input: ideapad_slidebar: new input driver

Hi Andrey,

Quoted 171 lines · Andrey Moiseev

v5: __initconst goes after var name

ideapad_slidebar is a new driver which enables slidebars on some Lenovo IdeaPad laptops (the slidebars work with SlideNav/Desktop Navigator under Windows)

Fixes this: https://bugzilla.kernel.org/show_bug.cgi?id=16004

Registers 'IdeaPad Slidebar' input device and /sys/devices/platform/ideapad_slidebar/slidebar_mode for switching slidebar's modes.

Now works on:
IdeaPad Y550, Y550P.

May work on (testing and adding new models is needed):
Ideapad Y560, Y460, Y450, Y650,
and, probably, some others.

Driver source: https://github.com/o2genum/ideapad-slidebar.git

Patch is generated against current mainline kernel.

Signed-off-by Andrey Moiseev <[email protected]>

---
 MAINTAINERS                           |   7 +
 drivers/input/misc/Kconfig            |   9 +
 drivers/input/misc/Makefile           |   1 +
 drivers/input/misc/ideapad_slidebar.c | 380 ++++++++++++++++++++++++++++++++++
 4 files changed, 397 insertions(+)
 create mode 100644 drivers/input/misc/ideapad_slidebar.c

MAINTAINERS +7 -0

index defc053..2ff3dd8 100644
@@ -4096,6 +4096,13 @@ W:	http://launchpad.net/ideapad-laptop
 S:	Maintained
 F:	drivers/platform/x86/ideapad-laptop.c
 
+IDEAPAD LAPTOP SLIDEBAR DRIVER
+M:	Andrey Moiseev <[email protected]>
+L:	[email protected]
+W:	https://github.com/o2genum/ideapad-slidebar
+S:	Maintained
+F:	drivers/input/misc/ideapad_slidebar.c
+
 IDE/ATAPI DRIVERS
 M:	Borislav Petkov <[email protected]>
 L:	[email protected]

drivers/input/misc/Kconfig +9 -0

index 0b541cd..45729a9 100644
@@ -647,4 +647,13 @@ config INPUT_SIRFSOC_ONKEY
 
 	  If unsure, say N.
 
+config INPUT_IDEAPAD_SLIDEBAR
+	tristate "IdeaPad Laptop Slidebar"
+	depends on INPUT
+	help
+	  Input driver for slidebars on some Lenovo IdeaPad laptops.
+
+	  If you have an IdeaPad laptop with a slidebar, say Y or M here.
+	  Module name is ideapad_slidebar.
+
 endif

drivers/input/misc/Makefile +1 -0

index 829de43..0ebfb6d 100644
@@ -61,3 +61,4 @@ obj-$(CONFIG_INPUT_WISTRON_BTNS)	+= wistron_btns.o
 obj-$(CONFIG_INPUT_WM831X_ON)		+= wm831x-on.o
 obj-$(CONFIG_INPUT_XEN_KBDDEV_FRONTEND)	+= xen-kbdfront.o
 obj-$(CONFIG_INPUT_YEALINK)		+= yealink.o
+obj-$(CONFIG_INPUT_IDEAPAD_SLIDEBAR)	+= ideapad_slidebar.o

drivers/input/misc/ideapad_slidebar.c new file +88 -0

new file mode 100644
index 0000000..df437a4
@@ -0,0 +1,380 @@
+/*
+ * Input driver for slidebars on some Lenovo IdeaPad laptops
+ *
+ * Copyright (C) 2013 Andrey Moiseev <[email protected]>
+ *
+ * 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
+ */
+
+#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/i8042.h>
+
+static bool force;
+module_param(force, bool, 0);
+MODULE_PARM_DESC(force, "Force driver load, ignore DMI data");
+

drivers/input/misc/ideapad_slidebar.c line 98

Quoted 10 lines

drivers/input/misc/ideapad_slidebar.c new file +10 -0

+static spinlock_t sio_lock = __SPIN_LOCK_UNLOCKED(sio_lock);
+
+static struct input_dev *slidebar_input_dev;
+static struct platform_device *slidebar_platform_dev;
+
+/* Hardware interacting */
+static int slidebar_pos_get(void)
+{
+	int res;
+	unsigned long flags;

A blank line between variables and code is appreciated.

