--- /dev/null
+/*
+ * Input driver for slidebars on some Lenovo IdeaPad laptops
+ *
+ * Copyright (C) 2013 Andrey Moiseev <o2g.org.ru@gmail.com>
+ *
+ * Reverse-engineered from Lenovo SlideNav software (SBarHook.dll).
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * Trademarks are the property of their respective owners.
+ */
+
+/*
+ * Currently tested and works on:
+ * Lenovo IdeaPad Y550
+ * Lenovo IdeaPad Y550P
+ *
+ * Other models can be added easily. To test,
+ * load with 'force' parameter set 'true'.
+ *
+ * LEDs blinking and input mode are managed via sysfs,
+ * (hex, unsigned byte value):
+ * /sys/devices/platform/ideapad_slidebar/slidebar_mode
+ *
+ * The value is in byte range, however, I only figured out
+ * how bits 0b10011001 work. Some other bits, probably,
+ * are meaningfull too.
+ *
+ * Possible states:
+ *
+ * STD_INT, ONMOV_INT, OFF_INT, LAST_POLL, OFF_POLL
+ *
+ * Meaning:
+ * released touched
+ * STD 'heartbeat' lights follow the finger
+ * ONMOV no lights lights follow the finger
+ * LAST at last pos lights follow the finger
+ * OFF no lights no lights
+ *
+ * INT all input events are generated, interrupts are used
+ * POLL no input events by default, to get them,
+ * send 0b10000000 (read below)
+ *
+ * Commands: write
+ *
+ * All | 0b01001 -> STD_INT
+ * possible | 0b10001 -> ONMOV_INT
+ * states | 0b01000 -> OFF_INT
+ *
+ * | 0b0 -> LAST_POLL
+ * STD_INT or ONMOV_INT |
+ * | 0b1 -> STD_INT
+ *
+ * | 0b0 -> OFF_POLL
+ * OFF_INT or OFF_POLL |
+ * | 0b1 -> OFF_INT
+ *
+ * Any state | 0b10000000 -> if the slidebar has updated data,
+ * produce one input event (last position),
+ * switch to respective POLL mode
+ * (like 0x0), if not in POLL mode yet.
+ *
+ * Get current state: read
+ *
+ * masked by 0x11 read value means:
+ *
+ * 0x00 LAST
+ * 0x01 STD
+ * 0x10 OFF
+ * 0x11 ONMOV
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/dmi.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/input.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/i8042.h>
+#include <linux/serio.h>
+
+#define IDEAPAD_BASE 0xff29
+
+static bool force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
+
+static DEFINE_SPINLOCK(io_lock);
+
+static struct input_dev *slidebar_input_dev;
+static struct platform_device *slidebar_platform_dev;
+
+static u8 slidebar_pos_get(void)
+{
+ u8 res;
+ unsigned long flags;
+
+ spin_lock_irqsave(&io_lock, flags);
+ outb(0xf4, 0xff29);
+ outb(0xbf, 0xff2a);
+ res = inb(0xff2b);
+ spin_unlock_irqrestore(&io_lock, flags);
+
+ return res;
+}
+
+static u8 slidebar_mode_get(void)
+{
+ u8 res;
+ unsigned long flags;
+
+ spin_lock_irqsave(&io_lock, flags);
+ outb(0xf7, 0xff29);
+ outb(0x8b, 0xff2a);
+ res = inb(0xff2b);
+ spin_unlock_irqrestore(&io_lock, flags);
+
+ return res;
+}
+
+static void slidebar_mode_set(u8 mode)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&io_lock, flags);
+ outb(0xf7, 0xff29);
+ outb(0x8b, 0xff2a);
+ outb(mode, 0xff2b);
+ spin_unlock_irqrestore(&io_lock, flags);
+}
+
+static bool slidebar_i8042_filter(unsigned char data, unsigned char str,
+ struct serio *port)
+{
+ static bool extended = false;
+
+ /* We are only interested in data coming form KBC port */
+ if (str & I8042_STR_AUXDATA)
+ return false;
+
+ /* Scancodes: e03b on move, e0bb on release. */
+ if (data == 0xe0) {
+ extended = true;
+ return true;
+ }
+
+ if (!extended)
+ return false;
+
+ extended = false;
+
+ if (likely((data & 0x7f) != 0x3b)) {
+ serio_interrupt(port, 0xe0, 0);
+ return false;
+ }
+
+ if (data & 0x80) {
+ input_report_key(slidebar_input_dev, BTN_TOUCH, 0);
+ } else {
+ input_report_key(slidebar_input_dev, BTN_TOUCH, 1);
+ input_report_abs(slidebar_input_dev, ABS_X, slidebar_pos_get());
+ }
+ input_sync(slidebar_input_dev);
+
+ return true;
+}
+
+static ssize_t show_slidebar_mode(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return sprintf(buf, "%x\n", slidebar_mode_get());
+}
+
+static ssize_t store_slidebar_mode(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ u8 mode;
