Date:   Fri, 24 Apr 2020 11:35:30 -0600
From:   Mathew King <mathewk@...omium.org>
To:     linux-kernel@...r.kernel.org
Cc:     Mathew King <mathewk@...omium.org>,
        Sebastian Reichel <sre@...nel.org>, linux-pm@...r.kernel.org
Subject: [PATCH 1/4] power_supply: Cleanup power supply sysfs attribute list

Make the device attribute list used to create sysfs attributes more
robust by decoupling the list order from order of the enum defined in
power_supply.h. This is done by using a designated initializer in the
POWER_SUPPLY_ATTR macro. Also properties not added to the list will
still be created with name in the format "prop_*".

Signed-off-by: Mathew King <mathewk@...omium.org>
---
 drivers/power/supply/power_supply.h       |   7 +-
 drivers/power/supply/power_supply_core.c  |   9 +-
 drivers/power/supply/power_supply_sysfs.c | 290 +++++++++++++---------
 3 files changed, 179 insertions(+), 127 deletions(-)

diff --git a/drivers/power/supply/power_supply.h b/drivers/power/supply/power_supply.h
index c310d4f36c10..e3475d35ec2a 100644
--- a/drivers/power/supply/power_supply.h
+++ b/drivers/power/supply/power_supply.h
@@ -15,12 +15,15 @@ struct power_supply;
 
 #ifdef CONFIG_SYSFS
 
-extern void power_supply_init_attrs(struct device_type *dev_type);
+extern int power_supply_init_attrs(struct device_type *dev_type);
+extern void power_supply_destroy_attrs(void);
 extern int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env);
 
 #else
 
-static inline void power_supply_init_attrs(struct device_type *dev_type) {}
+static inline int power_supply_init_attrs(struct device_type *dev_type)
+{ return 0; }
+static void power_supply_destroy_attrs(void) {}
 #define power_supply_uevent NULL
 
 #endif /* CONFIG_SYSFS */
diff --git a/drivers/power/supply/power_supply_core.c b/drivers/power/supply/power_supply_core.c
index 1a9a9fae73d3..7fb99302b532 100644
--- a/drivers/power/supply/power_supply_core.c
+++ b/drivers/power/supply/power_supply_core.c
@@ -1329,19 +1329,26 @@ EXPORT_SYMBOL_GPL(power_supply_get_drvdata);
 
 static int __init power_supply_class_init(void)
 {
+	int ret;
 	power_supply_class = class_create(THIS_MODULE, "power_supply");
 
 	if (IS_ERR(power_supply_class))
 		return PTR_ERR(power_supply_class);
 
 	power_supply_class->dev_uevent = power_supply_uevent;
-	power_supply_init_attrs(&power_supply_dev_type);
+
+	ret = power_supply_init_attrs(&power_supply_dev_type);
+	if (ret) {
+		class_destroy(power_supply_class);
+		return ret;
+	}
 
 	return 0;
 }
 
 static void __exit power_supply_class_exit(void)
 {
+	power_supply_destroy_attrs();
 	class_destroy(power_supply_class);
 }
 
diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index f37ad4eae60b..b579081599d7 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -18,27 +18,22 @@
 
 #include "power_supply.h"
 
-/*
- * This is because the name "current" breaks the device attr macro.
- * The "current" word resolves to "(get_current())" so instead of
- * "current" "(get_current())" appears in the sysfs.
- *
- * The source of this definition is the device.h which calls __ATTR
- * macro in sysfs.h which calls the __stringify macro.
- *
- * Only modification that the name is not tried to be resolved
- * (as a macro let's say).
- */
+#define UNDEF_PROP_NAME_FMT "PROP_%d"
+#define UNDEF_PROP_NAME_LEN (strlen(UNDEF_PROP_NAME_FMT) + 2)
+
+struct power_supply_attr {
+	const char *prop_name;
+	const char *upper_name;
+	const char *lower_name;
+	struct device_attribute dev_attr;
+};
 
-#define POWER_SUPPLY_ATTR(_name)					\
-{									\
-	.attr = { .name = #_name },					\
-	.show = power_supply_show_property,				\
-	.store = power_supply_store_property,				\
+#define POWER_SUPPLY_ATTR(_name)	\
+[POWER_SUPPLY_PROP_ ## _name] =		\
+{					\
+	.prop_name = #_name		\
 }
 
