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path: root/drivers/mmc/host/dw_mmc.c
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Diffstat (limited to 'drivers/mmc/host/dw_mmc.c')
-rw-r--r--drivers/mmc/host/dw_mmc.c17
1 files changed, 14 insertions, 3 deletions
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 1ca5e72ceb6..72dc3cde646 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -405,11 +405,23 @@ static void dw_mci_idmac_start_dma(struct dw_mci *host, unsigned int sg_len)
static int dw_mci_idmac_init(struct dw_mci *host)
{
struct idmac_desc *p;
- int i;
+ int i, dma_support;
/* Number of descriptors in the ring buffer */
host->ring_size = PAGE_SIZE / sizeof(struct idmac_desc);
+ /* Check if Hardware Configuration Register has support for DMA */
+ dma_support = (mci_readl(host, HCON) >> 16) & 0x3;
+
+ if (!dma_support || dma_support > 2) {
+ dev_err(&host->dev,
+ "Host Controller does not support IDMA Tx.\n");
+ host->dma_ops = NULL;
+ return -ENODEV;
+ }
+
+ dev_info(&host->dev, "Using internal DMA controller.\n");
+
/* Forward link the descriptor list */
for (i = 0, p = host->sg_cpu; i < host->ring_size - 1; i++, p++)
p->des3 = host->sg_dma + (sizeof(struct idmac_desc) * (i + 1));
@@ -1876,7 +1888,6 @@ static void dw_mci_init_dma(struct dw_mci *host)
/* Determine which DMA interface to use */
#ifdef CONFIG_MMC_DW_IDMAC
host->dma_ops = &dw_mci_idmac_ops;
- dev_info(&host->dev, "Using internal DMA controller.\n");
#endif
if (!host->dma_ops)
@@ -2175,7 +2186,7 @@ int dw_mci_resume(struct dw_mci *host)
return ret;
}
- if (host->dma_ops->init)
+ if (host->use_dma && host->dma_ops->init)
host->dma_ops->init(host);
/* Restore the old value at FIFOTH register */