1 files changed, 507 insertions, 0 deletions
diff --git a/drivers/hid/hid-appletb-kbd.c b/drivers/hid/hid-appletb-kbd.c
new file mode 100644
index 000000000000..029ccbaa1d12
--- /dev/null
+++ b/drivers/hid/hid-appletb-kbd.c
@@ -0,0 +1,507 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple Touch Bar Keyboard Mode Driver
+ *
+ * Copyright (c) 2017-2018 Ronald Tschalär
+ * Copyright (c) 2022-2023 Kerem Karabay <kekrby@gmail.com>
+ * Copyright (c) 2024-2025 Aditya Garg <gargaditya08@live.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/hid.h>
+#include <linux/usb.h>
+#include <linux/input.h>
+#include <linux/sysfs.h>
+#include <linux/bitops.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/backlight.h>
+#include <linux/timer.h>
+#include <linux/input/sparse-keymap.h>
+
+#include "hid-ids.h"
+
+#define APPLETB_KBD_MODE_ESC	0
+#define APPLETB_KBD_MODE_FN	1
+#define APPLETB_KBD_MODE_SPCL	2
+#define APPLETB_KBD_MODE_OFF	3
+#define APPLETB_KBD_MODE_MAX	APPLETB_KBD_MODE_OFF
+
+#define APPLETB_DEVID_KEYBOARD	1
+#define APPLETB_DEVID_TRACKPAD	2
+
+#define HID_USAGE_MODE		0x00ff0004
+
+static int appletb_tb_def_mode = APPLETB_KBD_MODE_SPCL;
+module_param_named(mode, appletb_tb_def_mode, int, 0444);
+MODULE_PARM_DESC(mode, "Default touchbar mode:\n"
+			 "    0 - escape key only\n"
+			 "    1 - function-keys\n"
+			 "    [2] - special keys");
+
+static bool appletb_tb_fn_toggle = true;
+module_param_named(fntoggle, appletb_tb_fn_toggle, bool, 0644);
+MODULE_PARM_DESC(fntoggle, "Switch between Fn and media controls on pressing Fn key");
+
+static bool appletb_tb_autodim = true;
+module_param_named(autodim, appletb_tb_autodim, bool, 0644);
+MODULE_PARM_DESC(autodim, "Automatically dim and turn off the Touch Bar after some time");
+
+static int appletb_tb_dim_timeout = 60;
+module_param_named(dim_timeout, appletb_tb_dim_timeout, int, 0644);
+MODULE_PARM_DESC(dim_timeout, "Dim timeout in sec");
+
+static int appletb_tb_idle_timeout = 15;
+module_param_named(idle_timeout, appletb_tb_idle_timeout, int, 0644);
+MODULE_PARM_DESC(idle_timeout, "Idle timeout in sec");
+
+struct appletb_kbd {
+	struct hid_field *mode_field;
+	struct input_handler inp_handler;
+	struct input_handle kbd_handle;
+	struct input_handle tpd_handle;
+	struct backlight_device *backlight_dev;
+	struct timer_list inactivity_timer;
+	bool has_dimmed;
+	bool has_turned_off;
+	u8 saved_mode;
+	u8 current_mode;
+};
+
+static const struct key_entry appletb_kbd_keymap[] = {
+	{ KE_KEY, KEY_ESC, { KEY_ESC } },
+	{ KE_KEY, KEY_F1,  { KEY_BRIGHTNESSDOWN } },
+	{ KE_KEY, KEY_F2,  { KEY_BRIGHTNESSUP } },
+	{ KE_KEY, KEY_F3,  { KEY_RESERVED } },
+	{ KE_KEY, KEY_F4,  { KEY_RESERVED } },
+	{ KE_KEY, KEY_F5,  { KEY_KBDILLUMDOWN } },
+	{ KE_KEY, KEY_F6,  { KEY_KBDILLUMUP } },
+	{ KE_KEY, KEY_F7,  { KEY_PREVIOUSSONG } },
+	{ KE_KEY, KEY_F8,  { KEY_PLAYPAUSE } },
+	{ KE_KEY, KEY_F9,  { KEY_NEXTSONG } },
+	{ KE_KEY, KEY_F10, { KEY_MUTE } },
+	{ KE_KEY, KEY_F11, { KEY_VOLUMEDOWN } },
+	{ KE_KEY, KEY_F12, { KEY_VOLUMEUP } },
+	{ KE_END, 0 }
+};
+
+static int appletb_kbd_set_mode(struct appletb_kbd *kbd, u8 mode)
+{
