platform/x86: ideapad-laptop: Add charge_types:Fast (Rapid Charge)

The GBMD/SBMC interface on recent devices supports Rapid Charge mode
(charge_types: Fast) in addition to Conservation Mode (charge_types:
Long_Life).

Query the GBMD interface on probe to determine if a device supports
Rapid Charge. If so, expose these two modes while carefully maintaining
their mutually exclusive state, which aligns with the behavior of
manufacturer utilities on Windows.

Signed-off-by: Rong Zhang <[e-mail]>
Acked-by: Ike Panhc <[e-mail]>
Reviewed-by: Mark Pearson <[e-mail]>
Tested-By: Jelle van der Waa <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Reviewed-by: Ilpo Järvinen <[e-mail]>
Signed-off-by: Ilpo Järvinen <[e-mail]>

drivers/platform/x86/lenovo/ideapad-laptop.c

···
 	CFG_OSD_CAM_BIT      = 31,
 };
 
+/*
+ * There are two charge modes supported by the GBMD/SBMC interface:
+ * - "Rapid Charge": increase power to speed up charging
+ * - "Conservation Mode": stop charging at 60-80% (depends on model)
+ *
+ * The interface doesn't prohibit enabling both modes at the same time.
+ * However, doing so is essentially meaningless, and the manufacturer utilities
+ * on Windows always make them mutually exclusive.
+ */
+
 enum {
+	GBMD_RAPID_CHARGE_STATE_BIT = 2,
 	GBMD_CONSERVATION_STATE_BIT = 5,
+	GBMD_RAPID_CHARGE_SUPPORTED_BIT = 17,
 };
 
 enum {
 	SBMC_CONSERVATION_ON  = 3,
 	SBMC_CONSERVATION_OFF = 5,
+	SBMC_RAPID_CHARGE_ON  = 7,
+	SBMC_RAPID_CHARGE_OFF = 8,
 };
 
 enum {
···
 	unsigned long cfg;
 	unsigned long r_touchpad_val;
 	struct {
+		bool rapid_charge         : 1;
 		bool conservation_mode    : 1;
 		bool dytc                 : 1;
 		bool fan_mode             : 1;
···
 			return err;
 	}
 
+	/*
+	 * For backward compatibility, ignore Rapid Charge while reporting the
+	 * state of Conservation Mode.
+	 */
 	return sysfs_emit(buf, "%d\n", !!test_bit(GBMD_CONSERVATION_STATE_BIT, &result));
 }
 
···
 		return err;
 
 	guard(mutex)(&priv->gbmd_sbmc_mutex);
+
+	/*
+	 * Prevent mutually exclusive modes from being set at the same time,
+	 * but do not disable Rapid Charge while disabling Conservation Mode.
+	 */
+	if (priv->features.rapid_charge && state) {
+		err = exec_sbmc(priv->adev->handle, SBMC_RAPID_CHARGE_OFF);
+		if (err)
+			return err;
+	}
 
 	err = exec_sbmc(priv->adev->handle, state ? SBMC_CONSERVATION_ON : SBMC_CONSERVATION_OFF);
 	if (err)
···
 				    const union power_supply_propval *val)
 {
 	struct ideapad_private *priv = ext_data;
-	unsigned long op;
+	unsigned long op1, op2;
+	int err;
 
 	switch (val->intval) {
+	case POWER_SUPPLY_CHARGE_TYPE_FAST:
+		if (WARN_ON(!priv->features.rapid_charge))
+			return -EINVAL;
+
+		op1 = SBMC_CONSERVATION_OFF;
+		op2 = SBMC_RAPID_CHARGE_ON;
+		break;
 	case POWER_SUPPLY_CHARGE_TYPE_LONGLIFE:
-		op = SBMC_CONSERVATION_ON;
+		op1 = SBMC_RAPID_CHARGE_OFF;
+		op2 = SBMC_CONSERVATION_ON;
 		break;
 	case POWER_SUPPLY_CHARGE_TYPE_STANDARD:
-		op = SBMC_CONSERVATION_OFF;
+		op1 = SBMC_RAPID_CHARGE_OFF;
+		op2 = SBMC_CONSERVATION_OFF;
 		break;
 	default:
 		return -EINVAL;
···
 
 	guard(mutex)(&priv->gbmd_sbmc_mutex);
 
