Soft start is required to avoid inrush current during LAB ramp-up and
IBB ramp-down, protecting connected hardware to which we supply voltage.
Since soft start is configurable on both LAB and IBB regulators, it
was necessary to add two DT properties, respectively "qcom,soft-start-us"
to control LAB ramp-up and "qcom,discharge-resistor-kohms" to control
the discharge resistor for IBB ramp-down, which obviously brought the
need of implementing a of_parse callback for both regulators.
Finally, also implement pull-down mode in order to avoid unpredictable
behavior when the regulators are disabled (random voltage spikes etc).
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
---
drivers/regulator/qcom-labibb-regulator.c | 94 +++++++++++++++++++++++
1 file changed, 94 insertions(+)
diff --git a/drivers/regulator/qcom-labibb-regulator.c b/drivers/regulator/qcom-labibb-regulator.c
index d364f54ad294..38ab1eba1c59 100644
--- a/drivers/regulator/qcom-labibb-regulator.c
+++ b/drivers/regulator/qcom-labibb-regulator.c
@@ -29,12 +29,23 @@
#define LABIBB_STATUS1_VREG_OK_BIT BIT(7)
#define LABIBB_CONTROL_ENABLE BIT(7)
+#define REG_LABIBB_PD_CTL 0x47
+ #define LAB_PD_CTL_MASK GENMASK(1, 0)
+ #define IBB_PD_CTL_MASK (BIT(0) | BIT(7))
+ #define LAB_PD_CTL_STRONG_PULL BIT(0)
+ #define IBB_PD_CTL_HALF_STRENGTH BIT(0)
+ #define IBB_PD_CTL_EN BIT(7)
+
#define REG_LABIBB_CURRENT_LIMIT 0x4b
#define LAB_CURRENT_LIMIT_MASK GENMASK(2, 0)
#define IBB_CURRENT_LIMIT_MASK GENMASK(4, 0)
#define LAB_CURRENT_LIMIT_OVERRIDE_EN BIT(3)
#define LABIBB_CURRENT_LIMIT_EN BIT(7)
+#define REG_IBB_PWRUP_PWRDN_CTL_1 0x58
+ #define IBB_CTL_1_DISCHARGE_EN BIT(2)
+
+#define REG_LABIBB_SOFT_START_CTL 0x5f
#define REG_LABIBB_SEC_ACCESS 0xd0
#define LABIBB_SEC_UNLOCK_CODE 0xa5
@@ -60,6 +71,8 @@ struct labibb_regulator {
struct labibb_current_limits uA_limits;
u16 base;
u8 type;
+ u8 dischg_sel;
+ u8 soft_start_sel;
};
struct labibb_regulator_data {
@@ -120,6 +133,70 @@ static int qcom_labibb_get_current_limit(struct regulator_dev *rdev)
return (cur_step * lim->uA_step) + lim->uA_min;
}
+static int qcom_labibb_set_soft_start(struct regulator_dev *rdev)
+{
+ struct labibb_regulator *vreg = rdev_get_drvdata(rdev);
+ u32 val = 0;
+
+ if (vreg->type == QCOM_IBB_TYPE)
+ val = vreg->dischg_sel;
+ else
+ val = vreg->soft_start_sel;
+
+ return regmap_write(rdev->regmap, rdev->desc->soft_start_reg, val);
+}
+
+static int qcom_labibb_get_table_sel(const int *table, int sz, u32 value)
+{
+ int i;
+
+ for (i = 0; i < sz; i++)
+ if (table[i] == value)
+ return i;
+ return -EINVAL;
+}
+
+/* IBB discharge resistor values in KOhms */
+static const int dischg_resistor_values[] = { 300, 64, 32, 16 };
+
+/* Soft start time in microseconds */
+static const int soft_start_values[] = { 200, 400, 600, 800 };
+
+static int qcom_labibb_of_parse_cb(struct device_node *np,
+ const struct regulator_desc *desc,
+ struct regulator_config *config)
+{
+ struct labibb_regulator *vreg = config->driver_data;
+ u32 dischg_kohms, soft_start_time;
+ int ret;
+
+ ret = of_property_read_u32(np, "qcom,discharge-resistor-kohms",
+ &dischg_kohms);
+ if (ret)
+ dischg_kohms = 300;