+	struct hid_report *report = kbd->mode_field->report;
+	struct hid_device *hdev = report->device;
+	int ret;
+
+	ret = hid_hw_power(hdev, PM_HINT_FULLON);
+	if (ret) {
+		hid_err(hdev, "Device didn't resume (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	ret = hid_set_field(kbd->mode_field, 0, mode);
+	if (ret) {
+		hid_err(hdev, "Failed to set mode field to %u (%pe)\n", mode, ERR_PTR(ret));
+		goto power_normal;
+	}
+
+	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
+
+	kbd->current_mode = mode;
+
+power_normal:
+	hid_hw_power(hdev, PM_HINT_NORMAL);
+
+	return ret;
+}
+
+static ssize_t mode_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct appletb_kbd *kbd = dev_get_drvdata(dev);
+
+	return sysfs_emit(buf, "%d\n", kbd->current_mode);
+}
+
+static ssize_t mode_store(struct device *dev,
+			  struct device_attribute *attr,
+			  const char *buf, size_t size)
+{
+	struct appletb_kbd *kbd = dev_get_drvdata(dev);
+	u8 mode;
+	int ret;
+
+	ret = kstrtou8(buf, 0, &mode);
+	if (ret)
+		return ret;
+
+	if (mode > APPLETB_KBD_MODE_MAX)
+		return -EINVAL;
+
+	ret = appletb_kbd_set_mode(kbd, mode);
+
+	return ret < 0 ? ret : size;
+}
+static DEVICE_ATTR_RW(mode);
+
+static struct attribute *appletb_kbd_attrs[] = {
+	&dev_attr_mode.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(appletb_kbd);
+
+static int appletb_tb_key_to_slot(unsigned int code)
+{
+	switch (code) {
+	case KEY_ESC:
+		return 0;
+	case KEY_F1 ... KEY_F10:
+		return code - KEY_F1 + 1;
+	case KEY_F11 ... KEY_F12:
+		return code - KEY_F11 + 11;
+
+	default:
+		return -EINVAL;
+	}
+}
+
+static void appletb_inactivity_timer(struct timer_list *t)
+{
+	struct appletb_kbd *kbd = from_timer(kbd, t, inactivity_timer);
+
+	if (kbd->backlight_dev && appletb_tb_autodim) {
+		if (!kbd->has_dimmed) {
+			backlight_device_set_brightness(kbd->backlight_dev, 1);
+			kbd->has_dimmed = true;
+			mod_timer(&kbd->inactivity_timer, jiffies + msecs_to_jiffies(appletb_tb_idle_timeout * 1000));
+		} else if (!kbd->has_turned_off) {
+			backlight_device_set_brightness(kbd->backlight_dev, 0);
+			kbd->has_turned_off = true;
+		}
+	}
+}
+
+static void reset_inactivity_timer(struct appletb_kbd *kbd)
+{
+	if (kbd->backlight_dev && appletb_tb_autodim) {
+		if (kbd->has_dimmed || kbd->has_turned_off) {
+			backlight_device_set_brightness(kbd->backlight_dev, 2);
+			kbd->has_dimmed = false;
+			kbd->has_turned_off = false;
+		}
+		mod_timer(&kbd->inactivity_timer, jiffies + msecs_to_jiffies(appletb_tb_dim_timeout * 1000));
+	}
+}
+
+static int appletb_kbd_hid_event(struct hid_device *hdev, struct hid_field *field,
+				      struct hid_usage *usage, __s32 value)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+	struct key_entry *translation;
+	struct input_dev *input;
+	int slot;
+
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_KEYBOARD || usage->type != EV_KEY)
+		return 0;
+
+	input = field->hidinput->input;
+
+	/*
+	 * Skip non-touch-bar keys.
+	 *
+	 * Either the touch bar itself or usbhid generate a slew of key-down
+	 * events for all the meta keys. None of which we're at all interested
+	 * in.
