bq27x00_battery: Introduce the use of the managed version of kzalloc

This patch moves data allocated using kzalloc to managed data allocated
using devm_kzalloc and cleans now unnecessary kfrees in probe and remove
functions for both platform and i2c drivers. Also, the unecessary
variable ret and labels batt_failed3, err_free were removed.

The following Coccinele script was used for making the change:

@platform@
identifier p, probefn, removefn;
@@
struct platform_driver p = {
  .probe = probefn,
  .remove = removefn,
};

@prb@
identifier platform.probefn, pdev;
expression e, e1, e2;
@@
probefn(struct platform_device *pdev, ...) {
  <+...
- e = kzalloc(e1, e2)
+ e = devm_kzalloc(&pdev->dev, e1, e2)
  ...
?-kfree(e);
  ...+>
}

@rem depends on prb@
identifier platform.removefn;
expression e;
@@
removefn(...) {
  <...
- kfree(e);
  ...>
}

Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Sebastian Reichel <sre@kernel.org>

drivers/power/bq27x00_battery.c

@@ -25,6 +25,7 @@
  * http://www.ti.com/product/bq27425-g1
  */
 
+#include <linux/device.h>
 #include <linux/module.h>
 #include <linux/param.h>
 #include <linux/jiffies.h>
@@ -804,7 +805,7 @@ static int bq27x00_battery_probe(struct i2c_client *client,
 		goto batt_failed_1;
 	}
 
-	di = kzalloc(sizeof(*di), GFP_KERNEL);
+	di = devm_kzalloc(&client->dev, sizeof(*di), GFP_KERNEL);
 	if (!di) {
 		dev_err(&client->dev, "failed to allocate device info data\n");
 		retval = -ENOMEM;
@@ -819,14 +820,12 @@ static int bq27x00_battery_probe(struct i2c_client *client,
 
 	retval = bq27x00_powersupply_init(di);
 	if (retval)
-		goto batt_failed_3;
+		goto batt_failed_2;
 
 	i2c_set_clientdata(client, di);
 
 	return 0;
 
-batt_failed_3:
-	kfree(di);
 batt_failed_2:
 	kfree(name);
 batt_failed_1:
@@ -849,8 +848,6 @@ static int bq27x00_battery_remove(struct i2c_client *client)
 	idr_remove(&battery_id, di->id);
 	mutex_unlock(&battery_mutex);
 
-	kfree(di);
-
 	return 0;
 }
 
@@ -933,7 +930,6 @@ static int bq27000_battery_probe(struct platform_device *pdev)
 {
 	struct bq27x00_device_info *di;
 	struct bq27000_platform_data *pdata = pdev->dev.platform_data;
-	int ret;
 
 	if (!pdata) {
 		dev_err(&pdev->dev, "no platform_data supplied\n");
@@ -945,7 +941,7 @@ static int bq27000_battery_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	di = kzalloc(sizeof(*di), GFP_KERNEL);
+	di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
 	if (!di) {
 		dev_err(&pdev->dev, "failed to allocate device info data\n");
 		return -ENOMEM;
@@ -959,16 +955,7 @@ static int bq27000_battery_probe(struct platform_device *pdev)
 	di->bat.name = pdata->name ?: dev_name(&pdev->dev);
 	di->bus.read = &bq27000_read_platform;
 
-	ret = bq27x00_powersupply_init(di);
-	if (ret)
-		goto err_free;
-
-	return 0;
-
-err_free:
-	kfree(di);
-
-	return ret;
+	return bq27x00_powersupply_init(di);
 }
 
 static int bq27000_battery_remove(struct platform_device *pdev)
@@ -977,8 +964,6 @@ static int bq27000_battery_remove(struct platform_device *pdev)
 
 	bq27x00_powersupply_unregister(di);
 
-	kfree(di);
-
 	return 0;
 }