regulator: mt6358: Merge VCN33_* regulators

The VCN33_BT and VCN33_WIFI regulators are actually the same regulator,
having the same voltage setting and output pin. There are simply two
enable bits that are ORed together to enable the regulator.

Having two regulators representing the same output pin is misleading
from a design matching standpoint, and also error-prone in driver
implementations. If consumers try to set different voltages on either
regulator, the one set later would override the one set before. There
are ways around this, such as chaining them together and having the
downstream one act as a switch. But given there's only one output pin,
such a workaround doesn't match reality.

Remove the VCN33_WIFI regulator. During the probe phase, have the driver
sync the enable status of VCN33_WIFI to VCN33_BT. Also drop the suffix
so that the regulator name matches the pin name in the datasheet.

Signed-off-by: Chen-Yu Tsai <wenst@chromium.org>
Link: https://lore.kernel.org/r/20230609083009.2822259-4-wenst@chromium.org
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/mt6358-regulator.c

@@ -277,7 +277,7 @@ static const unsigned int vcama_voltages[] = {
 	2800000, 2900000, 3000000,
 };
 
-static const unsigned int vcn33_bt_wifi_voltages[] = {
+static const unsigned int vcn33_voltages[] = {
 	3300000, 3400000, 3500000,
 };
 
@@ -321,7 +321,7 @@ static const u32 vcama_idx[] = {
 	0, 7, 9, 10, 11, 12,
 };
 
-static const u32 vcn33_bt_wifi_idx[] = {
+static const u32 vcn33_idx[] = {
 	1, 2, 3,
 };
 
@@ -566,12 +566,8 @@ static struct mt6358_regulator_info mt6358_regulators[] = {
 		   MT6358_LDO_VCAMA1_CON0, 0, MT6358_VCAMA1_ANA_CON0, 0xf00),
 	MT6358_LDO("ldo_vemc", VEMC, vmch_vemc_voltages, vmch_vemc_idx,
 		   MT6358_LDO_VEMC_CON0, 0, MT6358_VEMC_ANA_CON0, 0x700),
-	MT6358_LDO("ldo_vcn33_bt", VCN33_BT, vcn33_bt_wifi_voltages,
-		   vcn33_bt_wifi_idx, MT6358_LDO_VCN33_CON0_0,
-		   0, MT6358_VCN33_ANA_CON0, 0x300),
-	MT6358_LDO("ldo_vcn33_wifi", VCN33_WIFI, vcn33_bt_wifi_voltages,
-		   vcn33_bt_wifi_idx, MT6358_LDO_VCN33_CON0_1,
-		   0, MT6358_VCN33_ANA_CON0, 0x300),
+	MT6358_LDO("ldo_vcn33", VCN33, vcn33_voltages, vcn33_idx,
+		   MT6358_LDO_VCN33_CON0_0, 0, MT6358_VCN33_ANA_CON0, 0x300),
 	MT6358_LDO("ldo_vcama2", VCAMA2, vcama_voltages, vcama_idx,
 		   MT6358_LDO_VCAMA2_CON0, 0, MT6358_VCAMA2_ANA_CON0, 0xf00),
 	MT6358_LDO("ldo_vmc", VMC, vmc_voltages, vmc_idx,
@@ -662,12 +658,8 @@ static struct mt6358_regulator_info mt6366_regulators[] = {
 		   MT6358_LDO_VMCH_CON0, 0, MT6358_VMCH_ANA_CON0, 0x700),
 	MT6366_LDO("ldo_vemc", VEMC, vmch_vemc_voltages, vmch_vemc_idx,
 		   MT6358_LDO_VEMC_CON0, 0, MT6358_VEMC_ANA_CON0, 0x700),
-	MT6366_LDO("ldo_vcn33_bt", VCN33_BT, vcn33_bt_wifi_voltages,
-		   vcn33_bt_wifi_idx, MT6358_LDO_VCN33_CON0_0,
-		   0, MT6358_VCN33_ANA_CON0, 0x300),
-	MT6366_LDO("ldo_vcn33_wifi", VCN33_WIFI, vcn33_bt_wifi_voltages,
-		   vcn33_bt_wifi_idx, MT6358_LDO_VCN33_CON0_1,
-		   0, MT6358_VCN33_ANA_CON0, 0x300),
+	MT6366_LDO("ldo_vcn33", VCN33, vcn33_voltages, vcn33_idx,
+		   MT6358_LDO_VCN33_CON0_0, 0, MT6358_VCN33_ANA_CON0, 0x300),
 	MT6366_LDO("ldo_vmc", VMC, vmc_voltages, vmc_idx,
 		   MT6358_LDO_VMC_CON0, 0, MT6358_VMC_ANA_CON0, 0xf00),
 	MT6366_LDO("ldo_vsim2", VSIM2, vsim_voltages, vsim_idx,
@@ -690,13 +682,56 @@ static struct mt6358_regulator_info mt6366_regulators[] = {
 		    MT6358_LDO_VSRAM_CON1, 0x7f),
 };
 
