@@ -719,6 +719,69 @@ static int set_machine_constraints(struc
else
name = "regulator";
+ /* constrain machine-level voltage specs to fit
+ * the actual range supported by this regulator.
+ */
+ if (ops->list_voltage && rdev->desc->n_voltages) {
+ int count = rdev->desc->n_voltages;
+ int i;
+ int min_uV = INT_MAX;
+ int max_uV = INT_MIN;
+ int cmin = constraints->min_uV;
+ int cmax = constraints->max_uV;
+
+ /* it's safe to autoconfigure fixed-voltage supplies */
+ if (count == 1 && !cmin) {
+ cmin = INT_MIN;
+ cmax = INT_MAX;
+ }
+
+ /* else require explicit machine-level constraints */
+ else if (cmin <= 0 || cmax <= 0 || cmax < cmin) {
+ pr_err("%s: %s '%s' voltage constraints\n",
+ __func__, "invalid", name);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* initial: [cmin..cmax] valid, [min_uV..max_uV] not */
+ for (i = 0; i < count; i++) {
+ int value;
+
+ value = ops->list_voltage(rdev, i);
+ if (value <= 0)
+ continue;
+
+ /* maybe adjust [min_uV..max_uV] */
+ if (value >= cmin && value < min_uV)
+ min_uV = value;
+ if (value <= cmax && value > max_uV)
+ max_uV = value;
+ }
+
+ /* final: [min_uV..max_uV] valid iff constraints valid */
+ if (max_uV < min_uV) {
+ pr_err("%s: %s '%s' voltage constraints\n",
+ __func__, "unsupportable", name);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* use regulator's subset of machine constraints */
+ if (constraints->min_uV < min_uV) {
+ pr_debug("%s: override '%s' %s, %d -> %d\n",
+ __func__, name, "min_uV",
+ constraints->min_uV, min_uV);
+ constraints->min_uV = min_uV;
+ }
+ if (constraints->max_uV > max_uV) {
+ pr_debug("%s: override '%s' %s, %d -> %d\n",
+ __func__, name, "max_uV",
+ constraints->max_uV, max_uV);
+ constraints->max_uV = max_uV;
+ }
+ }
+
rdev->constraints = constraints;
/* do we need to apply the constraint voltage */
@@ -1245,6 +1308,56 @@ int regulator_is_enabled(struct regulato
EXPORT_SYMBOL_GPL(regulator_is_enabled);
/**
+ * regulator_count_voltages - count regulator_list_voltage() selectors
+ * @regulator: regulator source
+ *
+ * Returns number of selectors, or negative errno. Selectors are
+ * numbered starting at zero, and typically correspond to bitfields
+ * in hardware registers.
+ */
+int regulator_count_voltages(struct regulator *regulator)
+{
+ struct regulator_dev *rdev = regulator->rdev;
+
+ return rdev->desc->n_voltages ? : -EINVAL;
+}
+EXPORT_SYMBOL_GPL(regulator_count_voltages);
+
+/**
+ * regulator_list_voltage - enumerate supported voltages
+ * @regulator: regulator source
+ * @selector: identify voltage to list
+ * Context: can sleep
+ *
+ * Returns a voltage that can be passed to @regulator_set_voltage(),
+ * zero if this selector code can't be used on this sytem, or a
+ * negative errno.
+ */
+int regulator_list_voltage(struct regulator *regulator, unsigned selector)
+{
+ struct regulator_dev *rdev = regulator->rdev;
+ struct regulator_ops *ops = rdev->desc->ops;
+ int ret;
+
+ if (!ops->list_voltage || selector >= rdev->desc->n_voltages)
+ return -EINVAL;
+
+ mutex_lock(&rdev->mutex);
+ ret = ops->list_voltage(rdev, selector);
+ mutex_unlock(&rdev->mutex);
+
+ if (ret > 0) {
+ if (ret < rdev->constraints->min_uV)
+ ret = 0;
+ else if (ret > rdev->constraints->max_uV)
+ ret = 0;
+ }
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regulator_list_voltage);
+
+/**
* regulator_set_voltage - set regulator output voltage
* @regulator: regulator source
* @min_uV: Minimum required voltage in uV
@@ -140,6 +140,8 @@ int regulator_bulk_disable(int num_consu
void regulator_bulk_free(int num_consumers,
struct regulator_bulk_data *consumers);
+int regulator_count_voltages(struct regulator *regulator);
+int regulator_list_voltage(struct regulator *regulator, unsigned selector);
int regulator_set_voltage(struct regulator *regulator, int min_uV, int max_uV);
int regulator_get_voltage(struct regulator *regulator);
int regulator_set_current_limit(struct regulator *regulator,
@@ -40,6 +40,10 @@ enum regulator_status {
* @set_voltage: Set the voltage for the regulator within the range specified.
* The driver should select the voltage closest to min_uV.
* @get_voltage: Return the currently configured voltage for the regulator.
+ * @list_voltage: Return one of the supported voltages, in microvolts; zero
+ * if the selector indicates a voltage that is unusable on this system;
+ * or negative errno. Selectors range from zero to one less than
+ * regulator_desc.n_voltages. Voltages may be reported in any order.
* @set_current_limit: Configure a limit for a current-limited regulator.
* @get_current_limit: Get the configured limit for a current-limited regulator.
* @set_mode: Set the operating mode for the regulator.
@@ -62,6 +66,9 @@ enum regulator_status {
*/
struct regulator_ops {
+ /* enumerate supported voltages */
+ int (*list_voltage) (struct regulator_dev *, unsigned selector);
+
/* get/set regulator voltage */
int (*set_voltage) (struct regulator_dev *, int min_uV, int max_uV);
int (*get_voltage) (struct regulator_dev *);
@@ -121,6 +128,7 @@ enum regulator_type {
*
* @name: Identifying name for the regulator.
* @id: Numerical identifier for the regulator.
+ * @n_voltages: Number of selectors available for ops.list_voltage().
* @ops: Regulator operations table.
* @irq: Interrupt number for the regulator.
* @type: Indicates if the regulator is a voltage or current regulator.
@@ -129,6 +137,7 @@ enum regulator_type {
struct regulator_desc {
const char *name;
int id;
+ unsigned n_voltages;
struct regulator_ops *ops;
int irq;
enum regulator_type type;