HID: apple: Add support for magic keyboard backlight on T2 Macs

Commit Message

Aditya Garg July 1, 2024, 10:45 a.m. UTC

From: Orlando Chamberlain <[e-mail]>

Unlike T2 Macs with Butterfly keyboard, who have their keyboard backlight
on the USB device the T2 Macs with Magic keyboard have their backlight on
the Touchbar backlight device (05ac:8102). 

Support for Butterfly keyboards has already been added in 9018eacbe623
("HID: apple: Add support for keyboard backlight on certain T2 Macs.").
This patch adds support for the Magic keyboards.

Co-developed-by: Aditya Garg <[e-mail]>
Signed-off-by: Aditya Garg <[e-mail]>
Signed-off-by: Orlando Chamberlain <[e-mail]>
---
 drivers/hid/hid-apple.c | 87 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 86 insertions(+), 1 deletion(-)

Comments

Aditya Garg July 1, 2024, 6:19 p.m. UTC | #1

Apparently this patch is breaking touchbar functionality is some cases.

Jiri we previously had sent this as a separate driver, but you asked us to add it to hid-apple. Do you still think a separate driver is bad?

> On 1 Jul 2024, at 4:15 PM, Aditya Garg <[e-mail]> wrote:
> 
> From: Orlando Chamberlain <[e-mail]>
> 
> Unlike T2 Macs with Butterfly keyboard, who have their keyboard backlight
> on the USB device the T2 Macs with Magic keyboard have their backlight on
> the Touchbar backlight device (05ac:8102).
> 
> Support for Butterfly keyboards has already been added in 9018eacbe623
> ("HID: apple: Add support for keyboard backlight on certain T2 Macs.").
> This patch adds support for the Magic keyboards.
> 
> Co-developed-by: Aditya Garg <[e-mail]>
> Signed-off-by: Aditya Garg <[e-mail]>
> Signed-off-by: Orlando Chamberlain <[e-mail]>
> ---
> drivers/hid/hid-apple.c | 87 ++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 86 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hid/hid-apple.c b/drivers/hid/hid-apple.c
> index bd022e004..db279948c 100644
> --- a/drivers/hid/hid-apple.c
> +++ b/drivers/hid/hid-apple.c
> @@ -8,6 +8,8 @@
>  *  Copyright (c) 2006-2007 Jiri Kosina
>  *  Copyright (c) 2008 Jiri Slaby <[e-mail]>
>  *  Copyright (c) 2019 Paul Pawlowski <[e-mail]>
> + *  Copyright (c) 2023 Orlando Chamberlain <[e-mail]>
> + *  Copyright (c) 2024 Aditya Garg <[e-mail]>
>  */
> 
> /*
> @@ -23,6 +25,7 @@
> #include <linux/timer.h>
> #include <linux/string.h>
> #include <linux/leds.h>
> +#include <dt-bindings/leds/common.h>
> 
> #include "hid-ids.h"
> 
> @@ -37,13 +40,18 @@
> #define APPLE_NUMLOCK_EMULATION    BIT(8)
> #define APPLE_RDESC_BATTERY    BIT(9)
> #define APPLE_BACKLIGHT_CTL    BIT(10)
> -#define APPLE_IS_NON_APPLE    BIT(11)
> +#define APPLE_MAGIC_BACKLIGHT    BIT(11)
> +#define APPLE_IS_NON_APPLE    BIT(12)
> 
> #define APPLE_FLAG_FKEY        0x01
> 
> #define HID_COUNTRY_INTERNATIONAL_ISO    13
> #define APPLE_BATTERY_TIMEOUT_MS    60000
> 
> +#define HID_USAGE_MAGIC_BL            0xff00000f
> +#define APPLE_MAGIC_REPORT_ID_POWER        3
> +#define APPLE_MAGIC_REPORT_ID_BRIGHTNESS    1
> +
> static unsigned int fnmode = 3;
> module_param(fnmode, uint, 0644);
> MODULE_PARM_DESC(fnmode, "Mode of fn key on Apple keyboards (0 = disabled, "
> @@ -81,6 +89,12 @@ struct apple_sc_backlight {
>    struct hid_device *hdev;
> };
> 
> +struct apple_magic_backlight {
> +    struct led_classdev cdev;
> +    struct hid_report *brightness;
> +    struct hid_report *power;
> +};
> +
> struct apple_sc {
>    struct hid_device *hdev;
