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regulator: core: Provide a dummy regulator with full constraints

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When a system has said that it has fully specified constraints for its
regulators it is still possible that some supplies may be missing,
especially if regulator support has been added to a driver after the
board was integrated. We can handle such situations more gracefully by
providing a dummy regulator.

Unless the caller has specifically indicated that the system design may
not include a given regulator by using regulator_get_optional() or that
it needs its interactions to have an effect using regulator_get_exclusive()
provide a dummy regulator if we can't locate a real one.

The kconfig option REGULATOR_DUMMY that provided similar behaviour for all
regulators has been removed, systems that need it should flag that they
have full constraints instead.

Signed-off-by: Mark Brown <broonie@linaro.org>
This commit is contained in:
Mark Brown 2013-09-13 19:50:37 +01:00
parent 272b98c645
commit 4ddfebd3b0
2 changed files with 19 additions and 27 deletions
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10
drivers/regulator/Kconfig
View File

@ -28,16 +28,6 @@ config REGULATOR_DEBUG
help
Say yes here to enable debugging support.
config REGULATOR_DUMMY
bool "Provide a dummy regulator if regulator lookups fail"
help
If this option is enabled then when a regulator lookup fails
and the board has not specified that it has provided full
constraints the regulator core will provide an always
enabled dummy regulator, allowing consumer drivers to continue.
A warning will be generated when this substitution is done.
config REGULATOR_FIXED_VOLTAGE
tristate "Fixed voltage regulator support"
help

36
drivers/regulator/core.c
View File

@ -1243,7 +1243,7 @@ static struct regulator_dev *regulator_dev_lookup(struct device *dev,
/* Internal regulator request function */
static struct regulator *_regulator_get(struct device *dev, const char *id,
bool exclusive)
bool exclusive, bool allow_dummy)
{
struct regulator_dev *rdev;
struct regulator *regulator = ERR_PTR(-EPROBE_DEFER);
@ -1268,30 +1268,32 @@ static struct regulator *_regulator_get(struct device *dev, const char *id,
* If we have return value from dev_lookup fail, we do not expect to
* succeed, so, quit with appropriate error value
*/
if (ret) {
if (ret && ret != -ENODEV) {
regulator = ERR_PTR(ret);
goto out;
}
if (board_wants_dummy_regulator) {
rdev = dummy_regulator_rdev;
goto found;
}
#ifdef CONFIG_REGULATOR_DUMMY
if (!devname)
devname = "deviceless";
/* If the board didn't flag that it was fully constrained then
* substitute in a dummy regulator so consumers can continue.
/*
* Assume that a regulator is physically present and enabled
* even if it isn't hooked up and just provide a dummy.
*/
if (!has_full_constraints) {
pr_warn("%s supply %s not found, using dummy regulator\n",
devname, id);
if (has_full_constraints && allow_dummy) {
/*
* Log the substitution if regulator configuration is
* not complete to help development.
*/
if (!has_full_constraints)
pr_warn("%s supply %s not found, using dummy regulator\n",
devname, id);
rdev = dummy_regulator_rdev;
goto found;
} else {
dev_err(dev, "dummy supplies not allowed\n");
}
#endif
mutex_unlock(&regulator_list_mutex);
return regulator;
@ -1349,7 +1351,7 @@ out:
*/
struct regulator *regulator_get(struct device *dev, const char *id)
{
return _regulator_get(dev, id, false);
return _regulator_get(dev, id, false, true);
}
EXPORT_SYMBOL_GPL(regulator_get);
@ -1410,7 +1412,7 @@ EXPORT_SYMBOL_GPL(devm_regulator_get);
*/
struct regulator *regulator_get_exclusive(struct device *dev, const char *id)
{
return _regulator_get(dev, id, true);
return _regulator_get(dev, id, true, false);
}
EXPORT_SYMBOL_GPL(regulator_get_exclusive);
@ -1439,7 +1441,7 @@ EXPORT_SYMBOL_GPL(regulator_get_exclusive);
*/
struct regulator *regulator_get_optional(struct device *dev, const char *id)
{
return _regulator_get(dev, id, 0);
return _regulator_get(dev, id, false, false);
}
EXPORT_SYMBOL_GPL(regulator_get_optional);