Commit 9018eacb authored by Paul Pawlowski's avatar Paul Pawlowski Committed by Jiri Kosina
Browse files

HID: apple: Add support for keyboard backlight on certain T2 Macs. 



This patch introduces the requisite plumbing for supporting keyboard
backlight on T2-attached, USB exposed models. The quirk mechanism was
used to reuse the existing hid-apple driver.

Signed-off-by: default avatarPaul Pawlowski <paul@mrarm.io>
Signed-off-by: default avatarAun-Ali Zaidi <admin@kodeit.net>
Signed-off-by: default avatarAditya Garg <gargaditya08@live.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent cbfcfbfc

drivers/hid/hid-apple.c

+125 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
 *  Copyright (c) 2005 Michael Haboustak <mike-@cinci.rr.com> for Concept2, Inc

 *  Copyright (c) 2006-2007 Jiri Kosina

 *  Copyright (c) 2008 Jiri Slaby <jirislaby@gmail.com>

 *  Copyright (c) 2019 Paul Pawlowski <paul@mrarm.io>

 */



/*
@@ -33,6 +34,7 @@ 
/* BIT(7) reserved, was: APPLE_IGNORE_HIDINPUT */

#define APPLE_NUMLOCK_EMULATION	BIT(8)

#define APPLE_RDESC_BATTERY	BIT(9)

#define APPLE_BACKLIGHT_CTL	BIT(10)



#define APPLE_FLAG_FKEY		0x01
@@ -61,6 +63,12 @@ MODULE_PARM_DESC(swap_fn_leftctrl, "Swap the Fn and left Control keys. " 
		"(For people who want to keep PC keyboard muscle memory. "

		"[0] = as-is, Mac layout, 1 = swapped, PC layout)");



struct apple_sc_backlight {

	struct led_classdev cdev;

	struct hid_device *hdev;

	unsigned short backlight_off, backlight_on_min, backlight_on_max;

};



struct apple_sc {

	struct hid_device *hdev;

	unsigned long quirks;
@@ -68,6 +76,7 @@ struct apple_sc { 
	unsigned int fn_found;

	DECLARE_BITMAP(pressed_numlock, KEY_CNT);

	struct timer_list battery_timer;

	struct apple_sc_backlight *backlight;

};



struct apple_key_translation {
@@ -117,6 +126,20 @@ static const struct apple_key_translation magic_keyboard_2015_fn_keys[] = { 
	{ }

};



struct apple_backlight_config_report {

	u8 report_id;

	u8 version;

	u16 backlight_off, backlight_on_min, backlight_on_max;

};



struct apple_backlight_set_report {

	u8 report_id;

	u8 version;

	u16 backlight;

	u16 rate;

};





static const struct apple_key_translation apple2021_fn_keys[] = {

	{ KEY_BACKSPACE, KEY_DELETE },

	{ KEY_ENTER,	KEY_INSERT },
@@ -582,6 +605,105 @@ static int apple_input_configured(struct hid_device *hdev, 
	return 0;

}



static bool apple_backlight_check_support(struct hid_device *hdev)

{

	int i;

	unsigned int hid;

	struct hid_report *report;



	list_for_each_entry(report, &hdev->report_enum[HID_INPUT_REPORT].report_list, list) {

		for (i = 0; i < report->maxfield; i++) {

			hid = report->field[i]->usage->hid;

			if ((hid & HID_USAGE_PAGE) == HID_UP_MSVENDOR && (hid & HID_USAGE) == 0xf)

				return true;

		}

	}



	return false;

}



static int apple_backlight_set(struct hid_device *hdev, u16 value, u16 rate)

{

	int ret = 0;

	struct apple_backlight_set_report *rep;



	rep = kmalloc(sizeof(*rep), GFP_KERNEL);

	if (rep == NULL)

		return -ENOMEM;



	rep->report_id = 0xB0;

	rep->version = 1;

	rep->backlight = value;

	rep->rate = rate;



	ret = hid_hw_raw_request(hdev, 0xB0u, (u8 *) rep, sizeof(*rep),

				 HID_OUTPUT_REPORT, HID_REQ_SET_REPORT);



	kfree(rep);

	return ret;

}



static int apple_backlight_led_set(struct led_classdev *led_cdev,

	enum led_brightness brightness)

{

	struct apple_sc_backlight *backlight = container_of(led_cdev,

							    struct apple_sc_backlight, cdev);



	return apple_backlight_set(backlight->hdev, brightness, 0);

}



static int apple_backlight_init(struct hid_device *hdev)

{

	int ret;

	struct apple_sc *asc = hid_get_drvdata(hdev);

	struct apple_backlight_config_report *rep;



	if (!apple_backlight_check_support(hdev))

		return -EINVAL;



	rep = kmalloc(0x200, GFP_KERNEL);

	if (rep == NULL)

		return -ENOMEM;



	ret = hid_hw_raw_request(hdev, 0xBFu, (u8 *) rep, sizeof(*rep),

				 HID_FEATURE_REPORT, HID_REQ_GET_REPORT);

	if (ret < 0) {

		hid_err(hdev, "backlight request failed: %d\n", ret);

		goto cleanup_and_exit;

	}

	if (ret < 8 || rep->version != 1) {

		hid_err(hdev, "backlight config struct: bad version %i\n", rep->version);

		ret = -EINVAL;

		goto cleanup_and_exit;

	}



	hid_dbg(hdev, "backlight config: off=%u, on_min=%u, on_max=%u\n",

		rep->backlight_off, rep->backlight_on_min, rep->backlight_on_max);



	asc->backlight = devm_kzalloc(&hdev->dev, sizeof(*asc->backlight), GFP_KERNEL);

	if (!asc->backlight) {

		ret = -ENOMEM;

		goto cleanup_and_exit;

	}



	asc->backlight->hdev = hdev;

	asc->backlight->cdev.name = "apple::kbd_backlight";

	asc->backlight->cdev.max_brightness = rep->backlight_on_max;

	asc->backlight->cdev.brightness_set_blocking = apple_backlight_led_set;



	ret = apple_backlight_set(hdev, 0, 0);

	if (ret < 0) {

		hid_err(hdev, "backlight set request failed: %d\n", ret);

		goto cleanup_and_exit;

	}



	ret = devm_led_classdev_register(&hdev->dev, &asc->backlight->cdev);



cleanup_and_exit:

	kfree(rep);

	return ret;

}



static int apple_probe(struct hid_device *hdev,

		const struct hid_device_id *id)

{
@@ -617,6 +739,9 @@ static int apple_probe(struct hid_device *hdev, 
		  jiffies + msecs_to_jiffies(APPLE_BATTERY_TIMEOUT_MS));

	apple_fetch_battery(hdev);



	if (quirks & APPLE_BACKLIGHT_CTL)

		apple_backlight_init(hdev);



	return 0;

}