[PATCH RESEND v2 0/4] Touch Bar driver for Apple Macs with T2 Security Chip

[PATCH RESEND v2 0/4] Touch Bar driver for Apple Macs with T2 Security Chip

[Aditya Garg]

From: Aditya Garg <gargaditya08@live.com>

This patch series adds support for Touch Bar on found on MacBook Pro
models with T2 Security Chip. These drivers support the mode found on
Windows Bootcamp drivers.

V2: Added checks to the keyboard driver to ensure backlight driver is
initialised first.

Aditya Garg (2):
  HID: hid-appletb-kbd: add support for fn toggle between media and
    function mode
  HID: hid-appletb-kbd: add support for automatic brightness control
    while using the touchbar

Kerem Karabay (2):
  HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars
  HID: hid-appletb-kbd: add driver for the keyboard mode of Apple Touch
    Bars

 .../ABI/testing/sysfs-driver-hid-appletb-kbd  |  13 +
 drivers/hid/Kconfig                           |  25 +
 drivers/hid/Makefile                          |   2 +
 drivers/hid/hid-appletb-bl.c                  | 207 +++++++
 drivers/hid/hid-appletb-kbd.c                 | 506 ++++++++++++++++++
 drivers/hid/hid-quirks.c                      |   8 +-
 6 files changed, 759 insertions(+), 2 deletions(-)
 create mode 100644 Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
 create mode 100644 drivers/hid/hid-appletb-bl.c
 create mode 100644 drivers/hid/hid-appletb-kbd.c

-- 
2.43.0

[PATCH RESEND v2 1/4] HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

This commit adds a driver for the backlight of Apple Touch Bars on x86
Macs. Note that currently only T2 Macs are supported.

This driver is based on previous work done by Ronald Tschalär
<ronald@innovation.ch>.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Co-developed-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 drivers/hid/Kconfig          |  10 ++
 drivers/hid/Makefile         |   1 +
 drivers/hid/hid-appletb-bl.c | 207 +++++++++++++++++++++++++++++++++++
 drivers/hid/hid-quirks.c     |   4 +-
 4 files changed, 221 insertions(+), 1 deletion(-)
 create mode 100644 drivers/hid/hid-appletb-bl.c

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 4d2a89d65..f6678db27 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -148,6 +148,16 @@ config HID_APPLEIR
 
 	Say Y here if you want support for Apple infrared remote control.
 
