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mmc: sdhci-esdhc-imx: only enable DAT[0] and CMD line auto tuning for SDIO device

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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@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20221223025022.1893102-3-haibo.chen@nxp.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
This commit is contained in:
Haibo Chen 2022-12-23 10:50:22 +08:00 committed by Ulf Hansson
parent c8c49a5a0b
commit 52e4c32bae
1 changed files with 41 additions and 0 deletions
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41
drivers/mmc/host/sdhci-esdhc-imx.c
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@ -338,6 +338,16 @@ 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 */
@ -432,6 +442,8 @@ 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;
@ -449,6 +461,20 @@ 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);
@ -1056,6 +1082,15 @@ 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);
@ -1681,6 +1716,12 @@ 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);