PM / AVS: SmartReflex: use devm_* API to initialize SmartReflex

Use of of devm_* API for resource allocation provides benefits such
as auto handling of resource free. This reduces possibility have
memory leaks in case of wrong error handling. All direct release
calls should be removed to avoid races.

Reported-by: Grygorii Strashko <[e-mail]>
Signed-off-by: Andrii Tseglytskyi <[e-mail]>
Signed-off-by: Kevin Hilman <[e-mail]>

drivers/power/avs/smartreflex.c

···
 #include <linux/power/smartreflex.h>
 
 #define DRIVER_NAME	"smartreflex"
-#define SMARTREFLEX_NAME_LEN	16
+#define SMARTREFLEX_NAME_LEN	32
 #define NVALUE_NAME_LEN		40
 #define SR_DISABLE_TIMEOUT	200
 
···
 static int sr_late_init(struct omap_sr *sr_info)
 {
 	struct omap_sr_data *pdata = sr_info->pdev->dev.platform_data;
-	struct resource *mem;
 	int ret = 0;
 
 	if (sr_class->notify && sr_class->notify_flags && sr_info->irq) {
-		ret = request_irq(sr_info->irq, sr_interrupt,
-				  0, sr_info->name, sr_info);
+		ret = devm_request_irq(&sr_info->pdev->dev, sr_info->irq,
+				       sr_interrupt, 0, sr_info->name, sr_info);
 		if (ret)
 			goto error;
 		disable_irq(sr_info->irq);
···
 	return ret;
 
 error:
-	iounmap(sr_info->base);
-	mem = platform_get_resource(sr_info->pdev, IORESOURCE_MEM, 0);
-	release_mem_region(mem->start, resource_size(mem));
 	list_del(&sr_info->node);
 	dev_err(&sr_info->pdev->dev, "%s: ERROR in registering"
 		"interrupt handler. Smartreflex will"
 		"not function as desired\n", __func__);
-	kfree(sr_info);
 
 	return ret;
 }
···
 	struct dentry *nvalue_dir;
 	int i, ret = 0;
 
-	sr_info = kzalloc(sizeof(struct omap_sr), GFP_KERNEL);
+	sr_info = devm_kzalloc(&pdev->dev, sizeof(struct omap_sr), GFP_KERNEL);
 	if (!sr_info) {
 		dev_err(&pdev->dev, "%s: unable to allocate sr_info\n",
+			__func__);
+		return -ENOMEM;
+	}
+
+	sr_info->name = devm_kzalloc(&pdev->dev,
+				     SMARTREFLEX_NAME_LEN, GFP_KERNEL);
+	if (!sr_info->name) {
+		dev_err(&pdev->dev, "%s: unable to allocate SR instance name\n",
 			__func__);
 		return -ENOMEM;
 	}
···
 
 	if (!pdata) {
 		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
-		ret = -EINVAL;
-		goto err_free_devinfo;
+		return -EINVAL;
 	}
 
 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!mem) {
-		dev_err(&pdev->dev, "%s: no mem resource\n", __func__);
-		ret = -ENODEV;
-		goto err_free_devinfo;
-	}
-
-	mem = request_mem_region(mem->start, resource_size(mem),
-					dev_name(&pdev->dev));
-	if (!mem) {
-		dev_err(&pdev->dev, "%s: no mem region\n", __func__);
-		ret = -EBUSY;
-		goto err_free_devinfo;
+	sr_info->base = devm_ioremap_resource(&pdev->dev, mem);
+	if (IS_ERR(sr_info->base)) {
+		dev_err(&pdev->dev, "%s: ioremap fail\n", __func__);
+		return PTR_ERR(sr_info->base);
 	}
 
 	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
···
 	pm_runtime_enable(&pdev->dev);
 	pm_runtime_irq_safe(&pdev->dev);
 
-	sr_info->name = kasprintf(GFP_KERNEL, "%s", pdata->name);
-	if (!sr_info->name) {
-		dev_err(&pdev->dev, "%s: Unable to alloc SR instance name\n",
-			__func__);
-		ret = -ENOMEM;
-		goto err_release_region;
-	}
+	snprintf(sr_info->name, SMARTREFLEX_NAME_LEN, "%s", pdata->name);
 
 	sr_info->pdev = pdev;
 	sr_info->srid = pdev->id;
···
 	sr_info->autocomp_active = false;
 	sr_info->ip_type = pdata->ip_type;
 
-	sr_info->base = ioremap(mem->start, resource_size(mem));
-	if (!sr_info->base) {
-		dev_err(&pdev->dev, "%s: ioremap fail\n", __func__);
-		ret = -ENOMEM;
-		goto err_free_name;
-	}
-
 	if (irq)
 		sr_info->irq = irq->start;
 
···
 		ret = sr_late_init(sr_info);
 		if (ret) {
 			pr_warning("%s: Error in SR late init\n", __func__);
-			goto err_iounmap;
+			goto err_list_del;
 		}
 	}
 
···
 			ret = PTR_ERR(sr_dbg_dir);
 			pr_err("%s:sr debugfs dir creation failed(%d)\n",
 				__func__, ret);
-			goto err_iounmap;
+			goto err_list_del;
 		}
 	}
 
···
 
 err_debugfs:
 	debugfs_remove_recursive(sr_info->dbg_dir);
-err_iounmap:
+err_list_del:
 	list_del(&sr_info->node);
-	iounmap(sr_info->base);
-err_free_name:
-	kfree(sr_info->name);
-err_release_region:
-	release_mem_region(mem->start, resource_size(mem));
-err_free_devinfo:
-	kfree(sr_info);
-
 	return ret;
 }
 
···
 {
 	struct omap_sr_data *pdata = pdev->dev.platform_data;
 	struct omap_sr *sr_info;
-	struct resource *mem;
 
 	if (!pdata) {
 		dev_err(&pdev->dev, "%s: platform data missing\n", __func__);
···
 
 	pm_runtime_disable(&pdev->dev);
 	list_del(&sr_info->node);
-	iounmap(sr_info->base);
-	kfree(sr_info->name);
-	kfree(sr_info);
-	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	release_mem_region(mem->start, resource_size(mem));
-
 	return 0;
 }