linux-kernel - [PATCH v3] power: bq24735-charger: Request status GPIO with initial input setup

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Message-Id: <20160901212700.29747-1-contact@paulk.fr>
Date:   Thu,  1 Sep 2016 23:27:00 +0200
From:   Paul Kocialkowski <contact@...lk.fr>
To:     linux-kernel@...r.kernel.org
Cc:     Sebastian Reichel <sre@...nel.org>, linux-pm@...r.kernel.org,
        linux-tegra@...r.kernel.org,
        Dmitry Eremin-Solenikov <dbaryshkov@...il.com>,
        David Woodhouse <dwmw2@...radead.org>,
        Paul Kocialkowski <contact@...lk.fr>
Subject: [PATCH v3] power: bq24735-charger: Request status GPIO with initial input setup

This requests the status GPIO with initial input setup. it is required
to read the GPIO status at probe time and thus correctly avoid sending
i2c messages when AC is not plugged.

When requesting the GPIO without initial input setup, it always reads 0
which causes probe to fail as it assumes the charger is connected, sends
i2c messages and fails.

While at it, this switches the driver over to gpio consumer.

Signed-off-by: Paul Kocialkowski <contact@...lk.fr>
---
 drivers/power/bq24735-charger.c       | 42 +++++++++++++----------------------
 include/linux/power/bq24735-charger.h |  4 +---
 2 files changed, 17 insertions(+), 29 deletions(-)

diff --git a/drivers/power/bq24735-charger.c b/drivers/power/bq24735-charger.c
index dc460bb..7f9b305 100644
--- a/drivers/power/bq24735-charger.c
+++ b/drivers/power/bq24735-charger.c
@@ -25,7 +25,8 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
-#include <linux/of_gpio.h>
+#include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/power_supply.h>
 #include <linux/slab.h>
 
@@ -178,11 +179,9 @@ static int bq24735_config_charger(struct bq24735 *charger)
 static bool bq24735_charger_is_present(struct bq24735 *charger)
 {
 	struct bq24735_platform *pdata = charger->pdata;
-	int ret;
 
-	if (pdata->status_gpio_valid) {
-		ret = gpio_get_value_cansleep(pdata->status_gpio);
-		return ret ^= pdata->status_gpio_active_low == 0;
+	if (pdata->status_gpio) {
+		return !gpiod_get_value_cansleep(pdata->status_gpio);
 	} else {
 		int ac = 0;
 
@@ -308,7 +307,6 @@ static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
 	struct device_node *np = client->dev.of_node;
 	u32 val;
 	int ret;
-	enum of_gpio_flags flags;
 
 	pdata = devm_kzalloc(&client->dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata) {
@@ -317,11 +315,13 @@ static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client)
 		return NULL;
 	}
 
-	pdata->status_gpio = of_get_named_gpio_flags(np, "ti,ac-detect-gpios",
-						     0, &flags);
-
-	if (flags & OF_GPIO_ACTIVE_LOW)
-		pdata->status_gpio_active_low = 1;
+	pdata->status_gpio = devm_gpiod_get_optional(&client->dev,
+				"ti,ac-detect", GPIOD_IN);
+	if (IS_ERR(pdata->status_gpio)) {
+		ret = PTR_ERR(pdata->status_gpio);
+		dev_err(&client->dev, "Getting gpio failed: %d\n", ret);
+		return (struct bq24735_platform *) pdata->status_gpio;
+	}
 
 	ret = of_property_read_u32(np, "ti,charge-current", &val);
 	if (!ret)
@@ -357,8 +357,11 @@ static int bq24735_charger_probe(struct i2c_client *client,
 	charger->charging = true;
 	charger->pdata = client->dev.platform_data;
 
-	if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node)
+	if (IS_ENABLED(CONFIG_OF) && !charger->pdata && client->dev.of_node) {
 		charger->pdata = bq24735_parse_dt_data(client);
+		if (IS_ERR(charger->pdata))
+			return PTR_ERR(charger->pdata);
+	}
 
 	if (!charger->pdata) {
 		dev_err(&client->dev, "no platform data provided\n");
@@ -396,20 +399,7 @@ static int bq24735_charger_probe(struct i2c_client *client,
 
 	i2c_set_clientdata(client, charger);
 
-	if (gpio_is_valid(charger->pdata->status_gpio)) {
-		ret = devm_gpio_request(&client->dev,
-					charger->pdata->status_gpio,
-					name);
-		if (ret) {
-			dev_err(&client->dev,
-				"Failed GPIO request for GPIO %d: %d\n",
-				charger->pdata->status_gpio, ret);
-		}
-
-		charger->pdata->status_gpio_valid = !ret;
-	}
-
-	if (!charger->pdata->status_gpio_valid
+	if (!charger->pdata->status_gpio
 	    || bq24735_charger_is_present(charger)) {
 		ret = bq24735_read_word(client, BQ24735_MANUFACTURER_ID);
 		if (ret < 0) {
diff --git a/include/linux/power/bq24735-charger.h b/include/linux/power/bq24735-charger.h
index 6b750c1a..afdb3704 100644
--- a/include/linux/power/bq24735-charger.h
+++ b/include/linux/power/bq24735-charger.h
@@ -28,9 +28,7 @@ struct bq24735_platform {
 
 	const char *name;
 
-	int status_gpio;
-	int status_gpio_active_low;
-	bool status_gpio_valid;
+	struct gpio_desc *status_gpio;
 
 	bool ext_control;
 
-- 
2.9.3