On 28 September 2015 at 05:23, Barry Song <21cnbao@xxxxxxxxx> wrote:
> From: Weijun Yang <york.yang@xxxxxxx>
>
> As SD Specifications Part1 Physical Layer Specification Version
> 3.01 says, CMD19 tuning is available for unlocked cards in transfer
> state of 1.8V signaling mode. The small difference between v3.00
> and 3.01 spec means that CMD19 tuning is also available for DDR50
> mode.
>
> Signed-off-by: Weijun Yang <york.yang@xxxxxxx>
> Signed-off-by: Barry Song <Baohua.Song@xxxxxxx>
> ---
> drivers/mmc/core/sd.c | 19 +++++++++++++++++--
> drivers/mmc/host/sdhci.c | 1 +
Sorry for not pointing out this is the first round, but I would rather
split @subject patch into two parts.
One for core and one for sdhci, as it then becomes obvious that sdhci
will start using the option to do tuning for DDR50 mode.
> 2 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index 4e7366a..eaf8cb3 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -628,9 +628,24 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card)
> * SDR104 mode SD-cards. Note that tuning is mandatory for SDR104.
> */
> if (!mmc_host_is_spi(card->host) &&
> - (card->sd_bus_speed == UHS_SDR50_BUS_SPEED ||
> - card->sd_bus_speed == UHS_SDR104_BUS_SPEED))
> + (card->sd_bus_speed == UHS_SDR50_BUS_SPEED ||
> + card->sd_bus_speed == UHS_DDR50_BUS_SPEED ||
> + card->sd_bus_speed == UHS_SDR104_BUS_SPEED)) {
> err = mmc_execute_tuning(card);
> +
> + /*
> + * As SD Specifications Part1 Physical Layer Specification Version
> + * 3.01 says, CMD19 tuning is available for unlocked cards in transfer
> + * state of 1.8V signaling mode. The small difference between v3.00
> + * and 3.01 spec means that CMD19 tuning is also available for DDR50
> + * mode.
> + */
> + if (err && (card->sd_bus_speed == UHS_DDR50_BUS_SPEED)) {
> + pr_warn("%s: ddr50 tuning failed\n", mmc_hostname(card->host));
> + err = 0;
> + }
> + }
> +
> out:
> kfree(status);
>
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 64b7fdb..382810d 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -1915,6 +1915,7 @@ static int sdhci_execute_tuning(struct mmc_host *mmc, u32 opcode)
> break;
>
> case MMC_TIMING_UHS_SDR104:
> + case MMC_TIMING_UHS_DDR50:
> break;
>
> case MMC_TIMING_UHS_SDR50:
> --
> 1.9.1
>
Kind regards
Uffe
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