input/misc/ideapad_slidebar.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * Input driver for slidebars on some Lenovo IdeaPad laptops
0004  *
0005  * Copyright (C) 2013 Andrey Moiseev <o2g.org.ru@gmail.com>
0006  *
0007  * Reverse-engineered from Lenovo SlideNav software (SBarHook.dll).
0008  *
0009  * Trademarks are the property of their respective owners.
0010  */
0011
0012 /*
0013  * Currently tested and works on:
0014  *  Lenovo IdeaPad Y550
0015  *  Lenovo IdeaPad Y550P
0016  *
0017  * Other models can be added easily. To test,
0018  * load with 'force' parameter set 'true'.
0019  *
0020  * LEDs blinking and input mode are managed via sysfs,
0021  * (hex, unsigned byte value):
0022  * /sys/devices/platform/ideapad_slidebar/slidebar_mode
0023  *
0024  * The value is in byte range, however, I only figured out
0025  * how bits 0b10011001 work. Some other bits, probably,
0026  * are meaningfull too.
0027  *
0028  * Possible states:
0029  *
0030  * STD_INT, ONMOV_INT, OFF_INT, LAST_POLL, OFF_POLL
0031  *
0032  * Meaning:
0033  *           released      touched
0034  * STD       'heartbeat'   lights follow the finger
0035  * ONMOV     no lights     lights follow the finger
0036  * LAST      at last pos   lights follow the finger
0037  * OFF       no lights     no lights
0038  *
0039  * INT       all input events are generated, interrupts are used
0040  * POLL      no input events by default, to get them,
0041  *       send 0b10000000 (read below)
0042  *
0043  * Commands: write
0044  *
0045  * All      |  0b01001 -> STD_INT
0046  * possible |  0b10001 -> ONMOV_INT
0047  * states   |  0b01000 -> OFF_INT
0048  *
0049  *                      |  0b0 -> LAST_POLL
0050  * STD_INT or ONMOV_INT |
0051  *                      |  0b1 -> STD_INT
0052  *
0053  *                      |  0b0 -> OFF_POLL
0054  * OFF_INT or OFF_POLL  |
0055  *                      |  0b1 -> OFF_INT
0056  *
0057  * Any state |   0b10000000 ->  if the slidebar has updated data,
0058  *              produce one input event (last position),
0059  *              switch to respective POLL mode
0060  *              (like 0x0), if not in POLL mode yet.
0061  *
0062  * Get current state: read
0063  *
0064  * masked by 0x11 read value means:
0065  *
0066  * 0x00   LAST
0067  * 0x01   STD
0068  * 0x10   OFF
0069  * 0x11   ONMOV
0070  */
0071
0072 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0073
0074 #include <linux/module.h>
0075 #include <linux/kernel.h>
0076 #include <linux/dmi.h>
0077 #include <linux/spinlock.h>
0078 #include <linux/platform_device.h>
0079 #include <linux/input.h>
0080 #include <linux/io.h>
0081 #include <linux/ioport.h>
0082 #include <linux/i8042.h>
0083 #include <linux/serio.h>
0084
0085 #define IDEAPAD_BASE    0xff29
0086
0087 static bool force;
0088 module_param(force, bool, 0);
0089 MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
0090
0091 static DEFINE_SPINLOCK(io_lock);
0092
0093 static struct input_dev *slidebar_input_dev;
0094 static struct platform_device *slidebar_platform_dev;
0095
0096 static u8 slidebar_pos_get(void)
0097 {
0098     u8 res;
0099     unsigned long flags;
0100
0101     spin_lock_irqsave(&io_lock, flags);
0102     outb(0xf4, 0xff29);
0103     outb(0xbf, 0xff2a);
0104     res = inb(0xff2b);
0105     spin_unlock_irqrestore(&io_lock, flags);
0106
0107     return res;
0108 }
0109
0110 static u8 slidebar_mode_get(void)
0111 {
0112     u8 res;
0113     unsigned long flags;
0114
0115     spin_lock_irqsave(&io_lock, flags);
0116     outb(0xf7, 0xff29);
