[PATCH v4 0/2] Apple Magic Keyboard Backlight

[PATCH v4 0/2] Apple Magic Keyboard Backlight

[Orlando Chamberlain]

This patchseries adds support for the internal keyboard backlight of
Macs with Apple's "Magic" keyboard (MacBookPro16,* and MacBookAir9,1),
and also documents what names should be used for keyboard backlight
leds in Documentation/leds/well-known-leds.txt.

v3->v4:
- collect reviews from Andy and Thomas
- remove now unused hdev member of apple_magic_backlight

v2->v3:
- remove unneeded header inclusion
- use s32 for report value type
- remove unneeded null check
- don't set drvdata as its never used
- prepend "hid-" to module name

v1->v2:
- drop unneeded remove function
- combine set functions
- add missing header inclusions
- avoid char as argument in favour of u8
- handful of style/formatting fixes
- use standard led name ":white:kbd_backlight"
- rename USAGE_MAGIC_BL to HID_USAGE_MAGIC_BL
- New patch documenting preferred keyboard backlight names

v1: https://lore.kernel.org/linux-input/7D70F1FE-7F54-4D0A-8922-5466AA2AD364@live.com/
v2: https://lore.kernel.org/linux-input/20230216041224.4731-1-orlandoch.dev@gmail.com/
v3: https://lore.kernel.org/linux-input/20230217102319.3419-1-orlandoch.dev@gmail.com/

Orlando Chamberlain (2):
  Documentation: leds: standardise keyboard backlight led names
  HID: hid-apple-magic-backlight: Add driver for keyboard backlight on
    internal Magic Keyboards

 Documentation/leds/well-known-leds.txt  |   8 ++
 MAINTAINERS                             |   6 ++
 drivers/hid/Kconfig                     |  13 +++
 drivers/hid/Makefile                    |   1 +
 drivers/hid/hid-apple-magic-backlight.c | 120 ++++++++++++++++++++++++
 5 files changed, 148 insertions(+)
 create mode 100644 drivers/hid/hid-apple-magic-backlight.c

-- 
2.39.1

[PATCH v4 1/2] Documentation: leds: standardise keyboard backlight led names

[Orlando Chamberlain]

Advice use of either "input*:*:kbd_backlight" or ":*:kbd_backlight". We
don't want people using vendor or product name (e.g. "smc", "apple",
"asus") as this information is available from sysfs anyway, and it made the
folder names inconsistent.

Signed-off-by: Orlando Chamberlain <orlandoch.dev@gmail.com>
---
 Documentation/leds/well-known-leds.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Documentation/leds/well-known-leds.txt b/Documentation/leds/well-known-leds.txt
index 2160382c86be..4e5429fce4d8 100644
--- a/Documentation/leds/well-known-leds.txt
+++ b/Documentation/leds/well-known-leds.txt
@@ -44,6 +44,14 @@ Legacy: "lp5523:kb{1,2,3,4,5,6}" (Nokia N900)
 
 Frontlight/backlight of main keyboard.
 
+Good: ":*:kbd_backlight"
+Good: "input*:*:kbd_backlight"
+Legacy: "*:*:kbd_backlight"
+
+Many drivers have the vendor or product name as the first field of the led name,
+this makes names inconsistent and is redundant as that information is already in
+sysfs.
+
 Legacy: "button-backlight" (Motorola Droid 4)
 
 Some phones have touch buttons below screen; it is different from main
-- 
2.39.1

[PATCH v4 2/2] HID: hid-apple-magic-backlight: Add driver for keyboard backlight on internal Magic Keyboards

[Orlando Chamberlain]

This driver adds support for the keyboard backlight on Intel T2 Macs
with internal Magic Keyboards (MacBookPro16,x and MacBookAir9,1)

Co-developed-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Kerem Karabay <kekrby@gmail.com>
Signed-off-by: Orlando Chamberlain <orlandoch.dev@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
---
v3->v4:
- collect reviews from Andy and Thomas
- remove now unused hdev member of apple_magic_backlight
v2->v3:
- remove unneeded inclusion
- use s32 for report value type
- remove unneeded null check
- don't set drvdata as its never used
- prepend "hid-" to module name
v1->v2:
- drop unneeded remove function
- combine set functions
- add missing header inclusions
- avoid char as argument in favour of u8
- handful of style/formatting fixes
- use standard led name ":white:kbd_backlight"
- rename USAGE_MAGIC_BL to HID_USAGE_MAGIC_BL