+config HID_APPLETB_BL
+	tristate "Apple Touch Bar Backlight"
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want support for the backlight of Touch Bars on x86
+	  MacBook Pros.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hid-appletb-bl.
+
 config HID_ASUS
 	tristate "Asus"
 	depends on USB_HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 24de45f36..444d24cec 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_HID_ALPS)		+= hid-alps.o
 obj-$(CONFIG_HID_ACRUX)		+= hid-axff.o
 obj-$(CONFIG_HID_APPLE)		+= hid-apple.o
 obj-$(CONFIG_HID_APPLEIR)	+= hid-appleir.o
+obj-$(CONFIG_HID_APPLETB_BL)	+= hid-appletb-bl.o
 obj-$(CONFIG_HID_CREATIVE_SB0540)	+= hid-creative-sb0540.o
 obj-$(CONFIG_HID_ASUS)		+= hid-asus.o
 obj-$(CONFIG_HID_AUREAL)	+= hid-aureal.o
diff --git a/drivers/hid/hid-appletb-bl.c b/drivers/hid/hid-appletb-bl.c
new file mode 100644
index 000000000..819157686
--- /dev/null
+++ b/drivers/hid/hid-appletb-bl.c
@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple Touch Bar Backlight Driver
+ *
+ * Copyright (c) 2017-2018 Ronald Tschalär
+ * Copyright (c) 2022-2023 Kerem Karabay <kekrby@gmail.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/hid.h>
+#include <linux/backlight.h>
+#include <linux/device.h>
+
+#include "hid-ids.h"
+
+#define APPLETB_BL_ON			1
+#define APPLETB_BL_DIM			3
+#define APPLETB_BL_OFF			4
+
+#define HID_UP_APPLEVENDOR_TB_BL	0xff120000
+
+#define HID_VD_APPLE_TB_BRIGHTNESS	0xff120001
+#define HID_USAGE_AUX1			0xff120020
+#define HID_USAGE_BRIGHTNESS		0xff120021
+
+static int appletb_bl_def_brightness = 2;
+module_param_named(brightness, appletb_bl_def_brightness, int, 0444);
+MODULE_PARM_DESC(brightness, "Default brightness:\n"
+			 "    0 - Touchbar is off\n"
+			 "    1 - Dim brightness\n"
+			 "    [2] - Full brightness");
+
+struct appletb_bl {
+	struct hid_field *aux1_field, *brightness_field;
+	struct backlight_device *bdev;
+
+	bool full_on;
+};
+
+static const u8 appletb_bl_brightness_map[] = {
+	APPLETB_BL_OFF,
+	APPLETB_BL_DIM,
+	APPLETB_BL_ON,
+};
+
+static int appletb_bl_set_brightness(struct appletb_bl *bl, u8 brightness)
+{
+	struct hid_report *report = bl->brightness_field->report;
+	struct hid_device *hdev = report->device;
+	int ret;
+
+	ret = hid_set_field(bl->aux1_field, 0, 1);
+	if (ret) {
+		hid_err(hdev, "Failed to set auxiliary field (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	ret = hid_set_field(bl->brightness_field, 0, brightness);
+	if (ret) {
+		hid_err(hdev, "Failed to set brightness field (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	if (!bl->full_on) {
+		ret = hid_hw_power(hdev, PM_HINT_FULLON);
+		if (ret < 0) {
+			hid_err(hdev, "Device didn't power on (%pe)\n", ERR_PTR(ret));
+			return ret;
+		}
+
+		bl->full_on = true;
+	}
+
+	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
+
+	if (brightness == APPLETB_BL_OFF) {
+		hid_hw_power(hdev, PM_HINT_NORMAL);
+		bl->full_on = false;
+	}
+
+	return 0;
+}
+
+static int appletb_bl_update_status(struct backlight_device *bdev)
+{
+	struct appletb_bl *bl = bl_get_data(bdev);
+	u8 brightness;
+
+	if (backlight_is_blank(bdev))
+		brightness = APPLETB_BL_OFF;
+	else
+		brightness = appletb_bl_brightness_map[backlight_get_brightness(bdev)];
+
+	return appletb_bl_set_brightness(bl, brightness);
+}
+
+static const struct backlight_ops appletb_bl_backlight_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.update_status = appletb_bl_update_status,
+};
+
+static int appletb_bl_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct hid_field *aux1_field, *brightness_field;
+	struct backlight_properties bl_props = { 0 };
+	struct device *dev = &hdev->dev;
+	struct appletb_bl *bl;
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID parse failed\n");
+
+	aux1_field = hid_find_field(hdev, HID_FEATURE_REPORT,
+				    HID_VD_APPLE_TB_BRIGHTNESS, HID_USAGE_AUX1);
+
+	brightness_field = hid_find_field(hdev, HID_FEATURE_REPORT,
+					  HID_VD_APPLE_TB_BRIGHTNESS, HID_USAGE_BRIGHTNESS);
+
+	if (!aux1_field || !brightness_field)
+		return -ENODEV;
+
+	if (aux1_field->report != brightness_field->report)
+		return dev_err_probe(dev, -ENODEV, "Encountered unexpected report structure\n");
+
+	bl = devm_kzalloc(dev, sizeof(*bl), GFP_KERNEL);
+	if (!bl)
+		return -ENOMEM;
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DRIVER);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID hardware start failed\n");
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		dev_err_probe(dev, ret, "HID hardware open failed\n");
+		goto stop_hw;
+	}
+
+	bl->aux1_field = aux1_field;
+	bl->brightness_field = brightness_field;
+
+	if (appletb_bl_def_brightness == 0)
+		ret = appletb_bl_set_brightness(bl, APPLETB_BL_OFF);
+	else if (appletb_bl_def_brightness == 1)
+		ret = appletb_bl_set_brightness(bl, APPLETB_BL_DIM);
+	else
+		ret = appletb_bl_set_brightness(bl, APPLETB_BL_ON);
+
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to set touch bar brightness to off\n");
+		goto close_hw;
+	}
+
+	bl_props.type = BACKLIGHT_RAW;
+	bl_props.max_brightness = ARRAY_SIZE(appletb_bl_brightness_map) - 1;
+
+	bl->bdev = devm_backlight_device_register(dev, "appletb_backlight", dev, bl,
+						  &appletb_bl_backlight_ops, &bl_props);
+	if (IS_ERR(bl->bdev)) {
+		ret = PTR_ERR(bl->bdev);
+		dev_err_probe(dev, ret, "Failed to register backlight device\n");
+		goto close_hw;
+	}
+
+	hid_set_drvdata(hdev, bl);
+
+	return 0;
+
+close_hw:
+	hid_hw_close(hdev);
+stop_hw:
+	hid_hw_stop(hdev);
+
+	return ret;
+}
+
+static void appletb_bl_remove(struct hid_device *hdev)
+{
+	struct appletb_bl *bl = hid_get_drvdata(hdev);
+
+	appletb_bl_set_brightness(bl, APPLETB_BL_OFF);
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+static const struct hid_device_id appletb_bl_hid_ids[] = {
+	/* MacBook Pro's 2018, 2019, with T2 chip: iBridge DFR Brightness */
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, appletb_bl_hid_ids);
+
+static struct hid_driver appletb_bl_hid_driver = {
+	.name = "hid-appletb-bl",
+	.id_table = appletb_bl_hid_ids,
+	.probe = appletb_bl_probe,
+	.remove = appletb_bl_remove,
+};
+module_hid_driver(appletb_bl_hid_driver);
+
+MODULE_AUTHOR("Ronald Tschalär");
+MODULE_AUTHOR("Kerem Karabay <kekrby@gmail.com>");
+MODULE_DESCRIPTION("MacBookPro Touch Bar Backlight Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index e0bbf0c63..818d41a35 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -328,7 +328,6 @@ static const struct hid_device_id hid_have_special_driver[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_GEYSER1_TP_ONLY) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_2021) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_FINGERPRINT_2021) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
 #endif
 #if IS_ENABLED(CONFIG_HID_APPLEIR)
@@ -338,6 +337,9 @@ static const struct hid_device_id hid_have_special_driver[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL4) },
 	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL5) },
 #endif
+#if IS_ENABLED(CONFIG_HID_APPLETB_BL)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
+#endif
 #if IS_ENABLED(CONFIG_HID_ASUS)
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD) },
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_TOUCHPAD) },
-- 
2.43.0

[PATCH RESEND v2 3/4] HID: hid-appletb-kbd: add support for fn toggle between media and function mode

[Aditya Garg]

From: Aditya Garg <gargaditya08@live.com>

This patch adds support for the switching between the Media and Function
keys on the touchbar by pressing the Fn key on Apple Internal Keyboard.

Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 drivers/hid/hid-appletb-kbd.c | 128 ++++++++++++++++++++++++++++++++++
 1 file changed, 128 insertions(+)

diff --git a/drivers/hid/hid-appletb-kbd.c b/drivers/hid/hid-appletb-kbd.c
index 80c87396f..de5770500 100644
--- a/drivers/hid/hid-appletb-kbd.c
+++ b/drivers/hid/hid-appletb-kbd.c
@@ -26,6 +26,8 @@
 #define APPLETB_KBD_MODE_OFF	3
 #define APPLETB_KBD_MODE_MAX	APPLETB_KBD_MODE_OFF
 
+#define APPLETB_DEVID_KEYBOARD	1
+
 #define HID_USAGE_MODE		0x00ff0004
 
 static int appletb_tb_def_mode = APPLETB_KBD_MODE_SPCL;
@@ -35,11 +37,18 @@ MODULE_PARM_DESC(mode, "Default touchbar mode:\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");
+
 struct appletb_kbd {
 	struct hid_field *mode_field;
 
 	u8 saved_mode;
 	u8 current_mode;
+	struct input_handler inp_handler;
+	struct input_handle kbd_handle;
+
 };
 
 static const struct key_entry appletb_kbd_keymap[] = {
@@ -172,6 +181,75 @@ static int appletb_kbd_hid_event(struct hid_device *hdev, struct hid_field *fiel
 	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;
+
+	if (type == EV_KEY && code == KEY_FN && appletb_tb_fn_toggle) {
+		if (value == 1) {
+			kbd->saved_mode = kbd->current_mode;
+			if (kbd->current_mode == APPLETB_KBD_MODE_SPCL)
+				appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_FN);
+			else if (kbd->current_mode == APPLETB_KBD_MODE_FN)
+				appletb_kbd_set_mode(kbd, 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 {
+		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;
@@ -195,6 +273,40 @@ static int appletb_kbd_input_configured(struct hid_device *hdev, struct hid_inpu
 	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,
+	},
+	{ }
+};
+
+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;
@@ -227,6 +339,20 @@ static int appletb_kbd_probe(struct hid_device *hdev, const struct hid_device_id
 		goto stop_hw;
 	}
 
+	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");
@@ -250,6 +376,8 @@ static void appletb_kbd_remove(struct hid_device *hdev)
 
 	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
 
+	input_unregister_handler(&kbd->inp_handler);
+
 	hid_hw_close(hdev);
 	hid_hw_stop(hdev);
 }
-- 
2.43.0

[PATCH RESEND v2 4/4] HID: hid-appletb-kbd: add support for automatic brightness control while using the touchbar

[Aditya Garg]

From: Aditya Garg <gargaditya08@live.com>

On Windows, if there is no input by the user for 60 sec, the Touch Bar dims
automatically, and after further 15 sec, it turns off. On receiving input,
the Touch Bar resets the timer and goes back to full brightness. This patch
implements the same functionality.

Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
 drivers/hid/Kconfig           |  2 +
 drivers/hid/hid-appletb-kbd.c | 83 +++++++++++++++++++++++++++++++++--
 2 files changed, 81 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 5b16bfadc..4dadf42a2 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -161,8 +161,10 @@ config HID_APPLETB_BL
 config HID_APPLETB_KBD
 	tristate "Apple Touch Bar Keyboard Mode"
 	depends on USB_HID
+	depends on BACKLIGHT_CLASS_DEVICE
 	depends on INPUT
 	select INPUT_SPARSEKMAP
+	select HID_APPLETB_BL
 	help
 	  Say Y here if you want support for the keyboard mode (escape,
 	  function, media and brightness keys) of Touch Bars on x86 MacBook
diff --git a/drivers/hid/hid-appletb-kbd.c b/drivers/hid/hid-appletb-kbd.c
index de5770500..fa28a691d 100644
--- a/drivers/hid/hid-appletb-kbd.c
+++ b/drivers/hid/hid-appletb-kbd.c
@@ -16,6 +16,8 @@
 #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"
@@ -27,6 +29,7 @@
 #define APPLETB_KBD_MODE_MAX	APPLETB_KBD_MODE_OFF
 
 #define APPLETB_DEVID_KEYBOARD	1
+#define APPLETB_DEVID_TRACKPAD	2
 
 #define HID_USAGE_MODE		0x00ff0004
 
@@ -41,14 +44,29 @@ 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;
-
-	u8 saved_mode;
-	u8 current_mode;
 	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[] = {
@@ -146,6 +164,34 @@ static int appletb_tb_key_to_slot(unsigned int code)
 	}
 }
 
+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)
 {
@@ -170,6 +216,8 @@ static int appletb_kbd_hid_event(struct hid_device *hdev, struct hid_field *fiel
 	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) {
@@ -186,6 +234,8 @@ static void appletb_kbd_inp_event(struct input_handle *handle, unsigned int type
 {
 	struct appletb_kbd *kbd = handle->private;
 
+	reset_inactivity_timer(kbd);
+
 	if (type == EV_KEY && code == KEY_FN && appletb_tb_fn_toggle) {
 		if (value == 1) {
 			kbd->saved_mode = kbd->current_mode;
@@ -211,6 +261,9 @@ static int appletb_kbd_inp_connect(struct input_handler *handler,
 	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;
 	}
@@ -283,6 +336,15 @@ static const struct input_device_id appletb_kbd_input_devices[] = {
 		.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,
+	},
 	{ }
 };
 
