The MMC framework in U-Boot does not support a systematic API for timing switch like mmc_set_timing() in Linux.
U-Boot just provides a hook to change the clock frequency via mmc_set_clock(). It is up to drivers if additional register settings are needed.
This driver needs to set a correct timing mode into a register when it migrates to a different speed mode. Only increasing clock frequency could result in setup/hold timing violation.
The timing mode should be decided by checking MMC_TIMING_* like drivers/mmc/host/sdhci-cadence.c in Linux, but "timing" is not supported by U-Boot for now. Just use mmc->clock to decide the timing mode.
Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com ---
drivers/mmc/sdhci-cadence.c | 48 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+)
diff --git a/drivers/mmc/sdhci-cadence.c b/drivers/mmc/sdhci-cadence.c index dc86d108a698..4e1c5f78a419 100644 --- a/drivers/mmc/sdhci-cadence.c +++ b/drivers/mmc/sdhci-cadence.c @@ -23,6 +23,18 @@ #define SDHCI_CDNS_HRS04_WDATA_SHIFT 8 #define SDHCI_CDNS_HRS04_ADDR_SHIFT 0
+#define SDHCI_CDNS_HRS06 0x18 /* eMMC control */ +#define SDHCI_CDNS_HRS06_TUNE_UP BIT(15) +#define SDHCI_CDNS_HRS06_TUNE_SHIFT 8 +#define SDHCI_CDNS_HRS06_TUNE_MASK 0x3f +#define SDHCI_CDNS_HRS06_MODE_MASK 0x7 +#define SDHCI_CDNS_HRS06_MODE_SD 0x0 +#define SDHCI_CDNS_HRS06_MODE_MMC_SDR 0x2 +#define SDHCI_CDNS_HRS06_MODE_MMC_DDR 0x3 +#define SDHCI_CDNS_HRS06_MODE_MMC_HS200 0x4 +#define SDHCI_CDNS_HRS06_MODE_MMC_HS400 0x5 +#define SDHCI_CDNS_HRS06_MODE_MMC_HS400ES 0x6 + /* SRS - Slot Register Set (SDHCI-compatible) */ #define SDHCI_CDNS_SRS_BASE 0x200
@@ -111,6 +123,41 @@ static int sdhci_cdns_phy_init(struct sdhci_cdns_plat *plat, return 0; }
+static void sdhci_cdns_set_control_reg(struct sdhci_host *host) +{ + struct mmc *mmc = host->mmc; + struct sdhci_cdns_plat *plat = dev_get_platdata(mmc->dev); + unsigned int clock = mmc->clock; + u32 mode, tmp; + + /* + * REVISIT: + * The mode should be decided by MMC_TIMING_* like Linux, but + * U-Boot does not support timing. Use the clock frequency instead. + */ + if (clock <= 26000000) + mode = SDHCI_CDNS_HRS06_MODE_SD; /* use this for Legacy */ + else if (clock <= 52000000) { + if (mmc->ddr_mode) + mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR; + else + mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR; + } else { + /* The IP supports HS200/HS400, but U-Boot does not. */ + printf("unsupported frequency %d\n", clock); + return; + } + + tmp = readl(plat->hrs_addr + SDHCI_CDNS_HRS06); + tmp &= ~SDHCI_CDNS_HRS06_MODE_MASK; + tmp |= mode; + writel(tmp, plat->hrs_addr + SDHCI_CDNS_HRS06); +} + +static const struct sdhci_ops sdhci_cdns_ops = { + .set_control_reg = sdhci_cdns_set_control_reg, +}; + static int sdhci_cdns_bind(struct udevice *dev) { struct sdhci_cdns_plat *plat = dev_get_platdata(dev); @@ -137,6 +184,7 @@ static int sdhci_cdns_probe(struct udevice *dev)
host->name = dev->name; host->ioaddr = plat->hrs_addr + SDHCI_CDNS_SRS_BASE; + host->ops = &sdhci_cdns_ops; host->quirks |= SDHCI_QUIRK_WAIT_SEND_CMD;
ret = sdhci_cdns_phy_init(plat, gd->fdt_blob, dev->of_offset);