1 files changed, 58 insertions, 21 deletions

diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c
index a74c075a30ec..3932f9276c07 100644
--- a/drivers/hwmon/hwmon.c
+++ b/drivers/hwmon/hwmon.c
@@ -38,12 +38,15 @@ struct hwmon_device {
 
 #define to_hwmon_device(d) container_of(d, struct hwmon_device, dev)
 
+#define MAX_SYSFS_ATTR_NAME_LENGTH	32
+
 struct hwmon_device_attribute {
 	struct device_attribute dev_attr;
 	const struct hwmon_ops *ops;
 	enum hwmon_sensor_types type;
 	u32 attr;
 	int index;
+	char name[MAX_SYSFS_ATTR_NAME_LENGTH];
 };
 
 #define to_hwmon_attr(d) \
@@ -178,6 +181,22 @@ static ssize_t hwmon_attr_show(struct device *dev,
 	return sprintf(buf, "%ld\n", val);
 }
 
+static ssize_t hwmon_attr_show_string(struct device *dev,
+				      struct device_attribute *devattr,
+				      char *buf)
+{
+	struct hwmon_device_attribute *hattr = to_hwmon_attr(devattr);
+	char *s;
+	int ret;
+
+	ret = hattr->ops->read_string(dev, hattr->type, hattr->attr,
+				      hattr->index, &s);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%s\n", s);
+}
+
 static ssize_t hwmon_attr_store(struct device *dev,
 				struct device_attribute *devattr,
 				const char *buf, size_t count)
@@ -205,6 +224,17 @@ static int hwmon_attr_base(enum hwmon_sensor_types type)
 	return 1;
 }
 
+static bool is_string_attr(enum hwmon_sensor_types type, u32 attr)
+{
+	return (type == hwmon_temp && attr == hwmon_temp_label) ||
+	       (type == hwmon_in && attr == hwmon_in_label) ||
+	       (type == hwmon_curr && attr == hwmon_curr_label) ||
+	       (type == hwmon_power && attr == hwmon_power_label) ||
+	       (type == hwmon_energy && attr == hwmon_energy_label) ||
+	       (type == hwmon_humidity && attr == hwmon_humidity_label) ||
+	       (type == hwmon_fan && attr == hwmon_fan_label);
+}
+
 static struct attribute *hwmon_genattr(struct device *dev,
 				       const void *drvdata,
 				       enum hwmon_sensor_types type,
@@ -218,6 +248,7 @@ static struct attribute *hwmon_genattr(struct device *dev,
 	struct attribute *a;
 	umode_t mode;
 	char *name;
+	bool is_string = is_string_attr(type, attr);
 
 	/* The attribute is invisible if there is no template string */
 	if (!template)
@@ -227,32 +258,31 @@ static struct attribute *hwmon_genattr(struct device *dev,
 	if (!mode)
 		return ERR_PTR(-ENOENT);
 
-	if ((mode & S_IRUGO) && !ops->read)
+	if ((mode & S_IRUGO) && ((is_string && !ops->read_string) ||
+				 (!is_string && !ops->read)))
 		return ERR_PTR(-EINVAL);
 	if ((mode & S_IWUGO) && !ops->write)
 		return ERR_PTR(-EINVAL);
 
+	hattr = devm_kzalloc(dev, sizeof(*hattr), GFP_KERNEL);
+	if (!hattr)
+		return ERR_PTR(-ENOMEM);
+
 	if (type == hwmon_chip) {
 		name = (char *)template;
 	} else {
-		name = devm_kzalloc(dev, strlen(template) + 16, GFP_KERNEL);
-		if (!name)
-			return ERR_PTR(-ENOMEM);
-		scnprintf(name, strlen(template) + 16, template,
+		scnprintf(hattr->name, sizeof(hattr->name), template,
 			  index + hwmon_attr_base(type));
+		name = hattr->name;
 	}
 
-	hattr = devm_kzalloc(dev, sizeof(*hattr), GFP_KERNEL);
-	if (!hattr)
-		return ERR_PTR(-ENOMEM);
-
 	hattr->type = type;
 	hattr->attr = attr;
 	hattr->index = index;
 	hattr->ops = ops;
 
 	dattr = &hattr->dev_attr;
-	dattr->show = hwmon_attr_show;
+	dattr->show = is_string ? hwmon_attr_show_string : hwmon_attr_show;
 	dattr->store = hwmon_attr_store;
 
 	a = &dattr->attr;
@@ -263,7 +293,11 @@ static struct attribute *hwmon_genattr(struct device *dev,
 	return a;
 }
 
