Merge remote-tracking branch 'regulator/topic/linear-range' into regulator-helpers

6 files changed, 187 insertions, 187 deletions

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 101f7cb14be6..1034e05fb00a 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2084,6 +2084,43 @@ int regulator_list_voltage_linear(struct regulator_dev *rdev,
 EXPORT_SYMBOL_GPL(regulator_list_voltage_linear);
 
 /**
+ * regulator_list_voltage_linear_range - List voltages for linear ranges
+ *
+ * @rdev: Regulator device
+ * @selector: Selector to convert into a voltage
+ *
+ * Regulators with a series of simple linear mappings between voltages
+ * and selectors can set linear_ranges in the regulator descriptor and
+ * then use this function as their list_voltage() operation,
+ */
+int regulator_list_voltage_linear_range(struct regulator_dev *rdev,
+					unsigned int selector)
+{
+	const struct regulator_linear_range *range;
+	int i;
+
+	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++) {
+		range = &rdev->desc->linear_ranges[i];
+
+		if (!(selector >= range->min_sel &&
+		      selector <= range->max_sel))
+			continue;
+
+		selector -= range->min_sel;
+
+		return range->min_uV + (range->uV_step * selector);
+	}
+
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(regulator_list_voltage_linear_range);
+
+/**
  * regulator_list_voltage_table - List voltages with table based mapping
  *
  * @rdev: Regulator device
@@ -2373,6 +2410,64 @@ int regulator_map_voltage_linear(struct regulator_dev *rdev,
 }
 EXPORT_SYMBOL_GPL(regulator_map_voltage_linear);
 
+/**
+ * regulator_map_voltage_linear - map_voltage() for multiple linear ranges
+ *
+ * @rdev: Regulator to operate on
+ * @min_uV: Lower bound for voltage
+ * @max_uV: Upper bound for voltage
+ *
+ * Drivers providing linear_ranges in their descriptor can use this as
+ * their map_voltage() callback.
+ */
+int regulator_map_voltage_linear_range(struct regulator_dev *rdev,
+				       int min_uV, int max_uV)
+{
+	const struct regulator_linear_range *range;
+	int ret = -EINVAL;
+	int voltage, i;
+
+	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++) {
+		range = &rdev->desc->linear_ranges[i];
+
+		if (!(min_uV <= range->max_uV && max_uV >= range->min_uV))
+			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 += range->min_sel;
+
+		break;
+	}
+
+	if (i == rdev->desc->n_linear_ranges)
+		return -EINVAL;
+
+	/* Map back into a voltage to verify we're still in bounds */
+	voltage = rdev->desc->ops->list_voltage(rdev, ret);
+	if (voltage < min_uV || voltage > max_uV)
+		return -EINVAL;
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_map_voltage_linear_range);
+
 static int _regulator_do_set_voltage(struct regulator_dev *rdev,
 				     int min_uV, int max_uV)
 {
diff --git a/drivers/regulator/da903x.c b/drivers/regulator/da903x.c
index 2afa5730f324..1378a242a3af 100644
--- a/drivers/regulator/da903x.c
+++ b/drivers/regulator/da903x.c
@@ -252,39 +252,12 @@ static int da9034_set_dvc_voltage_sel(struct regulator_dev *rdev,
 	return ret;
 }
 