@@ -339,6 +401,15 @@ static int appletb_kbd_probe(struct hid_device *hdev, const struct hid_device_id
 		goto stop_hw;
 	}
 
+	kbd->backlight_dev = backlight_device_get_by_name("appletb_backlight");
+		if (!kbd->backlight_dev)
+			dev_err_probe(dev, ret, "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;
@@ -377,6 +448,7 @@ static void appletb_kbd_remove(struct hid_device *hdev)
 	appletb_kbd_set_mode(kbd, APPLETB_KBD_MODE_OFF);
 
 	input_unregister_handler(&kbd->inp_handler);
+	del_timer_sync(&kbd->inactivity_timer);
 
 	hid_hw_close(hdev);
 	hid_hw_stop(hdev);
@@ -425,6 +497,9 @@ static struct hid_driver appletb_kbd_hid_driver = {
 };
 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_DESCRIPTION("MacBookPro Touch Bar Keyboard Mode Driver");
-- 
2.43.0

[PATCH RESEND v2 1/4] HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

This commit adds a driver for the backlight of Apple Touch Bars on x86
Macs. Note that currently only T2 Macs are supported.

This driver is based on previous work done by Ronald Tschalär
<ronald@innovation.ch>.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Co-developed-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
drivers/hid/Kconfig          |  10 ++
drivers/hid/Makefile         |   1 +
drivers/hid/hid-appletb-bl.c | 207 +++++++++++++++++++++++++++++++++++
drivers/hid/hid-quirks.c     |   4 +-
4 files changed, 221 insertions(+), 1 deletion(-)
create mode 100644 drivers/hid/hid-appletb-bl.c

diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index 4d2a89d65..f6678db27 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -148,6 +148,16 @@ config HID_APPLEIR

	Say Y here if you want support for Apple infrared remote control.

