Reviewed-by: Mikko Perttunen <mperttu...@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 <avien...@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"); }