-static int da9034_map_ldo12_voltage(struct regulator_dev *rdev,
-				    int min_uV, int max_uV)
-{
-	struct da903x_regulator_info *info = rdev_get_drvdata(rdev);
-	int sel;
-
-	if (check_range(info, min_uV, max_uV)) {
-		pr_err("invalid voltage range (%d, %d) uV\n", min_uV, max_uV);
-		return -EINVAL;
-	}
-
-	sel = DIV_ROUND_UP(min_uV - info->desc.min_uV, info->desc.uV_step);
-	sel = (sel >= 20) ? sel - 12 : ((sel > 7) ? 8 : sel);
-
-	return sel;
-}
-
-static int da9034_list_ldo12_voltage(struct regulator_dev *rdev,
-				     unsigned selector)
-{
-	struct da903x_regulator_info *info = rdev_get_drvdata(rdev);
-	int volt;
-
-	if (selector >= 8)
-		volt = 2700000 + rdev->desc->uV_step * (selector - 8);
-	else
-		volt = rdev->desc->min_uV + rdev->desc->uV_step * selector;
-
-	if (volt > info->max_uV)
-		return -EINVAL;
-
-	return volt;
-}
+static const struct regulator_linear_range da9034_ldo12_ranges[] = {
+	{ .min_uV = 1700000, .max_uV = 2050000, .min_sel =  0, .max_sel = 7,
+	  .uV_step =  50000 },
+	{ .min_uV = 2700000, .max_uV = 3050000, .min_sel =  8, .max_sel = 15,
+	  .uV_step =  50000 },
+};
 
 static struct regulator_ops da903x_regulator_ldo_ops = {
 	.set_voltage_sel = da903x_set_voltage_sel,
@@ -332,8 +305,8 @@ static struct regulator_ops da9034_regulator_dvc_ops = {
 static struct regulator_ops da9034_regulator_ldo12_ops = {
 	.set_voltage_sel = da903x_set_voltage_sel,
 	.get_voltage_sel = da903x_get_voltage_sel,
-	.list_voltage	= da9034_list_ldo12_voltage,
-	.map_voltage	= da9034_map_ldo12_voltage,
+	.list_voltage	= regulator_list_voltage_linear_range,
+	.map_voltage	= regulator_map_voltage_linear_range,
 	.enable		= da903x_enable,
 	.disable	= da903x_disable,
 	.is_enabled	= da903x_is_enabled,
@@ -476,6 +449,8 @@ static int da903x_regulator_probe(struct platform_device *pdev)
 	if (ri->desc.id == DA9034_ID_LDO12) {
 		ri->desc.ops = &da9034_regulator_ldo12_ops;
 		ri->desc.n_voltages = 16;
+		ri->desc.linear_ranges = da9034_ldo12_ranges;
+		ri->desc.n_linear_ranges = ARRAY_SIZE(da9034_ldo12_ranges);
 	}
 
 	if (ri->desc.id == DA9030_ID_LDO14)
diff --git a/drivers/regulator/wm831x-ldo.c b/drivers/regulator/wm831x-ldo.c
index 9ff883f80878..76792c7d86f3 100644
--- a/drivers/regulator/wm831x-ldo.c
+++ b/drivers/regulator/wm831x-ldo.c
@@ -62,41 +62,12 @@ static irqreturn_t wm831x_ldo_uv_irq(int irq, void *data)
  * General purpose LDOs
  */
 
-#define WM831X_GP_LDO_SELECTOR_LOW 0xe
-#define WM831X_GP_LDO_MAX_SELECTOR 0x1f
-
-static int wm831x_gp_ldo_list_voltage(struct regulator_dev *rdev,
-				      unsigned int selector)
-{
-	/* 0.9-1.6V in 50mV steps */
-	if (selector <= WM831X_GP_LDO_SELECTOR_LOW)
-		return 900000 + (selector * 50000);
-	/* 1.7-3.3V in 100mV steps */
-	if (selector <= WM831X_GP_LDO_MAX_SELECTOR)
-		return 1600000 + ((selector - WM831X_GP_LDO_SELECTOR_LOW)
-				  * 100000);
-	return -EINVAL;
-}
-
-static int wm831x_gp_ldo_map_voltage(struct regulator_dev *rdev,
-				     int min_uV, int max_uV)
-{
-	int volt, vsel;
-
-	if (min_uV < 900000)
-		vsel = 0;
-	else if (min_uV < 1700000)
-		vsel = ((min_uV - 900000) / 50000);
-	else
-		vsel = ((min_uV - 1700000) / 100000)
-			+ WM831X_GP_LDO_SELECTOR_LOW + 1;
-
-	volt = wm831x_gp_ldo_list_voltage(rdev, vsel);
-	if (volt < min_uV || volt > max_uV)
-		return -EINVAL;
-
-	return vsel;
-}
+static const struct regulator_linear_range wm831x_gp_ldo_ranges[] = {
+	{ .min_uV =  900000, .max_uV = 1650000, .min_sel =  0, .max_sel = 14,
+	  .uV_step =  50000 },
+	{ .min_uV = 1700000, .max_uV = 3300000, .min_sel = 15, .max_sel = 31,
+	  .uV_step = 100000 },
+};
 