 MAINTAINERS                             |   6 ++
 drivers/hid/Kconfig                     |  13 +++
 drivers/hid/Makefile                    |   1 +
 drivers/hid/hid-apple-magic-backlight.c | 120 ++++++++++++++++++++++++
 4 files changed, 140 insertions(+)
 create mode 100644 drivers/hid/hid-apple-magic-backlight.c

diff --git a/MAINTAINERS b/MAINTAINERS
index fb1471cb5ed3..3319f0c3ed1e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9201,6 +9201,12 @@ F:	include/linux/pm.h
 F:	include/linux/suspend.h
 F:	kernel/power/
 
+HID APPLE MAGIC BACKLIGHT DRIVER
+M:	Orlando Chamberlain <orlandoch.dev@gmail.com>
+L:	linux-input@vger.kernel.org
+S:	Maintained
+F:	drivers/hid/apple-magic-backlight.c
+
 HID CORE LAYER
 M:	Jiri Kosina <jikos@kernel.org>
 M:	Benjamin Tissoires <benjamin.tissoires@redhat.com>
diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
index e2a5d30c8895..fe489632bfd9 100644
--- a/drivers/hid/Kconfig
+++ b/drivers/hid/Kconfig
@@ -130,6 +130,19 @@ config HID_APPLE
 	Say Y here if you want support for keyboards of	Apple iBooks, PowerBooks,
 	MacBooks, MacBook Pros and Apple Aluminum.
 
+config HID_APPLE_MAGIC_BACKLIGHT
+	tristate "Apple Magic Keyboard Backlight"
+	depends on USB_HID
+	depends on LEDS_CLASS
+	depends on NEW_LEDS
+	help
+	Say Y here if you want support for the keyboard backlight on Macs with
+	the magic keyboard (MacBookPro16,x and MacBookAir9,1). Note that this
+	driver is not for external magic keyboards.
+
+	To compile this driver as a module, choose M here: the
+	module will be called hid-apple-magic-backlight.
+
 config HID_APPLEIR
 	tristate "Apple infrared receiver"
 	depends on (USB_HID)
diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
index e8014c1a2f8b..dc8df002bc86 100644
--- a/drivers/hid/Makefile
+++ b/drivers/hid/Makefile
@@ -26,6 +26,7 @@ obj-$(CONFIG_HID_ACCUTOUCH)	+= hid-accutouch.o
 obj-$(CONFIG_HID_ALPS)		+= hid-alps.o
 obj-$(CONFIG_HID_ACRUX)		+= hid-axff.o
 obj-$(CONFIG_HID_APPLE)		+= hid-apple.o
+obj-$(CONFIG_HID_APPLE_MAGIC_BACKLIGHT)	+= hid-apple-magic-backlight.o
 obj-$(CONFIG_HID_APPLEIR)	+= hid-appleir.o
 obj-$(CONFIG_HID_CREATIVE_SB0540)	+= hid-creative-sb0540.o
 obj-$(CONFIG_HID_ASUS)		+= hid-asus.o
diff --git a/drivers/hid/hid-apple-magic-backlight.c b/drivers/hid/hid-apple-magic-backlight.c
new file mode 100644
index 000000000000..f0fc02ff3b2d
--- /dev/null
+++ b/drivers/hid/hid-apple-magic-backlight.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Apple Magic Keyboard Backlight Driver
+ *
+ * For Intel Macs with internal Magic Keyboard (MacBookPro16,1-4 and MacBookAir9,1)
+ *
+ * Copyright (c) 2022 Kerem Karabay <kekrby@gmail.com>
+ * Copyright (c) 2023 Orlando Chamberlain <orlandoch.dev@gmail.com>
+ */
+
+#include <linux/hid.h>
+#include <linux/leds.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <dt-bindings/leds/common.h>
+
+#include "hid-ids.h"
+
+#define HID_USAGE_MAGIC_BL	0xff00000f
+
+#define APPLE_MAGIC_REPORT_ID_POWER 3
+#define APPLE_MAGIC_REPORT_ID_BRIGHTNESS 1
+
+struct apple_magic_backlight {
+	struct led_classdev cdev;
+	struct hid_report *brightness;
+	struct hid_report *power;
+};
+
+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_probe(struct hid_device *hdev,
+				       const struct hid_device_id *id)
+{
+	struct apple_magic_backlight *backlight;
+	int rc;
+
+	rc = hid_parse(hdev);
+	if (rc)
+		return 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;
+
+	rc = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (rc)
+		return rc;
+
+	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 const struct hid_device_id apple_magic_backlight_hid_ids[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, apple_magic_backlight_hid_ids);
+
+static struct hid_driver apple_magic_backlight_hid_driver = {
+	.name = "hid-apple-magic-backlight",
+	.id_table = apple_magic_backlight_hid_ids,
+	.probe = apple_magic_backlight_probe,
+};
+module_hid_driver(apple_magic_backlight_hid_driver);
+
+MODULE_DESCRIPTION("MacBook Magic Keyboard Backlight");
+MODULE_AUTHOR("Orlando Chamberlain <orlandoch.dev@gmail.com>");
+MODULE_LICENSE("GPL");
-- 
2.39.1

