regulator: core: Add set/get_current_limit helpers for regmap users

By setting curr_table, n_current_limits, csel_reg and csel_mask, the
regmap users can use regulator_set_current_limit_regmap and
regulator_get_current_limit_regmap for set/get_current_limit callbacks.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/helpers.c

@@ -780,3 +780,89 @@ int regulator_set_active_discharge_regmap(struct regulator_dev *rdev,
 				  rdev->desc->active_discharge_mask, val);
 }
 EXPORT_SYMBOL_GPL(regulator_set_active_discharge_regmap);
+
+/**
+ * regulator_set_current_limit_regmap - set_current_limit for regmap users
+ *
+ * @rdev: regulator to operate on
+ * @min_uA: Lower bound for current limit
+ * @max_uA: Upper bound for current limit
+ *
+ * Regulators that use regmap for their register I/O can set curr_table,
+ * csel_reg and csel_mask fields in their descriptor and then use this
+ * as their set_current_limit operation, saving some code.
+ */
+int regulator_set_current_limit_regmap(struct regulator_dev *rdev,
+				       int min_uA, int max_uA)
+{
+	unsigned int n_currents = rdev->desc->n_current_limits;
+	int i, sel = -1;
+
+	if (n_currents == 0)
+		return -EINVAL;
+
+	if (rdev->desc->curr_table) {
+		const unsigned int *curr_table = rdev->desc->curr_table;
+		bool ascend = curr_table[n_currents - 1] > curr_table[0];
+
+		/* search for closest to maximum */
+		if (ascend) {
+			for (i = n_currents - 1; i >= 0; i--) {
+				if (min_uA <= curr_table[i] &&
+				    curr_table[i] <= max_uA) {
+					sel = i;
+					break;
+				}
+			}
+		} else {
+			for (i = 0; i < n_currents; i++) {
+				if (min_uA <= curr_table[i] &&
+				    curr_table[i] <= max_uA) {
+					sel = i;
+					break;
+				}
+			}
+		}
+	}
+
+	if (sel < 0)
+		return -EINVAL;
+
+	sel <<= ffs(rdev->desc->csel_mask) - 1;
+
+	return regmap_update_bits(rdev->regmap, rdev->desc->csel_reg,
+				  rdev->desc->csel_mask, sel);
+}
+EXPORT_SYMBOL_GPL(regulator_set_current_limit_regmap);
+
+/**
+ * regulator_get_current_limit_regmap - get_current_limit for regmap users
+ *
+ * @rdev: regulator to operate on
+ *
+ * Regulators that use regmap for their register I/O can set the
+ * csel_reg and csel_mask fields in their descriptor and then use this
+ * as their get_current_limit operation, saving some code.
+ */
+int regulator_get_current_limit_regmap(struct regulator_dev *rdev)
+{
+	unsigned int val;
+	int ret;
+
+	ret = regmap_read(rdev->regmap, rdev->desc->csel_reg, &val);
+	if (ret != 0)
+		return ret;
+
+	val &= rdev->desc->csel_mask;
+	val >>= ffs(rdev->desc->csel_mask) - 1;
+
+	if (rdev->desc->curr_table) {
+		if (val >= rdev->desc->n_current_limits)
+			return -EINVAL;
+
+		return rdev->desc->curr_table[val];
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(regulator_get_current_limit_regmap);

include/linux/regulator/driver.h

@@ -264,6 +264,7 @@ enum regulator_type {
  * @continuous_voltage_range: Indicates if the regulator can set any
  *                            voltage within constrains range.
  * @n_voltages: Number of selectors available for ops.list_voltage().
+ * @n_current_limits: Number of selectors available for current limits
  *
  * @min_uV: Voltage given by the lowest selector (if linear mapping)
  * @uV_step: Voltage increase with each selector (if linear mapping)
@@ -278,6 +279,7 @@ enum regulator_type {
  * @n_linear_ranges: Number of entries in the @linear_ranges (and in
  *		     linear_range_selectors if used) table(s).
  * @volt_table: Voltage mapping table (if table based mapping)
+ * @curr_table: Current limit mapping table (if table based mapping)
  *
  * @vsel_range_reg: Register for range selector when using pickable ranges
  *		    and regulator_regmap_X_voltage_X_pickable functions.
@@ -333,6 +335,7 @@ struct regulator_desc {
 	int id;
 	unsigned int continuous_voltage_range:1;
 	unsigned n_voltages;
+	unsigned int n_current_limits;
 	const struct regulator_ops *ops;
 	int irq;
 	enum regulator_type type;
@@ -351,6 +354,7 @@ struct regulator_desc {
 	int n_linear_ranges;
 
 	const unsigned int *volt_table;
+	const unsigned int *curr_table;
 
 	unsigned int vsel_range_reg;
 	unsigned int vsel_range_mask;
@@ -534,6 +538,9 @@ int regulator_set_pull_down_regmap(struct regulator_dev *rdev);
 
 int regulator_set_active_discharge_regmap(struct regulator_dev *rdev,
 					  bool enable);
+int regulator_set_current_limit_regmap(struct regulator_dev *rdev,
+				       int min_uA, int max_uA);
+int regulator_get_current_limit_regmap(struct regulator_dev *rdev);
 void *regulator_get_init_drvdata(struct regulator_init_data *reg_init_data);
 
 void regulator_lock(struct regulator_dev *rdev);