[PATCH v2 1/4] power_supply: Cleanup power supply sysfs attribute list

From: Mathew King
Date: Mon May 04 2020 - 16:29:56 EST


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.

Signed-off-by: Mathew King <mathewk@xxxxxxxxxxxx>
---
v2: - Don't create attributes for unlisted properties
- Use a char array for lower case name so no allocations needed
in init
---
drivers/power/supply/power_supply_sysfs.c | 260 +++++++++++-----------
1 file changed, 132 insertions(+), 128 deletions(-)

diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index f37ad4eae60b..69be80b321ea 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -18,26 +18,20 @@

#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 MAX_PROP_NAME_LEN 30

-#define POWER_SUPPLY_ATTR(_name) \
-{ \
- .attr = { .name = #_name }, \
- .show = power_supply_show_property, \
- .store = power_supply_store_property, \
-}
+struct power_supply_attr {
+ const char *prop_name;
+ char attr_name[MAX_PROP_NAME_LEN + 1];
+ struct device_attribute dev_attr;
+};

-static struct device_attribute power_supply_attrs[];
+#define POWER_SUPPLY_ATTR(_name) \
+[POWER_SUPPLY_PROP_ ## _name] = \
+{ \
+ .prop_name = #_name, \
+ .attr_name = #_name "\0", \
+}

static const char * const power_supply_type_text[] = {
"Unknown", "Battery", "UPS", "Mains", "USB",
@@ -77,6 +71,91 @@ 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 +196,7 @@ 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 +265,7 @@ 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 +314,6 @@ 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)
@@ -324,6 +323,9 @@ static umode_t power_supply_attr_is_visible(struct kobject *kobj,
umode_t mode = S_IRUSR | S_IRGRP | S_IROTH;
int i;

+ if (!power_supply_attrs[attrno].prop_name)
+ return 0;
+
if (attrno == POWER_SUPPLY_PROP_TYPE)
return mode;

@@ -352,31 +354,38 @@ static const struct attribute_group *power_supply_attr_groups[] = {
NULL,
};

-void power_supply_init_attrs(struct device_type *dev_type)
+static void str_to_lower(char *str)
{
- 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;
+ while (*str) {
+ *str = tolower(*str);
+ str++;
+ }
}

-static char *kstruprdup(const char *str, gfp_t gfp)
+void power_supply_init_attrs(struct device_type *dev_type)
{
- char *ret, *ustr;
+ int i;

- ustr = ret = kmalloc(strlen(str) + 1, gfp);
+ dev_type->groups = power_supply_attr_groups;

- if (!ret)
- return NULL;
+ for (i = 0; i < ARRAY_SIZE(power_supply_attrs); i++) {
+ struct device_attribute *attr;

- while (*str)
- *ustr++ = toupper(*str++);
+ if (!power_supply_attrs[i].prop_name) {
+ pr_warn("%s: Property %d skipped because is is missing from power_supply_attrs\n",
+ __func__, i);
+ sprintf(power_supply_attrs[i].attr_name, "_err_%d", i);
+ } else {
+ str_to_lower(power_supply_attrs[i].attr_name);
+ }

- *ustr = 0;
+ attr = &power_supply_attrs[i].dev_attr;

- return ret;
+ attr->attr.name = power_supply_attrs[i].attr_name;
+ attr->show = power_supply_show_property;
+ attr->store = power_supply_store_property;
+ __power_supply_attrs[i] = &attr->attr;
+ }
}

int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
@@ -384,7 +393,6 @@ 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 +408,14 @@ 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 +430,8 @@ 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->prop_name, prop_buf);
if (ret)
goto out;
}
--
2.26.2.526.g744177e7f7-goog