mailbox: test: really ignore optional memory resources

Memory resources are optional but if the resource is empty
devm_platform_get_and_ioremap_resource() prints an error nonetheless.
Refactor the code to check the resources locally first and process them
only if they are present. The -EBUSY error message of ioremap_resource()
is still kept because it is correct. The comment which explains that a
plain ioremap() is tried as a workaround is turned into a info message.
So, a user will be informed about it, too.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Jassi Brar <jassisinghbrar@gmail.com>

diff --git a/drivers/mailbox/mailbox-test.c b/drivers/mailbox/mailbox-test.c
index 3a28ab5c42e575e803a7ee4050420d3b38ffd7e7..058c0fe4b9c2d65c73bb06c9ac6a71d761bd971a 100644 (file)
--- a/drivers/mailbox/mailbox-test.c
+++ b/drivers/mailbox/mailbox-test.c
@@ -355,11 +355,27 @@ mbox_test_request_channel(struct platform_device *pdev, const char *name)
        return channel;
 }
 
+static void __iomem *mbox_test_ioremap(struct platform_device *pdev, unsigned int res_num)
+{
+       struct resource *res;
+       void __iomem *mmio;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, res_num);
+       if (!res)
+               return NULL;
+
+       mmio = devm_ioremap_resource(&pdev->dev, res);
+       if (PTR_ERR(mmio) == -EBUSY) {
+               dev_info(&pdev->dev, "trying workaround with plain ioremap\n");
+               return devm_ioremap(&pdev->dev, res->start, resource_size(res));
+       }
+
+       return IS_ERR(mmio) ? NULL : mmio;
+}
+
 static int mbox_test_probe(struct platform_device *pdev)
 {
        struct mbox_test_device *tdev;
-       struct resource *res;
-       resource_size_t size;
        int ret;
 
        tdev = devm_kzalloc(&pdev->dev, sizeof(*tdev), GFP_KERNEL);
@@ -367,23 +383,12 @@ static int mbox_test_probe(struct platform_device *pdev)
                return -ENOMEM;
 
        /* It's okay for MMIO to be NULL */
-       tdev->tx_mmio = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
-       if (PTR_ERR(tdev->tx_mmio) == -EBUSY) {
-               /* if reserved area in SRAM, try just ioremap */
-               size = resource_size(res);
-               tdev->tx_mmio = devm_ioremap(&pdev->dev, res->start, size);
-       } else if (IS_ERR(tdev->tx_mmio)) {
-               tdev->tx_mmio = NULL;
-       }
+       tdev->tx_mmio = mbox_test_ioremap(pdev, 0);
 
        /* If specified, second reg entry is Rx MMIO */
-       tdev->rx_mmio = devm_platform_get_and_ioremap_resource(pdev, 1, &res);
-       if (PTR_ERR(tdev->rx_mmio) == -EBUSY) {
-               size = resource_size(res);
-               tdev->rx_mmio = devm_ioremap(&pdev->dev, res->start, size);
-       } else if (IS_ERR(tdev->rx_mmio)) {
+       tdev->rx_mmio = mbox_test_ioremap(pdev, 1);
+       if (!tdev->rx_mmio)
                tdev->rx_mmio = tdev->tx_mmio;
-       }
 
        tdev->tx_channel = mbox_test_request_channel(pdev, "tx");
        tdev->rx_channel = mbox_test_request_channel(pdev, "rx");