power_supply: Use attribute groups

This fixes a race between power supply device and initial
attributes creation, plus makes it possible to implement
writable properties.

[Daniel Mack - removed superflous return statement
 and dropped .mode attribute from POWER_SUPPLY_ATTR]

Suggested-by: Greg KH <gregkh@suse.de>
Suggested-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Tested-by: Daniel Mack <daniel@caiaq.de>

diff --git a/drivers/power/power_supply.h b/drivers/power/power_supply.h
index f38ba48..018de2b 100644 (file)
--- a/drivers/power/power_supply.h
+++ b/drivers/power/power_supply.h
@@ -12,15 +12,12 @@
 
 #ifdef CONFIG_SYSFS
 
-extern int power_supply_create_attrs(struct power_supply *psy);
-extern void power_supply_remove_attrs(struct power_supply *psy);
+extern void power_supply_init_attrs(struct device_type *dev_type);
 extern int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env);
 
 #else
 
-static inline int power_supply_create_attrs(struct power_supply *psy)
-{ return 0; }
-static inline void power_supply_remove_attrs(struct power_supply *psy) {}
+static inline void power_supply_init_attrs(struct device_type *dev_type) {}
 #define power_supply_uevent NULL
 
 #endif /* CONFIG_SYSFS */

diff --git a/drivers/power/power_supply_core.c b/drivers/power/power_supply_core.c
index cce75b4..91606bb 100644 (file)
--- a/drivers/power/power_supply_core.c
+++ b/drivers/power/power_supply_core.c
@@ -13,6 +13,7 @@
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/init.h>
+#include <linux/slab.h>
 #include <linux/device.h>
 #include <linux/err.h>
 #include <linux/power_supply.h>
@@ -22,6 +23,8 @@
 struct class *power_supply_class;
 EXPORT_SYMBOL_GPL(power_supply_class);
 
+static struct device_type power_supply_dev_type;
+
 static int __power_supply_changed_work(struct device *dev, void *data)
 {
        struct power_supply *psy = (struct power_supply *)data;
@@ -144,22 +147,39 @@ struct power_supply *power_supply_get_by_name(char *name)
 }
 EXPORT_SYMBOL_GPL(power_supply_get_by_name);
 
+static void power_supply_dev_release(struct device *dev)
+{
+       pr_debug("device: '%s': %s\n", dev_name(dev), __func__);
+       kfree(dev);
+}
+
 int power_supply_register(struct device *parent, struct power_supply *psy)
 {
-       int rc = 0;
+       struct device *dev;
+       int rc;
 
-       psy->dev = device_create(power_supply_class, parent, 0, psy,
-                                "%s", psy->name);
-       if (IS_ERR(psy->dev)) {
-               rc = PTR_ERR(psy->dev);
-               goto dev_create_failed;
-       }
+       dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+       if (!dev)
+               return -ENOMEM;
 
-       INIT_WORK(&psy->changed_work, power_supply_changed_work);
+       device_initialize(dev);
 
-       rc = power_supply_create_attrs(psy);
+       dev->class = power_supply_class;
+       dev->type = &power_supply_dev_type;
+       dev->parent = parent;
+       dev->release = power_supply_dev_release;
+       dev_set_drvdata(dev, psy);
+       psy->dev = dev;
+
+       rc = kobject_set_name(&dev->kobj, "%s", psy->name);
+       if (rc)
+               goto kobject_set_name_failed;
+
+       rc = device_add(dev);
        if (rc)
-               goto create_attrs_failed;
+               goto device_add_failed;
+
+       INIT_WORK(&psy->changed_work, power_supply_changed_work);
 
        rc = power_supply_create_triggers(psy);
        if (rc)
@@ -170,10 +190,10 @@ int power_supply_register(struct device *parent, struct power_supply *psy)
        goto success;
 
