Re: [BUG] bitland-mifs-wmi: Power profiles not working on Xiaomi Mi NoteBook Ultra

diff --git a/drivers/platform/x86/bitland-mifs-wmi.c b/drivers/platform/x86/bitland-mifs-wmi.c
index 6031b1cef..e8d2059ed 100644
--- a/drivers/platform/x86/bitland-mifs-wmi.c
+++ b/drivers/platform/x86/bitland-mifs-wmi.c
@@ -11,6 +11,7 @@
 #include <linux/array_size.h>
 #include <linux/bits.h>
 #include <linux/container_of.h>
+#include <linux/delay.h>
 #include <linux/dev_printk.h>
 #include <linux/device.h>
 #include <linux/device/devres.h>
@@ -125,6 +126,8 @@ struct bitland_mifs_ops {
 	bool has_full_speed;
 	bool has_cpu_power;
 	bool quirk_refresh_rate_toggle;
+	int (*custom_profile_get)(struct bitland_mifs_wmi_data *data, u8 *mode);
+	int (*custom_profile_set)(struct bitland_mifs_wmi_data *data, u8 mode);
 };
 
 static const struct bitland_mifs_ops bitland_ops = {
@@ -151,7 +154,101 @@ static const struct bitland_mifs_ops redmi_g_ops = {
 	.quirk_refresh_rate_toggle = true,
 };
 
+/*
+ * TM2017 quirk: The WMI method 0x08 is a dummy stub on this firmware.
+ * Instead, use the native ACPI methods QV20/EV20/FUNR to control
+ * performance profiles via the Embedded Controller.
+ *
+ * ACPI method signatures (from ssdt12.dsl):
+ *   FUNR(0x16)  → reads EC register STNM, returns current mode (0/1/2)
+ *   QV20(0x16)  → sets EVFN=0x16 and fires Notify(WMID, 0x20)
+ *   EV20()      → reads FUNR(0x16), computes next state, writes ECWT(val, RefOf(STNM))
+ *
+ * State machine (EV20):
+ *   0 (Balanced)    → 2 (Quiet)
+ *   1 (Performance) → 2 (Quiet) [if MITE==0] or 0 (Balanced) [if MITE==1]
+ *   2 (Quiet)       → 1 (Performance)
+ */
+
+/* ACPI paths */
+#define TM2017_ACPI_QV20	"\\_SB.PC00.WMID.QV20"
+#define TM2017_ACPI_EV20	"\\_SB.PC00.WMID.EV20"
+#define TM2017_ACPI_FUNR	"\\_SB.PC00.LPCB.H_EC.FUNR"
+
+/* Maximum cycle iterations to prevent infinite loops */
+#define TM2017_MAX_CYCLES	4
+
+static int tm2017_acpi_read_mode(void)
+{
+	acpi_status status;
+	unsigned long long result;
+	struct acpi_object_list params;
+	union acpi_object arg;
+
+	arg.type = ACPI_TYPE_INTEGER;
+	arg.integer.value = 0x16;
+
+	params.count = 1;
+	params.pointer = &arg;
+
+	status = acpi_evaluate_integer(NULL, TM2017_ACPI_FUNR, &params, &result);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return (int)result;
+}
+
+static int tm2017_acpi_cycle_mode(void)
+{
+	acpi_status status;
+	struct acpi_object_list params;
+	union acpi_object arg;
+
+	/* Step 1: QV20(0x16) — queue the Fn+K event */
+	arg.type = ACPI_TYPE_INTEGER;
+	arg.integer.value = 0x16;
+
+	params.count = 1;
+	params.pointer = &arg;
+
+	status = acpi_evaluate_object(NULL, TM2017_ACPI_QV20, &params, NULL);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	/* Step 2: EV20() — execute the event handler */
+	status = acpi_evaluate_object(NULL, TM2017_ACPI_EV20, NULL, NULL);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return 0;
+}
+
+static int tm2017_pp_check_capability(struct bitland_mifs_wmi_data *data)
+{
+	/* TM2017 supports all modes regardless of AC type */
+	return 0;
+}
+
+static int tm2017_profile_get(struct bitland_mifs_wmi_data *data, u8 *mode);
+static int tm2017_profile_set(struct bitland_mifs_wmi_data *data, u8 mode);
+
+static const struct bitland_mifs_ops tm2017_ops = {
+	.name = "Mi NoteBook Ultra TM2017",
+	.mode_map = &bitland_mode_map,  /* same 0/1/2 mapping */
+	.check_performance_capability = tm2017_pp_check_capability,
+	.has_full_speed = false,        /* TM2017 only has 3 modes */
+	.custom_profile_get = tm2017_profile_get,
+	.custom_profile_set = tm2017_profile_set,
+};
+
 static const struct dmi_system_id bitland_mifs_dmi_table[] = {
+	{
+		/* Xiaomi Mi NoteBook Ultra — WMI profile is a dummy */
+		.matches = {
+			DMI_MATCH(DMI_BOARD_NAME, "TM2017"),
+		},
+		.driver_data = (void *)&tm2017_ops,
+	},
 	{
 		/* Redmi G */
 		.matches = {
@@ -296,26 +393,80 @@ static int bitland_mifs_wmi_call(struct bitland_mifs_wmi_data *data,
 	return 0;
 }
 