Quoted 64 lines

drivers/input/misc/ideapad_slidebar.c new file +64 -0

+	spin_lock_irqsave(&sio_lock, flags);
+	outb(0xf4, 0xff29);
+	outb(0xbf, 0xff2a);
+	res = inb(0xff2b);
+	spin_unlock_irqrestore(&sio_lock, flags);
+	return res;
+}
+
+static unsigned char slidebar_mode_get(void)
+{
+	int res;
+	unsigned long flags;
+	spin_lock_irqsave(&sio_lock, flags);
+	outb(0xf7, 0xff29);
+	outb(0x8b, 0xff2a);
+	res = inb(0xff2b);
+	spin_unlock_irqrestore(&sio_lock, flags);
+	return res;
+}
+
+static void slidebar_mode_set(unsigned char mode)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&sio_lock, flags);
+	outb(0xf7, 0xff29);
+	outb(0x8b, 0xff2a);
+	outb(mode, 0xff2b);
+	spin_unlock_irqrestore(&sio_lock, flags);
+}
+
+/* Listening the keyboard (i8042 filter) */
+static bool slidebar_i8042_filter(unsigned char data, unsigned char str,
+				struct serio *port)
+{
+	static bool extended = false, touched = false;
+
+	/* Scancodes: e03b on move, e0bb on release */
+	if (unlikely(data == 0xe0)) {
+		extended = true;
+		return false;
+	} else if (unlikely(extended && (data == 0x3b))) {
+		extended = false;
+		if (!touched)
+			input_report_key(slidebar_input_dev, BTN_TOUCH, 1);
+		touched = true;
+		input_report_abs(slidebar_input_dev, ABS_X, slidebar_pos_get());
+		input_sync(slidebar_input_dev);
+		return false;
+	} else if (unlikely(extended && (data == 0xbb))) {
+		touched = false;
+		input_report_key(slidebar_input_dev, BTN_TOUCH, 0);
+		input_sync(slidebar_input_dev);
+	}
+
+	return false;
+}
+
+/* Input device */
+static int setup_input_dev(void)
+{
+	int err;
+
+	slidebar_input_dev = input_allocate_device();
+	if (!slidebar_input_dev) {

drivers/input/misc/ideapad_slidebar.c line 172

Quoted 10 lines

drivers/input/misc/ideapad_slidebar.c new file +10 -0

+		pr_err("ideapad_slidebar: Not enough memory\n");
+		return -ENOMEM;
+	}
+
+	slidebar_input_dev->name = "IdeaPad Slidebar";
+	slidebar_input_dev->id.bustype = BUS_HOST;
+	slidebar_input_dev->dev.parent = &slidebar_platform_dev->dev;
+	input_set_capability(slidebar_input_dev, EV_KEY, BTN_TOUCH);
+	input_set_capability(slidebar_input_dev, EV_ABS, ABS_X);
+	input_alloc_absinfo(slidebar_input_dev);

This call is not needed, it will be done for you.

Quoted 9 lines

drivers/input/misc/ideapad_slidebar.c new file +9 -0

+	input_set_abs_params(slidebar_input_dev, ABS_X, 0, 0xff, 0, 0);
+
+	err = input_register_device(slidebar_input_dev);
+	if (err) {
+		pr_err("ideapad_slidebar: Failed to register device\n");
+		goto err_free_dev;
+	}
+
+	err = i8042_install_filter(slidebar_i8042_filter);

drivers/input/misc/ideapad_slidebar.c line 191

Quoted 10 lines

drivers/input/misc/ideapad_slidebar.c new file +10 -0

+	if (err) {
+		pr_err("ideapad_slidebar: Can't install i8042 filter \n");
+		goto err_unregister_dev;
+	}
+	return 0;
+
+err_unregister_dev:
+	input_unregister_device(slidebar_input_dev);
+err_free_dev:
+	input_free_device(slidebar_input_dev);

No free after unregister for input devices. Consider swapping registering device and installing the filter (allocated but not registered input device can take events emitted by the filter just fine).

drivers/input/misc/ideapad_slidebar.c line 199

Quoted 8 lines

drivers/input/misc/ideapad_slidebar.c new file +8 -0

+	return err;
+}
+
+static void remove_input_dev(void)
+{
+	i8042_remove_filter(slidebar_i8042_filter);
+	input_unregister_device(slidebar_input_dev);
+	input_free_device(slidebar_input_dev);

No free after unregister for input devices.

Quoted 31 lines

drivers/input/misc/ideapad_slidebar.c new file +31 -0

+}
+
+/* Sysfs slidebar_mode interface */
+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)
+{
+	int mode;
+	if (!count)
+		return 0;
+
+	if (sscanf(buf, "%x", &mode) != 1)
+		return -EINVAL;
+
+	slidebar_mode_set(mode);
+	return count;
+}
+
+static DEVICE_ATTR(slidebar_mode, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH,
+				show_slidebar_mode, store_slidebar_mode);
+
+static struct attribute *ideapad_attributes[] = {
+	&dev_attr_slidebar_mode.attr,
+	NULL

drivers/input/misc/ideapad_slidebar.c line 240

Quoted 10 lines

drivers/input/misc/ideapad_slidebar.c new file +10 -0

+};
+
+static struct attribute_group ideapad_attribute_group = {
+	.attrs = ideapad_attributes
+};
+
+static int setup_slidebar_mode_dev(void)
+{
+	return sysfs_create_group(&slidebar_platform_dev->dev.kobj,
+				  &ideapad_attribute_group);

To avoid races between creating device and attributes you want to simply assign your group to the devices group pointer and then it will be created for you by device core.

