regulator: Add a routine to set the current limit for QCOM PMIC VBUS

Add hooks to regulator_get_current_limit_regmap() and
regulator_set_current_limit_regmap() with an accompanying map of amperages.

This lets us use the existing helper functions to map requested current
settings to register bit-map/indicies.

This change is required to elevate the default 2 Amps set by the bootloader
to 3 Amps or indeed to constrain the value lower as the system design may
dictate.

The valid range is 500 mA to 3 A in increments of 500 mA.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Link: https://lore.kernel.org/r/20210427130712.2005456-2-bryan.odonoghue@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/regulator/qcom_usb_vbus-regulator.c b/drivers/regulator/qcom_usb_vbus-regulator.c
index 457788b..2e627c2 100644 (file)
--- a/drivers/regulator/qcom_usb_vbus-regulator.c
+++ b/drivers/regulator/qcom_usb_vbus-regulator.c
@@ -16,13 +16,21 @@
 
 #define CMD_OTG                                0x40
 #define OTG_EN                         BIT(0)
+#define OTG_CURRENT_LIMIT_CFG          0x52
+#define OTG_CURRENT_LIMIT_MASK         GENMASK(2, 0)
 #define OTG_CFG                                0x53
 #define OTG_EN_SRC_CFG                 BIT(1)
 
+static const unsigned int curr_table[] = {
+       500000, 1000000, 1500000, 2000000, 2500000, 3000000,
+};
+
 static const struct regulator_ops qcom_usb_vbus_reg_ops = {
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
+       .get_current_limit = regulator_get_current_limit_regmap,
+       .set_current_limit = regulator_set_current_limit_regmap,
 };
 
 static struct regulator_desc qcom_usb_vbus_rdesc = {
@@ -30,6 +38,8 @@ static struct regulator_desc qcom_usb_vbus_rdesc = {
        .ops = &qcom_usb_vbus_reg_ops,
        .owner = THIS_MODULE,
        .type = REGULATOR_VOLTAGE,
+       .curr_table = curr_table,
+       .n_current_limits = ARRAY_SIZE(curr_table),
 };
 
 static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
@@ -61,6 +71,8 @@ static int qcom_usb_vbus_regulator_probe(struct platform_device *pdev)
 
        qcom_usb_vbus_rdesc.enable_reg = base + CMD_OTG;
        qcom_usb_vbus_rdesc.enable_mask = OTG_EN;
+       qcom_usb_vbus_rdesc.csel_reg = base + OTG_CURRENT_LIMIT_CFG;
+       qcom_usb_vbus_rdesc.csel_mask = OTG_CURRENT_LIMIT_MASK;
        config.dev = dev;
        config.init_data = init_data;
        config.of_node = dev->of_node;