0117     outb(0x8b, 0xff2a);
0118     res = inb(0xff2b);
0119     spin_unlock_irqrestore(&io_lock, flags);
0120
0121     return res;
0122 }
0123
0124 static void slidebar_mode_set(u8 mode)
0125 {
0126     unsigned long flags;
0127
0128     spin_lock_irqsave(&io_lock, flags);
0129     outb(0xf7, 0xff29);
0130     outb(0x8b, 0xff2a);
0131     outb(mode, 0xff2b);
0132     spin_unlock_irqrestore(&io_lock, flags);
0133 }
0134
0135 static bool slidebar_i8042_filter(unsigned char data, unsigned char str,
0136                   struct serio *port)
0137 {
0138     static bool extended = false;
0139
0140     /* We are only interested in data coming form KBC port */
0141     if (str & I8042_STR_AUXDATA)
0142         return false;
0143
0144     /* Scancodes: e03b on move, e0bb on release. */
0145     if (data == 0xe0) {
0146         extended = true;
0147         return true;
0148     }
0149
0150     if (!extended)
0151         return false;
0152
0153     extended = false;
0154
0155     if (likely((data & 0x7f) != 0x3b)) {
0156         serio_interrupt(port, 0xe0, 0);
0157         return false;
0158     }
0159
0160     if (data & 0x80) {
0161         input_report_key(slidebar_input_dev, BTN_TOUCH, 0);
0162     } else {
0163         input_report_key(slidebar_input_dev, BTN_TOUCH, 1);
0164         input_report_abs(slidebar_input_dev, ABS_X, slidebar_pos_get());
0165     }
0166     input_sync(slidebar_input_dev);
0167
0168     return true;
0169 }
0170
0171 static ssize_t show_slidebar_mode(struct device *dev,
0172                   struct device_attribute *attr,
0173                   char *buf)
0174 {
0175     return sprintf(buf, "%x\n", slidebar_mode_get());
0176 }
0177
0178 static ssize_t store_slidebar_mode(struct device *dev,
0179                    struct device_attribute *attr,
0180                    const char *buf, size_t count)
0181 {
0182     u8 mode;
0183     int error;
0184
0185     error = kstrtou8(buf, 0, &mode);
0186     if (error)
0187         return error;
0188
0189     slidebar_mode_set(mode);
0190
0191     return count;
0192 }
0193
0194 static DEVICE_ATTR(slidebar_mode, S_IWUSR | S_IRUGO,
0195            show_slidebar_mode, store_slidebar_mode);
0196
0197 static struct attribute *ideapad_attrs[] = {
0198     &dev_attr_slidebar_mode.attr,
0199     NULL
0200 };
0201
0202 static struct attribute_group ideapad_attr_group = {
0203     .attrs = ideapad_attrs
0204 };
0205
0206 static const struct attribute_group *ideapad_attr_groups[] = {
0207     &ideapad_attr_group,
0208     NULL
0209 };
0210
0211 static int __init ideapad_probe(struct platform_device* pdev)
0212 {
0213     int err;
0214
0215     if (!request_region(IDEAPAD_BASE, 3, "ideapad_slidebar")) {
0216         dev_err(&pdev->dev, "IO ports are busy\n");
0217         return -EBUSY;
0218     }
0219
0220     slidebar_input_dev = input_allocate_device();
0221     if (!slidebar_input_dev) {
0222         dev_err(&pdev->dev, "Failed to allocate input device\n");
0223         err = -ENOMEM;
0224         goto err_release_ports;
0225     }
0226
0227     slidebar_input_dev->name = "IdeaPad Slidebar";
0228     slidebar_input_dev->id.bustype = BUS_HOST;
0229     slidebar_input_dev->dev.parent = &pdev->dev;
0230     input_set_capability(slidebar_input_dev, EV_KEY, BTN_TOUCH);
0231     input_set_capability(slidebar_input_dev, EV_ABS, ABS_X);
0232     input_set_abs_params(slidebar_input_dev, ABS_X, 0, 0xff, 0, 0);
0233
0234     err = i8042_install_filter(slidebar_i8042_filter);
0235     if (err) {
0236         dev_err(&pdev->dev,