 create_triggers_failed:
-       power_supply_remove_attrs(psy);
-create_attrs_failed:
        device_unregister(psy->dev);
-dev_create_failed:
+kobject_set_name_failed:
+device_add_failed:
+       kfree(dev);
 success:
        return rc;
 }
@@ -183,7 +203,6 @@ void power_supply_unregister(struct power_supply *psy)
 {
        flush_scheduled_work();
        power_supply_remove_triggers(psy);
-       power_supply_remove_attrs(psy);
        device_unregister(psy->dev);
 }
 EXPORT_SYMBOL_GPL(power_supply_unregister);
@@ -196,6 +215,7 @@ static int __init power_supply_class_init(void)
                return PTR_ERR(power_supply_class);
 
        power_supply_class->dev_uevent = power_supply_uevent;
+       power_supply_init_attrs(&power_supply_dev_type);
 
        return 0;
 }

diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
index 5b6e352..7d7593c 100644 (file)
--- a/drivers/power/power_supply_sysfs.c
+++ b/drivers/power/power_supply_sysfs.c
@@ -31,7 +31,7 @@
 
 #define POWER_SUPPLY_ATTR(_name)                                       \
 {                                                                      \
-       .attr = { .name = #_name, .mode = 0444 },       \
+       .attr = { .name = #_name },                                     \
        .show = power_supply_show_property,                             \
        .store = NULL,                                                  \
 }
@@ -41,6 +41,9 @@ static struct device_attribute power_supply_attrs[];
 static ssize_t power_supply_show_property(struct device *dev,
                                          struct device_attribute *attr,
                                          char *buf) {
+       static char *type_text[] = {
+               "Battery", "UPS", "Mains", "USB"
+       };
        static char *status_text[] = {
                "Unknown", "Charging", "Discharging", "Not charging", "Full"
        };
@@ -58,12 +61,15 @@ static ssize_t power_supply_show_property(struct device *dev,
        static char *capacity_level_text[] = {
                "Unknown", "Critical", "Low", "Normal", "High", "Full"
        };
-       ssize_t ret;
+       ssize_t ret = 0;
        struct power_supply *psy = dev_get_drvdata(dev);
        const ptrdiff_t off = attr - power_supply_attrs;
        union power_supply_propval value;
 
-       ret = psy->get_property(psy, off, &value);
+       if (off == POWER_SUPPLY_PROP_TYPE)
+               value.intval = psy->type;
+       else
+               ret = psy->get_property(psy, off, &value);
 
        if (ret < 0) {
                if (ret == -ENODATA)
@@ -85,6 +91,8 @@ static ssize_t power_supply_show_property(struct device *dev,
                return sprintf(buf, "%s\n", technology_text[value.intval]);
        else if (off == POWER_SUPPLY_PROP_CAPACITY_LEVEL)
                return sprintf(buf, "%s\n", capacity_level_text[value.intval]);
+       else if (off == POWER_SUPPLY_PROP_TYPE)
+               return sprintf(buf, "%s\n", type_text[value.intval]);
        else if (off >= POWER_SUPPLY_PROP_MODEL_NAME)
                return sprintf(buf, "%s\n", value.strval);
 
@@ -132,67 +140,50 @@ static struct device_attribute power_supply_attrs[] = {
        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),
        /* Properties of type `const char *' */
        POWER_SUPPLY_ATTR(model_name),
        POWER_SUPPLY_ATTR(manufacturer),
        POWER_SUPPLY_ATTR(serial_number),
 };
 
-static ssize_t power_supply_show_static_attrs(struct device *dev,
-                                             struct device_attribute *attr,
-                                             char *buf) {
-       static char *type_text[] = { "Battery", "UPS", "Mains", "USB" };
-       struct power_supply *psy = dev_get_drvdata(dev);
-
-       return sprintf(buf, "%s\n", type_text[psy->type]);
-}
-
-static struct device_attribute power_supply_static_attrs[] = {
-       __ATTR(type, 0444, power_supply_show_static_attrs, NULL),
-};
+static struct attribute *
+__power_supply_attrs[ARRAY_SIZE(power_supply_attrs) + 1];
 
