[PATCH v2 06/11] regulator: pca9450: Fix control register for LDO5

[Frieder Schrempf <frieder@fris.de>]

From: Frieder Schrempf <frieder.schrempf@kontron.de>

For LDO5 we need to be able to check the status of the SD_VSEL input in
order to know which control register is used. Read the status of the
SD_VSEL signal via GPIO and use the correct register accordingly.

To use this, the LDO5 node in the devicetree needs the sd-vsel-gpios
property to reference the GPIO that is used to read back the SD_VSEL
status internally. Please note that the SION bit in the IOMUX must be
set if the signal is muxed as VSELECT and controlled by the USDHC
controller.

Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
---
Changes for v2:
* rebase to current master and stop using generic helper from
  regulator core
---
 drivers/regulator/pca9450-regulator.c | 77 +++++++++++++++++++++++++--
 1 file changed, 74 insertions(+), 3 deletions(-)

diff --git a/drivers/regulator/pca9450-regulator.c b/drivers/regulator/pca9450-regulator.c
index 0f8a515a0b11a..8e525deaff0b7 100644
--- a/drivers/regulator/pca9450-regulator.c
+++ b/drivers/regulator/pca9450-regulator.c
@@ -5,6 +5,7 @@
  */
 
 #include <linux/err.h>
+#include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
@@ -31,6 +32,7 @@ struct pca9450_regulator_desc {
 struct pca9450 {
 	struct device *dev;
 	struct regmap *regmap;
+	struct gpio_desc *sd_vsel_gpio;
 	enum pca9450_chip_type type;
 	unsigned int rcnt;
 	int irq;
@@ -96,6 +98,58 @@ static const struct regulator_ops pca9450_ldo_regulator_ops = {
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 };
 
+static unsigned int pca9450_ldo5_get_reg_voltage_sel(struct regulator_dev *rdev)
+{
+	struct pca9450 *pca9450 = rdev_get_drvdata(rdev);
+
+	if (pca9450->sd_vsel_gpio && !gpiod_get_value(pca9450->sd_vsel_gpio))
+		return PCA9450_REG_LDO5CTRL_L;
+
+	return rdev->desc->vsel_reg;
+}
+
+static int pca9450_ldo5_get_voltage_sel_regmap(struct regulator_dev *rdev)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(rdev->regmap, pca9450_ldo5_get_reg_voltage_sel(rdev), &val);
+	if (ret != 0)
+		return ret;
+
+	val &= rdev->desc->vsel_mask;
+	val >>= ffs(rdev->desc->vsel_mask) - 1;
+
+	return val;
+}
+
+static int pca9450_ldo5_set_voltage_sel_regmap(struct regulator_dev *rdev, unsigned int sel)
+{
+	int ret;
+
+	sel <<= ffs(rdev->desc->vsel_mask) - 1;
+
+	ret = regmap_update_bits(rdev->regmap, pca9450_ldo5_get_reg_voltage_sel(rdev),
+				  rdev->desc->vsel_mask, sel);
+	if (ret)
+		return ret;
+
+	if (rdev->desc->apply_bit)
+		ret = regmap_update_bits(rdev->regmap, rdev->desc->apply_reg,
+					 rdev->desc->apply_bit,
+					 rdev->desc->apply_bit);
+	return ret;
+}
+
+static const struct regulator_ops pca9450_ldo5_regulator_ops = {
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+	.list_voltage = regulator_list_voltage_linear_range,
+	.set_voltage_sel = pca9450_ldo5_set_voltage_sel_regmap,
+	.get_voltage_sel = pca9450_ldo5_get_voltage_sel_regmap,
+};
+
 /*
  * BUCK1/2/3
  * 0.60 to 2.1875V (12.5mV step)
@@ -445,7 +499,7 @@ static const struct pca9450_regulator_desc pca9450a_regulators[] = {
 			.of_match = of_match_ptr("LDO5"),
 			.regulators_node = of_match_ptr("regulators"),
 			.id = PCA9450_LDO5,
-			.ops = &pca9450_ldo_regulator_ops,
+			.ops = &pca9450_ldo5_regulator_ops,
 			.type = REGULATOR_VOLTAGE,
 			.n_voltages = PCA9450_LDO5_VOLTAGE_NUM,
 			.linear_ranges = pca9450_ldo5_volts,
@@ -654,7 +708,7 @@ static const struct pca9450_regulator_desc pca9450bc_regulators[] = {
 			.of_match = of_match_ptr("LDO5"),
 			.regulators_node = of_match_ptr("regulators"),
 			.id = PCA9450_LDO5,
-			.ops = &pca9450_ldo_regulator_ops,
+			.ops = &pca9450_ldo5_regulator_ops,
 			.type = REGULATOR_VOLTAGE,
 			.n_voltages = PCA9450_LDO5_VOLTAGE_NUM,
 			.linear_ranges = pca9450_ldo5_volts,
@@ -826,7 +880,7 @@ static const struct pca9450_regulator_desc pca9451a_regulators[] = {
 			.of_match = of_match_ptr("LDO5"),
 			.regulators_node = of_match_ptr("regulators"),
 			.id = PCA9450_LDO5,
-			.ops = &pca9450_ldo_regulator_ops,
+			.ops = &pca9450_ldo5_regulator_ops,
 			.type = REGULATOR_VOLTAGE,
 			.n_voltages = PCA9450_LDO5_VOLTAGE_NUM,
 			.linear_ranges = pca9450_ldo5_volts,
@@ -884,6 +938,7 @@ static int pca9450_i2c_probe(struct i2c_client *i2c)
 				      of_device_get_match_data(&i2c->dev);
 	const struct pca9450_regulator_desc	*regulator_desc;
 	struct regulator_config config = { };
+	struct regulator_dev *ldo5;
 	struct pca9450 *pca9450;
 	unsigned int device_id, i;
 	unsigned int reset_ctrl;
@@ -949,6 +1004,7 @@ static int pca9450_i2c_probe(struct i2c_client *i2c)
 
 		config.regmap = pca9450->regmap;
 		config.dev = pca9450->dev;
+		config.driver_data = pca9450;
 
 		rdev = devm_regulator_register(pca9450->dev, desc, &config);
 		if (IS_ERR(rdev)) {
@@ -958,6 +1014,9 @@ static int pca9450_i2c_probe(struct i2c_client *i2c)
 				desc->name, ret);
 			return ret;
 		}
+
+		if (!strcmp(desc->name, "ldo5"))
+			ldo5 = rdev;
 	}
 
 	if (pca9450->irq) {
@@ -1013,6 +1072,18 @@ static int pca9450_i2c_probe(struct i2c_client *i2c)
 		}
 	}
 
+	/*
+	 * For LDO5 we need to be able to check the status of the SD_VSEL input in
+	 * order to know which control register is used. Most boards connect SD_VSEL
+	 * to the VSELECT signal, so we can use the GPIO that is internally routed
+	 * to this signal (if SION bit is set in IOMUX).
+	 */
+	pca9450->sd_vsel_gpio = gpiod_get_optional(&ldo5->dev, "sd-vsel", GPIOD_IN);
+	if (IS_ERR(pca9450->sd_vsel_gpio)) {
+		dev_err(&i2c->dev, "Failed to get SD_VSEL GPIO\n");
+		return ret;
+	}
+
 	dev_info(&i2c->dev, "%s probed.\n",
 		type == PCA9450_TYPE_PCA9450A ? "pca9450a" :
 		(type == PCA9450_TYPE_PCA9451A ? "pca9451a" : "pca9450bc"));
-- 
2.46.1