+ int error;
+
+ error = kstrtou8(buf, 0, &mode);
+ if (error)
+ return error;
+
+ slidebar_mode_set(mode);
+
+ return count;
+}
+
+static DEVICE_ATTR(slidebar_mode, S_IWUSR | S_IRUGO,
+ show_slidebar_mode, store_slidebar_mode);
+
+static struct attribute *ideapad_attrs[] = {
+ &dev_attr_slidebar_mode.attr,
+ NULL
+};
+
+static struct attribute_group ideapad_attr_group = {
+ .attrs = ideapad_attrs
+};
+
+static const struct attribute_group *ideapad_attr_groups[] = {
+ &ideapad_attr_group,
+ NULL
+};
+
+static int __init ideapad_probe(struct platform_device* pdev)
+{
+ int err;
+
+ if (!request_region(IDEAPAD_BASE, 3, "ideapad_slidebar")) {
+ dev_err(&pdev->dev, "IO ports are busy\n");
+ return -EBUSY;
+ }
+
+ slidebar_input_dev = input_allocate_device();
+ if (!slidebar_input_dev) {
+ dev_err(&pdev->dev, "Failed to allocate input device\n");
+ err = -ENOMEM;
+ goto err_release_ports;
+ }
+
+ slidebar_input_dev->name = "IdeaPad Slidebar";
+ slidebar_input_dev->id.bustype = BUS_HOST;
+ slidebar_input_dev->dev.parent = &pdev->dev;
+ input_set_capability(slidebar_input_dev, EV_KEY, BTN_TOUCH);
+ input_set_capability(slidebar_input_dev, EV_ABS, ABS_X);
+ input_set_abs_params(slidebar_input_dev, ABS_X, 0, 0xff, 0, 0);
+
+ err = i8042_install_filter(slidebar_i8042_filter);
+ if (err) {
+ dev_err(&pdev->dev,
+ "Failed to install i8042 filter: %d\n", err);
+ goto err_free_dev;
+ }
+
+ err = input_register_device(slidebar_input_dev);
+ if (err) {
+ dev_err(&pdev->dev,
+ "Failed to register input device: %d\n", err);
+ goto err_remove_filter;
+ }
+
+ return 0;
+
+err_remove_filter:
+ i8042_remove_filter(slidebar_i8042_filter);
+err_free_dev:
+ input_free_device(slidebar_input_dev);
+err_release_ports:
+ release_region(IDEAPAD_BASE, 3);
+ return err;
+}
+
+static int ideapad_remove(struct platform_device *pdev)
+{
+ i8042_remove_filter(slidebar_i8042_filter);
+ input_unregister_device(slidebar_input_dev);
+ release_region(IDEAPAD_BASE, 3);
+
+ return 0;
+}
+
+static struct platform_driver slidebar_drv = {
+ .driver = {
+ .name = "ideapad_slidebar",
+ .owner = THIS_MODULE,
+ },
+ .remove = ideapad_remove,
+};
+
+static int __init ideapad_dmi_check(const struct dmi_system_id *id)
+{
+ pr_info("Laptop model '%s'\n", id->ident);
+ return 1;
+}
+
+static const struct dmi_system_id ideapad_dmi[] __initconst = {
+ {
+ .ident = "Lenovo IdeaPad Y550",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "20017"),
+ DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550")
+ },
+ .callback = ideapad_dmi_check
+ },
+ {
+ .ident = "Lenovo IdeaPad Y550P",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "20035"),
+ DMI_MATCH(DMI_PRODUCT_VERSION, "Lenovo IdeaPad Y550P")
+ },
+ .callback = ideapad_dmi_check
+ },
+ { NULL, }
+};
+MODULE_DEVICE_TABLE(dmi, ideapad_dmi);
+
+static int __init slidebar_init(void)
+{
+ int err;
+
+ if (!force && !dmi_check_system(ideapad_dmi)) {
+ pr_err("DMI does not match\n");
+ return -ENODEV;
+ }
+
+ slidebar_platform_dev = platform_device_alloc("ideapad_slidebar", -1);
+ if (!slidebar_platform_dev) {
+ pr_err("Not enough memory\n");
+ return -ENOMEM;
+ }
+
+ slidebar_platform_dev->dev.groups = ideapad_attr_groups;
+
+ err = platform_device_add(slidebar_platform_dev);
+ if (err) {
+ pr_err("Failed to register platform device\n");
+ goto err_free_dev;
+ }
+
+ err = platform_driver_probe(&slidebar_drv, ideapad_probe);
+ if (err) {
+ pr_err("Failed to register platform driver\n");
+ goto err_delete_dev;
+ }
+
+ return 0;
+
+err_delete_dev:
+ platform_device_del(slidebar_platform_dev);
+err_free_dev:
+ platform_device_put(slidebar_platform_dev);
+ return err;
+}
+
+static void __exit slidebar_exit(void)
+{
+ platform_device_unregister(slidebar_platform_dev);
+ platform_driver_unregister(&slidebar_drv);
+}
+
+module_init(slidebar_init);
+module_exit(slidebar_exit);
+
+MODULE_AUTHOR("Andrey Moiseev <o2g.org.ru@gmail.com>");
+MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
+MODULE_LICENSE("GPL");