>    unsigned long quirks;
> @@ -822,6 +836,72 @@ static int apple_backlight_init(struct hid_device *hdev)
>    return ret;
> }
> 
> +static void apple_magic_backlight_report_set(struct hid_report *rep, s32 value, u8 rate)
> +{
> +    rep->field[0]->value[0] = value;
> +    rep->field[1]->value[0] = 0x5e; /* Mimic Windows */
> +    rep->field[1]->value[0] |= rate << 8;
> +
> +    hid_hw_request(rep->device, rep, HID_REQ_SET_REPORT);
> +}
> +
> +static void apple_magic_backlight_set(struct apple_magic_backlight *backlight,
> +                     int brightness, char rate)
> +{
> +    apple_magic_backlight_report_set(backlight->power, brightness ? 1 : 0, rate);
> +    if (brightness)
> +        apple_magic_backlight_report_set(backlight->brightness, brightness, rate);
> +}
> +
> +static int apple_magic_backlight_led_set(struct led_classdev *led_cdev,
> +                     enum led_brightness brightness)
> +{
> +    struct apple_magic_backlight *backlight = container_of(led_cdev,
> +            struct apple_magic_backlight, cdev);
> +
> +    apple_magic_backlight_set(backlight, brightness, 1);
> +    return 0;
> +}
> +
> +static int apple_magic_backlight_init(struct hid_device *hdev)
> +{
> +    struct apple_magic_backlight *backlight;
> +    int rc;
> +
> +    /*
> +     * Ensure this usb endpoint is for the keyboard backlight, not touchbar
> +     * backlight.
> +     */
> +    if (hdev->collection[0].usage != HID_USAGE_MAGIC_BL)
> +        return -ENODEV;
> +
> +    backlight = devm_kzalloc(&hdev->dev, sizeof(*backlight), GFP_KERNEL);
> +    if (!backlight)
> +        return -ENOMEM;
> +
> +    backlight->brightness = hid_register_report(hdev, HID_FEATURE_REPORT,
> +            APPLE_MAGIC_REPORT_ID_BRIGHTNESS, 0);
> +    backlight->power = hid_register_report(hdev, HID_FEATURE_REPORT,
> +            APPLE_MAGIC_REPORT_ID_POWER, 0);
> +
> +    if (!backlight->brightness || !backlight->power) {
> +        rc = -ENODEV;
> +        goto hw_stop;
> +    }
> +
> +    backlight->cdev.name = ":white:" LED_FUNCTION_KBD_BACKLIGHT;
> +    backlight->cdev.max_brightness = backlight->brightness->field[0]->logical_maximum;
> +    backlight->cdev.brightness_set_blocking = apple_magic_backlight_led_set;
> +
> +    apple_magic_backlight_set(backlight, 0, 0);
> +
> +    return devm_led_classdev_register(&hdev->dev, &backlight->cdev);
> +
> +hw_stop:
> +    hid_hw_stop(hdev);
> +    return rc;
> +}
> +
> static int apple_probe(struct hid_device *hdev,
>        const struct hid_device_id *id)
> {
> @@ -860,6 +940,9 @@ static int apple_probe(struct hid_device *hdev,
>    if (quirks & APPLE_BACKLIGHT_CTL)
>        apple_backlight_init(hdev);
> 
> +    if (quirks & APPLE_MAGIC_BACKLIGHT)
> +        apple_magic_backlight_init(hdev);
> +
>    return 0;
> }
> 
> @@ -1073,6 +1156,8 @@ static const struct hid_device_id apple_devices[] = {
>        .driver_data = APPLE_HAS_FN | APPLE_ISO_TILDE_QUIRK | APPLE_RDESC_BATTERY },
>    { HID_BLUETOOTH_DEVICE(BT_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_NUMPAD_2021),
>        .driver_data = APPLE_HAS_FN | APPLE_ISO_TILDE_QUIRK },
> +    { HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT),
> +        .driver_data = APPLE_MAGIC_BACKLIGHT },
> 
>    { }
> };
> --
> 2.43.0
>

Orlando Chamberlain July 1, 2024, 10:48 p.m. UTC | #2

> On 2 Jul 2024, at 4:19 AM, Aditya Garg <[e-mail]> wrote:
> Apparently this patch is breaking touchbar functionality is some cases.