0237             "Failed to install i8042 filter: %d\n", err);
0238         goto err_free_dev;
0239     }
0240
0241     err = input_register_device(slidebar_input_dev);
0242     if (err) {
0243         dev_err(&pdev->dev,
0244             "Failed to register input device: %d\n", err);
0245         goto err_remove_filter;
0246     }
0247
0248     return 0;
0249
0250 err_remove_filter:
0251     i8042_remove_filter(slidebar_i8042_filter);
0252 err_free_dev:
0253     input_free_device(slidebar_input_dev);
0254 err_release_ports:
0255     release_region(IDEAPAD_BASE, 3);
0256     return err;
0257 }
0258
0259 static int ideapad_remove(struct platform_device *pdev)
0260 {
0261     i8042_remove_filter(slidebar_i8042_filter);
0262     input_unregister_device(slidebar_input_dev);
0263     release_region(IDEAPAD_BASE, 3);
0264
0265     return 0;
0266 }
0267
0268 static struct platform_driver slidebar_drv = {
0269     .driver = {
0270         .name = "ideapad_slidebar",
0271     },
0272     .remove = ideapad_remove,
0273 };
0274
0275 static int __init ideapad_dmi_check(const struct dmi_system_id *id)
0276 {
0277     pr_info("Laptop model '%s'\n", id->ident);
0278     return 1;
0279 }
0280
0281 static const struct dmi_system_id ideapad_dmi[] __initconst = {
0282     {
0283         .ident = "Lenovo IdeaPad Y550",
0284         .matches = {
0285             DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
0286             DMI_MATCH(DMI_PRODUCT_NAME, "20017"),
0287             DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550")
0288         },
0289         .callback = ideapad_dmi_check
0290     },
0291     {
0292         .ident = "Lenovo IdeaPad Y550P",
0293         .matches = {
0294             DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
0295             DMI_MATCH(DMI_PRODUCT_NAME, "20035"),
0296             DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550P")
0297         },
0298         .callback = ideapad_dmi_check
0299     },
0300     { NULL, }
0301 };
0302 MODULE_DEVICE_TABLE(dmi, ideapad_dmi);
0303
0304 static int __init slidebar_init(void)
0305 {
0306     int err;
0307
0308     if (!force && !dmi_check_system(ideapad_dmi)) {
0309         pr_err("DMI does not match\n");
0310         return -ENODEV;
0311     }
0312
0313     slidebar_platform_dev = platform_device_alloc("ideapad_slidebar", -1);
0314     if (!slidebar_platform_dev) {
0315         pr_err("Not enough memory\n");
0316         return -ENOMEM;
0317     }
0318
0319     slidebar_platform_dev->dev.groups = ideapad_attr_groups;
0320
0321     err = platform_device_add(slidebar_platform_dev);
0322     if (err) {
0323         pr_err("Failed to register platform device\n");
0324         goto err_free_dev;
0325     }
0326
0327     err = platform_driver_probe(&slidebar_drv, ideapad_probe);
0328     if (err) {
0329         pr_err("Failed to register platform driver\n");
0330         goto err_delete_dev;
0331     }
0332
0333     return 0;
0334
0335 err_delete_dev:
0336     platform_device_del(slidebar_platform_dev);
0337 err_free_dev:
0338     platform_device_put(slidebar_platform_dev);
0339     return err;
0340 }
0341
0342 static void __exit slidebar_exit(void)
0343 {
0344     platform_device_unregister(slidebar_platform_dev);
0345     platform_driver_unregister(&slidebar_drv);
0346 }
0347
0348 module_init(slidebar_init);
0349 module_exit(slidebar_exit);
0350
0351 MODULE_AUTHOR("Andrey Moiseev <o2g.org.ru@gmail.com>");
0352 MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
0353 MODULE_LICENSE("GPL");