Re: [PATCH v4 2/2] HID: hid-apple-magic-backlight: Add driver for keyboard backlight on internal Magic Keyboards

[Andy Shevchenko]

On Sat, Feb 18, 2023 at 11:08 AM Orlando Chamberlain
<orlandoch.dev@gmail.com> wrote:
>
> This driver adds support for the keyboard backlight on Intel T2 Macs
> with internal Magic Keyboards (MacBookPro16,x and MacBookAir9,1)

...

> +       help
> +       Say Y here if you want support for the keyboard backlight on Macs with
> +       the magic keyboard (MacBookPro16,x and MacBookAir9,1). Note that this
> +       driver is not for external magic keyboards.
> +
> +       To compile this driver as a module, choose M here: the
> +       module will be called hid-apple-magic-backlight.

Is it my email client or is the indentation of the help text incorrect?

Hint: the text of the help should be <TAB><SPACE><SPACE> indented.

I believe checkpatch.pl at least in --strict mode should complain about this.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 2/2] HID: hid-apple-magic-backlight: Add driver for keyboard backlight on internal Magic Keyboards

[Orlando Chamberlain]

On Sun, 19 Feb 2023 16:09:26 +0200
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

> On Sat, Feb 18, 2023 at 11:08 AM Orlando Chamberlain
> <orlandoch.dev@gmail.com> wrote:
> >
> > This driver adds support for the keyboard backlight on Intel T2 Macs
> > with internal Magic Keyboards (MacBookPro16,x and MacBookAir9,1)  
> 
> ...
> 
> > +       help
> > +       Say Y here if you want support for the keyboard backlight
> > on Macs with
> > +       the magic keyboard (MacBookPro16,x and MacBookAir9,1). Note
> > that this
> > +       driver is not for external magic keyboards.
> > +
> > +       To compile this driver as a module, choose M here: the
> > +       module will be called hid-apple-magic-backlight.  
> 
> Is it my email client or is the indentation of the help text
> incorrect?
> 
> Hint: the text of the help should be <TAB><SPACE><SPACE> indented.
> 
> I believe checkpatch.pl at least in --strict mode should complain
> about this.

Looking at the hid Kconfig, it seems like some have it as you've
described, and some just have tab (and a few have just tab for the
first line, and tab space space for the rest of the lines).

checkpatch.pl --strict didn't complain about the indentation so
hopefully it's alright as is.

Re: [PATCH v4 2/2] HID: hid-apple-magic-backlight: Add driver for keyboard backlight on internal Magic Keyboards

[Aditya Garg]

