power_supply: Add a charge_type property, and use it for olpc driver

This adds a new sysfs file called 'charge_type' which displays the
type of charging (unknown, n/a, trickle charge, or fast charging).

This allows things like battery diagnostics to determine what the
battery/EC is doing without resorting to changing the 'status' sysfs
output.

Signed-off-by: Andres Salomon <dilinger@collabora.co.uk>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

4 files changed, 28 insertions, 0 deletions

diff --git a/Documentation/power/power_supply_class.txt b/Documentation/power/power_supply_class.txt
index 709d95571d7b..9f16c5178b66 100644
--- a/Documentation/power/power_supply_class.txt
+++ b/Documentation/power/power_supply_class.txt
@@ -76,6 +76,11 @@ STATUS - this attribute represents operating status (charging, full,
 discharging (i.e. powering a load), etc.). This corresponds to
 BATTERY_STATUS_* values, as defined in battery.h.
 
+CHARGE_TYPE - batteries can typically charge at different rates.
+This defines trickle and fast charges.  For batteries that
+are already charged or discharging, 'n/a' can be displayed (or
+'unknown', if the status is not known).
+
 HEALTH - represents health of the battery, values corresponds to
 POWER_SUPPLY_HEALTH_*, defined in battery.h.
 
diff --git a/drivers/power/olpc_battery.c b/drivers/power/olpc_battery.c
index 602bbd008f78..8fefe5a73558 100644
--- a/drivers/power/olpc_battery.c
+++ b/drivers/power/olpc_battery.c
@@ -233,6 +233,14 @@ static int olpc_bat_get_property(struct power_supply *psy,
                 if (ret)
                         return ret;
                 break;
+        case POWER_SUPPLY_PROP_CHARGE_TYPE:
+                if (ec_byte & BAT_STAT_TRICKLE)
+                        val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
+                else if (ec_byte & BAT_STAT_CHARGING)
+                        val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
+                else
+                        val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
+                break;
         case POWER_SUPPLY_PROP_PRESENT:
                 val->intval = !!(ec_byte & (BAT_STAT_PRESENT |
                                             BAT_STAT_TRICKLE));
@@ -325,6 +333,7 @@ static int olpc_bat_get_property(struct power_supply *psy,
 
 static enum power_supply_property olpc_bat_props[] = {
         POWER_SUPPLY_PROP_STATUS,
+        POWER_SUPPLY_PROP_CHARGE_TYPE,
         POWER_SUPPLY_PROP_PRESENT,
         POWER_SUPPLY_PROP_HEALTH,
         POWER_SUPPLY_PROP_TECHNOLOGY,
diff --git a/drivers/power/power_supply_sysfs.c b/drivers/power/power_supply_sysfs.c
index 9deabbde6fd6..08144393d64b 100644
--- a/drivers/power/power_supply_sysfs.c
+++ b/drivers/power/power_supply_sysfs.c
@@ -43,6 +43,9 @@ static ssize_t power_supply_show_property(struct device *dev,
         static char *status_text[] = {
                 "Unknown", "Charging", "Discharging", "Not charging", "Full"
         };
+        static char *charge_type[] = {
+                "Unknown", "N/A", "Trickle", "Fast"
+        };
         static char *health_text[] = {
                 "Unknown", "Good", "Overheat", "Dead", "Over voltage",
                 "Unspecified failure", "Cold",
@@ -70,6 +73,8 @@ static ssize_t power_supply_show_property(struct device *dev,
 
         if (off == POWER_SUPPLY_PROP_STATUS)
                 return sprintf(buf, "%s\n", status_text[value.intval]);
+        else if (off == POWER_SUPPLY_PROP_CHARGE_TYPE)
+                return sprintf(buf, "%s\n", charge_type[value.intval]);
         else if (off == POWER_SUPPLY_PROP_HEALTH)
                 return sprintf(buf, "%s\n", health_text[value.intval]);
         else if (off == POWER_SUPPLY_PROP_TECHNOLOGY)
@@ -86,6 +91,7 @@ static ssize_t power_supply_show_property(struct device *dev,
 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),
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 0ab6aa171241..4c7c6fc35487 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -39,6 +39,13 @@ enum {
 };
 
 enum {
+        POWER_SUPPLY_CHARGE_TYPE_UNKNOWN = 0,
+        POWER_SUPPLY_CHARGE_TYPE_NONE,
+        POWER_SUPPLY_CHARGE_TYPE_TRICKLE,
+        POWER_SUPPLY_CHARGE_TYPE_FAST,
+};
+
+enum {
         POWER_SUPPLY_HEALTH_UNKNOWN = 0,
         POWER_SUPPLY_HEALTH_GOOD,
         POWER_SUPPLY_HEALTH_OVERHEAT,
@@ -70,6 +77,7 @@ enum {
 enum power_supply_property {
         /* Properties of type `int' */
         POWER_SUPPLY_PROP_STATUS = 0,
+        POWER_SUPPLY_PROP_CHARGE_TYPE,
         POWER_SUPPLY_PROP_HEALTH,
         POWER_SUPPLY_PROP_PRESENT,
         POWER_SUPPLY_PROP_ONLINE,