regulator: Support regulators where voltage ranges are selectable

For example ROHM BD71837 and ROHM BD71847 Power management ICs have
regulators which provide multiple linear ranges. Ranges can be
selected by individual non contagious bit in vsel register. Add
regmap helper functions for selecting ranges.

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

2 files changed, 237 insertions, 0 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 9577d8941846..4b1755a8ef00 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2783,6 +2783,11 @@ static int regulator_map_voltage(struct regulator_dev *rdev, int min_uV,
 	if (desc->ops->list_voltage == regulator_list_voltage_linear_range)
 		return regulator_map_voltage_linear_range(rdev, min_uV, max_uV);
 
+	if (desc->ops->list_voltage ==
+		regulator_list_voltage_pickable_linear_range)
+		return regulator_map_voltage_pickable_linear_range(rdev,
+							min_uV, max_uV);
+
 	return regulator_map_voltage_iterate(rdev, min_uV, max_uV);
 }
 
diff --git a/drivers/regulator/helpers.c b/drivers/regulator/helpers.c
index 2ae7c3ac5940..d2b9fc359318 100644
--- a/drivers/regulator/helpers.c
+++ b/drivers/regulator/helpers.c
@@ -103,6 +103,128 @@ int regulator_disable_regmap(struct regulator_dev *rdev)
 }
 EXPORT_SYMBOL_GPL(regulator_disable_regmap);
 
+static int regulator_range_selector_to_index(struct regulator_dev *rdev,
+					     unsigned int rval)
+{
+	int i;
+
+	if (!rdev->desc->linear_range_selectors)
+		return -EINVAL;
+
+	rval &= rdev->desc->vsel_range_mask;
+
+	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {
+		if (rdev->desc->linear_range_selectors[i] == rval)
+			return i;
+	}
+	return -EINVAL;
+}
+
+/**
+ * regulator_get_voltage_sel_pickable_regmap - pickable range get_voltage_sel
+ *
+ * @rdev: regulator to operate on
+ *
+ * Regulators that use regmap for their register I/O and use pickable
+ * ranges can set the vsel_reg, vsel_mask, vsel_range_reg and vsel_range_mask
+ * fields in their descriptor and then use this as their get_voltage_vsel
+ * operation, saving some code.
+ */
+int regulator_get_voltage_sel_pickable_regmap(struct regulator_dev *rdev)
+{
+	unsigned int r_val;
+	int range;
+	unsigned int val;
+	int ret, i;
+	unsigned int voltages_in_range = 0;
+
+	if (!rdev->desc->linear_ranges)
+		return -EINVAL;
+
+	ret = regmap_read(rdev->regmap, rdev->desc->vsel_reg, &val);
+	if (ret != 0)
+		return ret;
+
+	ret = regmap_read(rdev->regmap, rdev->desc->vsel_range_reg, &r_val);
+	if (ret != 0)
+		return ret;
+
+	val &= rdev->desc->vsel_mask;
+	val >>= ffs(rdev->desc->vsel_mask) - 1;
+
+	range = regulator_range_selector_to_index(rdev, r_val);
+	if (range < 0)
+		return -EINVAL;
+
+	for (i = 0; i < range; i++)
+		voltages_in_range += (rdev->desc->linear_ranges[i].max_sel -
+				     rdev->desc->linear_ranges[i].min_sel) + 1;
+
+	return val + voltages_in_range;
+}
+EXPORT_SYMBOL_GPL(regulator_get_voltage_sel_pickable_regmap);
+
+/**
+ * regulator_set_voltage_sel_pickable_regmap - pickable range set_voltage_sel
+ *
+ * @rdev: regulator to operate on
+ * @sel: Selector to set
+ *
+ * Regulators that use regmap for their register I/O and use pickable
+ * ranges can set the vsel_reg, vsel_mask, vsel_range_reg and vsel_range_mask
+ * fields in their descriptor and then use this as their set_voltage_vsel
+ * operation, saving some code.
+ */
+int regulator_set_voltage_sel_pickable_regmap(struct regulator_dev *rdev,
+					      unsigned int sel)
+{
+	unsigned int range;
+	int ret, i;
+	unsigned int voltages_in_range = 0;
+
+	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {
+		voltages_in_range = (rdev->desc->linear_ranges[i].max_sel -
+				     rdev->desc->linear_ranges[i].min_sel) + 1;
+		if (sel < voltages_in_range)
+			break;
+		sel -= voltages_in_range;
+	}
+
+	if (i == rdev->desc->n_linear_ranges)
+		return -EINVAL;
+
+	sel <<= ffs(rdev->desc->vsel_mask) - 1;
+	sel += rdev->desc->linear_ranges[i].min_sel;
+
+	range = rdev->desc->linear_range_selectors[i];
+
+	if (rdev->desc->vsel_reg == rdev->desc->vsel_range_reg) {
+		ret = regmap_update_bits(rdev->regmap,
+					 rdev->desc->vsel_reg,
+					 rdev->desc->vsel_range_mask |
+					 rdev->desc->vsel_mask, sel | range);
+	} else {
+		ret = regmap_update_bits(rdev->regmap,
+					 rdev->desc->vsel_range_reg,
+					 rdev->desc->vsel_range_mask, range);
+		if (ret)
+			return ret;
+
+		ret = regmap_update_bits(rdev->regmap, rdev->desc->vsel_reg,
+				  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;
+}
+EXPORT_SYMBOL_GPL(regulator_set_voltage_sel_pickable_regmap);
+
 /**
  * regulator_get_voltage_sel_regmap - standard get_voltage_sel for regmap users
  *
@@ -337,6 +459,76 @@ int regulator_map_voltage_linear_range(struct regulator_dev *rdev,
 EXPORT_SYMBOL_GPL(regulator_map_voltage_linear_range);
 