 static int wm831x_gp_ldo_set_suspend_voltage(struct regulator_dev *rdev,
 					     int uV)
@@ -105,7 +76,7 @@ static int wm831x_gp_ldo_set_suspend_voltage(struct regulator_dev *rdev,
 	struct wm831x *wm831x = ldo->wm831x;
 	int sel, reg = ldo->base + WM831X_LDO_SLEEP_CONTROL;
 
-	sel = wm831x_gp_ldo_map_voltage(rdev, uV, uV);
+	sel = regulator_map_voltage_linear_range(rdev, uV, uV);
 	if (sel < 0)
 		return sel;
 
@@ -230,8 +201,8 @@ static unsigned int wm831x_gp_ldo_get_optimum_mode(struct regulator_dev *rdev,
 
 
 static struct regulator_ops wm831x_gp_ldo_ops = {
-	.list_voltage = wm831x_gp_ldo_list_voltage,
-	.map_voltage = wm831x_gp_ldo_map_voltage,
+	.list_voltage = regulator_list_voltage_linear_range,
+	.map_voltage = regulator_map_voltage_linear_range,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.set_suspend_voltage = wm831x_gp_ldo_set_suspend_voltage,
@@ -290,7 +261,7 @@ static int wm831x_gp_ldo_probe(struct platform_device *pdev)
 
 	ldo->desc.id = id;
 	ldo->desc.type = REGULATOR_VOLTAGE;
-	ldo->desc.n_voltages = WM831X_GP_LDO_MAX_SELECTOR + 1;
+	ldo->desc.n_voltages = 32;
 	ldo->desc.ops = &wm831x_gp_ldo_ops;
 	ldo->desc.owner = THIS_MODULE;
 	ldo->desc.vsel_reg = ldo->base + WM831X_LDO_ON_CONTROL;
@@ -299,6 +270,8 @@ static int wm831x_gp_ldo_probe(struct platform_device *pdev)
 	ldo->desc.enable_mask = 1 << id;
 	ldo->desc.bypass_reg = ldo->base;
 	ldo->desc.bypass_mask = WM831X_LDO1_SWI;
+	ldo->desc.linear_ranges = wm831x_gp_ldo_ranges;
+	ldo->desc.n_linear_ranges = ARRAY_SIZE(wm831x_gp_ldo_ranges);
 
 	config.dev = pdev->dev.parent;
 	if (pdata)
@@ -358,43 +331,12 @@ static struct platform_driver wm831x_gp_ldo_driver = {
  * Analogue LDOs
  */
 