-static const char * const hwmon_chip_attr_templates[] = {
+/*
+ * Chip attributes are not attribute templates but actual sysfs attributes.
+ * See hwmon_genattr() for special handling.
+ */
+static const char * const hwmon_chip_attrs[] = {
 	[hwmon_chip_temp_reset_history] = "temp_reset_history",
 	[hwmon_chip_in_reset_history] = "in_reset_history",
 	[hwmon_chip_curr_reset_history] = "curr_reset_history",
@@ -400,7 +434,7 @@ static const char * const hwmon_pwm_attr_templates[] = {
 };
 
 static const char * const *__templates[] = {
-	[hwmon_chip] = hwmon_chip_attr_templates,
+	[hwmon_chip] = hwmon_chip_attrs,
 	[hwmon_temp] = hwmon_temp_attr_templates,
 	[hwmon_in] = hwmon_in_attr_templates,
 	[hwmon_curr] = hwmon_curr_attr_templates,
@@ -412,7 +446,7 @@ static const char * const *__templates[] = {
 };
 
 static const int __templates_size[] = {
-	[hwmon_chip] = ARRAY_SIZE(hwmon_chip_attr_templates),
+	[hwmon_chip] = ARRAY_SIZE(hwmon_chip_attrs),
 	[hwmon_temp] = ARRAY_SIZE(hwmon_temp_attr_templates),
 	[hwmon_in] = ARRAY_SIZE(hwmon_in_attr_templates),
 	[hwmon_curr] = ARRAY_SIZE(hwmon_curr_attr_templates),
@@ -526,9 +560,9 @@ __hwmon_device_register(struct device *dev, const char *name, void *drvdata,
 
 	hdev = &hwdev->dev;
 
-	if (chip && chip->ops->is_visible) {
+	if (chip) {
 		struct attribute **attrs;
-		int ngroups = 2;
+		int ngroups = 2; /* terminating NULL plus &hwdev->groups */
 
 		if (groups)
 			for (i = 0; groups[i]; i++)
@@ -572,7 +606,7 @@ __hwmon_device_register(struct device *dev, const char *name, void *drvdata,
 	if (err)
 		goto free_hwmon;
 
-	if (chip && chip->ops->is_visible && chip->ops->read &&
+	if (chip && chip->ops->read &&
 	    chip->info[0]->type == hwmon_chip &&
 	    (chip->info[0]->config[0] & HWMON_C_REGISTER_TZ)) {
 		const struct hwmon_channel_info **info = chip->info;
@@ -626,8 +660,8 @@ EXPORT_SYMBOL_GPL(hwmon_device_register_with_groups);
  * @dev: the parent device
  * @name: hwmon name attribute
  * @drvdata: driver data to attach to created device
- * @info: Pointer to hwmon chip information
- * @groups - pointer to list of driver specific attribute groups
+ * @info: pointer to hwmon chip information
+ * @extra_groups: pointer to list of additional non-standard attribute groups
  *
  * hwmon_device_unregister() must be called when the device is no
  * longer needed.
@@ -638,12 +672,12 @@ struct device *
 hwmon_device_register_with_info(struct device *dev, const char *name,
 				void *drvdata,
 				const struct hwmon_chip_info *chip,
-				const struct attribute_group **groups)
+				const struct attribute_group **extra_groups)
 {
-	if (chip && (!chip->ops || !chip->info))
+	if (chip && (!chip->ops || !chip->ops->is_visible || !chip->info))
 		return ERR_PTR(-EINVAL);
 
-	return __hwmon_device_register(dev, name, drvdata, chip, groups);
+	return __hwmon_device_register(dev, name, drvdata, chip, extra_groups);
 }
 EXPORT_SYMBOL_GPL(hwmon_device_register_with_info);
 
@@ -658,6 +692,9 @@ EXPORT_SYMBOL_GPL(hwmon_device_register_with_info);
  */
 struct device *hwmon_device_register(struct device *dev)
 {
+	dev_warn(dev,
+		 "hwmon_device_register() is deprecated. Please convert the driver to use hwmon_device_register_with_info().\n");
+
 	return hwmon_device_register_with_groups(dev, NULL, NULL, NULL);
 }
 EXPORT_SYMBOL_GPL(hwmon_device_register);