Commit 4ddfebd3 authored by Mark Brown's avatar Mark Brown
Browse files

regulator: core: Provide a dummy regulator with full constraints 



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: default avatarMark Brown <broonie@linaro.org>
parent 272b98c6

drivers/regulator/Kconfig

+0 −10
Original line number Diff line number Diff line
@@ -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

drivers/regulator/core.c

+19 −17
Original line number Diff line number Diff line
@@ -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) {

	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);

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