diff options
| -rw-r--r-- | drivers/regulator/core.c | 113 | ||||
| -rw-r--r-- | include/linux/regulator/consumer.h | 2 | ||||
| -rw-r--r-- | include/linux/regulator/driver.h | 9 |
3 files changed, 124 insertions, 0 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 75abcd85e51..da357a07c98 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -692,6 +692,69 @@ static int set_machine_constraints(struct regulator_dev *rdev, 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 */ @@ -1251,6 +1314,56 @@ int regulator_is_enabled(struct regulator *regulator) 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 diff --git a/include/linux/regulator/consumer.h b/include/linux/regulator/consumer.h index df6c4bcf38f..277f4b964df 100644 --- a/include/linux/regulator/consumer.h +++ b/include/linux/regulator/consumer.h @@ -142,6 +142,8 @@ int regulator_bulk_disable(int num_consumers, 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, diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h index 0cf37bc85c4..2255468d456 100644 --- a/include/linux/regulator/driver.h +++ b/include/linux/regulator/driver.h @@ -45,6 +45,10 @@ 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 limit for a current-limited regulator. @@ -66,6 +70,9 @@ 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 *); @@ -124,6 +131,7 @@ 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. @@ -132,6 +140,7 @@ enum regulator_type { struct regulator_desc { const char *name; int id; + unsigned n_voltages; struct regulator_ops *ops; int irq; enum regulator_type type; |