Disable the card clock during automatic pad drive strength calibration
and re-enable it afterwards.
Signed-off-by: Aapo Vienamo <avienamo@xxxxxxxxxx>
---
drivers/mmc/host/sdhci-tegra.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 363490e..79ecdd0 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -259,11 +259,35 @@ 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);
+
+ 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)
{
+ bool card_clk_enabled;
u32 reg;
int ret;
+ 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);
@@ -277,6 +301,8 @@ 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 (ret)
dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n");
}
--
2.7.4
--
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