> On 18-Feb-2023, at 2:38 PM, Orlando Chamberlain <orlandoch.dev@gmail.com> wrote:
> 
> This driver adds support for the keyboard backlight on Intel T2 Macs
> with internal Magic Keyboards (MacBookPro16,x and MacBookAir9,1)
> 
> Co-developed-by: Kerem Karabay <kekrby@gmail.com>
> Signed-off-by: Kerem Karabay <kekrby@gmail.com>
> Signed-off-by: Orlando Chamberlain <orlandoch.dev@gmail.com>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
> ---
> v3->v4:
> - collect reviews from Andy and Thomas
> - remove now unused hdev member of apple_magic_backlight
> v2->v3:
> - remove unneeded inclusion
> - use s32 for report value type
> - remove unneeded null check
> - don't set drvdata as its never used
> - prepend "hid-" to module name
> v1->v2:
> - drop unneeded remove function
> - combine set functions
> - add missing header inclusions
> - avoid char as argument in favour of u8
> - handful of style/formatting fixes
> - use standard led name ":white:kbd_backlight"
> - rename USAGE_MAGIC_BL to HID_USAGE_MAGIC_BL
> 
> MAINTAINERS                             |   6 ++
> drivers/hid/Kconfig                     |  13 +++
> drivers/hid/Makefile                    |   1 +
> drivers/hid/hid-apple-magic-backlight.c | 120 ++++++++++++++++++++++++
> 4 files changed, 140 insertions(+)
> create mode 100644 drivers/hid/hid-apple-magic-backlight.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index fb1471cb5ed3..3319f0c3ed1e 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -9201,6 +9201,12 @@ F:    include/linux/pm.h
> F:    include/linux/suspend.h
> F:    kernel/power/
> 
> +HID APPLE MAGIC BACKLIGHT DRIVER
> +M:    Orlando Chamberlain <orlandoch.dev@gmail.com>
> +L:    linux-input@vger.kernel.org
> +S:    Maintained
> +F:    drivers/hid/apple-magic-backlight.c

drivers/hid/hid-apple-magic-backlight.c

Looks like you forgot to change that.

> +
> HID CORE LAYER
> M:    Jiri Kosina <jikos@kernel.org>
> M:    Benjamin Tissoires <benjamin.tissoires@redhat.com>
> diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> index e2a5d30c8895..fe489632bfd9 100644
> --- a/drivers/hid/Kconfig
> +++ b/drivers/hid/Kconfig
> @@ -130,6 +130,19 @@ config HID_APPLE
>    Say Y here if you want support for keyboards of    Apple iBooks, PowerBooks,
>    MacBooks, MacBook Pros and Apple Aluminum.
> 
> +config HID_APPLE_MAGIC_BACKLIGHT
> +    tristate "Apple Magic Keyboard Backlight"
> +    depends on USB_HID
> +    depends on LEDS_CLASS
> +    depends on NEW_LEDS
> +    help
> +    Say Y here if you want support for the keyboard backlight on Macs with
> +    the magic keyboard (MacBookPro16,x and MacBookAir9,1). Note that this
> +    driver is not for external magic keyboards.
> +
> +    To compile this driver as a module, choose M here: the
> +    module will be called hid-apple-magic-backlight.
> +
> config HID_APPLEIR
>    tristate "Apple infrared receiver"
>    depends on (USB_HID)
> diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> index e8014c1a2f8b..dc8df002bc86 100644
> --- a/drivers/hid/Makefile
> +++ b/drivers/hid/Makefile
> @@ -26,6 +26,7 @@ obj-$(CONFIG_HID_ACCUTOUCH)    += hid-accutouch.o
> obj-$(CONFIG_HID_ALPS)        += hid-alps.o
> obj-$(CONFIG_HID_ACRUX)        += hid-axff.o
> obj-$(CONFIG_HID_APPLE)        += hid-apple.o
> +obj-$(CONFIG_HID_APPLE_MAGIC_BACKLIGHT)    += hid-apple-magic-backlight.o
> obj-$(CONFIG_HID_APPLEIR)    += hid-appleir.o
> obj-$(CONFIG_HID_CREATIVE_SB0540)    += hid-creative-sb0540.o
> obj-$(CONFIG_HID_ASUS)        += hid-asus.o
> diff --git a/drivers/hid/hid-apple-magic-backlight.c b/drivers/hid/hid-apple-magic-backlight.c
> new file mode 100644
> index 000000000000..f0fc02ff3b2d
> --- /dev/null
> +++ b/drivers/hid/hid-apple-magic-backlight.c
> @@ -0,0 +1,120 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Apple Magic Keyboard Backlight Driver
> + *
> + * For Intel Macs with internal Magic Keyboard (MacBookPro16,1-4 and MacBookAir9,1)
> + *
> + * Copyright (c) 2022 Kerem Karabay <kekrby@gmail.com>
> + * Copyright (c) 2023 Orlando Chamberlain <orlandoch.dev@gmail.com>
> + */
> +
> +#include <linux/hid.h>
> +#include <linux/leds.h>
> +#include <linux/device.h>
> +#include <linux/errno.h>
> +#include <dt-bindings/leds/common.h>
> +
> +#include "hid-ids.h"
> +
> +#define HID_USAGE_MAGIC_BL    0xff00000f
> +
> +#define APPLE_MAGIC_REPORT_ID_POWER 3
> +#define APPLE_MAGIC_REPORT_ID_BRIGHTNESS 1
> +
> +struct apple_magic_backlight {
> +    struct led_classdev cdev;
> +    struct hid_report *brightness;
> +    struct hid_report *power;
> +};
> +
> +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_probe(struct hid_device *hdev,
> +                       const struct hid_device_id *id)
> +{
> +    struct apple_magic_backlight *backlight;
> +    int rc;
> +
> +    rc = hid_parse(hdev);
> +    if (rc)
> +        return 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;
> +
> +    rc = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
> +    if (rc)
> +        return rc;
> +
> +    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 const struct hid_device_id apple_magic_backlight_hid_ids[] = {
> +    { HID_USB_DEVICE(USB_VENDOR_ID_APPLE, USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
> +    { }
> +};
> +MODULE_DEVICE_TABLE(hid, apple_magic_backlight_hid_ids);
> +
> +static struct hid_driver apple_magic_backlight_hid_driver = {
> +    .name = "hid-apple-magic-backlight",
> +    .id_table = apple_magic_backlight_hid_ids,
> +    .probe = apple_magic_backlight_probe,
> +};
> +module_hid_driver(apple_magic_backlight_hid_driver);
> +
> +MODULE_DESCRIPTION("MacBook Magic Keyboard Backlight");
> +MODULE_AUTHOR("Orlando Chamberlain <orlandoch.dev@gmail.com>");
> +MODULE_LICENSE("GPL");
> -- 
> 2.39.1
> 