-static struct device_attribute power_supply_attrs[];
-
 static const char * const power_supply_type_text[] = {
 	"Unknown", "Battery", "UPS", "Mains", "USB",
 	"USB_DCP", "USB_CDP", "USB_ACA", "USB_C",
@@ -77,6 +72,91 @@ static const char * const power_supply_scope_text[] = {
 	"Unknown", "System", "Device"
 };
 
+static struct power_supply_attr power_supply_attrs[] = {
+	/* Properties of type `int' */
+	POWER_SUPPLY_ATTR(STATUS),
+	POWER_SUPPLY_ATTR(CHARGE_TYPE),
+	POWER_SUPPLY_ATTR(HEALTH),
+	POWER_SUPPLY_ATTR(PRESENT),
+	POWER_SUPPLY_ATTR(ONLINE),
+	POWER_SUPPLY_ATTR(AUTHENTIC),
+	POWER_SUPPLY_ATTR(TECHNOLOGY),
+	POWER_SUPPLY_ATTR(CYCLE_COUNT),
+	POWER_SUPPLY_ATTR(VOLTAGE_MAX),
+	POWER_SUPPLY_ATTR(VOLTAGE_MIN),
+	POWER_SUPPLY_ATTR(VOLTAGE_MAX_DESIGN),
+	POWER_SUPPLY_ATTR(VOLTAGE_MIN_DESIGN),
+	POWER_SUPPLY_ATTR(VOLTAGE_NOW),
+	POWER_SUPPLY_ATTR(VOLTAGE_AVG),
+	POWER_SUPPLY_ATTR(VOLTAGE_OCV),
+	POWER_SUPPLY_ATTR(VOLTAGE_BOOT),
+	POWER_SUPPLY_ATTR(CURRENT_MAX),
+	POWER_SUPPLY_ATTR(CURRENT_NOW),
+	POWER_SUPPLY_ATTR(CURRENT_AVG),
+	POWER_SUPPLY_ATTR(CURRENT_BOOT),
+	POWER_SUPPLY_ATTR(POWER_NOW),
+	POWER_SUPPLY_ATTR(POWER_AVG),
+	POWER_SUPPLY_ATTR(CHARGE_FULL_DESIGN),
+	POWER_SUPPLY_ATTR(CHARGE_EMPTY_DESIGN),
+	POWER_SUPPLY_ATTR(CHARGE_FULL),
+	POWER_SUPPLY_ATTR(CHARGE_EMPTY),
+	POWER_SUPPLY_ATTR(CHARGE_NOW),
+	POWER_SUPPLY_ATTR(CHARGE_AVG),
+	POWER_SUPPLY_ATTR(CHARGE_COUNTER),
+	POWER_SUPPLY_ATTR(CONSTANT_CHARGE_CURRENT),
+	POWER_SUPPLY_ATTR(CONSTANT_CHARGE_CURRENT_MAX),
+	POWER_SUPPLY_ATTR(CONSTANT_CHARGE_VOLTAGE),
+	POWER_SUPPLY_ATTR(CONSTANT_CHARGE_VOLTAGE_MAX),
+	POWER_SUPPLY_ATTR(CHARGE_CONTROL_LIMIT),
+	POWER_SUPPLY_ATTR(CHARGE_CONTROL_LIMIT_MAX),
+	POWER_SUPPLY_ATTR(CHARGE_CONTROL_START_THRESHOLD),
+	POWER_SUPPLY_ATTR(CHARGE_CONTROL_END_THRESHOLD),
+	POWER_SUPPLY_ATTR(INPUT_CURRENT_LIMIT),
+	POWER_SUPPLY_ATTR(INPUT_VOLTAGE_LIMIT),
+	POWER_SUPPLY_ATTR(INPUT_POWER_LIMIT),
