[PATCH v6 10/11] regulator: bq257xx: Add support for BQ25792

[Alexey Charkov <alchark@flipper.net>]

Add support for TI BQ25792, an integrated battery charger and buck/boost
regulator. This enables VBUS output from the charger's boost converter
for use in USB OTG applications, supporting 2.8-22V output at up to 3.32A
with 10mV and 40mA resolution.

Acked-by: Mark Brown <broonie@kernel.org>
Tested-by: Chris Morgan <macromorgan@hotmail.com>
Signed-off-by: Alexey Charkov <alchark@flipper.net>
---
 drivers/regulator/bq257xx-regulator.c | 98 ++++++++++++++++++++++++++++++++++-
 1 file changed, 97 insertions(+), 1 deletion(-)

diff --git a/drivers/regulator/bq257xx-regulator.c b/drivers/regulator/bq257xx-regulator.c
index 0bb58ab4b8d4..f197162382cc 100644
--- a/drivers/regulator/bq257xx-regulator.c
+++ b/drivers/regulator/bq257xx-regulator.c
@@ -31,6 +31,32 @@ static int bq25703_vbus_get_cur_limit(struct regulator_dev *rdev)
 	return FIELD_GET(BQ25703_OTG_CUR_MASK, reg) * BQ25703_OTG_CUR_STEP_UA;
 }
 
+static int bq25792_vbus_get_cur_limit(struct regulator_dev *rdev)
+{
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	int ret;
+	unsigned int reg;
+
+	ret = regmap_read(regmap, BQ25792_REG0D_IOTG_REGULATION, &reg);
+	if (ret)
+		return ret;
+	return FIELD_GET(BQ25792_REG0D_IOTG_MASK, reg) * BQ25792_OTG_CUR_STEP_UA;
+}
+
+static int bq25792_vbus_get_voltage_sel(struct regulator_dev *rdev)
+{
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	__be16 reg;
+	int ret;
+
+	ret = regmap_raw_read(regmap, BQ25792_REG0B_VOTG_REGULATION,
+			      &reg, sizeof(reg));
+	if (ret)
+		return ret;
+
+	return FIELD_GET(BQ25792_REG0B_VOTG_MASK, be16_to_cpu(reg));
+}
+
 /*
  * Check if the minimum current and maximum current requested are
  * sane values, then set the register accordingly.
@@ -54,6 +80,37 @@ static int bq25703_vbus_set_cur_limit(struct regulator_dev *rdev,
 			    FIELD_PREP(BQ25703_OTG_CUR_MASK, reg));
 }
 
+static int bq25792_vbus_set_cur_limit(struct regulator_dev *rdev,
+				      int min_uA, int max_uA)
+{
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	unsigned int reg;
+
+	if ((min_uA > BQ25792_OTG_CUR_MAX_UA) ||
+	    (max_uA < BQ25792_OTG_CUR_MIN_UA))
+		return -EINVAL;
+
+	reg = (max_uA / BQ25792_OTG_CUR_STEP_UA);
+
+	/* Catch rounding errors since our step is 40000uA. */
+	if ((reg * BQ25792_OTG_CUR_STEP_UA) < min_uA)
+		return -EINVAL;
+
+	return regmap_write(regmap, BQ25792_REG0D_IOTG_REGULATION,
+			    FIELD_PREP(BQ25792_REG0D_IOTG_MASK, reg));
+}
+
+static int bq25792_vbus_set_voltage_sel(struct regulator_dev *rdev,
+					unsigned int sel)
+{
+	struct regmap *regmap = rdev_get_regmap(rdev);
+	__be16 reg;
+
+	reg = cpu_to_be16(FIELD_PREP(BQ25792_REG0B_VOTG_MASK, sel));
+	return regmap_raw_write(regmap, BQ25792_REG0B_VOTG_REGULATION,
+				&reg, sizeof(reg));
+}
+
 static int bq25703_vbus_enable(struct regulator_dev *rdev)
 {
 	struct bq257xx_reg_data *pdata = rdev_get_drvdata(rdev);
@@ -101,6 +158,34 @@ static const struct regulator_desc bq25703_vbus_desc = {
 	.vsel_mask = BQ25703_OTG_VOLT_MASK,
 };
 
+static const struct regulator_ops bq25792_vbus_ops = {
+	/* No GPIO for enabling the OTG regulator */
+	.enable = regulator_enable_regmap,
+	.disable = regulator_disable_regmap,
+	.is_enabled = regulator_is_enabled_regmap,
+	.list_voltage = regulator_list_voltage_linear,
+	.get_voltage_sel = bq25792_vbus_get_voltage_sel,
+	.set_voltage_sel = bq25792_vbus_set_voltage_sel,
+	.get_current_limit = bq25792_vbus_get_cur_limit,
+	.set_current_limit = bq25792_vbus_set_cur_limit,
+};
+
+static const struct regulator_desc bq25792_vbus_desc = {
+	.name = "vbus",
+	.of_match = of_match_ptr("vbus"),
+	.regulators_node = of_match_ptr("regulators"),
+	.type = REGULATOR_VOLTAGE,
+	.owner = THIS_MODULE,
+	.ops = &bq25792_vbus_ops,
+	.min_uV = BQ25792_OTG_VOLT_MIN_UV,
+	.uV_step = BQ25792_OTG_VOLT_STEP_UV,
+	.n_voltages = BQ25792_OTG_VOLT_NUM_VOLT,
+	.enable_mask = BQ25792_REG12_EN_OTG,
+	.enable_reg = BQ25792_REG12_CHARGER_CONTROL_3,
+	.enable_val = BQ25792_REG12_EN_OTG,
+	.disable_val = 0,
+};
+
 /* Get optional GPIO for OTG regulator enable. */
 static void bq257xx_reg_dt_parse_gpio(struct platform_device *pdev)
 {
@@ -141,6 +226,7 @@ static void bq257xx_reg_dt_parse_gpio(struct platform_device *pdev)
 static int bq257xx_regulator_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
+	struct bq257xx_device *bq = dev_get_drvdata(pdev->dev.parent);
 	struct bq257xx_reg_data *pdata;
 	struct device_node *np = dev->of_node;
 	struct regulator_config cfg = {};
@@ -153,7 +239,17 @@ static int bq257xx_regulator_probe(struct platform_device *pdev)
 	if (!pdata)
 		return -ENOMEM;
 
-	pdata->desc = bq25703_vbus_desc;
+	switch (bq->type) {
+	case BQ25703A:
+		pdata->desc = bq25703_vbus_desc;
+		break;
+	case BQ25792:
+		pdata->desc = bq25792_vbus_desc;
+		break;
+	default:
+		return dev_err_probe(&pdev->dev, -EINVAL,
+				     "Unsupported device type\n");
+	}
 
 	platform_set_drvdata(pdev, pdata);
 	bq257xx_reg_dt_parse_gpio(pdev);

-- 
2.52.0