Hi,
On 04/12/18 12:54 PM, Chunyan Zhang wrote:
> Some standard SD host controllers can support both external dma
> controllers as well as ADMA/SDMA in which the SD host controller
> acts as DMA master. TI's omap controller is the case as an example.
>
> Currently the generic SDHCI code supports ADMA/SDMA integrated in
> the host controller but does not have any support for external DMA
> controllers implemented using dmaengine, meaning that custom code is
> needed for any systems that use an external DMA controller with SDHCI.
>
...
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index b001cf4..8e50a97 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -475,6 +475,7 @@ struct sdhci_host {
>
> int irq; /* Device IRQ */
> void __iomem *ioaddr; /* Mapped address */
> + phys_addr_t mapbase; /* physical address base */
> char *bounce_buffer; /* For packing SDMA reads/writes */
> dma_addr_t bounce_addr;
> unsigned int bounce_buffer_size;
> @@ -524,6 +525,7 @@ struct sdhci_host {
> bool pending_reset; /* Cmd/data reset is pending */
> bool irq_wake_enabled; /* IRQ wakeup is enabled */
> bool v4_mode; /* Host Version 4 Enable */
> + bool use_external_dma;
>
> struct mmc_request *mrqs_done[SDHCI_MAX_MRQS]; /* Requests done */
> struct mmc_command *cmd; /* Current command */
> @@ -552,6 +554,11 @@ struct sdhci_host {
> struct timer_list timer; /* Timer for timeouts */
> struct timer_list data_timer; /* Timer for data timeouts */
>
> +#if IS_ENABLED(CONFIG_MMC_SDHCI_EXTERNAL_DMA)
> + struct dma_chan *rx_chan;
> + struct dma_chan *tx_chan;
> +#endif
> +
> u32 caps; /* CAPABILITY_0 */
> u32 caps1; /* CAPABILITY_1 */
> bool read_caps; /* Capability flags have been read */
> @@ -785,5 +792,6 @@ void sdhci_start_tuning(struct sdhci_host *host);
> void sdhci_end_tuning(struct sdhci_host *host);
> void sdhci_reset_tuning(struct sdhci_host *host);
> void sdhci_send_tuning(struct sdhci_host *host, u32 opcode);
> +void sdhci_switch_external_dma(struct sdhci_host *host, bool en);
>
Can you also add a new attribute in sdhci_host->flags for external dma
in this file? The log still shows
[ 3.675028] mmc2: SDHCI controller on 4809c000.mmc [4809c000.mmc]
using ADMA
when using external dma.
Thanks,
Faiz