+	POWER_SUPPLY_ATTR(ENERGY_FULL_DESIGN),
+	POWER_SUPPLY_ATTR(ENERGY_EMPTY_DESIGN),
+	POWER_SUPPLY_ATTR(ENERGY_FULL),
+	POWER_SUPPLY_ATTR(ENERGY_EMPTY),
+	POWER_SUPPLY_ATTR(ENERGY_NOW),
+	POWER_SUPPLY_ATTR(ENERGY_AVG),
+	POWER_SUPPLY_ATTR(CAPACITY),
+	POWER_SUPPLY_ATTR(CAPACITY_ALERT_MIN),
+	POWER_SUPPLY_ATTR(CAPACITY_ALERT_MAX),
+	POWER_SUPPLY_ATTR(CAPACITY_LEVEL),
+	POWER_SUPPLY_ATTR(TEMP),
+	POWER_SUPPLY_ATTR(TEMP_MAX),
+	POWER_SUPPLY_ATTR(TEMP_MIN),
+	POWER_SUPPLY_ATTR(TEMP_ALERT_MIN),
+	POWER_SUPPLY_ATTR(TEMP_ALERT_MAX),
+	POWER_SUPPLY_ATTR(TEMP_AMBIENT),
+	POWER_SUPPLY_ATTR(TEMP_AMBIENT_ALERT_MIN),
+	POWER_SUPPLY_ATTR(TEMP_AMBIENT_ALERT_MAX),
+	POWER_SUPPLY_ATTR(TIME_TO_EMPTY_NOW),
+	POWER_SUPPLY_ATTR(TIME_TO_EMPTY_AVG),
+	POWER_SUPPLY_ATTR(TIME_TO_FULL_NOW),
+	POWER_SUPPLY_ATTR(TIME_TO_FULL_AVG),
+	POWER_SUPPLY_ATTR(TYPE),
+	POWER_SUPPLY_ATTR(USB_TYPE),
+	POWER_SUPPLY_ATTR(SCOPE),
+	POWER_SUPPLY_ATTR(PRECHARGE_CURRENT),
+	POWER_SUPPLY_ATTR(CHARGE_TERM_CURRENT),
+	POWER_SUPPLY_ATTR(CALIBRATE),
+	/* Properties of type `const char *' */
+	POWER_SUPPLY_ATTR(MODEL_NAME),
+	POWER_SUPPLY_ATTR(MANUFACTURER),
+	POWER_SUPPLY_ATTR(SERIAL_NUMBER),
+};
+
+static struct attribute *
+__power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
+
+static enum power_supply_property dev_attr_psp(struct device_attribute *attr)
+{
+	return container_of(attr, struct power_supply_attr, dev_attr) -
+		power_supply_attrs;
+}
+
 static ssize_t power_supply_show_usb_type(struct device *dev,
 					  enum power_supply_usb_type *usb_types,
 					  ssize_t num_usb_types,
@@ -117,7 +197,7 @@ static ssize_t power_supply_show_property(struct device *dev,
 					  char *buf) {
 	ssize_t ret;
 	struct power_supply *psy = dev_get_drvdata(dev);
-	enum power_supply_property psp = attr - power_supply_attrs;
+	enum power_supply_property psp = dev_attr_psp(attr);
 	union power_supply_propval value;
 
