linux/drivers/input/misc/ideapad_slidebar.c
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   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 int 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        return 0;
 266}
 267
 268static struct platform_driver slidebar_drv = {
 269        .driver = {
 270                .name = "ideapad_slidebar",
 271        },
 272        .remove = ideapad_remove,
 273};
 274
 275static int __init ideapad_dmi_check(const struct dmi_system_id *id)
 276{
 277        pr_info("Laptop model '%s'\n", id->ident);
 278        return 1;
 279}
 280
 281static const struct dmi_system_id ideapad_dmi[] __initconst = {
 282        {
 283                .ident = "Lenovo IdeaPad Y550",
 284                .matches = {
 285                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 286                        DMI_MATCH(DMI_PRODUCT_NAME, "20017"),
 287                        DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550")
 288                },
 289                .callback = ideapad_dmi_check
 290        },
 291        {
 292                .ident = "Lenovo IdeaPad Y550P",
 293                .matches = {
 294                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
 295                        DMI_MATCH(DMI_PRODUCT_NAME, "20035"),
 296                        DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550P")
 297                },
 298                .callback = ideapad_dmi_check
 299        },
 300        { NULL, }
 301};
 302MODULE_DEVICE_TABLE(dmi, ideapad_dmi);
 303
 304static int __init slidebar_init(void)
 305{
 306        int err;
 307
 308        if (!force && !dmi_check_system(ideapad_dmi)) {
 309                pr_err("DMI does not match\n");
 310                return -ENODEV;
 311        }
 312
 313        slidebar_platform_dev = platform_device_alloc("ideapad_slidebar", -1);
 314        if (!slidebar_platform_dev) {
 315                pr_err("Not enough memory\n");
 316                return -ENOMEM;
 317        }
 318
 319        slidebar_platform_dev->dev.groups = ideapad_attr_groups;
 320
 321        err = platform_device_add(slidebar_platform_dev);
 322        if (err) {
 323                pr_err("Failed to register platform device\n");
 324                goto err_free_dev;
 325        }
 326
 327        err = platform_driver_probe(&slidebar_drv, ideapad_probe);
 328        if (err) {
 329                pr_err("Failed to register platform driver\n");
 330                goto err_delete_dev;
 331        }
 332
 333        return 0;
 334
 335err_delete_dev:
 336        platform_device_del(slidebar_platform_dev);
 337err_free_dev:
 338        platform_device_put(slidebar_platform_dev);
 339        return err;
 340}
 341
 342static void __exit slidebar_exit(void)
 343{
 344        platform_device_unregister(slidebar_platform_dev);
 345        platform_driver_unregister(&slidebar_drv);
 346}
 347
 348module_init(slidebar_init);
 349module_exit(slidebar_exit);
 350
 351MODULE_AUTHOR("Andrey Moiseev <o2g.org.ru@gmail.com>");
 352MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
 353MODULE_LICENSE("GPL");
 354