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Subject[PATCH V4 3/3] mmc: tegra: SDMMC pads auto-calibration
Date
Program initial drive code offsets which will be used by auto
calibration process.

Program fixed drive strengths for SDMMC pads in pad control
register when auto cal timeouts.
Fixed settings are based on Pre-SI analysis of the pad design.

Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com>
---
drivers/mmc/host/sdhci-tegra.c | 160 ++++++++++++++++++++++++++++++-----------
1 file changed, 119 insertions(+), 41 deletions(-)

diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
index e6ace31e2a41..7d681a8fa4ba 100644
--- a/drivers/mmc/host/sdhci-tegra.c
+++ b/drivers/mmc/host/sdhci-tegra.c
@@ -75,6 +75,7 @@
#define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_VREF_SEL_MASK 0x0000000f
#define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_VREF_SEL_VAL 0x7
#define SDHCI_TEGRA_SDMEM_COMP_PADCTRL_E_INPUT_E_PWRD BIT(31)
+#define SDHCI_COMP_PADCTRL_DRVUPDN_OFFSET_MASK 0x07FFF000

#define SDHCI_TEGRA_AUTO_CAL_STATUS 0x1ec
#define SDHCI_TEGRA_AUTO_CAL_ACTIVE BIT(31)
@@ -121,6 +122,8 @@ struct sdhci_tegra {
struct pinctrl *pinctrl_sdmmc;
struct pinctrl_state *pinctrl_state_3v3;
struct pinctrl_state *pinctrl_state_1v8;
+ struct pinctrl_state *pinctrl_state_3v3_drv;
+ struct pinctrl_state *pinctrl_state_1v8_drv;

struct sdhci_tegra_autocal_offsets autocal_offsets;
ktime_t last_calib;
@@ -411,6 +414,76 @@ static void tegra_sdhci_set_pad_autocal_offset(struct sdhci_host *host,
sdhci_writel(host, reg, SDHCI_TEGRA_AUTO_CAL_CONFIG);
}

+static int tegra_sdhci_set_padctrl(struct sdhci_host *host, int voltage,
+ bool state_drvupdn)
+{
+ 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 pinctrl_state *pinctrl_drvupdn = NULL;
+ int ret = 0;
+ u8 drvup = 0, drvdn = 0;
+ u32 reg;
+
+ if (!state_drvupdn) {
+ /* PADS Drive Strength */
+ if (voltage == MMC_SIGNAL_VOLTAGE_180) {
+ if (tegra_host->pinctrl_state_1v8_drv) {
+ pinctrl_drvupdn =
+ tegra_host->pinctrl_state_1v8_drv;
+ } else {
+ drvup = offsets->pull_up_1v8_timeout;
+ drvdn = offsets->pull_down_1v8_timeout;
+ }
+ } else {
+ if (tegra_host->pinctrl_state_3v3_drv) {
+ pinctrl_drvupdn =
+ tegra_host->pinctrl_state_3v3_drv;
+ } else {
+ drvup = offsets->pull_up_3v3_timeout;
+ drvdn = offsets->pull_down_3v3_timeout;
+ }
+ }
+
+ if (pinctrl_drvupdn != NULL) {
+ ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
+ pinctrl_drvupdn);
+ if (ret < 0)
+ dev_err(mmc_dev(host->mmc),
+ "failed pads drvupdn, ret: %d\n", ret);
+ } else if ((drvup) || (drvdn)) {
+ reg = sdhci_readl(host,
+ SDHCI_TEGRA_SDMEM_COMP_PADCTRL);
+ reg &= ~SDHCI_COMP_PADCTRL_DRVUPDN_OFFSET_MASK;
+ reg |= (drvup << 20) | (drvdn << 12);
+ sdhci_writel(host, reg,
+ SDHCI_TEGRA_SDMEM_COMP_PADCTRL);
+ }
+
+ } else {
+ /* Dual Voltage PADS Voltage selection */
+ if (!tegra_host->pad_control_available)
+ return 0;
+
+ if (voltage == MMC_SIGNAL_VOLTAGE_180) {
+ ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
+ tegra_host->pinctrl_state_1v8);
+ if (ret < 0)
+ dev_err(mmc_dev(host->mmc),
+ "setting 1.8V failed, ret: %d\n", ret);
+ } else {
+ ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
+ tegra_host->pinctrl_state_3v3);
+ if (ret < 0)
+ dev_err(mmc_dev(host->mmc),
+ "setting 3.3V failed, ret: %d\n", ret);
+ }
+ }
+
+ return ret;
+}
+
static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -437,6 +510,7 @@ static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
pdpu = offsets.pull_down_3v3 << 8 | offsets.pull_up_3v3;
}

+ /* Set initial offset before auto-calibration */
tegra_sdhci_set_pad_autocal_offset(host, pdpu);

card_clk_enabled = tegra_sdhci_configure_card_clk(host, false);
@@ -460,19 +534,15 @@ static void tegra_sdhci_pad_autocalib(struct sdhci_host *host)
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 */
+ /* Disable automatic cal and use fixed Drive Strengths */
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);
+ ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage, false);
+ if (ret < 0)
+ dev_err(mmc_dev(host->mmc),
+ "Setting drive strengths failed: %d\n", ret);
}
}