 	if (psp == POWER_SUPPLY_PROP_TYPE) {
@@ -186,7 +266,7 @@ static ssize_t power_supply_store_property(struct device *dev,
 					   const char *buf, size_t count) {
 	ssize_t ret;
 	struct power_supply *psy = dev_get_drvdata(dev);
-	enum power_supply_property psp = attr - power_supply_attrs;
+	enum power_supply_property psp = dev_attr_psp(attr);
 	union power_supply_propval value;
 
 	switch (psp) {
@@ -235,86 +315,6 @@ static ssize_t power_supply_store_property(struct device *dev,
 	return count;
 }
 
-/* Must be in the same order as POWER_SUPPLY_PROP_* */
-static struct device_attribute power_supply_attrs[] = {
-	/* Properties of type `int' */
-	POWER_SUPPLY_ATTR(status),
-	POWER_SUPPLY_ATTR(charge_type),
-	POWER_SUPPLY_ATTR(health),
-	POWER_SUPPLY_ATTR(present),
-	POWER_SUPPLY_ATTR(online),
-	POWER_SUPPLY_ATTR(authentic),
-	POWER_SUPPLY_ATTR(technology),
-	POWER_SUPPLY_ATTR(cycle_count),
-	POWER_SUPPLY_ATTR(voltage_max),
-	POWER_SUPPLY_ATTR(voltage_min),
-	POWER_SUPPLY_ATTR(voltage_max_design),
-	POWER_SUPPLY_ATTR(voltage_min_design),
-	POWER_SUPPLY_ATTR(voltage_now),
-	POWER_SUPPLY_ATTR(voltage_avg),
-	POWER_SUPPLY_ATTR(voltage_ocv),
-	POWER_SUPPLY_ATTR(voltage_boot),
-	POWER_SUPPLY_ATTR(current_max),
-	POWER_SUPPLY_ATTR(current_now),
-	POWER_SUPPLY_ATTR(current_avg),
-	POWER_SUPPLY_ATTR(current_boot),
-	POWER_SUPPLY_ATTR(power_now),
-	POWER_SUPPLY_ATTR(power_avg),
-	POWER_SUPPLY_ATTR(charge_full_design),
-	POWER_SUPPLY_ATTR(charge_empty_design),
-	POWER_SUPPLY_ATTR(charge_full),
-	POWER_SUPPLY_ATTR(charge_empty),
-	POWER_SUPPLY_ATTR(charge_now),
-	POWER_SUPPLY_ATTR(charge_avg),
-	POWER_SUPPLY_ATTR(charge_counter),
-	POWER_SUPPLY_ATTR(constant_charge_current),
-	POWER_SUPPLY_ATTR(constant_charge_current_max),
-	POWER_SUPPLY_ATTR(constant_charge_voltage),
-	POWER_SUPPLY_ATTR(constant_charge_voltage_max),
-	POWER_SUPPLY_ATTR(charge_control_limit),
-	POWER_SUPPLY_ATTR(charge_control_limit_max),
-	POWER_SUPPLY_ATTR(charge_control_start_threshold),
-	POWER_SUPPLY_ATTR(charge_control_end_threshold),
-	POWER_SUPPLY_ATTR(input_current_limit),
-	POWER_SUPPLY_ATTR(input_voltage_limit),
-	POWER_SUPPLY_ATTR(input_power_limit),
-	POWER_SUPPLY_ATTR(energy_full_design),
-	POWER_SUPPLY_ATTR(energy_empty_design),
-	POWER_SUPPLY_ATTR(energy_full),
-	POWER_SUPPLY_ATTR(energy_empty),
-	POWER_SUPPLY_ATTR(energy_now),
-	POWER_SUPPLY_ATTR(energy_avg),
-	POWER_SUPPLY_ATTR(capacity),
-	POWER_SUPPLY_ATTR(capacity_alert_min),
-	POWER_SUPPLY_ATTR(capacity_alert_max),
-	POWER_SUPPLY_ATTR(capacity_level),
-	POWER_SUPPLY_ATTR(temp),
-	POWER_SUPPLY_ATTR(temp_max),
-	POWER_SUPPLY_ATTR(temp_min),
-	POWER_SUPPLY_ATTR(temp_alert_min),
-	POWER_SUPPLY_ATTR(temp_alert_max),
-	POWER_SUPPLY_ATTR(temp_ambient),
-	POWER_SUPPLY_ATTR(temp_ambient_alert_min),
-	POWER_SUPPLY_ATTR(temp_ambient_alert_max),
-	POWER_SUPPLY_ATTR(time_to_empty_now),
-	POWER_SUPPLY_ATTR(time_to_empty_avg),
-	POWER_SUPPLY_ATTR(time_to_full_now),
-	POWER_SUPPLY_ATTR(time_to_full_avg),
-	POWER_SUPPLY_ATTR(type),
-	POWER_SUPPLY_ATTR(usb_type),
-	POWER_SUPPLY_ATTR(scope),
-	POWER_SUPPLY_ATTR(precharge_current),
-	POWER_SUPPLY_ATTR(charge_term_current),
-	POWER_SUPPLY_ATTR(calibrate),
-	/* Properties of type `const char *' */
-	POWER_SUPPLY_ATTR(model_name),
-	POWER_SUPPLY_ATTR(manufacturer),
-	POWER_SUPPLY_ATTR(serial_number),
-};
-
-static struct attribute *
-__power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
-
 static umode_t power_supply_attr_is_visible(struct kobject *kobj,
 					   struct attribute *attr,
 					   int attrno)
@@ -352,17 +352,7 @@ static const struct attribute_group *power_supply_attr_groups[] = {
 	NULL,
 };
 
