sdmmc_driver.c

/*
 * Copyright (c) 2018 naehrwert
 * Copyright (c) 2018-2025 CTCaer
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <string.h>

#include <storage/mmc_def.h>
#include <storage/sdmmc.h>
#include <gfx_utils.h>
#include <power/max7762x.h>
#include <soc/bpmp.h>
#include <soc/clock.h>
#include <soc/gpio.h>
#include <soc/hw_init.h>
#include <soc/pinmux.h>
#include <soc/pmc.h>
#include <soc/timer.h>
#include <soc/t210.h>

//#define DPRINTF(...) gfx_printf(__VA_ARGS__)
//#define ERROR_EXTRA_PRINTING
#define DPRINTF(...)

#ifdef BDK_SDMMC_EXTRA_PRINT
#define ERROR_EXTRA_PRINTING
#endif

/*! SCMMC controller base addresses. */
static const u16 _sdmmc_base_offsets[4] = { 0x0, 0x200, 0x400, 0x600 };

int sdmmc_get_io_power(sdmmc_t *sdmmc)
{
	u32 p = sdmmc->regs->pwrcon;
	if (!(p & SDHCI_POWER_ON))
		return SDMMC_POWER_OFF;
	if (p & SDHCI_POWER_180)
		return SDMMC_POWER_1_8;
	if (p & SDHCI_POWER_330)
		return SDMMC_POWER_3_3;
	return -1;
}

static int _sdmmc_set_io_power(sdmmc_t *sdmmc, u32 power)
{
	switch (power)
	{
	case SDMMC_POWER_OFF:
		sdmmc->regs->pwrcon &= ~SDHCI_POWER_ON;
		break;

	case SDMMC_POWER_1_8:
		sdmmc->regs->pwrcon = SDHCI_POWER_180;
		break;

	case SDMMC_POWER_3_3:
		sdmmc->regs->pwrcon = SDHCI_POWER_330;
		break;

	default:
		return 1;
	}

	if (power != SDMMC_POWER_OFF)
		sdmmc->regs->pwrcon |= SDHCI_POWER_ON;

	return 0;
}

u32 sdmmc_get_bus_width(sdmmc_t *sdmmc)
{
	u32 h = sdmmc->regs->hostctl;
	if (h & SDHCI_CTRL_8BITBUS) // eMMC only (or UHS-II).
		return SDMMC_BUS_WIDTH_8;
	if (h & SDHCI_CTRL_4BITBUS) // SD only.
		return SDMMC_BUS_WIDTH_4;
	return SDMMC_BUS_WIDTH_1;
}

void sdmmc_set_bus_width(sdmmc_t *sdmmc, u32 bus_width)
{
	u32 host_control = sdmmc->regs->hostctl & ~(SDHCI_CTRL_4BITBUS | SDHCI_CTRL_8BITBUS);

	if (bus_width == SDMMC_BUS_WIDTH_1)
		sdmmc->regs->hostctl = host_control;
	else if (bus_width == SDMMC_BUS_WIDTH_4)
		sdmmc->regs->hostctl = host_control | SDHCI_CTRL_4BITBUS; // SD only.
	else if (bus_width == SDMMC_BUS_WIDTH_8)
		sdmmc->regs->hostctl = host_control | SDHCI_CTRL_8BITBUS; // eMMC only (or UHS-II).
}

void sdmmc_save_tap_value(sdmmc_t *sdmmc)
{
	sdmmc->venclkctl_tap = (sdmmc->regs->venclkctl & 0xFF0000) >> 16;
	sdmmc->venclkctl_set = 1;
}

static int _sdmmc_config_tap_val(sdmmc_t *sdmmc, u32 type)
{
	static const u32 dqs_trim_val = 40; // 24 if HS533/HS667.
	static const u8  tap_values_t210[4] = { 4, 0, 3, 0 };

	u32 tap_val = 0;

	if (type == SDHCI_TIMING_MMC_HS400)
		sdmmc->regs->vencapover = (sdmmc->regs->vencapover & ~0x3F00) | (dqs_trim_val << 8);

	sdmmc->regs->ventunctl0 &= ~SDHCI_TEGRA_TUNING_TAP_HW_UPDATED;

	if (type == SDHCI_TIMING_MMC_HS400)
	{
		// Tap is saved during HS200 switch.
		if (!sdmmc->venclkctl_set)
			return 1;

		tap_val = sdmmc->venclkctl_tap;
	}
	else
		tap_val = sdmmc->t210b01 ? 11 : tap_values_t210[sdmmc->id];

	sdmmc->regs->venclkctl = (sdmmc->regs->venclkctl & ~0xFF0000) | (tap_val << 16);

