Re: [PATCH v3 11/38] mmc: tegra: Reconfigure pad voltages during voltage switching

Ulf Hansson
2018-08-31T13:16:17Z

On 30 August 2018 at 17:06, Aapo Vienamo <avienamo@nvidia.com> wrote:
> Parse the pinctrl state and nvidia,only-1-8-v properties from the device
> tree. Validate the pinctrl and regulator configuration before unmasking
> UHS modes. Implement pad voltage state reconfiguration in the mmc
> start_signal_voltage_switch() callback. Add NVQUIRK_NEEDS_PAD_CONTROL
> and add set it for Tegra210 and Tegra186.
>
> The pad configuration is done in the mmc callback because the order of
> pad reconfiguration and sdhci voltage switch depend on the voltage to
> which the transition occurs.
>
> Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
> Acked-by: Thierry Reding <treding@nvidia.com>

Applied this one the rest of the mmc changes, up and to patch27.

Those changes I haven't picked in this series, I am assuming those
will go through some another tree? Thierry, will you pick them up?

Kind regards
Uffe

> ---
> drivers/mmc/host/sdhci-tegra.c | 136 +++++++++++++++++++++++++++++++--
> 1 file changed, 129 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-tegra.c b/drivers/mmc/host/sdhci-tegra.c
> index 908b23e6a03c..11185e96f3c3 100644
> --- a/drivers/mmc/host/sdhci-tegra.c
> +++ b/drivers/mmc/host/sdhci-tegra.c
> @@ -21,6 +21,8 @@
> #include <linux/io.h>
> #include <linux/of.h>
> #include <linux/of_device.h>
> +#include <linux/pinctrl/consumer.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/reset.h>
> #include <linux/mmc/card.h>
> #include <linux/mmc/host.h>
> @@ -55,6 +57,7 @@
> #define NVQUIRK_ENABLE_SDR104 BIT(4)
> #define NVQUIRK_ENABLE_DDR50 BIT(5)
> #define NVQUIRK_HAS_PADCALIB BIT(6)
> +#define NVQUIRK_NEEDS_PAD_CONTROL BIT(7)
>
> struct sdhci_tegra_soc_data {
> const struct sdhci_pltfm_data *pdata;
> @@ -66,8 +69,12 @@ struct sdhci_tegra {
> struct gpio_desc *power_gpio;
> bool ddr_signaling;
> bool pad_calib_required;
> + bool pad_control_available;
>
> struct reset_control *rst;
> + struct pinctrl *pinctrl_sdmmc;
> + struct pinctrl_state *pinctrl_state_3v3;
> + struct pinctrl_state *pinctrl_state_1v8;
> };
>
> static u16 tegra_sdhci_readw(struct sdhci_host *host, int reg)
> @@ -138,6 +145,39 @@ static unsigned int tegra_sdhci_get_ro(struct sdhci_host *host)
> return mmc_gpio_get_ro(host->mmc);
> }
>
> +static bool tegra_sdhci_is_pad_and_regulator_valid(struct sdhci_host *host)
> +{
> + struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> + struct sdhci_tegra *tegra_host = sdhci_pltfm_priv(pltfm_host);
> + int has_1v8, has_3v3;
> +
> + /*
> + * The SoCs which have NVQUIRK_NEEDS_PAD_CONTROL require software pad
> + * voltage configuration in order to perform voltage switching. This
> + * means that valid pinctrl info is required on SDHCI instances capable
> + * of performing voltage switching. Whether or not an SDHCI instance is
> + * capable of voltage switching is determined based on the regulator.
> + */
> +
> + if (!(tegra_host->soc_data->nvquirks & NVQUIRK_NEEDS_PAD_CONTROL))
> + return true;
> +
> + if (IS_ERR(host->mmc->supply.vqmmc))
> + return false;
> +
> + has_1v8 = regulator_is_supported_voltage(host->mmc->supply.vqmmc,
> + 1700000, 1950000);
> +
> + has_3v3 = regulator_is_supported_voltage(host->mmc->supply.vqmmc,
> + 2700000, 3600000);
> +
> + if (has_1v8 == 1 && has_3v3 == 1)
> + return tegra_host->pad_control_available;
> +
> + /* Fixed voltage, no pad control required. */
> + return true;
> +}
> +
> static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
> {
> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -160,13 +200,7 @@ static void tegra_sdhci_reset(struct sdhci_host *host, u8 mask)
>
> clk_ctrl &= ~SDHCI_CLOCK_CTRL_SPI_MODE_CLKEN_OVERRIDE;
>
> - /*
> - * If the board does not define a regulator for the SDHCI
> - * IO voltage, then don't advertise support for UHS modes
> - * even if the device supports it because the IO voltage
> - * cannot be configured.
> - */
> - if (!IS_ERR(host->mmc->supply.vqmmc)) {
> + if (tegra_sdhci_is_pad_and_regulator_valid(host)) {
> /* Erratum: Enable SDHCI spec v3.00 support */
> if (soc_data->nvquirks & NVQUIRK_ENABLE_SDHCI_SPEC_300)
> misc_ctrl |= SDHCI_MISC_CTRL_ENABLE_SDHCI_SPEC_300;
> @@ -301,6 +335,84 @@ 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)
> +{
> + struct sdhci_host *host = mmc_priv(mmc);
> + int ret = 0;
> +
> + if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330) {
> + ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage);
> + if (ret < 0)
> + return ret;
> + ret = sdhci_start_signal_voltage_switch(mmc, ios);
> + } else if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180) {
> + ret = sdhci_start_signal_voltage_switch(mmc, ios);
> + if (ret < 0)
> + return ret;
> + ret = tegra_sdhci_set_padctrl(host, ios->signal_voltage);
> + }
> +
> + return ret;
> +}
> +
> +static int tegra_sdhci_init_pinctrl_info(struct device *dev,
> + struct sdhci_tegra *tegra_host)
> +{
> + tegra_host->pinctrl_sdmmc = devm_pinctrl_get(dev);
> + if (IS_ERR(tegra_host->pinctrl_sdmmc)) {
> + dev_dbg(dev, "No pinctrl info, err: %ld\n",
> + PTR_ERR(tegra_host->pinctrl_sdmmc));
> + return -1;
> + }
> +
> + tegra_host->pinctrl_state_3v3 =
> + pinctrl_lookup_state(tegra_host->pinctrl_sdmmc, "sdmmc-3v3");
> + if (IS_ERR(tegra_host->pinctrl_state_3v3)) {
> + dev_warn(dev, "Missing 3.3V pad state, err: %ld\n",
> + PTR_ERR(tegra_host->pinctrl_state_3v3));
> + return -1;
> + }
> +
> + tegra_host->pinctrl_state_1v8 =
> + pinctrl_lookup_state(tegra_host->pinctrl_sdmmc, "sdmmc-1v8");
> + if (IS_ERR(tegra_host->pinctrl_state_1v8)) {
> + dev_warn(dev, "Missing 1.8V pad state, err: %ld\n",
> + PTR_ERR(tegra_host->pinctrl_state_3v3));
> + return -1;
> + }
> +
> + tegra_host->pad_control_available = true;
> +
> + return 0;
> +}
> +
> static void tegra_sdhci_voltage_switch(struct sdhci_host *host)
> {
> struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
> @@ -434,6 +546,7 @@ static const struct sdhci_pltfm_data sdhci_tegra210_pdata = {
>
> static const struct sdhci_tegra_soc_data soc_data_tegra210 = {
> .pdata = &sdhci_tegra210_pdata,
> + .nvquirks = NVQUIRK_NEEDS_PAD_CONTROL,
> };
>
> static const struct sdhci_pltfm_data sdhci_tegra186_pdata = {
> @@ -457,6 +570,7 @@ static const struct sdhci_pltfm_data sdhci_tegra186_pdata = {
>
> static const struct sdhci_tegra_soc_data soc_data_tegra186 = {
> .pdata = &sdhci_tegra186_pdata,
> + .nvquirks = NVQUIRK_NEEDS_PAD_CONTROL,
> };
>
> static const struct of_device_id sdhci_tegra_dt_match[] = {
> @@ -493,8 +607,16 @@ static int sdhci_tegra_probe(struct platform_device *pdev)
> tegra_host = sdhci_pltfm_priv(pltfm_host);
> tegra_host->ddr_signaling = false;
> tegra_host->pad_calib_required = false;
> + tegra_host->pad_control_available = false;
> tegra_host->soc_data = soc_data;
>
> + if (soc_data->nvquirks & NVQUIRK_NEEDS_PAD_CONTROL) {
> + rc = tegra_sdhci_init_pinctrl_info(&pdev->dev, tegra_host);
> + if (rc == 0)
> + host->mmc_host_ops.start_signal_voltage_switch =
> + sdhci_tegra_start_signal_voltage_switch;
> + }
> +
> rc = mmc_of_parse(host->mmc);
> if (rc)
> goto err_parse_dt;
> --
> 2.18.0
>