[PATCH 4.19 234/234] Revert "hwmon: Make chip parameter for with_info API mandatory"

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

This reverts commit 1ec0bc72f5dab3ab367ae5230cf6f212d805a225 which is
commit ddaefa209c4ac791c1262e97c9b2d0440c8ef1d5 upstream.  It should not
have been applied to the stable trees.

Link: https://lore.kernel.org/r/20220622154454.GA1864037@xxxxxxxxxxxx
Reported-by: Julian Haller <julian.haller@xxxxxxxxxxx>
Reported-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: Sasha Levin <sashal@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 Documentation/hwmon/hwmon-kernel-api.txt |    2 +-
 drivers/hwmon/hwmon.c                    |   16 +++++++++-------
 2 files changed, 10 insertions(+), 8 deletions(-)

--- a/Documentation/hwmon/hwmon-kernel-api.txt
+++ b/Documentation/hwmon/hwmon-kernel-api.txt
@@ -71,7 +71,7 @@ hwmon_device_register_with_info is the m
 to register a hardware monitoring device. It creates the standard sysfs
 attributes in the hardware monitoring core, letting the driver focus on reading
 from and writing to the chip instead of having to bother with sysfs attributes.
-The parent device parameter as well as the chip parameter must not be NULL. Its
+The parent device parameter cannot be NULL with non-NULL chip info. Its
 parameters are described in more detail below.
 
 devm_hwmon_device_register_with_info is similar to
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -695,12 +695,11 @@ EXPORT_SYMBOL_GPL(hwmon_device_register_
 
 /**
  * hwmon_device_register_with_info - register w/ hwmon
- * @dev: the parent device (mandatory)
- * @name: hwmon name attribute (mandatory)
- * @drvdata: driver data to attach to created device (optional)
- * @chip: pointer to hwmon chip information (mandatory)
+ * @dev: the parent device
+ * @name: hwmon name attribute
+ * @drvdata: driver data to attach to created device
+ * @chip: pointer to hwmon chip information
  * @extra_groups: pointer to list of additional non-standard attribute groups
- *	(optional)
  *
  * hwmon_device_unregister() must be called when the device is no
  * longer needed.
@@ -713,10 +712,13 @@ hwmon_device_register_with_info(struct d
 				const struct hwmon_chip_info *chip,
 				const struct attribute_group **extra_groups)
 {
-	if (!dev || !name || !chip)
+	if (!name)
 		return ERR_PTR(-EINVAL);
 
-	if (!chip->ops || !chip->ops->is_visible || !chip->info)
+	if (chip && (!chip->ops || !chip->ops->is_visible || !chip->info))
+		return ERR_PTR(-EINVAL);
+
+	if (chip && !dev)
 		return ERR_PTR(-EINVAL);
 
 	return __hwmon_device_register(dev, name, drvdata, chip, extra_groups);