I think this is because apple_magic_backlight_init will return an error when it finds the touchbar interface, but this return value is not checked, so hid-apple still binds to the touchbar backlight.

This should be fixable so I don't think we need to still have the separate driver.

>> 
>> static int apple_probe(struct hid_device *hdev,
>>       const struct hid_device_id *id)
>> {
>> @@ -860,6 +940,9 @@ static int apple_probe(struct hid_device *hdev,
>>   if (quirks & APPLE_BACKLIGHT_CTL)
>>       apple_backlight_init(hdev);
>> 
>> +    if (quirks & APPLE_MAGIC_BACKLIGHT)
>> +        apple_magic_backlight_init(hdev);

return value isn't checked here ^, we return 0 unconditionally below.

>> +
>>   return 0;
>> }

Orlando Chamberlain July 1, 2024, 10:57 p.m. UTC | #3

> On 2 Jul 2024, at 8:48 AM, Orlando Chamberlain <[e-mail]> wrote:
> 
>> On 2 Jul 2024, at 4:19 AM, Aditya Garg <[e-mail]> wrote:
>> Apparently this patch is breaking touchbar functionality is some cases.
> 
> I think this is because apple_magic_backlight_init will return an error when it finds the touchbar interface, but this return value is not checked, so hid-apple still binds to the touchbar backlight.

We may also need to make sure hid_hw_stop is called in this case. Perhaps we can move this logic from apple_magic_backlight_init to apple_probe?

> 
> This should be fixable so I don't think we need to still have the separate driver.
> 
>>> 
>>> static int apple_probe(struct hid_device *hdev,
>>>      const struct hid_device_id *id)
>>> {
>>> @@ -860,6 +940,9 @@ static int apple_probe(struct hid_device *hdev,
>>>  if (quirks & APPLE_BACKLIGHT_CTL)
>>>      apple_backlight_init(hdev);
>>> 
>>> +    if (quirks & APPLE_MAGIC_BACKLIGHT)
>>> +        apple_magic_backlight_init(hdev);
> 
> return value isn't checked here ^, we return 0 unconditionally below.
> 
>>> +
>>>  return 0;
>>> }

Aditya Garg July 2, 2024, 9:50 a.m. UTC | #4

Hi Orlando

I resubmitted the patch which included only the backlight driver had no replies. Let's see if jiri is fine with the separate driver or not.

> On 2 Jul 2024, at 4:27 AM, Orlando Chamberlain <[e-mail]> wrote:
> 
> 
> 
>>> On 2 Jul 2024, at 8:48 AM, Orlando Chamberlain <[e-mail]> wrote:
>>> 
>>>> On 2 Jul 2024, at 4:19 AM, Aditya Garg <[e-mail]> wrote:
>>> Apparently this patch is breaking touchbar functionality is some cases.
>> 
>> I think this is because apple_magic_backlight_init will return an error when it finds the touchbar interface, but this return value is not checked, so hid-apple still binds to the touchbar backlight.
> 
> We may also need to make sure hid_hw_stop is called in this case. Perhaps we can move this logic from apple_magic_backlight_init to apple_probe?
> 
>> 
>> This should be fixable so I don't think we need to still have the separate driver.
>> 
>>>> 
>>>> static int apple_probe(struct hid_device *hdev,
>>>>     const struct hid_device_id *id)
>>>> {
>>>> @@ -860,6 +940,9 @@ static int apple_probe(struct hid_device *hdev,
>>>> if (quirks & APPLE_BACKLIGHT_CTL)
>>>>     apple_backlight_init(hdev);
>>>> 
>>>> +    if (quirks & APPLE_MAGIC_BACKLIGHT)
>>>> +        apple_magic_backlight_init(hdev);
>> 
>> return value isn't checked here ^, we return 0 unconditionally below.
>> 
>>>> +
>>>> return 0;
>>>> }

