> On 24-Jan-2022, at 8:38 PM, Aditya Garg <gargaditya08@xxxxxxxx> wrote:
>
> From: Paul Pawlowski <paul@xxxxxxxx>
>
> 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: Paul Pawlowski <paul@xxxxxxxx>
> Signed-off-by: Aun-Ali Zaidi <admin@xxxxxxxxxx>
> Signed-off-by: Aditya Garg <gargaditya08@xxxxxxxx>
> ---
> drivers/hid/hid-apple.c | 125 ++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 125 insertions(+)
>
> diff --git a/drivers/hid/hid-apple.c b/drivers/hid/hid-apple.c
> index 24802a4a6..c22d445a9 100644
> --- a/drivers/hid/hid-apple.c
> +++ b/drivers/hid/hid-apple.c
> @@ -7,6 +7,7 @@
> * Copyright (c) 2005 Michael Haboustak <mike-@xxxxxxxxxxxx> for Concept2, Inc
> * Copyright (c) 2006-2007 Jiri Kosina
> * Copyright (c) 2008 Jiri Slaby <jirislaby@xxxxxxxxx>
> + * Copyright (c) 2019 Paul Pawlowski <paul@xxxxxxxx>
> */
>
> /*
> @@ -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 0x0200
Jiri, should it be BIT(10)? 0x0200 is BIT(9) if I ain’t wrong.
>
> #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 {
> @@ -76,6 +85,20 @@ struct apple_key_translation {
> u8 flags;
> };
>
> +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 },
> @@ -530,6 +553,105 @@ 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)
> {
> @@ -565,6 +687,9 @@ 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;
> }
>
> --
> 2.25.1
>
>
