From: Mark Brown broonie@linaro.org

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. Some more thought is needed for a more elegant way of handling non-DT systems.

Signed-off-by: Mark Brown broonie@linaro.org --- drivers/regulator/Kconfig | 10 ---------- drivers/regulator/core.c | 36 +++++++++++++++++++----------------- 2 files changed, 19 insertions(+), 27 deletions(-)

diff --git a/drivers/regulator/Kconfig b/drivers/regulator/Kconfig index dfe5809..0417ce3 100644 --- a/drivers/regulator/Kconfig +++ b/drivers/regulator/Kconfig @@ -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 diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 02af90e..c9740b5 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1225,7 +1225,7 @@ 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); @@ -1250,30 +1250,32 @@ 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; @@ -1331,7 +1333,7 @@ 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);

@@ -1358,7 +1360,7 @@ EXPORT_SYMBOL_GPL(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);

@@ -1387,7 +1389,7 @@ 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);