+static int mt6358_sync_vcn33_setting(struct device *dev)
+{
+	struct mt6397_chip *mt6397 = dev_get_drvdata(dev->parent);
+	unsigned int val;
+	int ret;
+
+	/*
+	 * VCN33_WIFI and VCN33_BT are two separate enable bits for the same
+	 * regulator. They share the same voltage setting and output pin.
+	 * Instead of having two potentially conflicting regulators, just have
+	 * one VCN33 regulator. Sync the two enable bits and only use one in
+	 * the regulator device.
+	 */
+	ret = regmap_read(mt6397->regmap, MT6358_LDO_VCN33_CON0_1, &val);
+	if (ret) {
+		dev_err(dev, "Failed to read VCN33_WIFI setting\n");
+		return ret;
+	}
+
+	if (!(val & BIT(0)))
+		return 0;
+
+	/* Sync VCN33_WIFI enable status to VCN33_BT */
+	ret = regmap_update_bits(mt6397->regmap, MT6358_LDO_VCN33_CON0_0, BIT(0), BIT(0));
+	if (ret) {
+		dev_err(dev, "Failed to sync VCN33_WIFI setting to VCN33_BT\n");
+		return ret;
+	}
+
+	/* Disable VCN33_WIFI */
+	ret = regmap_update_bits(mt6397->regmap, MT6358_LDO_VCN33_CON0_1, BIT(0), 0);
+	if (ret) {
+		dev_err(dev, "Failed to disable VCN33_BT\n");
+		return ret;
+	}
+
+	return 0;
+}
+
 static int mt6358_regulator_probe(struct platform_device *pdev)
 {
 	struct mt6397_chip *mt6397 = dev_get_drvdata(pdev->dev.parent);
 	struct regulator_config config = {};
 	struct regulator_dev *rdev;
 	struct mt6358_regulator_info *mt6358_info;
-	int i, max_regulator;
+	int i, max_regulator, ret;
+
+	ret = mt6358_sync_vcn33_setting(&pdev->dev);
+	if (ret)
+		return ret;
 
 	if (mt6397->chip_id == MT6366_CHIP_ID) {
 		max_regulator = MT6366_MAX_REGULATOR;

include/linux/regulator/mt6358-regulator.h

@@ -41,8 +41,7 @@ enum {
 	MT6358_ID_VIO28,
 	MT6358_ID_VA12,
 	MT6358_ID_VRF18,
-	MT6358_ID_VCN33_BT,
-	MT6358_ID_VCN33_WIFI,
+	MT6358_ID_VCN33,
 	MT6358_ID_VCAMA2,
 	MT6358_ID_VMC,
 	MT6358_ID_VLDO28,
@@ -85,8 +84,7 @@ enum {
 	MT6366_ID_VIO28,
 	MT6366_ID_VA12,
 	MT6366_ID_VRF18,
-	MT6366_ID_VCN33_BT,
-	MT6366_ID_VCN33_WIFI,
+	MT6366_ID_VCN33,
 	MT6366_ID_VMC,
 	MT6366_ID_VAUD28,
 	MT6366_ID_VSIM2,