| Message ID | 1532442865-6391-2-git-send-email-avienamo@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Update the pad autocal procedure | expand |
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com> On 24.07.2018 17:34, Aapo Vienamo wrote: > Automatic pad drive strength calibration is performed on a separate pad > identical to the ones used for driving the actual bus. Power on the > calibration pad during the calibration procedure and power it off > afterwards to save power. > > Signed-off-by: Aapo Vienamo <avienamo@nvidia.com> > --- > drivers/mmc/host/sdhci-tegra.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c > index 6008e2f..61067b7 100644 > --- a/drivers/mmc/host/sdhci-tegra.c > +++ b/drivers/mmc/host/sdhci-tegra.c > @@ -209,11 +209,30 @@ static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask) > tegra_host->ddr_signaling = false; > } > > +static void tegra_sdhci_configure_cal_pad(struct sdhci_host *host, bool enable) > +{ > + u32 reg; > + > + /* > + * Enable or disable the additional I/O pad used by the drive strength > + * calibration process. > + */ > + reg = sdhci_readl(host, SDHCI_TEGRA_SDMEM_COMP_PADCTRL); > + if (enable) > + reg |= SDHCI_TEGRA_PAD_E_INPUT_OR_E_PWRD; > + else > + reg &= ~SDHCI_TEGRA_PAD_E_INPUT_OR_E_PWRD; > + sdhci_writel(host, reg, SDHCI_TEGRA_SDMEM_COMP_PADCTRL); > + udelay(1); > +} > + > static void tegra_sdhci_pad_autocalib(struct sdhci_host *host) > { > unsigned timeout = 10; > u32 reg; > > + tegra_sdhci_configure_cal_pad(host, true); > + > reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG); > reg |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START; > sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG); > @@ -227,6 +246,8 @@ static void tegra_sdhci_pad_autocalib(struct sdhci_host *host) > timeout--; > } while (timeout); > > + tegra_sdhci_configure_cal_pad(host, false); > + > if (timeout == 0) > dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n"); > } > -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c index 6008e2f..61067b7 100644 --- a/drivers/mmc/host/sdhci-tegra.c +++ b/drivers/mmc/host/sdhci-tegra.c @@ -209,11 +209,30 @@ static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask) tegra_host->ddr_signaling = false; } +static void tegra_sdhci_configure_cal_pad(struct sdhci_host *host, bool enable) +{ + u32 reg; + + /* + * Enable or disable the additional I/O pad used by the drive strength + * calibration process. + */ + reg = sdhci_readl(host, SDHCI_TEGRA_SDMEM_COMP_PADCTRL); + if (enable) + reg |= SDHCI_TEGRA_PAD_E_INPUT_OR_E_PWRD; + else + reg &= ~SDHCI_TEGRA_PAD_E_INPUT_OR_E_PWRD; + sdhci_writel(host, reg, SDHCI_TEGRA_SDMEM_COMP_PADCTRL); + udelay(1); +} + static void tegra_sdhci_pad_autocalib(struct sdhci_host *host) { unsigned timeout = 10; u32 reg; + tegra_sdhci_configure_cal_pad(host, true); + reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG); reg |= SDHCI_AUTO_CAL_ENABLE | SDHCI_AUTO_CAL_START; sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG); @@ -227,6 +246,8 @@ static void tegra_sdhci_pad_autocalib(struct sdhci_host *host) timeout--; } while (timeout); + tegra_sdhci_configure_cal_pad(host, false); + if (timeout == 0) dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n"); }
Automatic pad drive strength calibration is performed on a separate pad identical to the ones used for driving the actual bus. Power on the calibration pad during the calibration procedure and power it off afterwards to save power. Signed-off-by: Aapo Vienamo <avienamo@nvidia.com> --- drivers/mmc/host/sdhci-tegra.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)