[PATCH v3 16/38] mmc: tegra: Program pad autocal offsets from dt

Aapo Vienamo
2018-08-30T15:06:17Z

Parse the pad drive strength calibration offsets from the device tree.
Program the calibration offsets in accordance with the current signaling
mode.

Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
---
drivers/mmc/host/sdhci-tegra.c | 152 ++++++++++++++++++++++++++++++++-
1 file changed, 151 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index ec07a3ce0247..a3e31f18db48 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -50,6 +50,7 @@
#define SDHCI_TEGRA_AUTO_CAL_CONFIG 0x1e4
#define SDHCI_AUTO_CAL_START BIT(31)
#define SDHCI_AUTO_CAL_ENABLE BIT(29)
+#define SDHCI_AUTO_CAL_PDPU_OFFSET_MASK 0x0000ffff

#define SDHCI_TEGRA_SDMEM_COMP_PADCTRL 0x1e0
#define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_VREF_SEL_MASK 0x0000000f
@@ -73,6 +74,22 @@ struct sdhci_tegra_soc_data {
u32 nvquirks;
};

+/* Magic pull up and pull down pad calibration offsets */
+struct sdhci_tegra_autocal_offsets {
+ u32 pull_up_3v3;
+ u32 pull_down_3v3;
+ u32 pull_up_3v3_timeout;
+ u32 pull_down_3v3_timeout;
+ u32 pull_up_1v8;
+ u32 pull_down_1v8;
+ u32 pull_up_1v8_timeout;
+ u32 pull_down_1v8_timeout;
+ u32 pull_up_sdr104;
+ u32 pull_down_sdr104;
+ u32 pull_up_hs400;
+ u32 pull_down_hs400;
+};
+
struct sdhci_tegra {
const struct sdhci_tegra_soc_data *soc_data;
struct gpio_desc *power_gpio;
@@ -84,6 +101,8 @@ struct sdhci_tegra {
struct pinctrl *pinctrl_sdmmc;
struct pinctrl_state *pinctrl_state_3v3;
struct pinctrl_state *pinctrl_state_1v8;
+
+ struct sdhci_tegra_autocal_offsets autocal_offsets;
};

static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
@@ -281,12 +300,45 @@ static bool tegra_sdhci_configure_card_clk(struct sdhci_host *host, bool enable)
return status;
}

+static void tegra_sdhci_set_pad_autocal_offset(struct sdhci_host *host,
+ u16 pdpu)
+{
+ u32 reg;
+
+ reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+ reg &= ~SDHCI_AUTO_CAL_PDPU_OFFSET_MASK;
+ reg |= pdpu;
+ sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+}
+
static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
+ struct sdhci_tegra_autocal_offsets offsets =
+ tegra_host->autocal_offsets;
+ struct mmc_ios *ios = &host->mmc->ios;
bool card_clk_enabled;
+ u16 pdpu;
u32 reg;
int ret;

+ switch (ios->timing) {
+ case MMC_TIMING_UHS_SDR104:
+ pdpu = offsets.pull_down_sdr104 << 8 | offsets.pull_up_sdr104;
+ break;
+ case MMC_TIMING_MMC_HS400:
+ pdpu = offsets.pull_down_hs400 << 8 | offsets.pull_up_hs400;
+ break;
+ default:
+ if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
+ pdpu = offsets.pull_down_1v8 << 8 | offsets.pull_up_1v8;
+ else
+ pdpu = offsets.pull_down_3v3 << 8 | offsets.pull_up_3v3;
+ }
+
+ tegra_sdhci_set_pad_autocal_offset(host, pdpu);
+
card_clk_enabled = tegra_sdhci_configure_card_clk(host, false);

tegra_sdhci_configure_cal_pad(host, true);
@@ -305,8 +357,104 @@ static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)

tegra_sdhci_configure_card_clk(host, card_clk_enabled);

- if (ret)
+ if (ret) {
dev_err(mmc_dev(host->mmc), "Pad autocal timed out\n");
+
+ if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180)
+ pdpu = offsets.pull_down_1v8_timeout << 8 |
+ offsets.pull_up_1v8_timeout;
+ else
+ pdpu = offsets.pull_down_3v3_timeout << 8 |
+ offsets.pull_up_3v3_timeout;
+
+ /* Disable automatic calibration and use fixed offsets */
+ reg = sdhci_readl(host, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+ reg &= ~SDHCI_AUTO_CAL_ENABLE;
+ sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG);
+
+ tegra_sdhci_set_pad_autocal_offset(host, pdpu);
+ }
+}
+
+static void tegra_sdhci_parse_pad_autocal_dt(struct sdhci_host *host)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
+ struct sdhci_tegra_autocal_offsets *autocal =
+ &tegra_host->autocal_offsets;
+ int err;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-up-offset-3v3",
+ &autocal->pull_up_3v3);
+ if (err)
+ autocal->pull_up_3v3 = 0;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-down-offset-3v3",
+ &autocal->pull_down_3v3);
+ if (err)
+ autocal->pull_down_3v3 = 0;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-up-offset-1v8",
+ &autocal->pull_up_1v8);
+ if (err)
+ autocal->pull_up_1v8 = 0;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-down-offset-1v8",
+ &autocal->pull_down_1v8);
+ if (err)
+ autocal->pull_down_1v8 = 0;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-up-offset-3v3-timeout",
+ &autocal->pull_up_3v3);
+ if (err)
+ autocal->pull_up_3v3_timeout = 0;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-down-offset-3v3-timeout",
+ &autocal->pull_down_3v3);
+ if (err)
+ autocal->pull_down_3v3_timeout = 0;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-up-offset-1v8-timeout",
+ &autocal->pull_up_1v8);
+ if (err)
+ autocal->pull_up_1v8_timeout = 0;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-down-offset-1v8-timeout",
+ &autocal->pull_down_1v8);
+ if (err)
+ autocal->pull_down_1v8_timeout = 0;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-up-offset-sdr104",
+ &autocal->pull_up_sdr104);
+ if (err)
+ autocal->pull_up_sdr104 = autocal->pull_up_1v8;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-down-offset-sdr104",
+ &autocal->pull_down_sdr104);
+ if (err)
+ autocal->pull_down_sdr104 = autocal->pull_down_1v8;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-up-offset-hs400",
+ &autocal->pull_up_hs400);
+ if (err)
+ autocal->pull_up_hs400 = autocal->pull_up_1v8;
+
+ err = device_property_read_u32(host->mmc->parent,
+ "nvidia,pad-autocal-pull-down-offset-hs400",
+ &autocal->pull_down_hs400);
+ if (err)
+ autocal->pull_down_hs400 = autocal->pull_down_1v8;
}

static void tegra_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
@@ -698,6 +846,8 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
if (tegra_host->soc_data->nvquirks & NVQUIRK_ENABLE_DDR50)
host->mmc->caps |= MMC_CAP_1_8V_DDR;

+ tegra_sdhci_parse_pad_autocal_dt(host);
+
tegra_host->power_gpio = devm_gpiod_get_optional(&pdev->dev, "power",
GPIOD_OUT_HIGH);
if (IS_ERR(tegra_host->power_gpio)) {
--
2.18.0