On 22/01/19 9:56 PM, Sowjanya Komatineni wrote:
> Below are the supported DMA types in Host Control1 Register
> with Version 4 enable
> b'00 - SDMA
> b'01 - Not Used
> b'10 - ADMA2
> b'11 - ADMA2 or ADMA3
> 
> ADMA3 uses Command Descriptor to issue an SD command.
> A multi-block data transfer is performed by using a pair of CMD
> descriptor and ADMA2 descriptor.
> 
> ADMA3 performs multiple of multi-block data transfer by using
> Integrated Descriptor which is more suitable for Command Queuing
> to fetch both Command and Transfer descriptors.
> 
> Host Capabilities register indiactes the supports of ADMA3 DMA.

indiactes -> indicates

> 
> Signed-off-by: Sowjanya Komatineni <skomatin...@nvidia.com>

Acked-by: Adrian Hunter <adrian.hun...@intel.com>

> ---
>  [V10]: Changes are same as V9 except this series has SDHCI core changes
>       into seperate patch 
> 
>  drivers/mmc/host/sdhci.c | 9 ++++++++-
>  drivers/mmc/host/sdhci.h | 2 ++
>  2 files changed, 10 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index a22e11a65658..c6afe793399e 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -3353,7 +3353,14 @@ void sdhci_cqe_enable(struct mmc_host *mmc)
>  
>       ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
>       ctrl &= ~SDHCI_CTRL_DMA_MASK;
> -     if (host->flags & SDHCI_USE_64_BIT_DMA)
> +     /*
> +      * Host from V4.10 supports ADMA3 DMA type.
> +      * ADMA3 performs integrated descriptor which is more suitable
> +      * for cmd queuing to fetch both command and transfer descriptors.
> +      */
> +     if (host->v4_mode && (host->caps1 & SDHCI_CAN_DO_ADMA3))
> +             ctrl |= SDHCI_CTRL_ADMA3;
> +     else if (host->flags & SDHCI_USE_64_BIT_DMA)
>               ctrl |= SDHCI_CTRL_ADMA64;
>       else
>               ctrl |= SDHCI_CTRL_ADMA32;
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 6cc9a3c2ac66..4070be49d947 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -88,6 +88,7 @@
>  #define   SDHCI_CTRL_ADMA1   0x08
>  #define   SDHCI_CTRL_ADMA32  0x10
>  #define   SDHCI_CTRL_ADMA64  0x18
> +#define   SDHCI_CTRL_ADMA3   0x18
>  #define   SDHCI_CTRL_8BITBUS 0x20
>  #define  SDHCI_CTRL_CDTEST_INS       0x40
>  #define  SDHCI_CTRL_CDTEST_EN        0x80
> @@ -230,6 +231,7 @@
>  #define  SDHCI_RETUNING_MODE_SHIFT           14
>  #define  SDHCI_CLOCK_MUL_MASK        0x00FF0000
>  #define  SDHCI_CLOCK_MUL_SHIFT       16
> +#define  SDHCI_CAN_DO_ADMA3  0x08000000
>  #define  SDHCI_SUPPORT_HS400 0x80000000 /* Non-standard */
>  
>  #define SDHCI_CAPABILITIES_1 0x44
> 

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