From 4ed460ce13710f7f2cf22e0c9e66c7add13c7a53 Mon Sep 17 00:00:00 2001 From: "Yo-Jung Leo Lin (AMD)" Date: Thu, 9 Jul 2026 14:58:18 +0800 Subject: [PATCH] platform/x86/amd: Introduce Halo Box RGB LED driver MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The Halo Box features an RGB LED light bar that can be controlled through WMI methods to display any color combination. The driver exposes the LED through the LED multicolor subsystem, allowing userspace to control RGB values via sysfs: /sys/class/leds/amd_halo:multicolor:status/multi_intensity /sys/class/leds/amd_halo:multicolor:status/brightness Hardware interface: - Three separate RGB channels (Red, Green, Blue) - All 3 channels are configured at once with a single WMI method call - Value range: 0-100 (matching hardware range directly) Co-developed-by: Mario Limonciello (AMD) Signed-off-by: Mario Limonciello (AMD) Reviewed-by: Shyam Sundar S K Reviewed-by: Armin Wolf Signed-off-by: Yo-Jung Leo Lin (AMD) Link: https://patch.msgid.link/20260709-halo-leds-v2-plus-v8-1-b34c64277193@amd.com Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- MAINTAINERS | 7 + drivers/platform/x86/amd/Kconfig | 11 + drivers/platform/x86/amd/Makefile | 1 + drivers/platform/x86/amd/amd_halo_led.c | 315 ++++++++++++++++++++++++ 4 files changed, 334 insertions(+) create mode 100644 drivers/platform/x86/amd/amd_halo_led.c diff --git a/MAINTAINERS b/MAINTAINERS index 4a8b0fd665ce..1ef1ec374eab 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1138,6 +1138,13 @@ F: drivers/char/hw_random/geode-rng.c F: drivers/crypto/geode* F: drivers/video/fbdev/geode/ +AMD HALO BOX RGB LED DRIVER +M: Mario Limonciello (AMD) +R: Yo-Jung Leo Lin (AMD) +L: platform-driver-x86@vger.kernel.org +S: Supported +F: drivers/platform/x86/amd/amd_halo_led.c + AMD HSMP DRIVER M: Naveen Krishna Chatradhi R: Carlos Bilbao diff --git a/drivers/platform/x86/amd/Kconfig b/drivers/platform/x86/amd/Kconfig index b813f9265368..a1a74ef6c859 100644 --- a/drivers/platform/x86/amd/Kconfig +++ b/drivers/platform/x86/amd/Kconfig @@ -34,6 +34,17 @@ config AMD_WBRF This mechanism will only be activated on platforms that advertise a need for it. +config AMD_HALO_LED + tristate "AMD Halo Box RGB LED Driver" + depends on ACPI_WMI && LEDS_CLASS_MULTICOLOR + help + This driver provides RGB LED control for AMD Halo Box devices + through the LED multicolor subsystem. The Halo Box light bar can + be controlled via sysfs to display any RGB color combination. + + To compile this driver as a module, choose M here: the module + will be called amd_halo_led. + config AMD_ISP_PLATFORM tristate "AMD ISP4 platform driver" depends on I2C && X86_64 && ACPI diff --git a/drivers/platform/x86/amd/Makefile b/drivers/platform/x86/amd/Makefile index f6ff0c837f34..2f467dbbfc8a 100644 --- a/drivers/platform/x86/amd/Makefile +++ b/drivers/platform/x86/amd/Makefile @@ -10,5 +10,6 @@ obj-$(CONFIG_AMD_PMC) += pmc/ obj-$(CONFIG_AMD_HSMP) += hsmp/ obj-$(CONFIG_AMD_PMF) += pmf/ obj-$(CONFIG_AMD_WBRF) += wbrf.o +obj-$(CONFIG_AMD_HALO_LED) += amd_halo_led.o obj-$(CONFIG_AMD_ISP_PLATFORM) += amd_isp4.o obj-$(CONFIG_AMD_HFI) += hfi/ diff --git a/drivers/platform/x86/amd/amd_halo_led.c b/drivers/platform/x86/amd/amd_halo_led.c new file mode 100644 index 000000000000..b21d956c7d96 --- /dev/null +++ b/drivers/platform/x86/amd/amd_halo_led.c @@ -0,0 +1,315 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * AMD Halo Box RGB LED Driver + * + * Copyright (C) 2026 Advanced Micro Devices, Inc. + * + * This driver provides RGB LED control for AMD Halo Box devices through + * the LED multicolor subsystem. The Halo Box light bar can be controlled + * via sysfs to display any RGB color combination. