Re: [PATCH V11 3/4] mmc: sdhci: Add ADMA3 DMA support for V4 enabled host
From: Ulf Hansson
Date: Thu Jan 31 2019 - 02:28:44 EST
On Wed, 23 Jan 2019 at 20:31, Sowjanya Komatineni
<skomatineni@xxxxxxxxxx> 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 indicates the supports of ADMA3 DMA.
>
> Signed-off-by: Sowjanya Komatineni <skomatineni@xxxxxxxxxx>
> Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> Reviewed-by: Thierry Reding <treding@xxxxxxxxxx>
Applied for next, thanks!
Kind regards
Uffe
> ---
> [V11]: Fixed typo in commit message of this patch.
> [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
> --
> 2.7.4
>