[PATCH v2 1/2] power_supply: Add more charge types and CHARGE_CONTROL_* properties

[Nick Crews <ncrews@chromium.org>]

Add "Standard", "Adaptive", and "Custom" modes to the charge_type
property, to expand the existing "Trickle" and "Fast" modes.
In addition, add POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD
and POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD properties, to expand
the existing CHARGE_CONTROL_* properties. I am adding them in order
to support a new Chrome OS device, but these properties should be
general enough that they can be used on other devices.

The meaning of "Standard" is obvious, but "Adaptive" and "Custom" are
more tricky: "Adaptive" means that the charge controller uses some
custom algorithm to change the charge type automatically, with no
configuration needed. "Custom" means that the charge controller uses the
POWER_SUPPLY_PROP_CHARGE_CONTROL_* properties as configuration for some
other algorithm. For example, in the use case that I am supporting,
this means the battery begins charging when the percentage
level drops below POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD and
charging ceases when the percentage level goes above
POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD.

Signed-off-by: Nick Crews <ncrews@chromium.org>
---
 drivers/power/supply/power_supply_sysfs.c |  4 +++-
 include/linux/power_supply.h              | 10 ++++++++--
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/power/supply/power_supply_sysfs.c b/drivers/power/supply/power_supply_sysfs.c
index dce24f596160..6104a3f03d46 100644
--- a/drivers/power/supply/power_supply_sysfs.c
+++ b/drivers/power/supply/power_supply_sysfs.c
@@ -56,7 +56,7 @@ static const char * const power_supply_status_text[] = {
 };
 
 static const char * const power_supply_charge_type_text[] = {
-	"Unknown", "N/A", "Trickle", "Fast"
+	"Unknown", "N/A", "Trickle", "Fast", "Standard", "Adaptive", "Custom"
 };
 
 static const char * const power_supply_health_text[] = {
@@ -274,6 +274,8 @@ static struct device_attribute power_supply_attrs[] = {
 	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(energy_full_design),
 	POWER_SUPPLY_ATTR(energy_empty_design),
diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 2f9c201a54d1..d59205170232 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -40,11 +40,15 @@ enum {
 	POWER_SUPPLY_STATUS_FULL,
 };
 
+/* What algorithm is the charger using? */
 enum {
 	POWER_SUPPLY_CHARGE_TYPE_UNKNOWN = 0,
 	POWER_SUPPLY_CHARGE_TYPE_NONE,
-	POWER_SUPPLY_CHARGE_TYPE_TRICKLE,
-	POWER_SUPPLY_CHARGE_TYPE_FAST,
+	POWER_SUPPLY_CHARGE_TYPE_TRICKLE,	/* slow speed */
+	POWER_SUPPLY_CHARGE_TYPE_FAST,		/* fast speed */
+	POWER_SUPPLY_CHARGE_TYPE_STANDARD,	/* normal speed */
+	POWER_SUPPLY_CHARGE_TYPE_ADAPTIVE,	/* dynamically adjusted speed */
+	POWER_SUPPLY_CHARGE_TYPE_CUSTOM,	/* use CHARGE_CONTROL_* props */
 };
 
 enum {
@@ -121,6 +125,8 @@ enum power_supply_property {
 	POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE_MAX,
 	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT,
 	POWER_SUPPLY_PROP_CHARGE_CONTROL_LIMIT_MAX,
+	POWER_SUPPLY_PROP_CHARGE_CONTROL_START_THRESHOLD, /* in percents! */
+	POWER_SUPPLY_PROP_CHARGE_CONTROL_END_THRESHOLD, /* in percents! */
 	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
 	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
 	POWER_SUPPLY_PROP_ENERGY_EMPTY_DESIGN,
-- 
2.20.1