Aditya Garg July 3, 2024, 11:13 a.m. UTC | #5

> On 2 Jul 2024, at 4:27 AM, Orlando Chamberlain <[e-mail]> wrote:
> 
> 
> 
>> On 2 Jul 2024, at 8:48 AM, Orlando Chamberlain <[e-mail]> wrote:
>> 
>>> On 2 Jul 2024, at 4:19 AM, Aditya Garg <[e-mail]> wrote:
>>> Apparently this patch is breaking touchbar functionality is some cases.
>> 
>> I think this is because apple_magic_backlight_init will return an error when it finds the touchbar interface, but this return value is not checked, so hid-apple still binds to the touchbar backlight.
> 
> We may also need to make sure hid_hw_stop is called in this case. Perhaps we can move this logic from apple_magic_backlight_init to apple_probe?
> 
Thanks for your help Orlando. Sending a working and well tested version 2
>> 
>> This should be fixable so I don't think we need to still have the separate driver.
>> 
>>>> 
>>>> static int apple_probe(struct hid_device *hdev,
>>>>     const struct hid_device_id *id)
>>>> {
>>>> @@ -860,6 +940,9 @@ static int apple_probe(struct hid_device *hdev,
>>>> if (quirks & APPLE_BACKLIGHT_CTL)
>>>>     apple_backlight_init(hdev);
>>>> 
>>>> +    if (quirks & APPLE_MAGIC_BACKLIGHT)
>>>> +        apple_magic_backlight_init(hdev);
>> 
>> return value isn't checked here ^, we return 0 unconditionally below.
>> 
>>>> +
>>>> return 0;
>>>> }

Patch

diff --git a/drivers/hid/hid-apple.c b/drivers/hid/hid-apple.c
index bd022e004..db279948c 100644
--- a/drivers/hid/hid-apple.c
+++ b/drivers/hid/hid-apple.c
@@ -8,6 +8,8 @@ 
  *  Copyright (c) 2006-2007 Jiri Kosina
  *  Copyright (c) 2008 Jiri Slaby <[e-mail]>
  *  Copyright (c) 2019 Paul Pawlowski <[e-mail]>
+ *  Copyright (c) 2023 Orlando Chamberlain <[e-mail]>
+ *  Copyright (c) 2024 Aditya Garg <[e-mail]>
  */
 
 /*
@@ -23,6 +25,7 @@ 
 #include <linux/timer.h>
 #include <linux/string.h>
 #include <linux/leds.h>
+#include <dt-bindings/leds/common.h>
 
 #include "hid-ids.h"
 
@@ -37,13 +40,18 @@ 
 #define APPLE_NUMLOCK_EMULATION	BIT(8)
 #define APPLE_RDESC_BATTERY	BIT(9)
 #define APPLE_BACKLIGHT_CTL	BIT(10)
-#define APPLE_IS_NON_APPLE	BIT(11)
+#define APPLE_MAGIC_BACKLIGHT	BIT(11)
+#define APPLE_IS_NON_APPLE	BIT(12)
 
 #define APPLE_FLAG_FKEY		0x01
 
 #define HID_COUNTRY_INTERNATIONAL_ISO	13
 #define APPLE_BATTERY_TIMEOUT_MS	60000
 
+#define HID_USAGE_MAGIC_BL			0xff00000f
+#define APPLE_MAGIC_REPORT_ID_POWER		3
+#define APPLE_MAGIC_REPORT_ID_BRIGHTNESS	1
+
 static unsigned int fnmode = 3;
 module_param(fnmode, uint, 0644);
 MODULE_PARM_DESC(fnmode, "Mode of fn key on Apple keyboards (0 = disabled, "
@@ -81,6 +89,12 @@  struct apple_sc_backlight {
 	struct hid_device *hdev;
 };
 