+config HID_APPLETB_BL
+	tristate "Apple Touch Bar Backlight"
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want support for the backlight of Touch Bars on x86
+	  MacBook Pros.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hid-appletb-bl.
+
config HID_ASUS
	tristate "Asus"
	depends on USB_HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 24de45f36..444d24cec 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_HID_ALPS)		+= hid-alps.o
obj-$(CONFIG_HID_ACRUX)		+= hid-axff.o
obj-$(CONFIG_HID_APPLE)		+= hid-apple.o
obj-$(CONFIG_HID_APPLEIR)	+= hid-appleir.o
+obj-$(CONFIG_HID_APPLETB_BL)	+= hid-appletb-bl.o
obj-$(CONFIG_HID_CREATIVE_SB0540)	+= hid-creative-sb0540.o
obj-$(CONFIG_HID_ASUS)		+= hid-asus.o
obj-$(CONFIG_HID_AUREAL)	+= hid-aureal.o
diff --git a/drivers/hid/hid-appletb-bl.c b/drivers/hid/hid-appletb-bl.c
new file mode 100644
index 000000000..819157686
--- /dev/null
+++ b/drivers/hid/hid-appletb-bl.c
@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple Touch Bar Backlight Driver
+ *
+ * Copyright (c) 2017-2018 Ronald Tschalär
+ * Copyright (c) 2022-2023 Kerem Karabay <kekrby@gmail.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/hid.h>
+#include <linux/backlight.h>
+#include <linux/device.h>
+
+#include "hid-ids.h"
+
+#define APPLETB_BL_ON			1
+#define APPLETB_BL_DIM			3
+#define APPLETB_BL_OFF			4
+
+#define HID_UP_APPLEVENDOR_TB_BL	0xff120000
+
+#define HID_VD_APPLE_TB_BRIGHTNESS	0xff120001
+#define HID_USAGE_AUX1			0xff120020
+#define HID_USAGE_BRIGHTNESS		0xff120021
+
+static int appletb_bl_def_brightness = 2;
+module_param_named(brightness, appletb_bl_def_brightness, int, 0444);
+MODULE_PARM_DESC(brightness, "Default brightness:\n"
+			 "    0 - Touchbar is off\n"
+			 "    1 - Dim brightness\n"
+			 "    [2] - Full brightness");
+
+struct appletb_bl {
+	struct hid_field *aux1_field, *brightness_field;
+	struct backlight_device *bdev;
+
+	bool full_on;
+};
+
+static const u8 appletb_bl_brightness_map[] = {
+	APPLETB_BL_OFF,
+	APPLETB_BL_DIM,
+	APPLETB_BL_ON,
+};
+
+static int appletb_bl_set_brightness(struct appletb_bl *bl, u8 brightness)
+{
+	struct hid_report *report = bl->brightness_field->report;
+	struct hid_device *hdev = report->device;
+	int ret;
+
+	ret = hid_set_field(bl->aux1_field, 0, 1);
+	if (ret) {
+		hid_err(hdev, "Failed to set auxiliary field (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	ret = hid_set_field(bl->brightness_field, 0, brightness);
+	if (ret) {
+		hid_err(hdev, "Failed to set brightness field (%pe)\n", ERR_PTR(ret));
+		return ret;
+	}
+
+	if (!bl->full_on) {
+		ret = hid_hw_power(hdev, PM_HINT_FULLON);
+		if (ret < 0) {
+			hid_err(hdev, "Device didn't power on (%pe)\n", ERR_PTR(ret));
+			return ret;
+		}
+
+		bl->full_on = true;
+	}
+
+	hid_hw_request(hdev, report, HID_REQ_SET_REPORT);
+
+	if (brightness == APPLETB_BL_OFF) {
+		hid_hw_power(hdev, PM_HINT_NORMAL);
+		bl->full_on = false;
+	}
+
+	return 0;
+}
+
+static int appletb_bl_update_status(struct backlight_device *bdev)
+{
+	struct appletb_bl *bl = bl_get_data(bdev);
+	u8 brightness;
+
+	if (backlight_is_blank(bdev))
+		brightness = APPLETB_BL_OFF;
+	else
+		brightness = appletb_bl_brightness_map[backlight_get_brightness(bdev)];
+
+	return appletb_bl_set_brightness(bl, brightness);
+}
+
+static const struct backlight_ops appletb_bl_backlight_ops = {
+	.options = BL_CORE_SUSPENDRESUME,
+	.update_status = appletb_bl_update_status,
+};
+
+static int appletb_bl_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	struct hid_field *aux1_field, *brightness_field;
+	struct backlight_properties bl_props = { 0 };
+	struct device *dev = &hdev->dev;
+	struct appletb_bl *bl;
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID parse failed\n");
+
+	aux1_field = hid_find_field(hdev, HID_FEATURE_REPORT,
+				    HID_VD_APPLE_TB_BRIGHTNESS, HID_USAGE_AUX1);
+
+	brightness_field = hid_find_field(hdev, HID_FEATURE_REPORT,
+					  HID_VD_APPLE_TB_BRIGHTNESS, HID_USAGE_BRIGHTNESS);
+
+	if (!aux1_field || !brightness_field)
+		return -ENODEV;
+
+	if (aux1_field->report != brightness_field->report)
+		return dev_err_probe(dev, -ENODEV, "Encountered unexpected report structure\n");
+
+	bl = devm_kzalloc(dev, sizeof(*bl), GFP_KERNEL);
+	if (!bl)
+		return -ENOMEM;
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DRIVER);
+	if (ret)
+		return dev_err_probe(dev, ret, "HID hardware start failed\n");
+
+	ret = hid_hw_open(hdev);
+	if (ret) {
+		dev_err_probe(dev, ret, "HID hardware open failed\n");
+		goto stop_hw;
+	}
+
+	bl->aux1_field = aux1_field;
+	bl->brightness_field = brightness_field;
+
+	if (appletb_bl_def_brightness == 0)
+		ret = appletb_bl_set_brightness(bl, APPLETB_BL_OFF);
+	else if (appletb_bl_def_brightness == 1)
+		ret = appletb_bl_set_brightness(bl, APPLETB_BL_DIM);
+	else
+		ret = appletb_bl_set_brightness(bl, APPLETB_BL_ON);
+
+	if (ret) {
+		dev_err_probe(dev, ret, "Failed to set touch bar brightness to off\n");
+		goto close_hw;
+	}
+
+	bl_props.type = BACKLIGHT_RAW;
+	bl_props.max_brightness = ARRAY_SIZE(appletb_bl_brightness_map) - 1;
+
+	bl->bdev = devm_backlight_device_register(dev, "appletb_backlight", dev, bl,
+						  &appletb_bl_backlight_ops, &bl_props);
+	if (IS_ERR(bl->bdev)) {
+		ret = PTR_ERR(bl->bdev);
+		dev_err_probe(dev, ret, "Failed to register backlight device\n");
+		goto close_hw;
+	}
+
+	hid_set_drvdata(hdev, bl);
+
+	return 0;
+
+close_hw:
+	hid_hw_close(hdev);
+stop_hw:
+	hid_hw_stop(hdev);
+
+	return ret;
+}
+
+static void appletb_bl_remove(struct hid_device *hdev)
+{
+	struct appletb_bl *bl = hid_get_drvdata(hdev);
+
+	appletb_bl_set_brightness(bl, APPLETB_BL_OFF);
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+static const struct hid_device_id appletb_bl_hid_ids[] = {
+	/* MacBook Pro's 2018, 2019, with T2 chip: iBridge DFR Brightness */
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, appletb_bl_hid_ids);
+
+static struct hid_driver appletb_bl_hid_driver = {
+	.name = "hid-appletb-bl",
+	.id_table = appletb_bl_hid_ids,
+	.probe = appletb_bl_probe,
+	.remove = appletb_bl_remove,
+};
+module_hid_driver(appletb_bl_hid_driver);
+
+MODULE_AUTHOR("Ronald Tschalär");
+MODULE_AUTHOR("Kerem Karabay <kekrby@gmail.com>");
+MODULE_DESCRIPTION("MacBookPro Touch Bar Backlight Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index e0bbf0c63..818d41a35 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -328,7 +328,6 @@ static const struct hid_device_id hid_have_special_driver[] = {
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_GEYSER1_TP_ONLY) },
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_2021) },
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_FINGERPRINT_2021) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
#endif
#if IS_ENABLED(CONFIG_HID_APPLEIR)
@@ -338,6 +337,9 @@ static const struct hid_device_id hid_have_special_driver[] = {
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL4) },
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL5) },
#endif
+#if IS_ENABLED(CONFIG_HID_APPLETB_BL)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
+#endif
#if IS_ENABLED(CONFIG_HID_ASUS)
	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD) },
	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_TOUCHPAD) },
-- 
2.43.0

[PATCH RESEND v2 2/4] HID: hid-appletb-kbd: add driver for the keyboard mode of Apple Touch Bars

[Aditya Garg]

From: Kerem Karabay <kekrby@gmail.com>

The Touch Bars found on x86 Macs support two USB configurations: one
where the device presents itself as a HID keyboard and can display
predefined sets of keys, and one where the operating system has full
control over what is displayed. This commit adds a driver for the
display functionality of the first configuration.