-	return exec_sbmc(priv->adev->handle, op);
+	/* If !rapid_charge, op1 must be SBMC_RAPID_CHARGE_OFF. Skip it. */
+	if (priv->features.rapid_charge) {
+		err = exec_sbmc(priv->adev->handle, op1);
+		if (err)
+			return err;
+	}
+
+	return exec_sbmc(priv->adev->handle, op2);
 }
 
 static int ideapad_psy_ext_get_prop(struct power_supply *psy,
···
 				    union power_supply_propval *val)
 {
 	struct ideapad_private *priv = ext_data;
+	bool is_rapid_charge, is_conservation;
 	unsigned long result;
 	int err;
 
···
 			return err;
 	}
 
-	if (test_bit(GBMD_CONSERVATION_STATE_BIT, &result))
+	is_rapid_charge = (priv->features.rapid_charge &&
+			   test_bit(GBMD_RAPID_CHARGE_STATE_BIT, &result));
+	is_conservation = test_bit(GBMD_CONSERVATION_STATE_BIT, &result);
+
+	if (unlikely(is_rapid_charge && is_conservation)) {
+		dev_err(&priv->platform_device->dev,
+			"unexpected charge_types: both [Fast] and [Long_Life] are enabled\n");
+		return -EINVAL;
+	}
+
+	if (is_rapid_charge)
+		val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
+	else if (is_conservation)
 		val->intval = POWER_SUPPLY_CHARGE_TYPE_LONGLIFE;
 	else
 		val->intval = POWER_SUPPLY_CHARGE_TYPE_STANDARD;
···
 
 DEFINE_IDEAPAD_POWER_SUPPLY_EXTENSION(ideapad_battery_ext_v1,
 	(BIT(POWER_SUPPLY_CHARGE_TYPE_STANDARD) |
+	 BIT(POWER_SUPPLY_CHARGE_TYPE_LONGLIFE))
+);
+
+DEFINE_IDEAPAD_POWER_SUPPLY_EXTENSION(ideapad_battery_ext_v2,
+	(BIT(POWER_SUPPLY_CHARGE_TYPE_STANDARD) |
+	 BIT(POWER_SUPPLY_CHARGE_TYPE_FAST) |
 	 BIT(POWER_SUPPLY_CHARGE_TYPE_LONGLIFE))
 );
 
···
 		priv->features.fan_mode = true;
 
 	if (acpi_has_method(handle, "GBMD") && acpi_has_method(handle, "SBMC")) {
-		priv->features.conservation_mode = true;
+		/* Not acquiring gbmd_sbmc_mutex as race condition is impossible on init */
+		if (!eval_gbmd(handle, &val)) {
+			priv->features.conservation_mode = true;
+			priv->features.rapid_charge = test_bit(GBMD_RAPID_CHARGE_SUPPORTED_BIT,
+							       &val);
 
-		priv->battery_ext = &ideapad_battery_ext_v1;
+			priv->battery_ext = priv->features.rapid_charge
+					    ? &ideapad_battery_ext_v2
+					    : &ideapad_battery_ext_v1;
 
-		priv->battery_hook.add_battery = ideapad_battery_add;
-		priv->battery_hook.remove_battery = ideapad_battery_remove;
-		priv->battery_hook.name = "Ideapad Battery Extension";
+			priv->battery_hook.add_battery = ideapad_battery_add;
+			priv->battery_hook.remove_battery = ideapad_battery_remove;
+			priv->battery_hook.name = "Ideapad Battery Extension";
 
-		err = devm_battery_hook_register(&priv->platform_device->dev, &priv->battery_hook);
-		if (err)
-			return err;
+			err = devm_battery_hook_register(&priv->platform_device->dev,
+							 &priv->battery_hook);
+			if (err)
+				return err;
+		}
 	}
 
 	if (acpi_has_method(handle, "DYTC"))