power: supply: charger-manager: fix race-condition in sysfs registration

This registers custom sysfs properties using the native functionality
of the power-supply framework, which cleans up the code a bit and
fixes a race-condition. Before this patch the sysfs attributes were
not properly registered to udev.

Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

1 files changed, 22 insertions, 29 deletions

diff --git a/drivers/power/supply/charger-manager.c b/drivers/power/supply/charger-manager.c
index 2e579da5c0b9..38be91f21cc4 100644
--- a/drivers/power/supply/charger-manager.c
+++ b/drivers/power/supply/charger-manager.c
@@ -1351,7 +1351,7 @@ static ssize_t charger_externally_control_store(struct device *dev,
 }
 
 /**
- * charger_manager_register_sysfs - Register sysfs entry for each charger
+ * charger_manager_prepare_sysfs - Prepare sysfs entry for each charger
  * @cm: the Charger Manager representing the battery.
  *
  * This function add sysfs entry for charger(regulator) to control charger from
@@ -1363,13 +1363,12 @@ static ssize_t charger_externally_control_store(struct device *dev,
  * externally_control, this charger isn't controlled from charger-manager and
  * always stay off state of regulator.
  */
-static int charger_manager_register_sysfs(struct charger_manager *cm)
+static int charger_manager_prepare_sysfs(struct charger_manager *cm)
 {
 	struct charger_desc *desc = cm->desc;
 	struct charger_regulator *charger;
 	int chargers_externally_control = 1;
 	char *name;
-	int ret;
 	int i;
 
 	/* Create sysfs entry to control charger(regulator) */
@@ -1384,8 +1383,10 @@ static int charger_manager_register_sysfs(struct charger_manager *cm)
 		charger->attrs[1] = &charger->attr_state.attr;
 		charger->attrs[2] = &charger->attr_externally_control.attr;
 		charger->attrs[3] = NULL;
-		charger->attr_g.name = name;
-		charger->attr_g.attrs = charger->attrs;
+
+		charger->attr_grp.name = name;
+		charger->attr_grp.attrs = charger->attrs;
+		desc->sysfs_groups[i] = &charger->attr_grp;
 
 		sysfs_attr_init(&charger->attr_name.attr);
 		charger->attr_name.attr.name = "name";
@@ -1412,14 +1413,6 @@ static int charger_manager_register_sysfs(struct charger_manager *cm)
 
 		dev_info(cm->dev, "'%s' regulator's externally_control is %d\n",
 			 charger->regulator_name, charger->externally_control);
-
-		ret = sysfs_create_group(&cm->charger_psy->dev.kobj,
-					&charger->attr_g);
-		if (ret < 0) {
-			dev_err(cm->dev, "Cannot create sysfs entry of %s regulator\n",
-				charger->regulator_name);
-			return ret;
-		}
 	}
 
 	if (chargers_externally_control) {
@@ -1560,6 +1553,13 @@ static struct charger_desc *of_cm_parse_desc(struct device *dev)
 
 		desc->charger_regulators = chg_regs;
 
+		desc->sysfs_groups = devm_kcalloc(dev,
+					desc->num_charger_regulators + 1,
+					sizeof(*desc->sysfs_groups),
+					GFP_KERNEL);
+		if (!desc->sysfs_groups)
+			return ERR_PTR(-ENOMEM);
+
 		for_each_child_of_node(np, child) {
 			struct charger_cable *cables;
 			struct device_node *_child;
@@ -1762,6 +1762,15 @@ static int charger_manager_probe(struct platform_device *pdev)
 
 	INIT_DELAYED_WORK(&cm->fullbatt_vchk_work, fullbatt_vchk);
 
+	/* Register sysfs entry for charger(regulator) */
+	ret = charger_manager_prepare_sysfs(cm);
+	if (ret < 0) {
+		dev_err(&pdev->dev,
+			"Cannot prepare sysfs entry of regulators\n");
+		return ret;
+	}
+	psy_cfg.attr_grp = desc->sysfs_groups;
+
 	cm->charger_psy = power_supply_register(&pdev->dev,
 						&cm->charger_psy_desc,
 						&psy_cfg);
@@ -1778,14 +1787,6 @@ static int charger_manager_probe(struct platform_device *pdev)
 		goto err_reg_extcon;
 	}
 
-	/* Register sysfs entry for charger(regulator) */
-	ret = charger_manager_register_sysfs(cm);
-	if (ret < 0) {
-		dev_err(&pdev->dev,
-			"Cannot initialize sysfs entry of regulator\n");
-		goto err_reg_sysfs;
-	}
-
 	/* Add to the list */
 	mutex_lock(&cm_list_mtx);
 	list_add(&cm->entry, &cm_list);
@@ -1809,14 +1810,6 @@ static int charger_manager_probe(struct platform_device *pdev)
 
 	return 0;
 
-err_reg_sysfs:
-	for (i = 0; i < desc->num_charger_regulators; i++) {
-		struct charger_regulator *charger;
-
-		charger = &desc->charger_regulators[i];
-		sysfs_remove_group(&cm->charger_psy->dev.kobj,
-				&charger->attr_g);
-	}
 err_reg_extcon:
 	for (i = 0; i < desc->num_charger_regulators; i++) {
 		struct charger_regulator *charger;