Quoted 24 lines

drivers/input/misc/ideapad_slidebar.c new file +24 -0

+}
+
+static void remove_slidebar_mode_dev(void)
+{
+	return sysfs_remove_group(&slidebar_platform_dev->dev.kobj,
+				  &ideapad_attribute_group);
+}
+
+/* Platform device */
+static int setup_platform_dev(void)
+{
+	int err;
+	slidebar_platform_dev = platform_device_alloc("ideapad_slidebar", -1);
+	if (!slidebar_platform_dev) {
+		pr_err("ideapad_slidebar: Not enough memory\n");
+		return -ENOMEM;
+	}
+
+	err = platform_device_add(slidebar_platform_dev);
+	if (err) {
+		pr_err("ideapad_slidebar: Failed to register plarform device\n");
+		goto err_free_platform_device;
+	}
+	return 0;

drivers/input/misc/ideapad_slidebar.c line 274

Quoted 10 lines

drivers/input/misc/ideapad_slidebar.c new file +10 -0

+
+err_free_platform_device:
+	platform_device_put(slidebar_platform_dev);
+	return err;
+}
+
+static void remove_platform_dev(void)
+{
+	platform_device_del(slidebar_platform_dev);
+	platform_device_put(slidebar_platform_dev);

I do nto understand why you need all these wrappers when you can simply call platform_device_unregister().

Quoted 96 lines

drivers/input/misc/ideapad_slidebar.c new file +96 -0

+}
+
+/* Platform driver */
+static struct platform_driver slidebar_drv = {
+	.driver = {
+		.name = "ideapad_slidebar",
+		.owner = THIS_MODULE,
+	},
+};
+
+static int register_platform_drv(void)
+{
+	int err;
+	err = platform_driver_register(&slidebar_drv);
+	if (err)
+		pr_err("ideapad_slidebar: Failed to register platform driver\n");
+
+	return err;
+}
+
+static void unregister_platform_drv(void)
+{
+	platform_driver_unregister(&slidebar_drv);
+}
+
+/* DMI */
+static int ideapad_dmi_check(const struct dmi_system_id *id)
+{
+	pr_info("ideapad_slidebar: Laptop model '%s'\n", id->ident);
+	return 1;
+}
+
+static struct dmi_system_id ideapad_dmi_table[] __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
+	},
+	{ }
+};
+
+/* Init and cleanup */
+static int __init slidebar_init(void)
+{
+	int err;
+
+	if (!force && !dmi_check_system(ideapad_dmi_table))
+		return -ENODEV;
+
+	err = setup_platform_dev();
+	if (err)
+		return err;
+
+	err = register_platform_drv();
+	if (err)
+		goto err_remove_platform_dev;
+
+	err = setup_input_dev();
+	if (err)
+		goto err_unregister_platform_drv;
+	
+	err = setup_slidebar_mode_dev();
+	if (err)
+		goto err_remove_input_dev;
+	return 0;
+
+err_remove_input_dev:
+	remove_input_dev();
+err_unregister_platform_drv:
+	unregister_platform_drv();
+err_remove_platform_dev:
+	remove_platform_dev();
+	return err;
+}
+
+static void __exit slidebar_exit(void)
+{
+	remove_slidebar_mode_dev();
+	remove_input_dev();
+	remove_platform_dev();
+	unregister_platform_drv();
+}
+

drivers/input/misc/ideapad_slidebar.c line 380

Quoted 10 lines

drivers/input/misc/ideapad_slidebar.c new file +10 -0

+module_init(slidebar_init);
+module_exit(slidebar_exit);
+
+MODULE_AUTHOR("Andrey Moiseev <[email protected]>");
+MODULE_DESCRIPTION("Slidebar input support for some Lenovo IdeaPad laptops");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("0.1");
+
+MODULE_ALIAS("dmi:*:svnLENOVO:pn20017:pvrLenovoIdeaPadY550:*");
+MODULE_ALIAS("dmi:*:svnLENOVO:pn20035:pvrLenovoIdeaPadY550P:*");

Why not create MODULE_DEVICE_TABLE from dmi table instead of doing it by hand?

Thanks.

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Dmitry