+	 */
+	slot = appletb_tb_key_to_slot(usage->code);
+	if (slot < 0)
+		return 0;
+
+	reset_inactivity_timer(kbd);
+
+	translation = sparse_keymap_entry_from_scancode(input, usage->code);
+
+	if (translation && kbd->current_mode == APPLETB_KBD_MODE_SPCL) {
+		input_event(input, usage->type, translation->keycode, value);
+
+		return 1;
+	}
+
+	return kbd->current_mode == APPLETB_KBD_MODE_OFF;
+}
+
+static void appletb_kbd_inp_event(struct input_handle *handle, unsigned int type,
+			      unsigned int code, int value)
+{
+	struct appletb_kbd *kbd = handle->private;
+
+	reset_inactivity_timer(kbd);
+
+	if (type == EV_KEY && code == KEY_FN && appletb_tb_fn_toggle &&
+		(kbd->current_mode == APPLETB_KBD_MODE_SPCL ||
+		 kbd->current_mode == APPLETB_KBD_MODE_FN)) {
+		if (value == 1) {
+			kbd->saved_mode = kbd->current_mode;
+			appletb_kbd_set_mode(kbd, kbd->current_mode == APPLETB_KBD_MODE_SPCL
+						? APPLETB_KBD_MODE_FN : APPLETB_KBD_MODE_SPCL);
+		} else if (value == 0) {
+			if (kbd->saved_mode != kbd->current_mode)
+				appletb_kbd_set_mode(kbd, kbd->saved_mode);
+		}
+	}
+}
+
+static int appletb_kbd_inp_connect(struct input_handler *handler,
+			       struct input_dev *dev,
+			       const struct input_device_id *id)
+{
+	struct appletb_kbd *kbd = handler->private;
+	struct input_handle *handle;
+	int rc;
+
+	if (id->driver_info == APPLETB_DEVID_KEYBOARD) {
+		handle = &kbd->kbd_handle;
+		handle->name = "tbkbd";
+	} else if (id->driver_info == APPLETB_DEVID_TRACKPAD) {
+		handle = &kbd->tpd_handle;
+		handle->name = "tbtpd";
+	} else {
+		return -ENOENT;
+	}
+
+	if (handle->dev)
+		return -EEXIST;
+
+	handle->open = 0;
+	handle->dev = input_get_device(dev);
+	handle->handler = handler;
+	handle->private = kbd;
+
+	rc = input_register_handle(handle);
+	if (rc)
+		goto err_free_dev;
+
+	rc = input_open_device(handle);
+	if (rc)
+		goto err_unregister_handle;
+
+	return 0;
+
+ err_unregister_handle:
+	input_unregister_handle(handle);
+ err_free_dev:
+	input_put_device(handle->dev);
+	handle->dev = NULL;
+	return rc;
+}
+
+static void appletb_kbd_inp_disconnect(struct input_handle *handle)
+{
+	input_close_device(handle);
+	input_unregister_handle(handle);
+
+	input_put_device(handle->dev);
+	handle->dev = NULL;
+}
+
+static int appletb_kbd_input_configured(struct hid_device *hdev, struct hid_input *hidinput)
+{
+	int idx;
+	struct input_dev *input = hidinput->input;
+
+	/*
+	 * Clear various input capabilities that are blindly set by the hid
+	 * driver (usbkbd.c)
+	 */
+	memset(input->evbit, 0, sizeof(input->evbit));
+	memset(input->keybit, 0, sizeof(input->keybit));
+	memset(input->ledbit, 0, sizeof(input->ledbit));
+
+	__set_bit(EV_REP, input->evbit);
+
+	sparse_keymap_setup(input, appletb_kbd_keymap, NULL);
+
+	for (idx = 0; appletb_kbd_keymap[idx].type != KE_END; idx++)
+		input_set_capability(input, EV_KEY, appletb_kbd_keymap[idx].code);
+
+	return 0;
+}
+
+static const struct input_device_id appletb_kbd_input_devices[] = {
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_BUS |
+			INPUT_DEVICE_ID_MATCH_VENDOR |
+			INPUT_DEVICE_ID_MATCH_KEYBIT,
+		.bustype = BUS_USB,
+		.vendor = USB_VENDOR_ID_APPLE,
+		.keybit = { [BIT_WORD(KEY_FN)] = BIT_MASK(KEY_FN) },
+		.driver_info = APPLETB_DEVID_KEYBOARD,
+	},
+	{
+		.flags = INPUT_DEVICE_ID_MATCH_BUS |
+			INPUT_DEVICE_ID_MATCH_VENDOR |
+			INPUT_DEVICE_ID_MATCH_KEYBIT,
+		.bustype = BUS_USB,
+		.vendor = USB_VENDOR_ID_APPLE,
+		.keybit = { [BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH) },
+		.driver_info = APPLETB_DEVID_TRACKPAD,
+	},
+	{ }
+};
+
+static bool appletb_kbd_match_internal_device(struct input_handler *handler,
+					  struct input_dev *inp_dev)
+{
+	struct device *dev = &inp_dev->dev;
+
+	/* in kernel: dev && !is_usb_device(dev) */
+	while (dev && !(dev->type && dev->type->name &&
+			!strcmp(dev->type->name, "usb_device")))
+		dev = dev->parent;
+
+	/*
+	 * Apple labels all their internal keyboards and trackpads as such,
+	 * instead of maintaining an ever expanding list of product-id's we
+	 * just look at the device's product name.
