Input driver for slidebars on some Lenovo IdeaPad laptops
  3 *
  4 * Copyright (C) 2013 Andrey Moiseev <o2g.org.ru@gmail.com>
  5 *
  6 * Reverse-engineered from Lenovo SlideNav software (SBarHook.dll).
  7 *
  8 * This program is free software; you can redistribute it and/or modify it
  9 * under the terms of the GNU General Public License as published by the Free
 10 * Software Foundation; either version 2 of the License, or (at your option)
 11 * any later version.
 12 *
 13 * Trademarks are the property of their respective owners.
 14 */
 15
 16/*
 17 * Currently tested and works on:
 18 *	Lenovo IdeaPad Y550
 19 *	Lenovo IdeaPad Y550P
 20 *
 21 * Other models can be added easily. To test,
 22 * load with 'force' parameter set 'true'.
 23 *
 24 * LEDs blinking and input mode are managed via sysfs,
 25 * (hex, unsigned byte value):
 26 * /sys/devices/platform/ideapad_slidebar/slidebar_mode
 27 *
 28 * The value is in byte range, however, I only figured out
 29 * how bits 0b10011001 work. Some other bits, probably,
 30 * are meaningfull too.
 31 *
 32 * Possible states:
 33 *
 34 * STD_INT, ONMOV_INT, OFF_INT, LAST_POLL, OFF_POLL
 35 *
 36 * Meaning:
 37 *           released      touched
 38 * STD       'heartbeat'   lights follow the finger
 39 * ONMOV     no lights     lights follow the finger
 40 * LAST      at last pos   lights follow the finger
 41 * OFF       no lights     no lights
 42 *
 43 * INT       all input events are generated, interrupts are used
 44 * POLL      no input events by default, to get them,
 45 *	     send 0b10000000 (read below)
 46 *
 47 * Commands: write
 48 *
 49 * All      |  0b01001 -> STD_INT
 50 * possible |  0b10001 -> ONMOV_INT
 51 * states   |  0b01000 -> OFF_INT
 52 *
 53 *                      |  0b0 -> LAST_POLL
 54 * STD_INT or ONMOV_INT |
 55 *                      |  0b1 -> STD_INT
 56 *
 57 *                      |  0b0 -> OFF_POLL
 58 * OFF_INT or OFF_POLL  |
 59 *                      |  0b1 -> OFF_INT
 60 *
 61 * Any state |   0b10000000 ->  if the slidebar has updated data,
 62 *				produce one input event (last position),
 63 *				switch to respective POLL mode
 64 *				(like 0x0), if not in POLL mode yet.
 65 *
 66 * Get current state: read
 67 *
 68 * masked by 0x11 read value means:
 69 *
 70 * 0x00   LAST
 71 * 0x01   STD
 72 * 0x10   OFF
 73 * 0x11   ONMOV
 74 */
 75
 76#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 77
 78#include <linux/module.h>
 79#include <linux/kernel.h>
 80#include <linux/dmi.h>
 81#include <linux/spinlock.h>
 82#include <linux/platform_device.h>
 83#include <linux/input.h>
 84#include <linux/io.h>
 85#include <linux/ioport.h>
 86#include <linux/i8042.h>
 87#include <linux/serio.h>
 88
 89#define IDEAPAD_BASE	0xff29
 90
 91static bool force;
 92module_param(force, bool, 0);
 93MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
 94
 95static DEFINE_SPINLOCK(io_lock);
 96
 97static struct input_dev *slidebar_input_dev;
 98static struct platform_device *slidebar_platform_dev;
 99
100static u8 slidebar_pos_get(void)
101{
102	u8 res;
103	unsigned long flags;
104
105	spin_lock_irqsave(&io_lock, flags);
106	outb(0xf4, 0xff29);
107	outb(0xbf, 0xff2a);
108	res = inb(0xff2b);
109	spin_unlock_irqrestore(&io_lock, flags);
110
111	return res;
112}
113
114static u8 slidebar_mode_get(void)
115{
116	u8 res;
117	unsigned long flags;
118
119	spin_lock_irqsave(&io_lock, flags);
120	outb(0xf7, 0xff29);
121	outb(0x8b, 0xff2a);
122	res = inb(0xff2b);
123	spin_unlock_irqrestore(&io_lock, flags);
124
125	return res;
126}
127
128static void slidebar_mode_set(u8 mode)
129{
130	unsigned long flags;
131
132	spin_lock_irqsave(&io_lock, flags);
133	outb(0xf7, 0xff29);
134	outb(0x8b, 0xff2a);
135	outb(mode, 0xff2b);
136	spin_unlock_irqrestore(&io_lock, flags);
137}
138
139static bool slidebar_i8042_filter(unsigned char data, unsigned char str,
140				  struct serio *port)
141{
142	static bool extended = false;
143
144	/* We are only interested in data coming form KBC port */
145	if (str & I8042_STR_AUXDATA)
146		return false;
147
148	/* Scancodes: e03b on move, e0bb on release. */
149	if (data == 0xe0) {
150		extended = true;
151		return true;
152	}
153
154	if (!extended)
155		return false;
156
157	extended = false;
158
159	if (likely((data & 0x7f) != 0x3b)) {
160		serio_interrupt(port, 0xe0, 0);
161		return false;
162	}
163
164	if (data & 0x80) {
165		input_report_key(slidebar_input_dev, BTN_TOUCH, 0);
166	} else {
167		input_report_key(slidebar_input_dev, BTN_TOUCH, 1);
168		input_report_abs(slidebar_input_dev, ABS_X, slidebar_pos_get());
169	}
170	input_sync(slidebar_input_dev);
171
172	return true;
173}
174
175static ssize_t show_slidebar_mode(struct device *dev,