+static int tm2017_profile_get(struct bitland_mifs_wmi_data *data, u8 *mode)
+{
+	int ret = tm2017_acpi_read_mode();
+	if (ret < 0)
+		return ret;
+
+	*mode = (u8)ret;
+	return 0;
+}
+
+static int tm2017_profile_set(struct bitland_mifs_wmi_data *data, u8 mode)
+{
+	int current_mode, i, ret;
+
+	current_mode = tm2017_acpi_read_mode();
+	if (current_mode < 0)
+		return current_mode;
+
+	/* Already at target? */
+	if ((u8)current_mode == mode)
+		return 0;
+
+	/* Cycle until we reach the target (max TM2017_MAX_CYCLES) */
+	for (i = 0; i < TM2017_MAX_CYCLES; i++) {
+		ret = tm2017_acpi_cycle_mode();
+		if (ret)
+			return ret;
+
+		/* Give the EC time to settle before reading back or cycling again */
+		msleep(50);
+
+		current_mode = tm2017_acpi_read_mode();
+		if (current_mode < 0)
+			return current_mode;
+
+		if ((u8)current_mode == mode)
+			return 0;
+	}
+
+	/* Could not reach target mode */
+	dev_warn(&data->wdev->dev,
+		 "TM2017: failed to reach target mode %u after %d cycles\n",
+		 mode, TM2017_MAX_CYCLES);
+	return -EIO;
+}
+
 static int laptop_profile_get(struct device *dev,
 			      enum platform_profile_option *profile)
 {
 	struct bitland_mifs_wmi_data *data = dev_get_drvdata(dev);
 	const struct bitland_profile_mode_map *map = data->ops->mode_map;
-	struct bitland_mifs_input input = {
-		.reserved1 = 0,
-		.operation = WMI_METHOD_GET,
-		.reserved2 = 0,
-		.function = WMI_FN_SYSTEM_PER_MODE,
-	};
-	struct bitland_mifs_output result;
 	u8 mode;
-	int ret;
 
-	ret = bitland_mifs_wmi_call(data, &input, &result);
-	if (ret)
-		return ret;
+	if (data->ops->custom_profile_get) {
+		int ret = data->ops->custom_profile_get(data, &mode);
+		if (ret)
+			return ret;
+	} else {
+		struct bitland_mifs_input input = {
+			.reserved1 = 0,
+			.operation = WMI_METHOD_GET,
+			.reserved2 = 0,
+			.function = WMI_FN_SYSTEM_PER_MODE,
+		};
+		struct bitland_mifs_output result;
+		int ret;
+
+		ret = bitland_mifs_wmi_call(data, &input, &result);
+		if (ret)
+			return ret;
+
+		mode = result.data[0];
+	}
 
-	mode = result.data[0];
 	if (mode == map->quiet)
 		*profile = PLATFORM_PROFILE_LOW_POWER;
 	else if (mode == map->balanced)
@@ -404,6 +555,9 @@ static int laptop_profile_set(struct device *dev,
 		return -EOPNOTSUPP;
 	}
 
+	if (data->ops->custom_profile_set)
+		return data->ops->custom_profile_set(data, mode);
+
 	input.payload[0] = mode;
 
 	return bitland_mifs_wmi_call(data, &input, NULL);