drivers/input/misc/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
  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
  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
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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");