Re: [PATCH 04/10] mmc: tegra: Disable card clock during pad calibration

[Mikko Perttunen]

On 24.07.2018 17:34, Aapo Vienamo wrote:

Disable the card clock during automatic pad drive strength calibration
and re-enable it aftewards.

s/aftewards/afterwards/.

Signed-off-by: Aapo Vienamo <avien...@nvidia.com>
---
  drivers/mmc/host/sdhci-tegra.c | 27 +++++++++++++++++++++++++++
  1 file changed, 27 insertions(+)

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 61067b7..0de74f4 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -52,6 +52,7 @@
  #define SDHCI_TEGRA_SDMEM_COMP_PADCTRL                        0x1e0
  #define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_VREF_SEL_MASK  0x0000000f
  #define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_VREF_SEL_VAL   0x7
+#define SDHCI_TEGRA_PAD_E_INPUT_OR_E_PWRD              BIT(31)

Looks like this should be in the previous patch.

#define SDHCI_TEGRA_AUTO_CAL_STATUS 0x1ec

  #define SDHCI_TEGRA_AUTO_CAL_ACTIVE     BIT(31)
@@ -226,11 +227,35 @@ static void tegra_sdhci_configure_cal_pad(struct 
sdhci_host *host, bool enable)
        udelay(1);
  }

+static bool tegra_sdhci_configure_card_clk(struct sdhci_host *host, bool enable)

+{
+       bool orig_enabled;
+       u32 reg;
+
+       reg = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+       orig_enabled = reg & SDHCI_CLOCK_CARD_EN;

I would do !!(reg & SDHCI_CLOCK_CARD_EN) here.

+
+       if (orig_enabled == enable)
+               return orig_enabled;
+
+       if (enable)
+               reg |= SDHCI_CLOCK_CARD_EN;
+       else
+               reg &= ~SDHCI_CLOCK_CARD_EN;
+
+       sdhci_writew(host, reg, SDHCI_CLOCK_CONTROL);
+
+       return orig_enabled;
+}
+
  static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
  {
        unsigned timeout = 10;
+       bool card_clk_enabled;
        u32 reg;

+ card_clk_enabled = tegra_sdhci_configure_card_clk(host, false);

+
        tegra_sdhci_configure_cal_pad(host, true);

reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);

@@ -248,6 +273,8 @@ static void tegra_sdhci_pad_autocalib(struct sdhci_host 
*host)

tegra_sdhci_configure_cal_pad(host, false); + tegra_sdhci_configure_card_clk(host, card_clk_enabled);

+
        if (timeout == 0)
                dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n");
  }