[PATCH v4 1/2] platform: x86-android-tablets: other: Add swnode for Xiaomi pad2 indicator LED

[Kate Hsuan <hpa@redhat.com>]

There is a KTD2026 LED controller to manage the indicator LED for Xiaomi
pad2. The ACPI for it is not properly made so the kernel can't get
a correct description of it.

This work add a description for this RGB LED controller and also set a
trigger to indicate the chaging event (bq27520-0-charging). When it is
charging, the indicator LED will be turn on.

Signed-off-by: Kate Hsuan <hpa@redhat.com>
---
 .../platform/x86/x86-android-tablets/other.c  | 85 +++++++++++++++++++
 .../x86/x86-android-tablets/shared-psy-info.h |  2 +
 2 files changed, 87 insertions(+)

diff --git a/drivers/platform/x86/x86-android-tablets/other.c b/drivers/platform/x86/x86-android-tablets/other.c
index bc6bbf7ec6ea..542ef6667b7b 100644
--- a/drivers/platform/x86/x86-android-tablets/other.c
+++ b/drivers/platform/x86/x86-android-tablets/other.c
@@ -12,6 +12,7 @@
 #include <linux/gpio/machine.h>
 #include <linux/input.h>
 #include <linux/platform_device.h>
+#include <dt-bindings/leds/common.h>
 
 #include "shared-psy-info.h"
 #include "x86-android-tablets.h"
@@ -593,6 +594,87 @@ const struct x86_dev_info whitelabel_tm800a550l_info __initconst = {
 	.gpiod_lookup_tables = whitelabel_tm800a550l_gpios,
 };
 
+/*
+ * The fwnode for ktd2026 on Xaomi pad2. It composed of a RGB LED node
+ * with three subnodes for each color (B/G/R). The RGB LED node is named
+ * "multi-led" to align with the name in the device tree.
+ */
+
+/* main fwnode for ktd2026 */
+static const struct software_node ktd2026_node = {
+};
+
+static const struct property_entry ktd2026_rgb_led_props[] = {
+	PROPERTY_ENTRY_U32("reg", 0),
+	PROPERTY_ENTRY_U32("color", LED_COLOR_ID_RGB),
+	PROPERTY_ENTRY_STRING("function", "indicator"),
+	PROPERTY_ENTRY_STRING("linux,default-trigger",
+			      "bq27520-0-charging"),
+
+	{ }
+};
+
+static const struct software_node ktd2026_rgb_led_node = {
+	.name = "multi-led",
+	.properties = ktd2026_rgb_led_props,
+	.parent = &ktd2026_node,
+};
+
+/* B */
+static const struct property_entry ktd2026_red_led_props[] = {
+	PROPERTY_ENTRY_U32("reg", 0),
+	PROPERTY_ENTRY_U32("color", LED_COLOR_ID_BLUE),
+	{ }
+};
+
+static const struct software_node ktd2026_red_led_node = {
+	.properties = ktd2026_red_led_props,
+	.parent = &ktd2026_rgb_led_node,
+};
+
+/* G */
+static const struct property_entry ktd2026_green_led_props[] = {
+	PROPERTY_ENTRY_U32("reg", 1),
+	PROPERTY_ENTRY_U32("color", LED_COLOR_ID_GREEN),
+	{ }
+};
+
+static const struct software_node ktd2026_green_led_node = {
+	.properties = ktd2026_green_led_props,
+	.parent = &ktd2026_rgb_led_node,
+};
+
+/* R */
+static const struct property_entry ktd2026_blue_led_props[] = {
+	PROPERTY_ENTRY_U32("reg", 2),
+	PROPERTY_ENTRY_U32("color", LED_COLOR_ID_RED),
+	{ }
+};
+
+static const struct software_node ktd2026_blue_led_node = {
+	.properties = ktd2026_blue_led_props,
+	.parent = &ktd2026_rgb_led_node,
+};
+
+static const struct software_node *ktd2026_node_group[] = {
+	&ktd2026_node,
+	&ktd2026_rgb_led_node,
+	&ktd2026_red_led_node,
+	&ktd2026_green_led_node,
+	&ktd2026_blue_led_node,
+	NULL
+};
+
+static int __init xiaomi_mipad2_init(void)
+{
+	return software_node_register_node_group(ktd2026_node_group);
+}
+
+static void xiaomi_mipad2_exit(void)
+{
+	software_node_unregister_node_group(ktd2026_node_group);
+}
+
 /*
  * If the EFI bootloader is not Xiaomi's own signed Android loader, then the
  * Xiaomi Mi Pad 2 X86 tablet sets OSID in the DSDT to 1 (Windows), causing
@@ -616,6 +698,7 @@ static const struct x86_i2c_client_info xiaomi_mipad2_i2c_clients[] __initconst
 			.type = "ktd2026",
 			.addr = 0x30,
 			.dev_name = "ktd2026",
+			.swnode = &ktd2026_node,
 		},
 		.adapter_path = "\\_SB_.PCI0.I2C3",
 	},
@@ -624,4 +707,6 @@ static const struct x86_i2c_client_info xiaomi_mipad2_i2c_clients[] __initconst
 const struct x86_dev_info xiaomi_mipad2_info __initconst = {
 	.i2c_client_info = xiaomi_mipad2_i2c_clients,
 	.i2c_client_count = ARRAY_SIZE(xiaomi_mipad2_i2c_clients),
+	.init = xiaomi_mipad2_init,
+	.exit = xiaomi_mipad2_exit,
 };
diff --git a/drivers/platform/x86/x86-android-tablets/shared-psy-info.h b/drivers/platform/x86/x86-android-tablets/shared-psy-info.h
index c2d2968cddc2..8c33ec47ee12 100644
--- a/drivers/platform/x86/x86-android-tablets/shared-psy-info.h
+++ b/drivers/platform/x86/x86-android-tablets/shared-psy-info.h
@@ -29,4 +29,6 @@ extern const char * const bq24190_modules[];
 extern const struct platform_device_info int3496_pdevs[];
 extern struct gpiod_lookup_table int3496_reference_gpios;
 
+extern const struct software_node ktd2026_leds_node;
+
 #endif
-- 
2.43.2