regulator: core: Allow to get voltage count and list from parent
authorJavier Martinez Canillas <javier.martinez@collabora.co.uk>
Tue, 29 Jul 2014 16:28:56 +0000 (18:28 +0200)
committerMark Brown <broonie@linaro.org>
Tue, 29 Jul 2014 18:24:43 +0000 (19:24 +0100)
Load switches are modeled as regulators but they just provide
the voltage of their parent input supply. So, the drivers for
these switches usually neither provide a .list_voltage handler
not set a .n_voltages count. But there is code in the kernel
that assumes that all regulators should be able to provide this
information (e.g: cpufreq and mmc subsystems).

If the voltage count and list are not available for a regulator
and it has a parent input supply, then use the parent values.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@linaro.org>
drivers/regulator/core.c

index 57fe446fabce85601d458a65761783232c7cfbb0..5299456d07eef8c6defa2dd6c48f83384f78109a 100644 (file)
@@ -2182,7 +2182,13 @@ int regulator_count_voltages(struct regulator *regulator)
 {
        struct regulator_dev    *rdev = regulator->rdev;
 
-       return rdev->desc->n_voltages ? : -EINVAL;
+       if (rdev->desc->n_voltages)
+               return rdev->desc->n_voltages;
+
+       if (!rdev->supply)
+               return -EINVAL;
+
+       return regulator_count_voltages(rdev->supply);
 }
 EXPORT_SYMBOL_GPL(regulator_count_voltages);
 
@@ -2205,12 +2211,17 @@ int regulator_list_voltage(struct regulator *regulator, unsigned selector)
        if (rdev->desc->fixed_uV && rdev->desc->n_voltages == 1 && !selector)
                return rdev->desc->fixed_uV;
 
-       if (!ops->list_voltage || selector >= rdev->desc->n_voltages)
+       if (ops->list_voltage) {
+               if (selector >= rdev->desc->n_voltages)
+                       return -EINVAL;
+               mutex_lock(&rdev->mutex);
+               ret = ops->list_voltage(rdev, selector);
+               mutex_unlock(&rdev->mutex);
+       } else if (rdev->supply) {
+               ret = regulator_list_voltage(rdev->supply, selector);
+       } else {
                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)