-int power_supply_create_attrs(struct power_supply *psy)
+static mode_t power_supply_attr_is_visible(struct kobject *kobj,
+                                          struct attribute *attr,
+                                          int attrno)
 {
-       int rc = 0;
-       int i, j;
-
-       for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++) {
-               rc = device_create_file(psy->dev,
-                           &power_supply_static_attrs[i]);
-               if (rc)
-                       goto statics_failed;
-       }
+       struct device *dev = container_of(kobj, struct device, kobj);
+       struct power_supply *psy = dev_get_drvdata(dev);
+       int i;
 
-       for (j = 0; j < psy->num_properties; j++) {
-               rc = device_create_file(psy->dev,
-                           &power_supply_attrs[psy->properties[j]]);
-               if (rc)
-                       goto dynamics_failed;
+       for (i = 0; i < psy->num_properties; i++) {
+               if (psy->properties[i] == attrno)
+                       return 0444;
        }
 
-       goto succeed;
-
-dynamics_failed:
-       while (j--)
-               device_remove_file(psy->dev,
-                          &power_supply_attrs[psy->properties[j]]);
-statics_failed:
-       while (i--)
-               device_remove_file(psy->dev, &power_supply_static_attrs[i]);
-succeed:
-       return rc;
+       return 0;
 }
 
-void power_supply_remove_attrs(struct power_supply *psy)
+static struct attribute_group power_supply_attr_group = {
+       .attrs = __power_supply_attrs,
+       .is_visible = power_supply_attr_is_visible,
+};
+
+static const struct attribute_group *power_supply_attr_groups[] = {
+       &power_supply_attr_group,
+       NULL,
+};
+
+void power_supply_init_attrs(struct device_type *dev_type)
 {
        int i;
 
-       for (i = 0; i < ARRAY_SIZE(power_supply_static_attrs); i++)
-               device_remove_file(psy->dev, &power_supply_static_attrs[i]);
+       dev_type->groups = power_supply_attr_groups;
 
-       for (i = 0; i < psy->num_properties; i++)
-               device_remove_file(psy->dev,
-                           &power_supply_attrs[psy->properties[i]]);
+       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)
@@ -236,36 +227,6 @@ int power_supply_uevent(struct device *dev, struct kobj_uevent_env *env)
        if (!prop_buf)
                return -ENOMEM;
 
-       for (j = 0; j < ARRAY_SIZE(power_supply_static_attrs); j++) {
-               struct device_attribute *attr;
-               char *line;
-
-               attr = &power_supply_static_attrs[j];
-
-               ret = power_supply_show_static_attrs(dev, attr, prop_buf);
-               if (ret < 0)
-                       goto out;
-
-               line = strchr(prop_buf, '\n');
-               if (line)
-                       *line = 0;
-
-               attrname = kstruprdup(attr->attr.name, GFP_KERNEL);
-               if (!attrname) {
-                       ret = -ENOMEM;
-                       goto out;
-               }
-
-               dev_dbg(dev, "Static prop %s=%s\n", attrname, prop_buf);
-
-               ret = add_uevent_var(env, "POWER_SUPPLY_%s=%s", attrname, prop_buf);
-               kfree(attrname);
-               if (ret)
-                       goto out;
-       }
-
-       dev_dbg(dev, "%zd dynamic props\n", psy->num_properties);
-
        for (j = 0; j < psy->num_properties; j++) {
                struct device_attribute *attr;
                char *line;

diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index ebd2b8f..c5f73a3 100644 (file)
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -114,6 +114,7 @@ enum power_supply_property {
        POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
        POWER_SUPPLY_PROP_TIME_TO_FULL_NOW,
        POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
+       POWER_SUPPLY_PROP_TYPE, /* use power_supply.type instead */
        /* Properties of type `const char *' */
        POWER_SUPPLY_PROP_MODEL_NAME,
        POWER_SUPPLY_PROP_MANUFACTURER,