leds: steamdeck: Add support for Steam Deck LED

(cherry picked from commit 85a86d19aa7022ff0555023d53aef78323a42d0c)
Signed-off-by: Cristian Ciocaltea <[email protected]>
Signed-off-by: Alexandre Frade <[email protected]>

drivers/leds/Kconfig

@@ -951,6 +951,13 @@ config LEDS_ACER_A500
 	  This option enables support for the Power Button LED of
 	  Acer Iconia Tab A500.
 
+config LEDS_STEAMDECK
+	tristate "LED support for Steam Deck"
+	depends on LEDS_CLASS && MFD_STEAMDECK
+	help
+	  This option enabled support for the status LED (next to the
+	  power button) on Steam Deck
+
 source "drivers/leds/blink/Kconfig"
 
 comment "Flash and Torch LED drivers"

drivers/leds/Makefile

@@ -81,6 +81,7 @@ obj-$(CONFIG_LEDS_POWERNV)		+= leds-powernv.o
 obj-$(CONFIG_LEDS_PWM)			+= leds-pwm.o
 obj-$(CONFIG_LEDS_REGULATOR)		+= leds-regulator.o
 obj-$(CONFIG_LEDS_SC27XX_BLTC)		+= leds-sc27xx-bltc.o
+obj-$(CONFIG_LEDS_STEAMDECK)		+= leds-steamdeck.o
 obj-$(CONFIG_LEDS_SUN50I_A100)		+= leds-sun50i-a100.o
 obj-$(CONFIG_LEDS_SUNFIRE)		+= leds-sunfire.o
 obj-$(CONFIG_LEDS_SYSCON)		+= leds-syscon.o

drivers/leds/leds-steamdeck.c

@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ * Steam Deck EC MFD LED cell driver
+ *
+ * Copyright (C) 2021-2022 Valve Corporation
+ *
+ */
+
+#include <linux/acpi.h>
+#include <linux/leds.h>
+#include <linux/platform_device.h>
+
+struct steamdeck_led {
+	struct acpi_device *adev;
+	struct led_classdev cdev;
+};
+
+static int steamdeck_leds_brightness_set(struct led_classdev *cdev,
+					 enum led_brightness value)
+{
+	struct steamdeck_led *sd = container_of(cdev, struct steamdeck_led,
+						cdev);
+
+	if (ACPI_FAILURE(acpi_execute_simple_method(sd->adev->handle,
+						    "CHBV", value)))
+		return -EIO;
+
+	return 0;
+}
+
+static int steamdeck_leds_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct steamdeck_led *sd;
+	int ret;
+
+	sd = devm_kzalloc(dev, sizeof(*sd), GFP_KERNEL);
+	if (!sd)
+		return -ENOMEM;
+
+	sd->adev = ACPI_COMPANION(dev->parent);
+
+	sd->cdev.name = "status:white";
+	sd->cdev.brightness_set_blocking = steamdeck_leds_brightness_set;
+	sd->cdev.max_brightness = 100;
+
+	ret = devm_led_classdev_register(dev, &sd->cdev);
+	if (ret) {
+		dev_err(dev, "Failed to register LEDs device: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static const struct platform_device_id steamdeck_leds_id_table[] = {
+	{ .name = "steamdeck-leds" },
+	{}
+};
+MODULE_DEVICE_TABLE(platform, steamdeck_leds_id_table);
+
+static struct platform_driver steamdeck_leds_driver = {
+	.probe = steamdeck_leds_probe,
+	.driver = {
+		.name = "steamdeck-leds",
+	},
+	.id_table = steamdeck_leds_id_table,
+};
+module_platform_driver(steamdeck_leds_driver);
+
+MODULE_AUTHOR("Andrey Smirnov <[email protected]>");
+MODULE_DESCRIPTION("Steam Deck LEDs driver");
+MODULE_LICENSE("GPL");