On 18/01/18 10:05, Vijay Viswanath wrote: > From: Krishna Konda <kkonda@xxxxxxxxxxxxxx> > > The PADs for sdhc controller are dual-voltage that support 3v/1.8v. > Those PADs have a control signal (io_pad_pwr_switch/mode18 ) that > indicates whether the PAD works in 3v or 1.8v. > > SDHC core on msm platforms should have IO_PAD_PWR_SWITCH bit set/unset > based on actual voltage used for IO lines. So when power irq is > triggered for io high or io low, the driver should check the voltages > supported and set the pad accordingly. > > Signed-off-by: Krishna Konda <kkonda@xxxxxxxxxxxxxx> > Signed-off-by: Venkat Gopalakrishnan <venkatg@xxxxxxxxxxxxxx> > Signed-off-by: Vijay Viswanath <vviswana@xxxxxxxxxxxxxx> > --- Not sure why this is RFC, but for sdhci: Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> > drivers/mmc/host/sdhci-msm.c | 38 ++++++++++++++++++++++++++++++++++++++ > 1 file changed, 38 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c > index 5c23e92..f5728a8 100644 > --- a/drivers/mmc/host/sdhci-msm.c > +++ b/drivers/mmc/host/sdhci-msm.c > @@ -78,6 +78,8 @@ > #define CORE_HC_MCLK_SEL_DFLT (2 << 8) > #define CORE_HC_MCLK_SEL_HS400 (3 << 8) > #define CORE_HC_MCLK_SEL_MASK (3 << 8) > +#define CORE_IO_PAD_PWR_SWITCH_EN (1 << 15) > +#define CORE_IO_PAD_PWR_SWITCH (1 << 16) > #define CORE_HC_SELECT_IN_EN BIT(18) > #define CORE_HC_SELECT_IN_HS400 (6 << 19) > #define CORE_HC_SELECT_IN_MASK (7 << 19) > @@ -1166,6 +1168,35 @@ static void sdhci_msm_handle_pwr_irq(struct sdhci_host *host, int irq) > */ > writel_relaxed(irq_ack, msm_host->core_mem + CORE_PWRCTL_CTL); > > + /* > + * SDHC has core_mem and hc_mem device memory and these memory > + * addresses do not fall within 1KB region. Hence, any update to > + * core_mem address space would require an mb() to ensure this gets > + * completed before its next update to registers within hc_mem. > + */ > + mb(); > + /* > + * We should unset IO PAD PWR switch only if the register write can > + * set IO lines high and the regulator also switches to 3 V. > + * Else, we should keep the IO PAD PWR switch set. > + * This is applicable to certain targets where eMMC vccq supply is only > + * 1.8V. In such targets, even during REQ_IO_HIGH, the IO PAD PWR > + * switch must be kept set to reflect actual regulator voltage. This > + * way, during initialization of controllers with only 1.8V, we will > + * set the IO PAD bit without waiting for a REQ_IO_LOW. > + */ > + if ((io_level & REQ_IO_HIGH) && (msm_host->caps_0 & CORE_3_0V_SUPPORT)) > + writel_relaxed((readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC) & > + ~CORE_IO_PAD_PWR_SWITCH), host->ioaddr + > + CORE_VENDOR_SPEC); > + else if ((io_level & REQ_IO_LOW) || > + (msm_host->caps_0 & CORE_1_8V_SUPPORT)) > + writel_relaxed((readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC) | > + CORE_IO_PAD_PWR_SWITCH), host->ioaddr + > + CORE_VENDOR_SPEC); > + /* Ensure that the IO PAD switches are updated before proceeding */ > + mb(); > + > if (pwr_state) > msm_host->curr_pwr_state = pwr_state; > if (io_level) > @@ -1518,6 +1549,13 @@ static int sdhci_msm_probe(struct platform_device *pdev) > } > > /* > + * Set the PAD_PWR_SWITCH_EN bit so that the PAD_PWR_SWITCH bit can > + * be used as required later on. > + */ > + writel_relaxed((readl_relaxed(host->ioaddr + CORE_VENDOR_SPEC) | > + CORE_IO_PAD_PWR_SWITCH_EN), host->ioaddr + > + CORE_VENDOR_SPEC); > + /* > * Power on reset state may trigger power irq if previous status of > * PWRCTL was either BUS_ON or IO_HIGH_V. So before enabling pwr irq > * interrupt in GIC, any pending power irq interrupt should be > -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