-
-#define WM831X_ALDO_SELECTOR_LOW 0xc
-#define WM831X_ALDO_MAX_SELECTOR 0x1f
-
-static int wm831x_aldo_list_voltage(struct regulator_dev *rdev,
-				      unsigned int selector)
-{
-	/* 1-1.6V in 50mV steps */
-	if (selector <= WM831X_ALDO_SELECTOR_LOW)
-		return 1000000 + (selector * 50000);
-	/* 1.7-3.5V in 100mV steps */
-	if (selector <= WM831X_ALDO_MAX_SELECTOR)
-		return 1600000 + ((selector - WM831X_ALDO_SELECTOR_LOW)
-				  * 100000);
-	return -EINVAL;
-}
-
-static int wm831x_aldo_map_voltage(struct regulator_dev *rdev,
-				   int min_uV, int max_uV)
-{
-	int volt, vsel;
-
-	if (min_uV < 1000000)
-		vsel = 0;
-	else if (min_uV < 1700000)
-		vsel = ((min_uV - 1000000) / 50000);
-	else
-		vsel = ((min_uV - 1700000) / 100000)
-			+ WM831X_ALDO_SELECTOR_LOW + 1;
-
-	volt = wm831x_aldo_list_voltage(rdev, vsel);
-	if (volt < min_uV || volt > max_uV)
-		return -EINVAL;
-
-	return vsel;
-
-}
+static const struct regulator_linear_range wm831x_aldo_ranges[] = {
+	{ .min_uV = 1000000, .max_uV = 1650000, .min_sel =  0, .max_sel = 12,
+	  .uV_step =  50000 },
+	{ .min_uV = 1700000, .max_uV = 3500000, .min_sel = 13, .max_sel = 31,
+	  .uV_step = 100000 },
+};
 
 static int wm831x_aldo_set_suspend_voltage(struct regulator_dev *rdev,
 					     int uV)
@@ -403,7 +345,7 @@ static int wm831x_aldo_set_suspend_voltage(struct regulator_dev *rdev,
 	struct wm831x *wm831x = ldo->wm831x;
 	int sel, reg = ldo->base + WM831X_LDO_SLEEP_CONTROL;
 
-	sel = wm831x_aldo_map_voltage(rdev, uV, uV);
+	sel = regulator_map_voltage_linear_range(rdev, uV, uV);
 	if (sel < 0)
 		return sel;
 
@@ -486,8 +428,8 @@ static int wm831x_aldo_get_status(struct regulator_dev *rdev)
 }
 
 static struct regulator_ops wm831x_aldo_ops = {
-	.list_voltage = wm831x_aldo_list_voltage,
-	.map_voltage = wm831x_aldo_map_voltage,
+	.list_voltage = regulator_list_voltage_linear_range,
+	.map_voltage = regulator_map_voltage_linear_range,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.set_suspend_voltage = wm831x_aldo_set_suspend_voltage,
@@ -545,7 +487,9 @@ static int wm831x_aldo_probe(struct platform_device *pdev)
 
 	ldo->desc.id = id;
 	ldo->desc.type = REGULATOR_VOLTAGE;
-	ldo->desc.n_voltages = WM831X_ALDO_MAX_SELECTOR + 1;
+	ldo->desc.n_voltages = 32;
+	ldo->desc.linear_ranges = wm831x_aldo_ranges;
+	ldo->desc.n_linear_ranges = ARRAY_SIZE(wm831x_aldo_ranges);
 	ldo->desc.ops = &wm831x_aldo_ops;
 	ldo->desc.owner = THIS_MODULE;
 	ldo->desc.vsel_reg = ldo->base + WM831X_LDO_ON_CONTROL;
diff --git a/drivers/regulator/wm8350-regulator.c b/drivers/regulator/wm8350-regulator.c
index 7f0fa22ef2aa..5453dd0105ed 100644
--- a/drivers/regulator/wm8350-regulator.c
+++ b/drivers/regulator/wm8350-regulator.c
@@ -542,41 +542,12 @@ static int wm8350_dcdc_set_suspend_mode(struct regulator_dev *rdev,
 	return 0;
 }
 