 /**
+ * regulator_map_voltage_pickable_linear_range - map_voltage, pickable ranges
+ *
+ * @rdev: Regulator to operate on
+ * @min_uV: Lower bound for voltage
+ * @max_uV: Upper bound for voltage
+ *
+ * Drivers providing pickable linear_ranges in their descriptor can use
+ * this as their map_voltage() callback.
+ */
+int regulator_map_voltage_pickable_linear_range(struct regulator_dev *rdev,
+						int min_uV, int max_uV)
+{
+	const struct regulator_linear_range *range;
+	int ret = -EINVAL;
+	int voltage, i;
+	unsigned int selector = 0;
+
+	if (!rdev->desc->n_linear_ranges) {
+		BUG_ON(!rdev->desc->n_linear_ranges);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {
+		int linear_max_uV;
+
+		range = &rdev->desc->linear_ranges[i];
+		linear_max_uV = range->min_uV +
+			(range->max_sel - range->min_sel) * range->uV_step;
+
+		if (!(min_uV <= linear_max_uV && max_uV >= range->min_uV)) {
+			selector += (range->max_sel - range->min_sel + 1);
+			continue;
+		}
+
+		if (min_uV <= range->min_uV)
+			min_uV = range->min_uV;
+
+		/* range->uV_step == 0 means fixed voltage range */
+		if (range->uV_step == 0) {
+			ret = 0;
+		} else {
+			ret = DIV_ROUND_UP(min_uV - range->min_uV,
+					   range->uV_step);
+			if (ret < 0)
+				return ret;
+		}
+
+		ret += selector;
+
+		voltage = rdev->desc->ops->list_voltage(rdev, ret);
+
+		/*
+		 * Map back into a voltage to verify we're still in bounds.
+		 * We may have overlapping voltage ranges. Hence we don't
+		 * exit but retry until we have checked all ranges.
+		 */
+		if (voltage < min_uV || voltage > max_uV)
+			selector += (range->max_sel - range->min_sel + 1);
+		else
+			break;
+	}
+
+	if (i == rdev->desc->n_linear_ranges)
+		return -EINVAL;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_map_voltage_pickable_linear_range);
+
+/**
  * regulator_list_voltage_linear - List voltages with simple calculation
  *
  * @rdev: Regulator device
@@ -361,6 +553,46 @@ int regulator_list_voltage_linear(struct regulator_dev *rdev,
 EXPORT_SYMBOL_GPL(regulator_list_voltage_linear);
 
 /**
+ * regulator_list_voltage_pickable_linear_range - pickable range list voltages
+ *
+ * @rdev: Regulator device
+ * @selector: Selector to convert into a voltage
+ *
+ * list_voltage() operation, intended to be used by drivers utilizing pickable
+ * ranges helpers.
+ */
+int regulator_list_voltage_pickable_linear_range(struct regulator_dev *rdev,
+						 unsigned int selector)
+{
+	const struct regulator_linear_range *range;
+	int i;
+	unsigned int all_sels = 0;
+
+	if (!rdev->desc->n_linear_ranges) {
+		BUG_ON(!rdev->desc->n_linear_ranges);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < rdev->desc->n_linear_ranges; i++) {
+		unsigned int sels_in_range;
+
+		range = &rdev->desc->linear_ranges[i];
+
+		sels_in_range = range->max_sel - range->min_sel;
+
+		if (all_sels + sels_in_range >= selector) {
+			selector -= all_sels;
+			return range->min_uV + (range->uV_step * selector);
+		}
+
+		all_sels += (sels_in_range + 1);
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(regulator_list_voltage_pickable_linear_range);
+
+/**
  * regulator_list_voltage_linear_range - List voltages for linear ranges
  *
  * @rdev: Regulator device