diff options
Diffstat (limited to 'drivers/mmc/host/dw_mmc.c')
| -rw-r--r-- | drivers/mmc/host/dw_mmc.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index 1ca5e72ceb6..5a600b3b319 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) |