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path: root/drivers/dma/altera-msgdma.c
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Diffstat (limited to 'drivers/dma/altera-msgdma.c')
-rw-r--r--drivers/dma/altera-msgdma.c37
1 files changed, 26 insertions, 11 deletions
diff --git a/drivers/dma/altera-msgdma.c b/drivers/dma/altera-msgdma.c
index 0fe0676f8e1d..5a2c7573b692 100644
--- a/drivers/dma/altera-msgdma.c
+++ b/drivers/dma/altera-msgdma.c
@@ -691,10 +691,14 @@ static void msgdma_tasklet(struct tasklet_struct *t)
spin_lock_irqsave(&mdev->lock, flags);
- /* Read number of responses that are available */
- count = ioread32(mdev->csr + MSGDMA_CSR_RESP_FILL_LEVEL);
- dev_dbg(mdev->dev, "%s (%d): response count=%d\n",
- __func__, __LINE__, count);
+ if (mdev->resp) {
+ /* Read number of responses that are available */
+ count = ioread32(mdev->csr + MSGDMA_CSR_RESP_FILL_LEVEL);
+ dev_dbg(mdev->dev, "%s (%d): response count=%d\n",
+ __func__, __LINE__, count);
+ } else {
+ count = 1;
+ }
while (count--) {
/*
@@ -703,8 +707,12 @@ static void msgdma_tasklet(struct tasklet_struct *t)
* have any real values, like transferred bytes or error
* bits. So we need to just drop these values.
*/
- size = ioread32(mdev->resp + MSGDMA_RESP_BYTES_TRANSFERRED);
- status = ioread32(mdev->resp + MSGDMA_RESP_STATUS);
+ if (mdev->resp) {
+ size = ioread32(mdev->resp +
+ MSGDMA_RESP_BYTES_TRANSFERRED);
+ status = ioread32(mdev->resp +
+ MSGDMA_RESP_STATUS);
+ }
msgdma_complete_descriptor(mdev);
msgdma_chan_desc_cleanup(mdev);
@@ -757,14 +765,21 @@ static void msgdma_dev_remove(struct msgdma_device *mdev)
}
static int request_and_map(struct platform_device *pdev, const char *name,
- struct resource **res, void __iomem **ptr)
+ struct resource **res, void __iomem **ptr,
+ bool optional)
{
struct resource *region;
struct device *device = &pdev->dev;
*res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
if (*res == NULL) {
- dev_err(device, "resource %s not defined\n", name);
+ if (optional) {
+ *ptr = NULL;
+ dev_info(device, "optional resource %s not defined\n",
+ name);
+ return 0;
+ }
+ dev_err(device, "mandatory resource %s not defined\n", name);
return -ENODEV;
}
@@ -805,17 +820,17 @@ static int msgdma_probe(struct platform_device *pdev)
mdev->dev = &pdev->dev;
/* Map CSR space */
- ret = request_and_map(pdev, "csr", &dma_res, &mdev->csr);
+ ret = request_and_map(pdev, "csr", &dma_res, &mdev->csr, false);
if (ret)
return ret;
/* Map (extended) descriptor space */
- ret = request_and_map(pdev, "desc", &dma_res, &mdev->desc);
+ ret = request_and_map(pdev, "desc", &dma_res, &mdev->desc, false);
if (ret)
return ret;
/* Map response space */
- ret = request_and_map(pdev, "resp", &dma_res, &mdev->resp);
+ ret = request_and_map(pdev, "resp", &dma_res, &mdev->resp, true);
if (ret)
return ret;