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>
diff --git a/drivers/net/can/bfin_can.c b/drivers/net/can/bfin_can.c
index 9cbf615..8039703 100644
--- a/drivers/net/can/bfin_can.c
+++ b/drivers/net/can/bfin_can.c
@@ -552,16 +552,10 @@
 		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 @@
 	}
 
 	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 @@
 	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 @@
 {
 	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);