+struct apple_magic_backlight {
+	struct led_classdev cdev;
+	struct hid_report *brightness;
+	struct hid_report *power;
+};
+
 struct apple_sc {
 	struct hid_device *hdev;
 	unsigned long quirks;
@@ -822,6 +836,72 @@  static int apple_backlight_init(struct hid_device *hdev)
 	return ret;
 }
 
+static void apple_magic_backlight_report_set(struct hid_report *rep, s32 value, u8 rate)
+{
+	rep->field[0]->value[0] = value;
+	rep->field[1]->value[0] = 0x5e; /* Mimic Windows */
+	rep->field[1]->value[0] |= rate << 8;
+
+	hid_hw_request(rep->device, rep, HID_REQ_SET_REPORT);
+}
+
+static void apple_magic_backlight_set(struct apple_magic_backlight *backlight,
+				     int brightness, char rate)
+{
+	apple_magic_backlight_report_set(backlight->power, brightness ? 1 : 0, rate);
+	if (brightness)
+		apple_magic_backlight_report_set(backlight->brightness, brightness, rate);
+}
+
+static int apple_magic_backlight_led_set(struct led_classdev *led_cdev,
+					 enum led_brightness brightness)
+{
+	struct apple_magic_backlight *backlight = container_of(led_cdev,
+			struct apple_magic_backlight, cdev);
+
+	apple_magic_backlight_set(backlight, brightness, 1);
+	return 0;
+}
+
+static int apple_magic_backlight_init(struct hid_device *hdev)
+{
+	struct apple_magic_backlight *backlight;
+	int rc;
+
+	/*
+	 * Ensure this usb endpoint is for the keyboard backlight, not touchbar
+	 * backlight.
+	 */
+	if (hdev->collection[0].usage != HID_USAGE_MAGIC_BL)
+		return -ENODEV;
+
+	backlight = devm_kzalloc(&hdev->dev, sizeof(*backlight), GFP_KERNEL);
+	if (!backlight)
+		return -ENOMEM;
+
+	backlight->brightness = hid_register_report(hdev, HID_FEATURE_REPORT,
+			APPLE_MAGIC_REPORT_ID_BRIGHTNESS, 0);
+	backlight->power = hid_register_report(hdev, HID_FEATURE_REPORT,
+			APPLE_MAGIC_REPORT_ID_POWER, 0);
+
+	if (!backlight->brightness || !backlight->power) {
+		rc = -ENODEV;
+		goto hw_stop;
+	}
+
+	backlight->cdev.name = ":white:" LED_FUNCTION_KBD_BACKLIGHT;
+	backlight->cdev.max_brightness = backlight->brightness->field[0]->logical_maximum;
+	backlight->cdev.brightness_set_blocking = apple_magic_backlight_led_set;
+
+	apple_magic_backlight_set(backlight, 0, 0);
+
+	return devm_led_classdev_register(&hdev->dev, &backlight->cdev);
+
+hw_stop:
+	hid_hw_stop(hdev);
+	return rc;
+}
+
 static int apple_probe(struct hid_device *hdev,
 		const struct hid_device_id *id)
 {
@@ -860,6 +940,9 @@  static int apple_probe(struct hid_device *hdev,
 	if (quirks & APPLE_BACKLIGHT_CTL)
 		apple_backlight_init(hdev);
 
+	if (quirks & APPLE_MAGIC_BACKLIGHT)
+		apple_magic_backlight_init(hdev);
+
 	return 0;
 }
 
@@ -1073,6 +1156,8 @@  static const struct hid_device_id apple_devices[] = {
 		.driver_data = APPLE_HAS_FN | APPLE_ISO_TILDE_QUIRK | APPLE_RDESC_BATTERY },
 	{ HID_BLUETOOTH_DEVICE(BT_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_MAGIC_KEYBOARD_NUMPAD_2021),
 		.driver_data = APPLE_HAS_FN | APPLE_ISO_TILDE_QUIRK },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT),
+		.driver_data = APPLE_MAGIC_BACKLIGHT },
 
 	{ }
 };