power: bq2477x: Add adapter detection through GPIO

Added support for AC adapter detection through GPIO
in bq2477x charger.

Bug 1457299

Change-Id: I344d264312142121342403194aa5adeaec66d47d
Signed-off-by: Chaitanya Bandi <bandik@nvidia.com>
Reviewed-on: http://git-master/r/380285
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>

3 files changed, 63 insertions, 1 deletions

diff --git a/Documentation/devicetree/bindings/power/bq2477x-charger.txt b/Documentation/devicetree/bindings/power/bq2477x-charger.txt
index 6f9eee6a943f..33e90da6e6f3 100644
--- a/Documentation/devicetree/bindings/power/bq2477x-charger.txt
+++ b/Documentation/devicetree/bindings/power/bq2477x-charger.txt
@@ -8,6 +8,10 @@ Required properties :
  - ti,dac-minsv : The minimum System voltage that must be programmed
  - ti,dac-iin : The input current that must be programmed
  - ti,wdt-refresh-timeout : watch dog timer that must be programmed
+ - charger-detect-gpio : the GPIO used for AC adapter detection
+ - ti,charger-detect-gpio-active-low : The flag that determines if AC adapter
+	presence is indicated by active low. Set this to 1 if active low
+	indicates adapter is present, else 0.
 
 Example:
 
@@ -19,4 +23,6 @@ Example:
 		ti,dac-minsv = <4608>;
 		ti,dac-iin = <4992>;
 		ti,wdt-refresh-timeout = <40>;
+		charger-detect-gpio = <&gpio 85 0>;
+		ti,charger-detect-gpio-active-low = <1>;
 	 };
diff --git a/drivers/power/bq2477x-charger.c b/drivers/power/bq2477x-charger.c
index 14e74cef142f..04b767392753 100644
--- a/drivers/power/bq2477x-charger.c
+++ b/drivers/power/bq2477x-charger.c
@@ -40,6 +40,8 @@
 #include <linux/rtc.h>
 #include <linux/alarmtimer.h>
 #include <linux/sched/rt.h>
+#include <linux/gpio.h>
+#include <linux/of_gpio.h>
 
 struct bq2477x_chip {
 	struct device	*dev;
@@ -48,6 +50,8 @@ struct bq2477x_chip {
 	struct regmap	*regmap_word;
 	struct mutex	mutex;
 	int	irq;
+	int	charger_detect_gpio;
+	int	charger_detect_gpio_active_low;
 	int	ac_online;
 	int	dac_ichg;
 	int	dac_v;
@@ -281,6 +285,29 @@ static void of_bq2477x_parse_platform_data(struct i2c_client *client,
 	else
 		dev_warn(&client->dev, "wdt-refresh-timeout not provided\n");
 
+	ret = of_property_read_u32(np, "ti,charger-detect-gpio-active-low", &pval);
+	if (!ret)
+		pdata->charger_detect_gpio_active_low = pval;
+	else
+		dev_warn(&client->dev, "charger_detect_gpio_active_low not provided\n");
+
+	pdata->charger_detect_gpio = of_get_named_gpio(np, "charger-detect-gpio", 0);
+	if (pdata->charger_detect_gpio < 0)
+		dev_warn(&client->dev, "invalid pdata->charger_detect_gpio\n");
+}
+
+static irqreturn_t bq2477x_charger_detect_irq(int irq, void *data)
+{
+	struct bq2477x_chip *bq2477x = data;
+	bq2477x->ac_online =
+			gpio_get_value_cansleep(bq2477x->charger_detect_gpio);
+	bq2477x->ac_online ^= bq2477x->charger_detect_gpio_active_low;
+
+	if (bq2477x->ac_online == 1)
+		bq2477x_hw_init(bq2477x);
+
+	power_supply_changed(&bq2477x->ac);
+	return IRQ_HANDLED;
 }
 
 static int bq2477x_probe(struct i2c_client *client,
@@ -317,9 +344,11 @@ static int bq2477x_probe(struct i2c_client *client,
 	bq2477x->dac_minsv = pdata->dac_minsv;
 	bq2477x->dac_iin = pdata->dac_iin;
 	bq2477x->wdt_refresh_timeout = pdata->wdt_refresh_timeout;
+	bq2477x->charger_detect_gpio = pdata->charger_detect_gpio;
+	bq2477x->charger_detect_gpio_active_low =
+					pdata->charger_detect_gpio_active_low;
 
 	i2c_set_clientdata(client, bq2477x);
-	bq2477x->irq = client->irq;
 	mutex_init(&bq2477x->mutex);
 
 	bq2477x->ac_online = 0;
@@ -359,6 +388,31 @@ static int bq2477x_probe(struct i2c_client *client,
 		return ret;
 	}
 
+	if (gpio_is_valid(bq2477x->charger_detect_gpio)) {
+		ret = devm_gpio_request_one(bq2477x->dev,
+				bq2477x->charger_detect_gpio, GPIOF_IN,
+						"bq2477x-charger-detect");
+		if (ret) {
+			dev_err(bq2477x->dev, "gpio request failed %d\n", ret);
+			goto psy_err;
+		}
+
+		bq2477x->irq = gpio_to_irq(bq2477x->charger_detect_gpio);
+		bq2477x->ac_online =
+			gpio_get_value_cansleep(bq2477x->charger_detect_gpio);
+		bq2477x->ac_online ^= bq2477x->charger_detect_gpio_active_low;
+
+		ret = devm_request_threaded_irq(bq2477x->dev, bq2477x->irq,
+			NULL, bq2477x_charger_detect_irq,
+			IRQF_ONESHOT | IRQF_TRIGGER_RISING
+			| IRQF_TRIGGER_FALLING, dev_name(bq2477x->dev),
+			bq2477x);
+		if (ret < 0) {
+                        dev_err(bq2477x->dev, "Failed to request irq %d\n", ret);
+			goto psy_err;
+		}
+	}
+
 	ret = bq2477x_hw_init(bq2477x);
 	if (ret < 0) {
 		dev_err(bq2477x->dev, "Hardware init failed %d\n", ret);
diff --git a/include/linux/power/bq2477x-charger.h b/include/linux/power/bq2477x-charger.h
index 0ccdb8d54435..d0b92a8c1b38 100644
--- a/include/linux/power/bq2477x-charger.h
+++ b/include/linux/power/bq2477x-charger.h
@@ -67,5 +67,7 @@ struct bq2477x_platform_data {
 	int     dac_iin;
 	int     wdt_refresh_timeout;
 	int     gpio;
+	int	charger_detect_gpio;
+	int	charger_detect_gpio_active_low;
 };
 #endif /* __LINUX_POWER_BQ2477X_CHARGER_H */