On 15/06/18 05:04, Chunyan Zhang wrote:
> For SD host controller version 4.00 or later ones, there're two
> modes of implementation - Version 3.00 compatible mode or
> Version 4 mode. This patch introduces a flag to record this.
>
> Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
> ---
> drivers/mmc/host/sdhci.c | 6 ++++++
> drivers/mmc/host/sdhci.h | 6 ++++++
> 2 files changed, 12 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 2ededa7f..cf5695f 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -3302,6 +3302,12 @@ void __sdhci_read_caps(struct sdhci_host *host, u16 *ver, u32 *caps, u32 *caps1)
> v = ver ? *ver : sdhci_readw(host, SDHCI_HOST_VERSION);
> host->version = (v & SDHCI_SPEC_VER_MASK) >> SDHCI_SPEC_VER_SHIFT;
>
> + if (host->version >= SDHCI_SPEC_400) {
> + if (sdhci_readw(host, SDHCI_HOST_CONTROL2) &
> + SDHCI_CTRL_V4_MODE)
> + host->v4_mode = true;
> + }
At this point the host controller has just been reset which would mean it
must be in version 3 compatibility mode, which would mean this code doesn't
do anything.
> +
> if (host->quirks & SDHCI_QUIRK_MISSING_CAPS)
> return;
>
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index c95b0a4..128b0ba 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -184,6 +184,7 @@
> #define SDHCI_CTRL_DRV_TYPE_D 0x0030
> #define SDHCI_CTRL_EXEC_TUNING 0x0040
> #define SDHCI_CTRL_TUNED_CLK 0x0080
> +#define SDHCI_CTRL_V4_MODE 0x1000
> #define SDHCI_CTRL_PRESET_VAL_ENABLE 0x8000
>
> #define SDHCI_CAPABILITIES 0x40
> @@ -270,6 +271,8 @@
> #define SDHCI_SPEC_100 0
> #define SDHCI_SPEC_200 1
> #define SDHCI_SPEC_300 2
> +#define SDHCI_SPEC_400 3
> +#define SDHCI_SPEC_410 4
>
> /*
> * End of controller registers.
> @@ -551,6 +554,9 @@ struct sdhci_host {
> u32 sdma_boundary;
>
> unsigned long private[0] ____cacheline_aligned;
> +
> + /* Host Version 4 Enable */
> + bool v4_mode;
> };
>
> struct sdhci_ops {
>
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