linux-kernel - [PATCH 5/6] regulator: core: Add external get type

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Message-Id: <20220504065252.6955-5-zev@bewilderbeest.net>
Date:   Tue,  3 May 2022 23:52:51 -0700
From:   Zev Weiss <zev@...ilderbeest.net>
To:     Mark Brown <broonie@...nel.org>,
        Liam Girdwood <lgirdwood@...il.com>
Cc:     Zev Weiss <zev@...ilderbeest.net>, linux-kernel@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        openbmc@...ts.ozlabs.org
Subject: [PATCH 5/6] regulator: core: Add external get type

EXTERNAL_GET is similar to EXCLUSIVE_GET, but requires opt-in
agreement from the supply (whose constraints must designate it as
external_output).  It is intended for use only within the regulator
subsystem, and hence is not exposed in the public headers.

Signed-off-by: Zev Weiss <zev@...ilderbeest.net>
---
 drivers/regulator/core.c     | 16 +++++++++++++---
 drivers/regulator/devres.c   |  7 +++++++
 drivers/regulator/internal.h |  3 +++
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index b7617926336f..d873606eb41f 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2087,6 +2087,7 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 	struct regulator_dev *rdev;
 	struct regulator *regulator;
 	struct device_link *link;
+	bool is_external;
 	int ret;
 
 	if (get_type >= MAX_GET_TYPE) {
@@ -2129,8 +2130,9 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 			break;
 
 		case EXCLUSIVE_GET:
+		case EXTERNAL_GET:
 			dev_warn(dev,
-				 "dummy supplies not allowed for exclusive requests\n");
+				 "dummy supplies not allowed for exclusive or external requests\n");
 			fallthrough;
 
 		default:
@@ -2144,12 +2146,20 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 		return regulator;
 	}
 
-	if (get_type == EXCLUSIVE_GET && rdev->open_count) {
+	if ((get_type == EXCLUSIVE_GET || get_type == EXTERNAL_GET) && rdev->open_count) {
 		regulator = ERR_PTR(-EBUSY);
 		put_device(&rdev->dev);
 		return regulator;
 	}
 
+	/* EXTERNAL_GET is valid if and only if the regulator is designated for external output */
+	is_external = rdev->constraints && rdev->constraints->external_output;
+	if ((get_type == EXTERNAL_GET) != is_external) {
+		regulator = ERR_PTR(-EINVAL);
+		put_device(&rdev->dev);
+		return regulator;
+	}
+
 	mutex_lock(&regulator_list_mutex);
 	ret = (rdev->coupling_desc.n_resolved != rdev->coupling_desc.n_coupled);
 	mutex_unlock(&regulator_list_mutex);
@@ -2182,7 +2192,7 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
 	}
 
 	rdev->open_count++;
-	if (get_type == EXCLUSIVE_GET) {
+	if (get_type == EXCLUSIVE_GET || get_type == EXTERNAL_GET) {
 		rdev->exclusive = 1;
 
 		ret = _regulator_is_enabled(rdev);
diff --git a/drivers/regulator/devres.c b/drivers/regulator/devres.c
index 9113233f41cd..36df9e9ff175 100644
--- a/drivers/regulator/devres.c
+++ b/drivers/regulator/devres.c
@@ -70,6 +70,13 @@ struct regulator *devm_regulator_get_exclusive(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(devm_regulator_get_exclusive);
 
+/* For regulator-core internal use only */
+struct regulator *devm_regulator_get_external(struct device *dev,
+					      const char *id)
+{
+	return _devm_regulator_get(dev, id, EXTERNAL_GET);
+}
+
 /**
  * devm_regulator_get_optional - Resource managed regulator_get_optional()
  * @dev: device to supply
diff --git a/drivers/regulator/internal.h b/drivers/regulator/internal.h
index 1e9c71642143..c176a416c571 100644
--- a/drivers/regulator/internal.h
+++ b/drivers/regulator/internal.h
@@ -116,10 +116,13 @@ static inline bool of_check_coupling_data(struct regulator_dev *rdev)
 enum regulator_get_type {
 	NORMAL_GET,
 	EXCLUSIVE_GET,
+	EXTERNAL_GET,
 	OPTIONAL_GET,
 	MAX_GET_TYPE
 };
 
 struct regulator *_regulator_get(struct device *dev, const char *id,
 				 enum regulator_get_type get_type);
+struct regulator *devm_regulator_get_external(struct device *dev,
+					      const char *id);
 #endif
-- 
2.36.0