-void power_supply_init_attrs(struct device_type *dev_type)
-{
-	int i;
-
-	dev_type->groups = power_supply_attr_groups;
-
-	for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++)
-		__power_supply_attrs[i] = &power_supply_attrs[i].attr;
-}
-
-static char *kstruprdup(const char *str, gfp_t gfp)
+static char *kstrlwrdup(const char *str, gfp_t gfp)
 {
 	char *ret, *ustr;
 
@@ -372,19 +362,75 @@ static char *kstruprdup(const char *str, gfp_t gfp)
 		return NULL;
 
 	while (*str)
-		*ustr++ = toupper(*str++);
+		*ustr++ = tolower(*str++);
 
 	*ustr = 0;
 
 	return ret;
 }
 
+int power_supply_init_attrs(struct device_type *dev_type)
+{
+	int i;
+
+	dev_type->groups = power_supply_attr_groups;
+
+	for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++) {
+		const char *upper, *lower;
+		struct device_attribute *attr;
+
+		upper = power_supply_attrs[i].prop_name;
+
+		if (!upper) {
+			char *name = kmalloc(UNDEF_PROP_NAME_LEN, GFP_KERNEL);
+
+			if (!name)
+				goto err_no_mem;
+
+			sprintf(name, UNDEF_PROP_NAME_FMT, i);
+			upper = name;
+		}
+
+		lower = kstrlwrdup(upper, GFP_KERNEL);
+
+		if (!lower)
+			goto err_no_mem;
+
+		power_supply_attrs[i].upper_name = upper;
+		power_supply_attrs[i].lower_name = lower;
+
+		attr = &power_supply_attrs[i].dev_attr;
+
+		attr->attr.name = lower;
+		attr->show = power_supply_show_property;
+		attr->store = power_supply_store_property;
+		__power_supply_attrs[i] = &attr->attr;
+	}
+
+	return 0;
+
+err_no_mem:
+	power_supply_destroy_attrs();
+	return -ENOMEM;
+}
+
+void power_supply_destroy_attrs(void)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++) {
+		kfree(power_supply_attrs[i].lower_name);
+
+		if (!power_supply_attrs[i].prop_name)
+			kfree(power_supply_attrs[i].upper_name);
+	}
+}
+
 int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 {
 	struct power_supply *psy = dev_get_drvdata(dev);
 	int ret = 0, j;
 	char *prop_buf;
-	char *attrname;
 
 	if (!psy || !psy->desc) {
 		dev_dbg(dev, "No power supply yet\n");
@@ -400,12 +446,14 @@ int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 		return -ENOMEM;
 
 	for (j = 0; j < psy->desc->num_properties; j++) {
-		struct device_attribute *attr;
+		struct power_supply_attr *pwr_attr;
+		struct device_attribute *dev_attr;
 		char *line;
 
-		attr = &power_supply_attrs[psy->desc->properties[j]];
+		pwr_attr = &power_supply_attrs[psy->desc->properties[j]];
+		dev_attr = &pwr_attr->dev_attr;
 
-		ret = power_supply_show_property(dev, attr, prop_buf);
+		ret = power_supply_show_property(dev, dev_attr, prop_buf);
 		if (ret == -ENODEV || ret == -ENODATA) {
 			/* When a battery is absent, we expect -ENODEV. Don't abort;
 			   send the uevent with at least the the PRESENT=0 property */
@@ -420,14 +468,8 @@ int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
 		if (line)
 			*line = 0;
 
-		attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
-		if (!attrname) {
-			ret = -ENOMEM;
-			goto out;
-		}
-
-		ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
-		kfree(attrname);
+		ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s",
+				     pwr_attr->upper_name, prop_buf);
 		if (ret)
 			goto out;
 	}
-- 
2.26.2.303.gf8c07b1a785-goog

Powered by blists - more mailing lists