On 05/12/16 04:10, Masahiro Yamada wrote:
> Some SDHCI-compat controllers support not only SD, but also eMMC,
> but they use different commands for tuning: CMD19 for SD, CMD21 for
> eMMC.
>
> Due to the difference of the underlying mechanism, some controllers
> (at least, the Cadence IP is the case) provide their own registers
> for the eMMC tuning.
>
> This commit will be useful when we want to override .execute_tuning
> callback (for eMMC HS200 tuning), but still let it fall back to
> sdhci_execute_tuning() for SD timing.
>
> Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
>
> I want to use this in the next commit.
> The Cadence IP supports eMMC as well as SD.
>
> I want to re-use the sdhci_execute_tuning() for SD timing.
>
> On the other hand, Cadence provides its own way for eMMC HS200 tuning;
> I need to touch some registers that are specific to Cadence's design.
>
>
> Changes in v4:
> - export sdhci_execute_tuning() instead of using
> execute_execute_tuning()
>
> Changes in v3: None
> Changes in v2: None
>
> drivers/mmc/host/sdhci.c | 3 ++-
> drivers/mmc/host/sdhci.h | 1 +
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 42ef3eb..0c03a89 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1948,7 +1948,7 @@ static int sdhci_prepare_hs400_tuning(struct mmc_host *mmc, struct mmc_ios *ios)
> return 0;
> }
>
> -static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> +int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> {
> struct sdhci_host *host = mmc_priv(mmc);
> u16 ctrl;
> @@ -2141,6 +2141,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> spin_unlock_irqrestore(&host->lock, flags);
> return err;
> }
> +EXPORT_SYMBOL_GPL(sdhci_execute_tuning);
>
> static int sdhci_select_drive_strength(struct mmc_card *card,
> unsigned int max_dtr, int host_drv,
> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 9c35776..786eee9 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -689,6 +689,7 @@ void sdhci_set_power_noreg(struct sdhci_host *host, unsigned char mode,
> void sdhci_set_bus_width(struct sdhci_host *host, int width);
> void sdhci_reset(struct sdhci_host *host, u8 mask);
> void sdhci_set_uhs_signaling(struct sdhci_host *host, unsigned timing);
> +int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode);
>
> #ifdef CONFIG_PM
> extern int sdhci_suspend_host(struct sdhci_host *host);
>
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