[PATCH v4 4/5] power: supply: adc-battery-helper: Add support for optional charge_finished GPIO

[Hans de Goede <hansg@kernel.org>]

Charger ICs often have a status pin which indicates when the charger has
finished charging the battery. Sometimes the status of this pin can be
read over a GPIO.

Add support for optionally reading a charge-finished GPIO and when
available use this to determine when to return POWER_SUPPLY_STATUS_FULL.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Hans de Goede <hansg@kernel.org>
---
 drivers/power/supply/adc-battery-helper.c | 18 +++++++++++++++---
 drivers/power/supply/adc-battery-helper.h |  5 ++++-
 drivers/power/supply/ug3105_battery.c     |  2 +-
 3 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/drivers/power/supply/adc-battery-helper.c b/drivers/power/supply/adc-battery-helper.c
index f8f6d2f8ec89..229b49fef8ad 100644
--- a/drivers/power/supply/adc-battery-helper.c
+++ b/drivers/power/supply/adc-battery-helper.c
@@ -51,6 +51,7 @@
 
 #include <linux/cleanup.h>
 #include <linux/devm-helpers.h>
+#include <linux/gpio/consumer.h>
 #include <linux/mutex.h>
 #include <linux/power_supply.h>
 #include <linux/workqueue.h>
@@ -82,8 +83,17 @@ static int adc_battery_helper_get_status(struct adc_battery_helper *help)
 	if (help->curr_ua < -CURR_HYST_UA)
 		return POWER_SUPPLY_STATUS_DISCHARGING;
 
-	if (help->supplied && help->ocv_avg_uv > full_uv)
-		return POWER_SUPPLY_STATUS_FULL;
+	if (help->supplied) {
+		bool full;
+
+		if (help->charge_finished)
+			full = gpiod_get_value_cansleep(help->charge_finished);
+		else
+			full = help->ocv_avg_uv > full_uv;
+
+		if (full)
+			return POWER_SUPPLY_STATUS_FULL;
+	}
 
 	return POWER_SUPPLY_STATUS_NOT_CHARGING;
 }
@@ -255,13 +265,15 @@ static void adc_battery_helper_start_work(struct adc_battery_helper *help)
 }
 
 int adc_battery_helper_init(struct adc_battery_helper *help, struct power_supply *psy,
-			    adc_battery_helper_get_func get_voltage_and_current_now)
+			    adc_battery_helper_get_func get_voltage_and_current_now,
+			    struct gpio_desc *charge_finished_gpio)
 {
 	struct device *dev = psy->dev.parent;
 	int ret;
 
 	help->psy = psy;
 	help->get_voltage_and_current_now = get_voltage_and_current_now;
+	help->charge_finished = charge_finished_gpio;
 
 	ret = devm_mutex_init(dev, &help->lock);
 	if (ret)
diff --git a/drivers/power/supply/adc-battery-helper.h b/drivers/power/supply/adc-battery-helper.h
index 90c7edcb9ab1..4e42181c8983 100644
--- a/drivers/power/supply/adc-battery-helper.h
+++ b/drivers/power/supply/adc-battery-helper.h
@@ -11,6 +11,7 @@
 #define ADC_BAT_HELPER_MOV_AVG_WINDOW_SIZE		8
 
 struct power_supply;
+struct gpio_desc;
 
 /*
  * The adc battery helper code needs voltage- and current-now to be sampled as
@@ -21,6 +22,7 @@ typedef int (*adc_battery_helper_get_func)(struct power_supply *psy, int *volt,
 
 struct adc_battery_helper {
 	struct power_supply *psy;
+	struct gpio_desc *charge_finished;
 	struct delayed_work work;
 	struct mutex lock;
 	adc_battery_helper_get_func get_voltage_and_current_now;
@@ -44,7 +46,8 @@ extern const enum power_supply_property adc_battery_helper_properties[];
 #define ADC_HELPER_NUM_PROPERTIES 7
 
 int adc_battery_helper_init(struct adc_battery_helper *help, struct power_supply *psy,
-			    adc_battery_helper_get_func get_voltage_and_current_now);
+			    adc_battery_helper_get_func get_voltage_and_current_now,
+			    struct gpio_desc *charge_finished_gpio);
 /*
  * The below functions can be directly used as power-supply / suspend-resume
  * callbacks. They cast the power_supply_get_drvdata() / dev_get_drvdata() data
diff --git a/drivers/power/supply/ug3105_battery.c b/drivers/power/supply/ug3105_battery.c
index c4d4ac859fa4..210e0f9aa5e0 100644
--- a/drivers/power/supply/ug3105_battery.c
+++ b/drivers/power/supply/ug3105_battery.c
@@ -161,7 +161,7 @@ static int ug3105_probe(struct i2c_client *client)
 	}
 
 	ret = adc_battery_helper_init(&chip->helper, chip->psy,
-				      ug3105_get_voltage_and_current_now);
+				      ug3105_get_voltage_and_current_now, NULL);
 	if (ret)
 		goto stop;
 
-- 
2.51.0