On 13 June 2015 at 22:24, Fabio Estevam <festevam@xxxxxxxxx> wrote:
> From: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
>
> Since commit 312449efd16bb06 ("mmc: core: Fix sequence for I/O voltage
> in DDR mode for eMMC") the mmc voltage is set to 1.8V inside
> mmc_select_hs_ddr(), even if 'no-1-8-v' property is present.
>
> This causes the following error on a mx6sl board with the 'no-1-8-v'
> property passed in the device tree:
>
> mmc0: power class selection to bus width 8 ddr 4 failed
> mmc0: error -110 whilst initialising MMC card
>
> Fix this problem by only setting the mmc voltage to 1.8V if the
> 'no-1-8-v' property is absent.
What card (eMMC, SD, MMC) and which host driver is being used here?
>
> Reported-by: Kevin Lemoi <kevin.lemoi@xxxxxxxxxx>
> Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
> ---
> Changes since v1:
> - Fix it in the core code instead of doing it inside the sdhci imx code
>
> drivers/mmc/core/host.c | 2 ++
> drivers/mmc/core/mmc.c | 8 +++++++-
> include/linux/mmc/host.h | 1 +
> include/linux/mmc/mmc.h | 1 +
> 4 files changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c
> index 01fa1ed..736c985 100644
> --- a/drivers/mmc/core/host.c
> +++ b/drivers/mmc/core/host.c
> @@ -527,6 +527,8 @@ int mmc_of_parse(struct mmc_host *host)
> host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
> if (of_find_property(np, "mmc-hs400-1_2v", &len))
> host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
> + if (of_find_property(np, "no-1-8-v", &len))
> + host->caps2 |= MMC_CAP_3_3V_ONLY_DDR;
Do you intend to use 3.3V as the I/O voltage level for an eMMCs
running in DDR mode? Isn't that violation of the eMMC spec?
>
> host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
> if (host->dsr_req && (host->dsr & ~0xffff)) {
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index e726903..e76b9af 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -205,6 +205,10 @@ static void mmc_select_card_type(struct mmc_card *card)
> avail_type |= EXT_CSD_CARD_TYPE_DDR_1_8V;
> }
>
> + if (caps2 & MMC_CAP_3_3V_ONLY_DDR &&
> + card_type & EXT_CSD_CARD_TYPE_DDR_1_8V)
> + avail_type |= EXT_CSD_CARD_TYPE_DDR_3_3V_ONLY;
> +
> if (caps & MMC_CAP_1_2V_DDR &&
> card_type & EXT_CSD_CARD_TYPE_DDR_1_2V) {
> hs_max_dtr = MMC_HIGH_DDR_MAX_DTR;
> @@ -1028,7 +1032,9 @@ static int mmc_select_hs_ddr(struct mmc_card *card)
> err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120);
>
> if (err && (card->mmc_avail_type & EXT_CSD_CARD_TYPE_DDR_1_8V))
> - err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
> + if (!(card->mmc_avail_type & EXT_CSD_CARD_TYPE_DDR_3_3V_ONLY))
> + err = __mmc_set_signal_voltage(host,
> + MMC_SIGNAL_VOLTAGE_180);
>
> /* make sure vccq is 3.3v after switching disaster */
> if (err)
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index 1369e54..5aa999f 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -289,6 +289,7 @@ struct mmc_host {
> #define MMC_CAP2_HSX00_1_2V (MMC_CAP2_HS200_1_2V_SDR | MMC_CAP2_HS400_1_2V)
> #define MMC_CAP2_SDIO_IRQ_NOTHREAD (1 << 17)
> #define MMC_CAP2_NO_WRITE_PROTECT (1 << 18) /* No physical write protect pin, assume that card is always read-write */
> +#define MMC_CAP_3_3V_ONLY_DDR (1 << 19) /* Only supports 3.3V DDR */
>
> mmc_pm_flag_t pm_caps; /* supported pm features */
>
> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> index 15f2c4a..b3cbd3c 100644
> --- a/include/linux/mmc/mmc.h
> +++ b/include/linux/mmc/mmc.h
> @@ -380,6 +380,7 @@ struct _mmc_csd {
> #define EXT_CSD_CARD_TYPE_HS400_1_2V (1<<7) /* Card can run at 200MHz DDR, 1.2V */
> #define EXT_CSD_CARD_TYPE_HS400 (EXT_CSD_CARD_TYPE_HS400_1_8V | \
> EXT_CSD_CARD_TYPE_HS400_1_2V)
> +#define EXT_CSD_CARD_TYPE_DDR_3_3V_ONLY (1<<8)
>
> #define EXT_CSD_BUS_WIDTH_1 0 /* Card is in 1 bit mode */
> #define EXT_CSD_BUS_WIDTH_4 1 /* Card is in 4 bit mode */
> --
> 1.9.1
>
Kind regards
Uffe
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