-static int wm8350_ldo_list_voltage(struct regulator_dev *rdev,
-				    unsigned selector)
-{
-	if (selector > WM8350_LDO1_VSEL_MASK)
-		return -EINVAL;
-
-	if (selector < 16)
-		return (selector * 50000) + 900000;
-	else
-		return ((selector - 16) * 100000) + 1800000;
-}
-
-static int wm8350_ldo_map_voltage(struct regulator_dev *rdev, int min_uV,
-				  int max_uV)
-{
-	int volt, sel;
-	int min_mV = min_uV / 1000;
-	int max_mV = max_uV / 1000;
-
-	if (min_mV < 900 || min_mV > 3300)
-		return -EINVAL;
-	if (max_mV < 900 || max_mV > 3300)
-		return -EINVAL;
-
-	if (min_mV < 1800) /* step size is 50mV < 1800mV */
-		sel = DIV_ROUND_UP(min_uV - 900, 50);
-	else /* step size is 100mV > 1800mV */
-		sel = DIV_ROUND_UP(min_uV - 1800, 100) + 16;
-
-	volt = wm8350_ldo_list_voltage(rdev, sel);
-	if (volt < min_uV || volt > max_uV)
-		return -EINVAL;
-
-	return sel;
-}
+static const struct regulator_linear_range wm8350_ldo_ranges[] = {
+	{ .min_uV =  900000, .max_uV = 1750000, .min_sel =  0, .max_sel = 15,
+	  .uV_step =  50000 },
+	{ .min_uV = 1800000, .max_uV = 3300000, .min_sel = 16, .max_sel = 31,
+	  .uV_step = 100000 },
+};
 
 static int wm8350_ldo_set_suspend_voltage(struct regulator_dev *rdev, int uV)
 {
@@ -603,7 +574,7 @@ static int wm8350_ldo_set_suspend_voltage(struct regulator_dev *rdev, int uV)
 		return -EINVAL;
 	}
 
-	sel = wm8350_ldo_map_voltage(rdev, uV, uV);
+	sel = regulator_map_voltage_linear_range(rdev, uV, uV);
 	if (sel < 0)
 		return -EINVAL;
 
@@ -998,10 +969,10 @@ static struct regulator_ops wm8350_dcdc2_5_ops = {
 };
 
 static struct regulator_ops wm8350_ldo_ops = {
-	.map_voltage = wm8350_ldo_map_voltage,
+	.map_voltage = regulator_map_voltage_linear_range,
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
-	.list_voltage = wm8350_ldo_list_voltage,
+	.list_voltage = regulator_list_voltage_linear_range,
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
 	.is_enabled = regulator_is_enabled_regmap,
@@ -1108,6 +1079,8 @@ static const struct regulator_desc wm8350_reg[NUM_WM8350_REGULATORS] = {
 		.irq = WM8350_IRQ_UV_LDO1,
 		.type = REGULATOR_VOLTAGE,
 		.n_voltages = WM8350_LDO1_VSEL_MASK + 1,
+		.linear_ranges = wm8350_ldo_ranges,
+		.n_linear_ranges = ARRAY_SIZE(wm8350_ldo_ranges),
 		.vsel_reg = WM8350_LDO1_CONTROL,
 		.vsel_mask = WM8350_LDO1_VSEL_MASK,
 		.enable_reg = WM8350_DCDC_LDO_REQUESTED,
@@ -1121,6 +1094,8 @@ static const struct regulator_desc wm8350_reg[NUM_WM8350_REGULATORS] = {
 		.irq = WM8350_IRQ_UV_LDO2,
 		.type = REGULATOR_VOLTAGE,
 		.n_voltages = WM8350_LDO2_VSEL_MASK + 1,
+		.linear_ranges = wm8350_ldo_ranges,
+		.n_linear_ranges = ARRAY_SIZE(wm8350_ldo_ranges),
 		.vsel_reg = WM8350_LDO2_CONTROL,
 		.vsel_mask = WM8350_LDO2_VSEL_MASK,
 		.enable_reg = WM8350_DCDC_LDO_REQUESTED,
@@ -1134,6 +1109,8 @@ static const struct regulator_desc wm8350_reg[NUM_WM8350_REGULATORS] = {
 		.irq = WM8350_IRQ_UV_LDO3,
 		.type = REGULATOR_VOLTAGE,
 		.n_voltages = WM8350_LDO3_VSEL_MASK + 1,
+		.linear_ranges = wm8350_ldo_ranges,
+		.n_linear_ranges = ARRAY_SIZE(wm8350_ldo_ranges),
 		.vsel_reg = WM8350_LDO3_CONTROL,
 		.vsel_mask = WM8350_LDO3_VSEL_MASK,
 		.enable_reg = WM8350_DCDC_LDO_REQUESTED,
@@ -1147,6 +1124,8 @@ static const struct regulator_desc wm8350_reg[NUM_WM8350_REGULATORS] = {
 		.irq = WM8350_IRQ_UV_LDO4,
 		.type = REGULATOR_VOLTAGE,
 		.n_voltages = WM8350_LDO4_VSEL_MASK + 1,
+		.linear_ranges = wm8350_ldo_ranges,
+		.n_linear_ranges = ARRAY_SIZE(wm8350_ldo_ranges),
 		.vsel_reg = WM8350_LDO4_CONTROL,
 		.vsel_mask = WM8350_LDO4_VSEL_MASK,
 		.enable_reg = WM8350_DCDC_LDO_REQUESTED,
diff --git a/drivers/regulator/wm8400-regulator.c b/drivers/regulator/wm8400-regulator.c
index a09f03ee5506..2ac7e1aceb05 100644
--- a/drivers/regulator/wm8400-regulator.c
+++ b/drivers/regulator/wm8400-regulator.c
@@ -19,47 +19,21 @@
 #include <linux/regulator/driver.h>
 #include <linux/mfd/wm8400-private.h>
 