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#define AMD_HALO_GUID "081E747B-E028-4232-AF24-EAAEAB2B1E86" + +/* WMI method IDs from MOF */ +enum { + AMD_HALO_WMI_TURN_OFF = 0x04, + AMD_HALO_WMI_RGB = 0x07, +}; + +/* Arg0 of the AMD_HALO_WMI_RGB Method */ +enum { + AMD_HALO_RGB_CMD_GET = 0x0, + AMD_HALO_RGB_CMD_SET = 0x1, +}; + +/* Status codes from spec */ +#define AMD_HALO_STATUS_SUCCESS 0x0000 +#define AMD_HALO_STATUS_INVALID_PARAM 0xFFFD + +/* Brightness uses 0-100 range */ +#define AMD_HALO_MAX_HW_BRIGHTNESS 100 + +/** + * struct amd_halo_led_data - Driver private data + * @wdev: WMI device pointer + * @led_mc: LED multicolor class device + * @subled_info: RGB channel information + * @lock: Mutex to protect WMI calls + */ +struct amd_halo_led_data { + struct wmi_device *wdev; + struct led_classdev_mc led_mc; + struct mc_subled subled_info[3]; + struct mutex lock; +}; + +struct amd_halo_wmi_args { + __le32 arg0; + __le32 arg1; +}; + +struct amd_halo_wmi_args_rgb { + __le32 cmd; + __le32 red; + __le32 green; + __le32 blue; +}; + +struct amd_halo_wmi_output_rgb { + __le16 status; + u8 red; + u8 green; + u8 blue; +} __packed; + +static inline int wmi_status_to_err(u16 status) +{ + switch (status) { + case AMD_HALO_STATUS_SUCCESS: + return 0; + case AMD_HALO_STATUS_INVALID_PARAM: + return -EINVAL; + default: + return -EIO; + } +} + +static int __amd_halo_wmi_call(struct wmi_device *wdev, + u32 method_id, void *data, size_t length) +{ + struct wmi_buffer input = { + .length = length, + .data = data, + }; + struct wmi_buffer output = { }; + int ret; + + /* Return buffer per spec: Bytes[0:1] = Status (little-endian) */ + ret = wmidev_invoke_method(wdev, 0, method_id, + &input, &output, sizeof(__le16)); + if (ret) + return ret; + + __le16 *result_status __free(kfree) = output.data; + + return wmi_status_to_err(le16_to_cpu(*result_status)); +} + +/** + * amd_halo_wmi_turn_off - Turn off all LED channels + * @wdev: WMI device pointer + * + * Return: 0 on success, negative error code on failure + */ +static int amd_halo_wmi_turn_off(struct wmi_device *wdev) +{ + struct amd_halo_wmi_args args = { }; + + return __amd_halo_wmi_call(wdev, AMD_HALO_WMI_TURN_OFF, &args, sizeof(args)); +} + +/** + * amd_halo_wmi_set_rgb - Set all RGB channels atomically + * @wdev: WMI device pointer + * @r: brightness for red channel (0 - 100) + * @g: brightness for green channel (0 - 100) + * @b: brightness for blue channel (0 - 100) + * + * Return: 0 on success, negative error code on failure + */ +static int amd_halo_wmi_set_rgb(struct wmi_device *wdev, u32 r, u32 g, u32 b) +{ + struct amd_halo_wmi_args_rgb args = { + .cmd = cpu_to_le32(AMD_HALO_RGB_CMD_SET), + .red = cpu_to_le32(r), + .green = cpu_to_le32(g), + .blue = cpu_to_le32(b), + }; + + if (r > AMD_HALO_MAX_HW_BRIGHTNESS || + g > AMD_HALO_MAX_HW_BRIGHTNESS || + b > AMD_HALO_MAX_HW_BRIGHTNESS) { + return -EINVAL; + } + + return __amd_halo_wmi_call(wdev, AMD_HALO_WMI_RGB, &args, sizeof(args)); +} + +/** + * amd_halo_wmi_get_rgb - Get RGB values + * @wdev: WMI device pointer + * @r: output buffer for red value + * @g: output buffer for green value + * @b: output buffer for blue value + * + * Return: 0 on success, negative error code on failure + */ +static int amd_halo_wmi_get_rgb(struct wmi_device *wdev, u8 *r, u8 *g, u8 *b) +{ + struct amd_halo_wmi_args_rgb args = { + .cmd = cpu_to_le32(AMD_HALO_RGB_CMD_GET), + }; + struct wmi_buffer input = { + .length = sizeof(args), + .data = &args, + }; + struct wmi_buffer output = { }; + int ret; + + ret = wmidev_invoke_method(wdev, 0, AMD_HALO_WMI_RGB, + &input, &output, sizeof(struct