bfin_can: introduce ioremap to comply to archs with MMU

Blackfin was built without MMU, old driver code access the IO space by
physical address, introduce the ioremap approach to be compitable with
the common style supporting MMU enabled arch.
Signed-off-by: Aaron Wu <Aaron.wu@analog.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/bfin_can.c

@@ -552,16 +552,10 @@ static int bfin_can_probe(struct platform_device *pdev)
 		goto exit;
 	}
 
-	if (!request_mem_region(res_mem->start, resource_size(res_mem),
-				dev_name(&pdev->dev))) {
-		err = -EBUSY;
-		goto exit;
-	}
-
 	/* request peripheral pins */
 	err = peripheral_request_list(pdata, dev_name(&pdev->dev));
 	if (err)
-		goto exit_mem_release;
+		goto exit;
 
 	dev = alloc_bfin_candev();
 	if (!dev) {
@@ -570,7 +564,13 @@ static int bfin_can_probe(struct platform_device *pdev)
 	}
 
 	priv = netdev_priv(dev);
-	priv->membase = (void __iomem *)res_mem->start;
+
+	priv->membase = devm_ioremap_resource(&pdev->dev, res_mem);
+	if (IS_ERR(priv->membase)) {
+		err = PTR_ERR(priv->membase);
+		goto exit_peri_pin_free;
+	}
+
 	priv->rx_irq = rx_irq->start;
 	priv->tx_irq = tx_irq->start;
 	priv->err_irq = err_irq->start;
@@ -602,8 +602,6 @@ static int bfin_can_probe(struct platform_device *pdev)
 	free_candev(dev);
 exit_peri_pin_free:
 	peripheral_free_list(pdata);
-exit_mem_release:
-	release_mem_region(res_mem->start, resource_size(res_mem));
 exit:
 	return err;
 }
@@ -612,15 +610,11 @@ static int bfin_can_remove(struct platform_device *pdev)
 {
 	struct net_device *dev = platform_get_drvdata(pdev);
 	struct bfin_can_priv *priv = netdev_priv(dev);
-	struct resource *res;
 
 	bfin_can_set_reset_mode(dev);
 
 	unregister_candev(dev);
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	release_mem_region(res->start, resource_size(res));
-
 	peripheral_free_list(priv->pin_list);
 
 	free_candev(dev);