-static int wm8400_ldo_list_voltage(struct regulator_dev *dev,
-				   unsigned selector)
-{
-	if (selector > WM8400_LDO1_VSEL_MASK)
-		return -EINVAL;
-
-	if (selector < 15)
-		return 900000 + (selector * 50000);
-	else
-		return 1700000 + ((selector - 15) * 100000);
-}
-
-static int wm8400_ldo_map_voltage(struct regulator_dev *dev,
-				  int min_uV, int max_uV)
-{
-	u16 val;
-	int volt;
-
-	if (min_uV < 900000 || min_uV > 3300000)
-		return -EINVAL;
-
-	if (min_uV < 1700000) /* Steps of 50mV from 900mV;  */
-		val = DIV_ROUND_UP(min_uV - 900000, 50000);
-	else /* Steps of 100mV from 1700mV */
-		val = DIV_ROUND_UP(min_uV - 1700000, 100000) + 15;
-
-	volt = wm8400_ldo_list_voltage(dev, val);
-	if (volt < min_uV || volt > max_uV)
-		return -EINVAL;
-
-	return val;
-}
+static const struct regulator_linear_range wm8400_ldo_ranges[] = {
+	{ .min_uV =  900000, .max_uV = 1600000, .min_sel = 0, .max_sel = 14,
+	  .uV_step =  50000 },
+	{ .min_uV = 1700000, .max_uV = 3300000, .min_sel = 15, .max_sel = 31,
+	  .uV_step = 100000 },
+};
 
 static struct regulator_ops wm8400_ldo_ops = {
 	.is_enabled = regulator_is_enabled_regmap,
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
-	.list_voltage = wm8400_ldo_list_voltage,
+	.list_voltage = regulator_list_voltage_linear_range,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
-	.map_voltage = wm8400_ldo_map_voltage,
+	.map_voltage = regulator_map_voltage_linear_range,
 };
 
