On 23/12/22 04:50, haibo.chen@xxxxxxx wrote:
> From: Haibo Chen <haibo.chen@xxxxxxx>
>
> USDHC IP has one limitation: the tuning circuit can't handle the async
> sdio device interrupt correctly. When sdio device use 4 data lines,
> async sdio interrupt will use the shared DAT[1], if enable auto tuning
> circuit to check these 4 data lines, include the DAT[1], this circuit
> will detect this interrupt, take this as data on DAT[1], and adjust the
> delay cell wrongly, finally will cause the DATA/CMD CRC error.
> So for SDIO device, only enable DAT[0] and CMD line for auto tuning.
> To distinguish the card type during card init, involve init_card().
>
> Signed-off-by: Haibo Chen <haibo.chen@xxxxxxx>
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/mmc/host/sdhci-esdhc-imx.c | 41 ++++++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
> index bf8d6f60a9ee..8f5ee5964396 100644
> --- a/drivers/mmc/host/sdhci-esdhc-imx.c
> +++ b/drivers/mmc/host/sdhci-esdhc-imx.c
> @@ -337,6 +337,16 @@ struct pltfm_imx_data {
> struct clk *clk_ahb;
> struct clk *clk_per;
> unsigned int actual_clock;
> +
> + /*
> + * USDHC has one limition, require the SDIO device a different
> + * register setting. Driver has to recognize card type during
> + * the card init, but at this stage, mmc_host->card is not
> + * available. So involve this field to save the card type
> + * during card init through usdhc_init_card().
> + */
> + unsigned int init_card_type;
> +
> enum {
> NO_CMD_PENDING, /* no multiblock command pending */
> MULTIBLK_IN_PROCESS, /* exact multiblock cmd in process */
> @@ -431,6 +441,8 @@ static inline void esdhc_wait_for_card_clock_gate_off(struct sdhci_host *host)
> /* Enable the auto tuning circuit to check the CMD line and BUS line */
> static inline void usdhc_auto_tuning_mode_sel_and_en(struct sdhci_host *host)
> {
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
> u32 buswidth, auto_tune_buswidth;
> u32 reg;
>
> @@ -448,6 +460,20 @@ static inline void usdhc_auto_tuning_mode_sel_and_en(struct sdhci_host *host)
> break;
> }
>
> + /*
> + * For USDHC, auto tuning circuit can not handle the async sdio
> + * device interrupt correctly. When sdio device use 4 data lines,
> + * async sdio interrupt will use the shared DAT[1], if enable auto
> + * tuning circuit check these 4 data lines, include the DAT[1],
> + * this circuit will detect this interrupt, take this as a data on
> + * DAT[1], and adjust the delay cell wrongly.
> + * This is the hardware design limitation, to avoid this, for sdio
> + * device, config the auto tuning circuit only check DAT[0] and CMD
> + * line.
> + */
> + if (imx_data->init_card_type == MMC_TYPE_SDIO)
> + auto_tune_buswidth = ESDHC_VEND_SPEC2_AUTO_TUNE_1BIT_EN;
> +
> esdhc_clrset_le(host, ESDHC_VEND_SPEC2_AUTO_TUNE_MODE_MASK,
> auto_tune_buswidth | ESDHC_VEND_SPEC2_AUTO_TUNE_CMD_EN,
> ESDHC_VEND_SPEC2);
> @@ -1055,6 +1081,15 @@ static void esdhc_reset_tuning(struct sdhci_host *host)
> }
> }
>
> +static void usdhc_init_card(struct mmc_host *mmc, struct mmc_card *card)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct pltfm_imx_data *imx_data = sdhci_pltfm_priv(pltfm_host);
> +
> + imx_data->init_card_type = card->type;
> +}
> +
> static int usdhc_execute_tuning(struct mmc_host *mmc, u32 opcode)
> {
> struct sdhci_host *host = mmc_priv(mmc);
> @@ -1673,6 +1708,12 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
> * to replace the standard one in sdhci_ops.
> */
> host->mmc_host_ops.execute_tuning = usdhc_execute_tuning;
> +
> + /*
> + * Link usdhc specific mmc_host_ops init card function,
> + * to distinguish the card type.
> + */
> + host->mmc_host_ops.init_card = usdhc_init_card;
> }
>
> err = sdhci_esdhc_imx_probe_dt(pdev, host, imx_data);
