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path: root/drivers/mmc/host/sdhci-tegra.c
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Diffstat (limited to 'drivers/mmc/host/sdhci-tegra.c')
-rw-r--r--drivers/mmc/host/sdhci-tegra.c55
1 files changed, 55 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index 20ce81b57d32..020154943732 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -22,6 +22,7 @@
#include <linux/of_device.h>
#include <linux/mmc/card.h>
#include <linux/mmc/host.h>
+#include <linux/mmc/mmc.h>
#include <linux/mmc/slot-gpio.h>
#include <linux/gpio/consumer.h>
@@ -29,6 +30,9 @@
/* Tegra SDHOST controller vendor register definitions */
#define SDHCI_TEGRA_VENDOR_CLOCK_CTRL 0x100
+#define SDHCI_CLOCK_CTRL_TAP_MASK 0x00ff0000
+#define SDHCI_CLOCK_CTRL_TAP_SHIFT 16
+#define SDHCI_CLOCK_CTRL_SDR50_TUNING_OVERRIDE BIT(5)
#define SDHCI_CLOCK_CTRL_PADPIPE_CLKEN_OVERRIDE BIT(3)
#define SDHCI_CLOCK_CTRL_SPI_MODE_CLKEN_OVERRIDE BIT(2)
@@ -151,6 +155,8 @@ static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
clk_ctrl = sdhci_readl(host, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
clk_ctrl &= ~SDHCI_CLOCK_CTRL_SPI_MODE_CLKEN_OVERRIDE;
+ if (!(soc_data->nvquirks & NVQUIRK_DISABLE_SDR50))
+ clk_ctrl |= SDHCI_CLOCK_CTRL_SDR50_TUNING_OVERRIDE;
sdhci_writel(host, clk_ctrl, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
tegra_host->ddr_signaling = false;
@@ -214,6 +220,50 @@ static unsigned int tegra_sdhci_get_max_clock(struct sdhci_host *host)
return clk_round_rate(pltfm_host->clk, UINT_MAX) / 2;
}
+static void tegra_sdhci_set_tap(struct sdhci_host *host, unsigned int tap)
+{
+ u32 reg;
+
+ reg = sdhci_readl(host, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
+ reg &= ~SDHCI_CLOCK_CTRL_TAP_MASK;
+ reg |= tap << SDHCI_CLOCK_CTRL_TAP_SHIFT;
+ sdhci_writel(host, reg, SDHCI_TEGRA_VENDOR_CLOCK_CTRL);
+}
+
+static int tegra_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
+{
+ unsigned int min, max;
+
+ /*
+ * Start search for minimum tap value at 10, as smaller values are
+ * may wrongly be reported as working but fail at higher speeds,
+ * according to the TRM.
+ */
+ min = 10;
+ while (min < 255) {
+ tegra_sdhci_set_tap(host, min);
+ if (!mmc_send_tuning(host->mmc, opcode, NULL))
+ break;
+ min++;
+ }
+
+ /* Find the maximum tap value that still passes. */
+ max = min + 1;
+ while (max < 255) {
+ tegra_sdhci_set_tap(host, max);
+ if (mmc_send_tuning(host->mmc, opcode, NULL)) {
+ max--;
+ break;
+ }
+ max++;
+ }
+
+ /* The TRM states the ideal tap value is at 75% in the passing range. */
+ tegra_sdhci_set_tap(host, min + ((max - min) * 3 / 4));
+
+ return mmc_send_tuning(host->mmc, opcode, NULL);
+}
+
static const struct sdhci_ops tegra_sdhci_ops = {
.get_ro = tegra_sdhci_get_ro,
.read_w = tegra_sdhci_readw,
@@ -221,6 +271,7 @@ static const struct sdhci_ops tegra_sdhci_ops = {
.set_clock = tegra_sdhci_set_clock,
.set_bus_width = tegra_sdhci_set_bus_width,
.reset = tegra_sdhci_reset,
+ .platform_execute_tuning = tegra_sdhci_execute_tuning,
.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
.get_max_clock = tegra_sdhci_get_max_clock,
};
@@ -266,6 +317,7 @@ static const struct sdhci_ops tegra114_sdhci_ops = {
.set_clock = tegra_sdhci_set_clock,
.set_bus_width = tegra_sdhci_set_bus_width,
.reset = tegra_sdhci_reset,
+ .platform_execute_tuning = tegra_sdhci_execute_tuning,
.set_uhs_signaling = tegra_sdhci_set_uhs_signaling,
.get_max_clock = tegra_sdhci_get_max_clock,
};
@@ -350,6 +402,9 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
if (rc)
goto err_parse_dt;
+ if (!(tegra_host->soc_data->nvquirks & NVQUIRK_DISABLE_DDR50))
+ host->mmc->caps |= MMC_CAP_1_8V_DDR;
+
tegra_host->power_gpio = devm_gpiod_get_optional(&pdev->dev, "power",
GPIOD_OUT_HIGH);
if (IS_ERR(tegra_host->power_gpio)) {