@@ -511,26 +581,46 @@ static void tegra_sdhci_parse_pad_autocal_dt(struct sdhci_host *host)
err = device_property_read_u32(host->mmc->parent,
"nvidia,pad-autocal-pull-up-offset-3v3-timeout",
&autocal->pull_up_3v3_timeout);
- if (err)
+ if (err) {
+ if (!IS_ERR(tegra_host->pinctrl_state_3v3) &&
+ (tegra_host->pinctrl_state_3v3_drv == NULL))
+ pr_warn("%s: Missing autocal timeout 3v3-pad drvs\n",
+ mmc_hostname(host->mmc));
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_timeout);
- if (err)
+ if (err) {
+ if (!IS_ERR(tegra_host->pinctrl_state_3v3) &&
+ (tegra_host->pinctrl_state_3v3_drv == NULL))
+ pr_warn("%s: Missing autocal timeout 3v3-pad drvs\n",
+ mmc_hostname(host->mmc));
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_timeout);
- if (err)
+ if (err) {
+ if (!IS_ERR(tegra_host->pinctrl_state_1v8) &&
+ (tegra_host->pinctrl_state_1v8_drv == NULL))
+ pr_warn("%s: Missing autocal timeout 1v8-pad drvs\n",
+ mmc_hostname(host->mmc));
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_timeout);
- if (err)
+ if (err) {
+ if (!IS_ERR(tegra_host->pinctrl_state_1v8) &&
+ (tegra_host->pinctrl_state_1v8_drv == NULL))
+ pr_warn("%s: Missing autocal timeout 1v8-pad drvs\n",
+ mmc_hostname(host->mmc));
autocal->pull_down_1v8_timeout = 0;
+ }

err = device_property_read_u32(host->mmc->parent,
"nvidia,pad-autocal-pull-up-offset-sdr104",
@@ -743,32 +833,6 @@ static int tegra_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
return mmc_send_tuning(host->mmc, opcode, NULL);
}

-static int tegra_sdhci_set_padctrl(struct sdhci_host *host, int voltage)
-{
- struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
- struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
- int ret;
-
- if (!tegra_host->pad_control_available)
- return 0;
-
- if (voltage == MMC_SIGNAL_VOLTAGE_180) {
- ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
- tegra_host->pinctrl_state_1v8);
- if (ret < 0)
- dev_err(mmc_dev(host->mmc),
- "setting 1.8V failed, ret: %d\n", ret);
- } else {
- ret = pinctrl_select_state(tegra_host->pinctrl_sdmmc,
- tegra_host->pinctrl_state_3v3);
- if (ret < 0)
- dev_err(mmc_dev(host->mmc),
- "setting 3.3V failed, ret: %d\n", ret);
- }
-
- return ret;
-}
-
static int sdhci_tegra_start_signal_voltage_switch(struct mmc_host *mmc,
struct mmc_ios *ios)
{
@@ -778,7 +842,7 @@ static int sdhci_tegra_start_signal_voltage_switch(struct mmc_host *mmc,
int ret = 0;

if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
- ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage);
+ ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage, true);
if (ret < 0)
return ret;
ret = sdhci_start_signal_voltage_switch(mmc, ios);
@@ -786,7 +850,7 @@ static int sdhci_tegra_start_signal_voltage_switch(struct mmc_host *mmc,
ret = sdhci_start_signal_voltage_switch(mmc, ios);
if (ret < 0)
return ret;
- ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage);
+ ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage, true);
}

if (tegra_host->pad_calib_required)
@@ -805,6 +869,20 @@ static int tegra_sdhci_init_pinctrl_info(struct device *dev,
return -1;
}

+ tegra_host->pinctrl_state_1v8_drv = pinctrl_lookup_state(
+ tegra_host->pinctrl_sdmmc, "sdmmc-1v8-drv");
+ if (IS_ERR(tegra_host->pinctrl_state_1v8_drv)) {
+ if (PTR_ERR(tegra_host->pinctrl_state_1v8_drv) == -ENODEV)
+ tegra_host->pinctrl_state_1v8_drv = NULL;
+ }
+
+ tegra_host->pinctrl_state_3v3_drv = pinctrl_lookup_state(
+ tegra_host->pinctrl_sdmmc, "sdmmc-3v3-drv");
+ if (IS_ERR(tegra_host->pinctrl_state_3v3_drv)) {
+ if (PTR_ERR(tegra_host->pinctrl_state_3v3_drv) == -ENODEV)
+ tegra_host->pinctrl_state_3v3_drv = NULL;
+ }
+
tegra_host->pinctrl_state_3v3 =
pinctrl_lookup_state(tegra_host->pinctrl_sdmmc, "sdmmc-3v3");
if (IS_ERR(tegra_host->pinctrl_state_3v3)) {
--
2.7.4
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