Re: [PATCH v4 2/2] HID: hid-apple-magic-backlight: Add driver for keyboard backlight on internal Magic Keyboards

[Andy Shevchenko]

On Mon, Feb 20, 2023 at 06:09:32PM +1100, Orlando Chamberlain wrote:
> On Sun, 19 Feb 2023 16:09:26 +0200
> Andy Shevchenko <andy.shevchenko@gmail.com> wrote:
> > On Sat, Feb 18, 2023 at 11:08 AM Orlando Chamberlain
> > <orlandoch.dev@gmail.com> wrote:

...

> > > +       help
> > > +       Say Y here if you want support for the keyboard backlight
> > > on Macs with
> > > +       the magic keyboard (MacBookPro16,x and MacBookAir9,1). Note
> > > that this
> > > +       driver is not for external magic keyboards.
> > > +
> > > +       To compile this driver as a module, choose M here: the
> > > +       module will be called hid-apple-magic-backlight.  
> > 
> > Is it my email client or is the indentation of the help text
> > incorrect?
> > 
> > Hint: the text of the help should be <TAB><SPACE><SPACE> indented.
> > 
> > I believe checkpatch.pl at least in --strict mode should complain
> > about this.
> 
> Looking at the hid Kconfig, it seems like some have it as you've
> described, and some just have tab (and a few have just tab for the
> first line, and tab space space for the rest of the lines).

Okay, I have checked in the other MUA I'm using for patch reviews and indeed
your Kconfig indentation is broken.

> checkpatch.pl --strict didn't complain about the indentation so
> hopefully it's alright as is.

No, it's not. Must be fixed.

https://www.kernel.org/doc/html/latest/process/coding-style.html#kconfig-configuration-files

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 2/2] HID: hid-apple-magic-backlight: Add driver for keyboard backlight on internal Magic Keyboards

[Orlando Chamberlain]

On Mon, 20 Feb 2023 13:29:31 +0200
Andy Shevchenko <andy.shevchenko@gmail.com> wrote:

> On Mon, Feb 20, 2023 at 06:09:32PM +1100, Orlando Chamberlain wrote:
> > On Sun, 19 Feb 2023 16:09:26 +0200
> > Andy Shevchenko <andy.shevchenko@gmail.com> wrote:  
> > > On Sat, Feb 18, 2023 at 11:08 AM Orlando Chamberlain
> > > <orlandoch.dev@gmail.com> wrote:  
> 
> ...
> 
> > > > +       help
> > > > +       Say Y here if you want support for the keyboard
> > > > backlight on Macs with
> > > > +       the magic keyboard (MacBookPro16,x and MacBookAir9,1).
> > > > Note that this
> > > > +       driver is not for external magic keyboards.
> > > > +
> > > > +       To compile this driver as a module, choose M here: the
> > > > +       module will be called hid-apple-magic-backlight.    
> > > 
> > > Is it my email client or is the indentation of the help text
> > > incorrect?
> > > 
> > > Hint: the text of the help should be <TAB><SPACE><SPACE> indented.
> > > 
> > > I believe checkpatch.pl at least in --strict mode should complain
> > > about this.  
> > 
> > Looking at the hid Kconfig, it seems like some have it as you've
> > described, and some just have tab (and a few have just tab for the
> > first line, and tab space space for the rest of the lines).  
> 
> Okay, I have checked in the other MUA I'm using for patch reviews and
> indeed your Kconfig indentation is broken.
> 
> > checkpatch.pl --strict didn't complain about the indentation so
> > hopefully it's alright as is.  
> 
> No, it's not. Must be fixed.
> 
> https://www.kernel.org/doc/html/latest/process/coding-style.html#kconfig-configuration-files
> 

