On Wed, Jul 25, 2018 at 11:57:28AM +0200, Lucas Stach wrote: > MMC cards need at least 74 clock pulses before any bus communication > can occur. The i.MX SDHC controller auto-gates the clock when inactive, > so if the SD enumeration is skipped for slots where we know that only a > MMC card can be present (which is possible since > b5289b742a89 "mmc: allow skipping SD card initialization") those > inititialization clock pulses won't be sent out, resulting in command > timeouts when trying to enumerate the card. > > Luckily the eSDHC controller has a hardware feature to send out 80 > clock pulses. This has been validated to be available by checking the > reference manual back to i.MX25. > > Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > --- > drivers/mci/imx-esdhc.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Applied, thanks Sascha > > diff --git a/drivers/mci/imx-esdhc.c b/drivers/mci/imx-esdhc.c > index c4daa9d12136..db96a813971a 100644 > --- a/drivers/mci/imx-esdhc.c > +++ b/drivers/mci/imx-esdhc.c > @@ -455,10 +455,13 @@ static void set_sysctl(struct mci_host *mci, u32 clock) > wait_on_timeout(10 * MSECOND, > esdhc_read32(regs + SDHCI_PRESENT_STATE) & PRSSTAT_SDSTB); > > - clk = SYSCTL_PEREN | SYSCTL_CKEN; > + clk = SYSCTL_PEREN | SYSCTL_CKEN | SYSCTL_INITA; > > esdhc_setbits32(regs + SDHCI_CLOCK_CONTROL__TIMEOUT_CONTROL__SOFTWARE_RESET, > clk); > + > + wait_on_timeout(1 * MSECOND, > + !(esdhc_read32(regs + SDHCI_CLOCK_CONTROL) & SYSCTL_INITA)); > } > > static void esdhc_set_ios(struct mci_host *mci, struct mci_ios *ios) > -- > 2.18.0 > > > _______________________________________________ > barebox mailing list > barebox@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/barebox > -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