Note that currently only T2 Macs are supported.

This driver is based on previous work done by Ronald Tschalär
<ronald@innovation.ch>.

Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Co-developed-by: Aditya Garg <gargaditya08@live.com>
Signed-off-by: Aditya Garg <gargaditya08@live.com>
---
.../ABI/testing/sysfs-driver-hid-appletb-kbd  |  13 +
drivers/hid/Kconfig                           |  13 +
drivers/hid/Makefile                          |   1 +
drivers/hid/hid-appletb-kbd.c                 | 303 ++++++++++++++++++
drivers/hid/hid-quirks.c                      |   4 +-
5 files changed, 333 insertions(+), 1 deletion(-)
create mode 100644 Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
create mode 100644 drivers/hid/hid-appletb-kbd.c

diff --git a/Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd b/Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
new file mode 100644
index 000000000..2a19584d0
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-driver-hid-appletb-kbd
@@ -0,0 +1,13 @@
+What:		/sys/bus/hid/drivers/hid-appletb-kbd/<dev>/mode
+Date:		September, 2023
+KernelVersion:	6.5
+Contact:	linux-input@vger.kernel.org
+Description:
+		The set of keys displayed on the Touch Bar.
+		Valid values are:
+		== =================
+		0  Escape key only
+		1  Function keys
+		2  Media/brightness keys
+		3  None
+		== =================
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index f6678db27..5b16bfadc 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -158,6 +158,19 @@ config HID_APPLETB_BL
	  To compile this driver as a module, choose M here: the
	  module will be called hid-appletb-bl.

+config HID_APPLETB_KBD
+	tristate "Apple Touch Bar Keyboard Mode"
+	depends on USB_HID
+	depends on INPUT
+	select INPUT_SPARSEKMAP
+	help
+	  Say Y here if you want support for the keyboard mode (escape,
+	  function, media and brightness keys) of Touch Bars on x86 MacBook
+	  Pros.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called hid-appletb-kbd.
+
config HID_ASUS
	tristate "Asus"
	depends on USB_HID
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index 444d24cec..1989288e0 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -30,6 +30,7 @@ obj-$(CONFIG_HID_ACRUX)		+= hid-axff.o
obj-$(CONFIG_HID_APPLE)		+= hid-apple.o
obj-$(CONFIG_HID_APPLEIR)	+= hid-appleir.o
obj-$(CONFIG_HID_APPLETB_BL)	+= hid-appletb-bl.o
+obj-$(CONFIG_HID_APPLETB_KBD)	+= hid-appletb-kbd.o
obj-$(CONFIG_HID_CREATIVE_SB0540)	+= hid-creative-sb0540.o
obj-$(CONFIG_HID_ASUS)		+= hid-asus.o
obj-$(CONFIG_HID_AUREAL)	+= hid-aureal.o
diff --git a/drivers/hid/hid-appletb-kbd.c b/drivers/hid/hid-appletb-kbd.c
new file mode 100644
index 000000000..80c87396f
--- /dev/null
+++ b/drivers/hid/hid-appletb-kbd.c
@@ -0,0 +1,303 @@
+// 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 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/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 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");
+
+struct appletb_kbd {
+	struct hid_field *mode_field;
+
+	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);
+
+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 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;
+
+	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 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 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;
+	}
+
+	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);
+
+	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);
+
+MODULE_AUTHOR("Ronald Tschalär");
+MODULE_AUTHOR("Kerem Karabay <kekrby@gmail.com>");
+MODULE_DESCRIPTION("MacBookPro Touch Bar Keyboard Mode Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index 818d41a35..7c576d654 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -328,7 +328,6 @@ static const struct hid_device_id hid_have_special_driver[] = {
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_GEYSER1_TP_ONLY) },
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_2021) },
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_FINGERPRINT_2021) },
-	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
#endif
#if IS_ENABLED(CONFIG_HID_APPLEIR)
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_IRCONTROL) },
@@ -340,6 +339,9 @@ static const struct hid_device_id hid_have_special_driver[] = {
#if IS_ENABLED(CONFIG_HID_APPLETB_BL)
	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
#endif
+#if IS_ENABLED(CONFIG_HID_APPLETB_KBD)
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_DISPLAY) },
+#endif
#if IS_ENABLED(CONFIG_HID_ASUS)
	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_KEYBOARD) },
	{ HID_I2C_DEVICE(USB_VENDOR_ID_ASUSTEK, USB_DEVICE_ID_ASUSTEK_I2C_TOUCHPAD) },
-- 
2.43.0

Re: [PATCH RESEND v2 1/4] HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars

[Jiri Kosina]

On Mon, 3 Feb 2025, Aditya Garg wrote:

> From: Kerem Karabay <kekrby@gmail.com>
> 
> This commit adds a driver for the backlight of Apple Touch Bars on x86
> Macs. Note that currently only T2 Macs are supported.
> 
> This driver is based on previous work done by Ronald Tschalär
> <ronald@innovation.ch>.
> 
> Signed-off-by: Kerem Karabay <kekrby@gmail.com>
> Co-developed-by: Aditya Garg <gargaditya08@live.com>
> Signed-off-by: Aditya Garg <gargaditya08@live.com>
> ---
>  drivers/hid/Kconfig          |  10 ++
>  drivers/hid/Makefile         |   1 +
>  drivers/hid/hid-appletb-bl.c | 207 +++++++++++++++++++++++++++++++++++
>  drivers/hid/hid-quirks.c     |   4 +-
>  4 files changed, 221 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/hid/hid-appletb-bl.c
> 
> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> index 4d2a89d65..f6678db27 100644
> --- a/drivers/hid/Kconfig
> +++ b/drivers/hid/Kconfig
> @@ -148,6 +148,16 @@ config HID_APPLEIR
>  
>  	Say Y here if you want support for Apple infrared remote control.
>  
> +config HID_APPLETB_BL
> +	tristate "Apple Touch Bar Backlight"
> +	depends on BACKLIGHT_CLASS_DEVICE
> +	help
> +	  Say Y here if you want support for the backlight of Touch Bars on x86
> +	  MacBook Pros.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called hid-appletb-bl.
> +
>  config HID_ASUS
>  	tristate "Asus"
>  	depends on USB_HID
> diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> index 24de45f36..444d24cec 100644
> --- a/drivers/hid/Makefile
> +++ b/drivers/hid/Makefile
> @@ -29,6 +29,7 @@ obj-$(CONFIG_HID_ALPS)		+= hid-alps.o
>  obj-$(CONFIG_HID_ACRUX)		+= hid-axff.o
>  obj-$(CONFIG_HID_APPLE)		+= hid-apple.o
>  obj-$(CONFIG_HID_APPLEIR)	+= hid-appleir.o
> +obj-$(CONFIG_HID_APPLETB_BL)	+= hid-appletb-bl.o

Is there a reason not to build hid-appletb-bl into hid-apple(.ko) driver 
proper?

Otherwise the code looks good to me, but I'd prefer to have this built-in 
as we generally try to keep things contained in one single per-vendor HID 
driver.

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH RESEND v2 1/4] HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars

[Aditya Garg]

Hi Jiri

> On 4 Feb 2025, at 3:25 AM, Jiri Kosina <jikos@kernel.org> wrote:
> 
> On Mon, 3 Feb 2025, Aditya Garg wrote:
> 
>> From: Kerem Karabay <kekrby@gmail.com>
>> 
>> This commit adds a driver for the backlight of Apple Touch Bars on x86
>> Macs. Note that currently only T2 Macs are supported.
>> 
>> This driver is based on previous work done by Ronald Tschalär
>> <ronald@innovation.ch>.
>> 
>> Signed-off-by: Kerem Karabay <kekrby@gmail.com>
>> Co-developed-by: Aditya Garg <gargaditya08@live.com>
>> Signed-off-by: Aditya Garg <gargaditya08@live.com>
>> ---
>> drivers/hid/Kconfig          |  10 ++
>> drivers/hid/Makefile         |   1 +
>> drivers/hid/hid-appletb-bl.c | 207 +++++++++++++++++++++++++++++++++++
>> drivers/hid/hid-quirks.c     |   4 +-
>> 4 files changed, 221 insertions(+), 1 deletion(-)
>> create mode 100644 drivers/hid/hid-appletb-bl.c
>> 
>> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
>> index 4d2a89d65..f6678db27 100644
>> --- a/drivers/hid/Kconfig
>> +++ b/drivers/hid/Kconfig
>> @@ -148,6 +148,16 @@ config HID_APPLEIR
>> 
>>    Say Y here if you want support for Apple infrared remote control.
>> 
>> +config HID_APPLETB_BL
>> +    tristate "Apple Touch Bar Backlight"
>> +    depends on BACKLIGHT_CLASS_DEVICE
>> +    help
>> +      Say Y here if you want support for the backlight of Touch Bars on x86
>> +      MacBook Pros.
>> +
>> +      To compile this driver as a module, choose M here: the
>> +      module will be called hid-appletb-bl.
>> +
>> config HID_ASUS
>>    tristate "Asus"
>>    depends on USB_HID
>> diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
>> index 24de45f36..444d24cec 100644
>> --- a/drivers/hid/Makefile
>> +++ b/drivers/hid/Makefile
>> @@ -29,6 +29,7 @@ obj-$(CONFIG_HID_ALPS)        += hid-alps.o
>> obj-$(CONFIG_HID_ACRUX)        += hid-axff.o
>> obj-$(CONFIG_HID_APPLE)        += hid-apple.o
>> obj-$(CONFIG_HID_APPLEIR)    += hid-appleir.o
>> +obj-$(CONFIG_HID_APPLETB_BL)    += hid-appletb-bl.o
> 
> Is there a reason not to build hid-appletb-bl into hid-apple(.ko) driver
> proper?
> 

You might have noticed that the hid-apple driver has code for the magic backlight. Now we have a case of MacBook Air 2020, which does not have a touchbar but still shows presence of the touchbar backlight device, just because it needs it for the keyboard backlight. In case we merge both the backlight and touchbar code in a driver, on that model, the backlight breaks. If kept separate, the touchbar driver simply doesn't load and backlight works.