No worries, I'll fix that in v5.

Re: [PATCH v4 2/2] HID: hid-apple-magic-backlight: Add driver for keyboard backlight on internal Magic Keyboards

[Orlando Chamberlain]

On Mon, 20 Feb 2023 08:33:10 +0000
Aditya Garg <gargaditya08@live.com> wrote:

> > On 18-Feb-2023, at 2:38 PM, Orlando Chamberlain
> > <orlandoch.dev@gmail.com> wrote:
> > 
> > This driver adds support for the keyboard backlight on Intel T2
> > Macs with internal Magic Keyboards (MacBookPro16,x and
> > MacBookAir9,1)
> > 
> > Co-developed-by: Kerem Karabay <kekrby@gmail.com>
> > Signed-off-by: Kerem Karabay <kekrby@gmail.com>
> > Signed-off-by: Orlando Chamberlain <orlandoch.dev@gmail.com>
> > Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
> > Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
> > ---
> > v3->v4:
> > - collect reviews from Andy and Thomas
> > - remove now unused hdev member of apple_magic_backlight
> > v2->v3:
> > - remove unneeded inclusion
> > - use s32 for report value type
> > - remove unneeded null check
> > - don't set drvdata as its never used
> > - prepend "hid-" to module name
> > v1->v2:
> > - drop unneeded remove function
> > - combine set functions
> > - add missing header inclusions
> > - avoid char as argument in favour of u8
> > - handful of style/formatting fixes
> > - use standard led name ":white:kbd_backlight"
> > - rename USAGE_MAGIC_BL to HID_USAGE_MAGIC_BL
> > 
> > MAINTAINERS                             |   6 ++
> > drivers/hid/Kconfig                     |  13 +++
> > drivers/hid/Makefile                    |   1 +
> > drivers/hid/hid-apple-magic-backlight.c | 120
> > ++++++++++++++++++++++++ 4 files changed, 140 insertions(+)
> > create mode 100644 drivers/hid/hid-apple-magic-backlight.c
> > 
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index fb1471cb5ed3..3319f0c3ed1e 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -9201,6 +9201,12 @@ F:    include/linux/pm.h
> > F:    include/linux/suspend.h
> > F:    kernel/power/
> > 
> > +HID APPLE MAGIC BACKLIGHT DRIVER
> > +M:    Orlando Chamberlain <orlandoch.dev@gmail.com>
> > +L:    linux-input@vger.kernel.org
> > +S:    Maintained
> > +F:    drivers/hid/apple-magic-backlight.c  
> 
> drivers/hid/hid-apple-magic-backlight.c
> 
> Looks like you forgot to change that.

