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regulator: Factor out voltage constraint setup 

This allows constraints to take effect on regulators that support
voltage setting but for which the board does not specify a voltage
range (for example, because it is fixed correctly at system startup).

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
This commit is contained in:
Mark Brown 2009-10-19 15:53:50 +01:00 committed by Liam Girdwood
parent 5b30762773
commit e79055d62e
1 changed files with 79 additions and 69 deletions
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148
drivers/regulator/core.c
View File

@ -672,6 +672,82 @@ static void print_constraints(struct regulator_dev *rdev)
printk(KERN_INFO "regulator: %s: %s\n", rdev->desc->name, buf);
}
static int machine_constraints_voltage(struct regulator_dev *rdev,
const char *name, struct regulation_constraints *constraints)
{
struct regulator_ops *ops = rdev->desc->ops;
/* 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
and the constraints are used by list_voltage. */
if (count == 1 && !cmin) {
cmin = 1;
cmax = INT_MAX;
constraints->min_uV = cmin;
constraints->max_uV = cmax;
}
/* voltage constraints are optional */
if ((cmin == 0) && (cmax == 0))
return 0;
/* else require explicit machine-level constraints */
if (cmin <= 0 || cmax <= 0 || cmax < cmin) {
pr_err("%s: %s '%s' voltage constraints\n",
__func__, "invalid", name);
return -EINVAL;
}
/* 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);
return -EINVAL;
}
/* 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;
}
}
return 0;
}
/**
* set_machine_constraints - sets regulator constraints
* @rdev: regulator source
@ -697,75 +773,9 @@ 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
and the constraints are used by list_voltage. */
if (count == 1 && !cmin) {
cmin = 1;
cmax = INT_MAX;
constraints->min_uV = cmin;
constraints->max_uV = cmax;
}
/* voltage constraints are optional */
if ((cmin == 0) && (cmax == 0))
goto out;
/* else require explicit machine-level constraints */
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;
}
}
ret = machine_constraints_voltage(rdev, name, constraints);
if (ret != 0)
goto out;
rdev->constraints = constraints;