In the future, we also shall send another driver, which shall support the macOS mode of the touchbar, that is we can use the touchbar as a second display. It shall be a drm driver and both current and the drm driver need the touchbar backlight driver in common.
> Otherwise the code looks good to me, but I'd prefer to have this built-in
> as we generally try to keep things contained in one single per-vendor HID
> driver.
> 
> Thanks,
> 
> --
> Jiri Kosina
> SUSE Labs
> 

Re: [PATCH RESEND v2 1/4] HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars

[Jiri Kosina]

On Tue, 4 Feb 2025, Aditya Garg wrote:

> You might have noticed that the hid-apple driver has code for the magic 
> backlight. Now we have a case of MacBook Air 2020, which does not have a 
> touchbar but still shows presence of the touchbar backlight device, just 
> because it needs it for the keyboard backlight. In case we merge both 
> the backlight and touchbar code in a driver, on that model, the 
> backlight breaks. If kept separate, the touchbar driver simply doesn't 
> load and backlight works.

Sorry for being dense, but does that mean that it's either hid-appletb-bl 
or hid-apple, but never both to make a good user experience on those 
devices?

If so, can you please point out what exactly is the reason?

Either those have different VID/PID combination, and then it can be easily 
made conditional both in code and in runtime.
Are we talking about conflicting VID/PID combinations, some of them 
needing current hid-apple, and some of them needing (in a mutually 
exclusive way) hid-appletb-bl?

Thanks,

-- 
Jiri Kosina
SUSE Labs

Re: [PATCH RESEND v2 1/4] HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars

[Aditya Garg]

> On 4 Feb 2025, at 7:47 AM, Jiri Kosina <jikos@kernel.org> wrote:
> 
> On Tue, 4 Feb 2025, Aditya Garg wrote:
> 
>> You might have noticed that the hid-apple driver has code for the magic
>> backlight. Now we have a case of MacBook Air 2020, which does not have a
>> touchbar but still shows presence of the touchbar backlight device, just
>> because it needs it for the keyboard backlight. In case we merge both
>> the backlight and touchbar code in a driver, on that model, the
>> backlight breaks. If kept separate, the touchbar driver simply doesn't
>> load and backlight works.
> 
> Sorry for being dense, but does that mean that it's either hid-appletb-bl
> or hid-apple, but never both to make a good user experience on those
> devices?
> 
> If so, can you please point out what exactly is the reason?
> 
> Either those have different VID/PID combination, and then it can be easily
> made conditional both in code and in runtime.
> Are we talking about conflicting VID/PID combinations, some of them
> needing current hid-apple, and some of them needing (in a mutually
> exclusive way) hid-appletb-bl?
> 

The driver uses the 0th interface for managing the touchbar and the 1st interface for backlight, but there is no touchbar on MacBook Air 2020, so the 0th interface is used for backlight on that.

I remember the author trying various combinations, but having a separate driver was the most feasible option, both for backlight, and the drivers for windows and macOS mode.

> Thanks,
> 
> --
> Jiri Kosina
> SUSE Labs
> 

Re: [PATCH RESEND v2 1/4] HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars

[Aditya Garg]

> On 4 Feb 2025, at 7:47 AM, Jiri Kosina <jikos@kernel.org> wrote:
> 
> On Tue, 4 Feb 2025, Aditya Garg wrote:
> 
>> You might have noticed that the hid-apple driver has code for the magic
>> backlight. Now we have a case of MacBook Air 2020, which does not have a
>> touchbar but still shows presence of the touchbar backlight device, just
>> because it needs it for the keyboard backlight. In case we merge both
>> the backlight and touchbar code in a driver, on that model, the
>> backlight breaks. If kept separate, the touchbar driver simply doesn't
>> load and backlight works.
> 
> Sorry for being dense, but does that mean that it's either hid-appletb-bl
> or hid-apple, but never both to make a good user experience on those
> devices?
> 
> If so, can you please point out what exactly is the reason?
> 
> Either those have different VID/PID combination, and then it can be easily
> made conditional both in code and in runtime.
> Are we talking about conflicting VID/PID combinations, some of them
> needing current hid-apple, and some of them needing (in a mutually
> exclusive way) hid-appletb-bl?
> 

Just to clarify a bit more,

The touchbar backlight device is 05ac:8102, in all the models with magic backlight, that is, with as well as without touchbar. The MacBook Air 2020 is the only model with this device but not having a touchbar.

This device is responsible for both the touchbar brightness and the keyboard backlight, the 0th interface being responsible for keyboard backlight on Air and 1st on others.
> Thanks,
> 
> --
> Jiri Kosina
> SUSE Labs
> 

Re: [PATCH RESEND v2 1/4] HID: hid-appletb-bl: add driver for the backlight of Apple Touch Bars

[Jiri Kosina]

On Wed, 5 Feb 2025, Aditya Garg wrote:

> > Sorry for being dense, but does that mean that it's either 
> > hid-appletb-bl or hid-apple, but never both to make a good user 
> > experience on those devices?
> > 
> > If so, can you please point out what exactly is the reason?
> > 
> > Either those have different VID/PID combination, and then it can be easily
> > made conditional both in code and in runtime.
> > Are we talking about conflicting VID/PID combinations, some of them
> > needing current hid-apple, and some of them needing (in a mutually
> > exclusive way) hid-appletb-bl?
> > 
> 
> Just to clarify a bit more,
> 
> The touchbar backlight device is 05ac:8102, in all the models with magic 
> backlight, that is, with as well as without touchbar. The MacBook Air 
> 2020 is the only model with this device but not having a touchbar.
> 
> This device is responsible for both the touchbar brightness and the 
> keyboard backlight, the 0th interface being responsible for keyboard 
> backlight on Air and 1st on others.

Ah, wow, ok, then it's indeed really messy. Thanks for the explanation.

-- 
Jiri Kosina
SUSE Labs