+	 */
+	if (dev)
+		return !!strstr(to_usb_device(dev)->product, "Internal Keyboard");
+
+	return false;
+}
+
+static int appletb_kbd_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct appletb_kbd *kbd;
+	struct device *dev = &hdev->dev;
+	struct hid_field *mode_field;
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID parse failed\n");
+
+	mode_field = hid_find_field(hdev, HID_OUTPUT_REPORT,
+				    HID_GD_KEYBOARD, HID_USAGE_MODE);
+	if (!mode_field)
+		return -ENODEV;
+
+	kbd = devm_kzalloc(dev, sizeof(*kbd), GFP_KERNEL);
+	if (!kbd)
+		return -ENOMEM;
+
+	kbd->mode_field = mode_field;
+
+	ret = hid_hw_start(hdev, HID_CONNECT_HIDINPUT);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID hw start failed\n");
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		dev_err_probe(dev, ret, "HID hw open failed\n");
+		goto stop_hw;
+	}
+
+	kbd->backlight_dev = backlight_device_get_by_name("appletb_backlight");
+	if (!kbd->backlight_dev) {
+		dev_err_probe(dev, -ENODEV, "Failed to get backlight device\n");
+	} else {
+		backlight_device_set_brightness(kbd->backlight_dev, 2);
+		timer_setup(&kbd->inactivity_timer, appletb_inactivity_timer, 0);
+		mod_timer(&kbd->inactivity_timer, jiffies + msecs_to_jiffies(appletb_tb_dim_timeout * 1000));
+	}
+
+	kbd->inp_handler.event = appletb_kbd_inp_event;
+	kbd->inp_handler.connect = appletb_kbd_inp_connect;
+	kbd->inp_handler.disconnect = appletb_kbd_inp_disconnect;
+	kbd->inp_handler.name = "appletb";
+	kbd->inp_handler.id_table = appletb_kbd_input_devices;
+	kbd->inp_handler.match = appletb_kbd_match_internal_device;
+	kbd->inp_handler.private = kbd;
+
+	ret = input_register_handler(&kbd->inp_handler);
+	if (ret) {
+		dev_err_probe(dev, ret, "Unable to register keyboard handler\n");
+		goto close_hw;
+	}
+
+	ret = appletb_kbd_set_mode(kbd, appletb_tb_def_mode);
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to set touchbar mode\n");
+		goto close_hw;
+	}
+
+	hid_set_drvdata(hdev, kbd);
+
+	return 0;
+
+close_hw:
+	hid_hw_close(hdev);
+stop_hw:
+	hid_hw_stop(hdev);
+	return ret;
+}
+
+static void appletb_kbd_remove(struct hid_device *hdev)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+
+	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
+
+	input_unregister_handler(&kbd->inp_handler);
+	timer_delete_sync(&kbd->inactivity_timer);
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+#ifdef CONFIG_PM
+static int appletb_kbd_suspend(struct hid_device *hdev, pm_message_t msg)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+
+	kbd->saved_mode = kbd->current_mode;
+	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
+
+	return 0;
+}
+
+static int appletb_kbd_reset_resume(struct hid_device *hdev)
+{
+	struct appletb_kbd *kbd = hid_get_drvdata(hdev);
+
+	appletb_kbd_set_mode(kbd, kbd->saved_mode);
+
+	return 0;
+}
+#endif
+
+static const struct hid_device_id appletb_kbd_hid_ids[] = {
+	/* MacBook Pro's 2018, 2019, with T2 chip: iBridge Display */
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, appletb_kbd_hid_ids);
+
+static struct hid_driver appletb_kbd_hid_driver = {
+	.name = "hid-appletb-kbd",
+	.id_table = appletb_kbd_hid_ids,
+	.probe = appletb_kbd_probe,
+	.remove = appletb_kbd_remove,
+	.event = appletb_kbd_hid_event,
+	.input_configured = appletb_kbd_input_configured,
+#ifdef CONFIG_PM
+	.suspend = appletb_kbd_suspend,
+	.reset_resume = appletb_kbd_reset_resume,
+#endif
+	.driver.dev_groups = appletb_kbd_groups,
+};
+module_hid_driver(appletb_kbd_hid_driver);
+
+/* The backlight driver should be loaded before the keyboard driver is initialised */
+MODULE_SOFTDEP("pre: hid_appletb_bl");
+
+MODULE_AUTHOR("Ronald Tschalär");
+MODULE_AUTHOR("Kerem Karabay <kekrby@gmail.com>");
+MODULE_AUTHOR("Aditya Garg <gargaditya08@live.com>");
+MODULE_DESCRIPTION("MacBook Pro Touch Bar Keyboard Mode driver");
+MODULE_LICENSE("GPL");