Yes I did, thanks for catching that. I'll fix it in v5.
> 
> > +
> > HID CORE LAYER
> > M:    Jiri Kosina <jikos@kernel.org>
> > M:    Benjamin Tissoires <benjamin.tissoires@redhat.com>
> > diff --git a/drivers/hid/Kconfig b/drivers/hid/Kconfig
> > index e2a5d30c8895..fe489632bfd9 100644
> > --- a/drivers/hid/Kconfig
> > +++ b/drivers/hid/Kconfig
> > @@ -130,6 +130,19 @@ config HID_APPLE
> >    Say Y here if you want support for keyboards of    Apple iBooks,
> > PowerBooks, MacBooks, MacBook Pros and Apple Aluminum.
> > 
> > +config HID_APPLE_MAGIC_BACKLIGHT
> > +    tristate "Apple Magic Keyboard Backlight"
> > +    depends on USB_HID
> > +    depends on LEDS_CLASS
> > +    depends on NEW_LEDS
> > +    help
> > +    Say Y here if you want support for the keyboard backlight on
> > Macs with
> > +    the magic keyboard (MacBookPro16,x and MacBookAir9,1). Note
> > that this
> > +    driver is not for external magic keyboards.
> > +
> > +    To compile this driver as a module, choose M here: the
> > +    module will be called hid-apple-magic-backlight.
> > +
> > config HID_APPLEIR
> >    tristate "Apple infrared receiver"
> >    depends on (USB_HID)
> > diff --git a/drivers/hid/Makefile b/drivers/hid/Makefile
> > index e8014c1a2f8b..dc8df002bc86 100644
> > --- a/drivers/hid/Makefile
> > +++ b/drivers/hid/Makefile
> > @@ -26,6 +26,7 @@ obj-$(CONFIG_HID_ACCUTOUCH)    += hid-accutouch.o
> > obj-$(CONFIG_HID_ALPS)        += hid-alps.o
> > obj-$(CONFIG_HID_ACRUX)        += hid-axff.o
> > obj-$(CONFIG_HID_APPLE)        += hid-apple.o
> > +obj-$(CONFIG_HID_APPLE_MAGIC_BACKLIGHT)    +=
> > hid-apple-magic-backlight.o obj-$(CONFIG_HID_APPLEIR)    +=
> > hid-appleir.o obj-$(CONFIG_HID_CREATIVE_SB0540)    +=
> > hid-creative-sb0540.o obj-$(CONFIG_HID_ASUS)        += hid-asus.o
> > diff --git a/drivers/hid/hid-apple-magic-backlight.c
> > b/drivers/hid/hid-apple-magic-backlight.c new file mode 100644
> > index 000000000000..f0fc02ff3b2d
> > --- /dev/null
> > +++ b/drivers/hid/hid-apple-magic-backlight.c
> > @@ -0,0 +1,120 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Apple Magic Keyboard Backlight Driver
> > + *
> > + * For Intel Macs with internal Magic Keyboard (MacBookPro16,1-4
> > and MacBookAir9,1)
> > + *
> > + * Copyright (c) 2022 Kerem Karabay <kekrby@gmail.com>
> > + * Copyright (c) 2023 Orlando Chamberlain <orlandoch.dev@gmail.com>
> > + */
> > +
> > +#include <linux/hid.h>
> > +#include <linux/leds.h>
> > +#include <linux/device.h>
> > +#include <linux/errno.h>
> > +#include <dt-bindings/leds/common.h>
> > +
> > +#include "hid-ids.h"
> > +
> > +#define HID_USAGE_MAGIC_BL    0xff00000f
> > +
> > +#define APPLE_MAGIC_REPORT_ID_POWER 3
> > +#define APPLE_MAGIC_REPORT_ID_BRIGHTNESS 1
> > +
> > +struct apple_magic_backlight {
> > +    struct led_classdev cdev;
> > +    struct hid_report *brightness;
> > +    struct hid_report *power;
> > +};
> > +
> > +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_probe(struct hid_device *hdev,
> > +                       const struct hid_device_id *id)
> > +{
> > +    struct apple_magic_backlight *backlight;
> > +    int rc;
> > +
> > +    rc = hid_parse(hdev);
> > +    if (rc)
> > +        return 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;
> > +
> > +    rc = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
> > +    if (rc)
> > +        return rc;
> > +
> > +    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 const struct hid_device_id apple_magic_backlight_hid_ids[]
> > = {
> > +    { HID_USB_DEVICE(USB_VENDOR_ID_APPLE,
> > USB_DEVICE_ID_APPLE_TOUCHBAR_BACKLIGHT) },
> > +    { }
> > +};
> > +MODULE_DEVICE_TABLE(hid, apple_magic_backlight_hid_ids);
> > +
> > +static struct hid_driver apple_magic_backlight_hid_driver = {
> > +    .name = "hid-apple-magic-backlight",
> > +    .id_table = apple_magic_backlight_hid_ids,
> > +    .probe = apple_magic_backlight_probe,
> > +};
> > +module_hid_driver(apple_magic_backlight_hid_driver);
> > +
> > +MODULE_DESCRIPTION("MacBook Magic Keyboard Backlight");
> > +MODULE_AUTHOR("Orlando Chamberlain <orlandoch.dev@gmail.com>");
> > +MODULE_LICENSE("GPL");
> > -- 
> > 2.39.1
> >