 static unsigned int wm8400_dcdc_get_mode(struct regulator_dev *dev)
@@ -155,6 +129,8 @@ static struct regulator_desc regulators[] = {
 		.enable_reg = WM8400_LDO1_CONTROL,
 		.enable_mask = WM8400_LDO1_ENA,
 		.n_voltages = WM8400_LDO1_VSEL_MASK + 1,
+		.linear_ranges = wm8400_ldo_ranges,
+		.n_linear_ranges = ARRAY_SIZE(wm8400_ldo_ranges),
 		.vsel_reg = WM8400_LDO1_CONTROL,
 		.vsel_mask = WM8400_LDO1_VSEL_MASK,
 		.type = REGULATOR_VOLTAGE,
@@ -167,6 +143,8 @@ static struct regulator_desc regulators[] = {
 		.enable_reg = WM8400_LDO2_CONTROL,
 		.enable_mask = WM8400_LDO2_ENA,
 		.n_voltages = WM8400_LDO2_VSEL_MASK + 1,
+		.linear_ranges = wm8400_ldo_ranges,
+		.n_linear_ranges = ARRAY_SIZE(wm8400_ldo_ranges),
 		.type = REGULATOR_VOLTAGE,
 		.vsel_reg = WM8400_LDO2_CONTROL,
 		.vsel_mask = WM8400_LDO2_VSEL_MASK,
@@ -179,6 +157,8 @@ static struct regulator_desc regulators[] = {
 		.enable_reg = WM8400_LDO3_CONTROL,
 		.enable_mask = WM8400_LDO3_ENA,
 		.n_voltages = WM8400_LDO3_VSEL_MASK + 1,
+		.linear_ranges = wm8400_ldo_ranges,
+		.n_linear_ranges = ARRAY_SIZE(wm8400_ldo_ranges),
 		.vsel_reg = WM8400_LDO3_CONTROL,
 		.vsel_mask = WM8400_LDO3_VSEL_MASK,
 		.type = REGULATOR_VOLTAGE,
@@ -191,6 +171,8 @@ static struct regulator_desc regulators[] = {
 		.enable_reg = WM8400_LDO4_CONTROL,
 		.enable_mask = WM8400_LDO4_ENA,
 		.n_voltages = WM8400_LDO4_VSEL_MASK + 1,
+		.linear_ranges = wm8400_ldo_ranges,
+		.n_linear_ranges = ARRAY_SIZE(wm8400_ldo_ranges),
 		.vsel_reg = WM8400_LDO4_CONTROL,
 		.vsel_mask = WM8400_LDO4_VSEL_MASK,
 		.type = REGULATOR_VOLTAGE,
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 6700cc94bdd1..67e13aa5a478 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -40,6 +40,24 @@ enum regulator_status {
 };
 
 /**
+ * Specify a range of voltages for regulator_map_linar_range() and
+ * regulator_list_linear_range().
+ *
+ * @min_uV:  Lowest voltage in range
+ * @max_uV:  Highest voltage in range
+ * @min_sel: Lowest selector for range
+ * @max_sel: Highest selector for range
+ * @uV_step: Step size
+ */
+struct regulator_linear_range {
+	unsigned int min_uV;
+	unsigned int max_uV;
+	unsigned int min_sel;
+	unsigned int max_sel;
+	unsigned int uV_step;
+};
+
+/**
  * struct regulator_ops - regulator operations.
  *
  * @enable: Configure the regulator as enabled.
@@ -223,6 +241,9 @@ struct regulator_desc {
 	unsigned int linear_min_sel;
 	unsigned int ramp_delay;
 
+	const struct regulator_linear_range *linear_ranges;
+	int n_linear_ranges;
+
 	const unsigned int *volt_table;
 
 	unsigned int vsel_reg;
@@ -326,10 +347,14 @@ int regulator_mode_to_status(unsigned int);
 
 int regulator_list_voltage_linear(struct regulator_dev *rdev,
 				  unsigned int selector);
+int regulator_list_voltage_linear_range(struct regulator_dev *rdev,
+					unsigned int selector);
 int regulator_list_voltage_table(struct regulator_dev *rdev,
 				  unsigned int selector);
 int regulator_map_voltage_linear(struct regulator_dev *rdev,
 				  int min_uV, int max_uV);
+int regulator_map_voltage_linear_range(struct regulator_dev *rdev,
+				       int min_uV, int max_uV);
 int regulator_map_voltage_iterate(struct regulator_dev *rdev,
 				  int min_uV, int max_uV);
 int regulator_map_voltage_ascend(struct regulator_dev *rdev,