176				  struct device_attribute *attr,
177				  char *buf)
178{
179	return sprintf(buf, "%x\n", slidebar_mode_get());
180}
181
182static ssize_t store_slidebar_mode(struct device *dev,
183				   struct device_attribute *attr,
184				   const char *buf, size_t count)
185{
186	u8 mode;
187	int error;
188
189	error = kstrtou8(buf, 0, &mode);
190	if (error)
191		return error;
192
193	slidebar_mode_set(mode);
194
195	return count;
196}
197
198static DEVICE_ATTR(slidebar_mode, S_IWUSR | S_IRUGO,
199		   show_slidebar_mode, store_slidebar_mode);
200
201static struct attribute *ideapad_attrs[] = {
202	&dev_attr_slidebar_mode.attr,
203	NULL
204};
205
206static struct attribute_group ideapad_attr_group = {
207	.attrs = ideapad_attrs
208};
209
210static const struct attribute_group *ideapad_attr_groups[] = {
211	&ideapad_attr_group,
212	NULL
213};
214
215static int __init ideapad_probe(struct platform_device* pdev)
216{
217	int err;
218
219	if (!request_region(IDEAPAD_BASE, 3, "ideapad_slidebar")) {
220		dev_err(&pdev->dev, "IO ports are busy\n");
221		return -EBUSY;
222	}
223
224	slidebar_input_dev = input_allocate_device();
225	if (!slidebar_input_dev) {
226		dev_err(&pdev->dev, "Failed to allocate input device\n");
227		err = -ENOMEM;
228		goto err_release_ports;
229	}
230
231	slidebar_input_dev->name = "IdeaPad Slidebar";
232	slidebar_input_dev->id.bustype = BUS_HOST;
233	slidebar_input_dev->dev.parent = &pdev->dev;
234	input_set_capability(slidebar_input_dev, EV_KEY, BTN_TOUCH);
235	input_set_capability(slidebar_input_dev, EV_ABS, ABS_X);
236	input_set_abs_params(slidebar_input_dev, ABS_X, 0, 0xff, 0, 0);
237
238	err = i8042_install_filter(slidebar_i8042_filter);
239	if (err) {
240		dev_err(&pdev->dev,
241			"Failed to install i8042 filter: %d\n", err);
242		goto err_free_dev;
243	}
244
245	err = input_register_device(slidebar_input_dev);
246	if (err) {
247		dev_err(&pdev->dev,
248			"Failed to register input device: %d\n", err);
249		goto err_remove_filter;
250	}
251
252	return 0;
253
254err_remove_filter:
255	i8042_remove_filter(slidebar_i8042_filter);
256err_free_dev:
257	input_free_device(slidebar_input_dev);
258err_release_ports:
259	release_region(IDEAPAD_BASE, 3);
260	return err;
261}
262
263static int ideapad_remove(struct platform_device *pdev)
264{
265	i8042_remove_filter(slidebar_i8042_filter);
266	input_unregister_device(slidebar_input_dev);
267	release_region(IDEAPAD_BASE, 3);
268
269	return 0;
270}
271
272static struct platform_driver slidebar_drv = {
273	.driver = {
274		.name = "ideapad_slidebar",
275	},
276	.remove = ideapad_remove,
277};
278
279static int __init ideapad_dmi_check(const struct dmi_system_id *id)
280{
281	pr_info("Laptop model '%s'\n", id->ident);
282	return 1;
283}
284
285static const struct dmi_system_id ideapad_dmi[] __initconst = {
286	{
287		.ident = "Lenovo IdeaPad Y550",
288		.matches = {
289			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
290			DMI_MATCH(DMI_PRODUCT_NAME, "20017"),
291			DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550")
292		},
293		.callback = ideapad_dmi_check
294	},
295	{
296		.ident = "Lenovo IdeaPad Y550P",
297		.matches = {
298			DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
299			DMI_MATCH(DMI_PRODUCT_NAME, "20035"),
300			DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550P")
301		},
302		.callback = ideapad_dmi_check
303	},
304	{ NULL, }
305};
306MODULE_DEVICE_TABLE(dmi, ideapad_dmi);
307
308static int __init slidebar_init(void)
309{
310	int err;
311
312	if (!force && !dmi_check_system(ideapad_dmi)) {
313		pr_err("DMI does not match\n");
314		return -ENODEV;
315	}
316
317	slidebar_platform_dev = platform_device_alloc("ideapad_slidebar", -1);
318	if (!slidebar_platform_dev) {
319		pr_err("Not enough memory\n");
320		return -ENOMEM;
321	}
322
323	slidebar_platform_dev->dev.groups = ideapad_attr_groups;
324
325	err = platform_device_add(slidebar_platform_dev);
326	if (err) {
327		pr_err("Failed to register platform device\n");
328		goto err_free_dev;
329	}
330
331	err = platform_driver_probe(&slidebar_drv, ideapad_probe);
332	if (err) {
333		pr_err("Failed to register platform driver\n");
334		goto err_delete_dev;
335	}
336
337	return 0;
338
339err_delete_dev:
340	platform_device_del(slidebar_platform_dev);
341err_free_dev:
342	platform_device_put(slidebar_platform_dev);
343	return err;
344}
345
346static void __exit slidebar_exit(void)
347{
348	platform_device_unregister(slidebar_platform_dev);
349	platform_driver_unregister(&slidebar_drv);
350}
351
352module_init(slidebar_init);
353module_exit(slidebar_exit);
354
355MODULE_AUTHOR("Andrey Moiseev <o2g.org.ru@gmail.com>");
356MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
357MODULE_LICENSE("GPL");