amd_halo_wmi_output_rgb)); + if (ret) + return ret; + + struct amd_halo_wmi_output_rgb *data __free(kfree) = output.data; + + ret = wmi_status_to_err(le16_to_cpu(data->status)); + if (ret) + return ret; + + if (data->red > AMD_HALO_MAX_HW_BRIGHTNESS || + data->green > AMD_HALO_MAX_HW_BRIGHTNESS || + data->blue > AMD_HALO_MAX_HW_BRIGHTNESS) { + return -EPROTO; + } + + *r = data->red; + *g = data->green; + *b = data->blue; + + return 0; +} + +/** + * amd_halo_brightness_set - Set LED brightness + * @cdev: LED class device + * @brightness: Brightness value + * + * Return: 0 on success, negative error code on failure + */ +static int amd_halo_brightness_set(struct led_classdev *cdev, + enum led_brightness brightness) +{ + struct led_classdev_mc *mc_cdev = lcdev_to_mccdev(cdev); + struct amd_halo_led_data *data = container_of(mc_cdev, + struct amd_halo_led_data, + led_mc); + u32 red_hw, green_hw, blue_hw; + int ret; + + guard(mutex)(&data->lock); + + led_mc_calc_color_components(mc_cdev, brightness); + + if (brightness == 0) + return amd_halo_wmi_turn_off(data->wdev); + + red_hw = mc_cdev->subled_info[0].brightness; + green_hw = mc_cdev->subled_info[1].brightness; + blue_hw = mc_cdev->subled_info[2].brightness; + + ret = amd_halo_wmi_set_rgb(data->wdev, red_hw, green_hw, blue_hw); + if (ret) + goto out; + + return 0; + +out: + /* + * Consider the light bar non-functional if AMD_HALO_WMI_RGB failed. + * Attempt to turn the LED off completely as clean-up. + */ + if (amd_halo_wmi_turn_off(data->wdev)) + dev_warn_ratelimited(&data->wdev->dev, "Failed to turn LED off on cleanup\n"); + + return ret; +} + +static int amd_halo_probe(struct wmi_device *wdev, const void *context) +{ + struct led_init_data led_init_data = { + .devicename = "amd_halo", + .default_label = "multicolor:" LED_FUNCTION_STATUS, + .devname_mandatory = true, + }; + struct amd_halo_led_data *data; + u8 r, g, b; + int ret; + + data = devm_kzalloc(&wdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + ret = devm_mutex_init(&wdev->dev, &data->lock); + if (ret) + return ret; + + data->wdev = wdev; + dev_set_drvdata(&wdev->dev, data); + + data->subled_info[0].color_index = LED_COLOR_ID_RED; + data->subled_info[1].color_index = LED_COLOR_ID_GREEN; + data->subled_info[2].color_index = LED_COLOR_ID_BLUE; + + data->led_mc.led_cdev.brightness = AMD_HALO_MAX_HW_BRIGHTNESS; + data->led_mc.led_cdev.max_brightness = AMD_HALO_MAX_HW_BRIGHTNESS; + data->led_mc.led_cdev.brightness_set_blocking = amd_halo_brightness_set; + data->led_mc.led_cdev.flags = LED_CORE_SUSPENDRESUME | LED_RETAIN_AT_SHUTDOWN; + data->led_mc.num_colors = ARRAY_SIZE(data->subled_info); + data->led_mc.subled_info = data->subled_info; + + ret = amd_halo_wmi_get_rgb(wdev, &r, &g, &b); + if (ret) + return ret; + + data->subled_info[0].intensity = r; + data->subled_info[1].intensity = g; + data->subled_info[2].intensity = b; + + ret = devm_led_classdev_multicolor_register_ext(&wdev->dev, &data->led_mc, + &led_init_data); + if (ret) + return dev_err_probe(&wdev->dev, ret, + "Failed to register multicolor LED\n"); + return 0; +} + +static const struct wmi_device_id amd_halo_id_table[] = { + { .guid_string = AMD_HALO_GUID }, + { } +}; +MODULE_DEVICE_TABLE(wmi, amd_halo_id_table); + +static struct wmi_driver amd_halo_driver = { + .driver = { + .name = "amd_halo_led", + }, + .id_table = amd_halo_id_table, + .probe = amd_halo_probe, + .no_singleton = true, +}; + +module_wmi_driver(amd_halo_driver); + +MODULE_AUTHOR("Mario Limonciello (AMD) "); +MODULE_AUTHOR("Yo-Jung Leo Lin (AMD) "); +MODULE_DESCRIPTION("AMD Halo Box RGB LED Control Driver"); +MODULE_LICENSE("GPL");