	return 0;
}

static void _sdmmc_commit_changes(sdmmc_t *sdmmc)
{
	(void)sdmmc->regs->clkcon;
}

static void _sdmmc_pad_config_fallback(sdmmc_t *sdmmc, u32 power)
{
	_sdmmc_commit_changes(sdmmc);
	switch (sdmmc->id)
	{
	case SDMMC_1: // 50 Ohm 2X Driver.
		if (power == SDMMC_POWER_OFF)
			break;
		u32 sdmmc1_pad_cfg = APB_MISC(APB_MISC_GP_SDMMC1_PAD_CFGPADCTRL) & 0xF8080FFF;
		if (sdmmc->t210b01)
			sdmmc1_pad_cfg |= (0x808 << 12); // Up:  8, Dn:  8. For 50 ohm.
		else if (power == SDMMC_POWER_1_8)
			sdmmc1_pad_cfg |= (0xB0F << 12); // Up: 11, Dn: 15. For 50 ohm.
		else if (power == SDMMC_POWER_3_3)
			sdmmc1_pad_cfg |= (0xC0C << 12); // Up: 12, Dn: 12. For 50 ohm.
		APB_MISC(APB_MISC_GP_SDMMC1_PAD_CFGPADCTRL) = sdmmc1_pad_cfg;
		(void)APB_MISC(APB_MISC_GP_SDMMC1_PAD_CFGPADCTRL); // Commit write.
		break;

	case SDMMC_2:
		if (sdmmc->t210b01)
			APB_MISC(APB_MISC_GP_EMMC2_PAD_CFGPADCTRL) = (APB_MISC(APB_MISC_GP_EMMC2_PAD_CFGPADCTRL) & 0xF8080FFF) | 0xA0A000;
		else
			APB_MISC(APB_MISC_GP_EMMC2_PAD_CFGPADCTRL) = (APB_MISC(APB_MISC_GP_EMMC2_PAD_CFGPADCTRL) & 0xFFFFC003) | 0x1040; // PU:16, PD:16.
		(void)APB_MISC(APB_MISC_GP_EMMC2_PAD_CFGPADCTRL);
		break;

	case SDMMC_4: // 50 Ohm 2X Driver. PU:16, PD:16, B01: PU:10, PD:10.
		APB_MISC(APB_MISC_GP_EMMC4_PAD_CFGPADCTRL) = (APB_MISC(APB_MISC_GP_EMMC4_PAD_CFGPADCTRL) & 0xFFFFC003) |
													 (sdmmc->t210b01 ? 0xA28 : 0x1040);
		(void)APB_MISC(APB_MISC_GP_EMMC4_PAD_CFGPADCTRL); // Commit write.
		break;
	}
}

static void _sdmmc_autocal_execute(sdmmc_t *sdmmc, u32 power)
{
	bool should_enable_sd_clock = false;
	if (sdmmc->regs->clkcon & SDHCI_CLOCK_CARD_EN)
	{
		should_enable_sd_clock = true;
		sdmmc->regs->clkcon &= ~SDHCI_CLOCK_CARD_EN;
	}

	// Enable E_INPUT (SD) or Disable E_PWRD (eMMC) power.
	if (!(sdmmc->regs->sdmemcmppadctl & SDHCI_TEGRA_PADCTRL_E_INPUT_PWRD))
	{
		sdmmc->regs->sdmemcmppadctl |= SDHCI_TEGRA_PADCTRL_E_INPUT_PWRD;
		_sdmmc_commit_changes(sdmmc);
		usleep(1);
	}

	// Enable auto calibration and start auto configuration.
	sdmmc->regs->autocalcfg |= SDHCI_TEGRA_AUTOCAL_ENABLE | SDHCI_TEGRA_AUTOCAL_START;
	_sdmmc_commit_changes(sdmmc);
	usleep(2);

	u32 timeout = get_tmr_ms() + 10;
	while (sdmmc->regs->autocalsts & SDHCI_TEGRA_AUTOCAL_ACTIVE)
	{
		if (get_tmr_ms() > timeout)
		{
			timeout = 0; // Set timeout to 0 if we timed out.
			break;
		}
	}

#ifdef ERROR_EXTRA_PRINTING
	// Check if Comp pad is open or short to ground.
	// SDMMC1: CZ pads - T210/T210B01: 7-bit/5-bit. SDMMC2/4: LV_CZ pads - 5-bit.
	// Use 0x1F mask for all.
	u8 autocal_pu_status = sdmmc->regs->autocalsts & 0x1F;
	if (!autocal_pu_status)
		EPRINTFARGS("SDMMC%d: Comp Pad open!", sdmmc->id + 1); // Or resistance is extreme.
	else if (autocal_pu_status == 0x1F)
		EPRINTFARGS("SDMMC%d: Comp Pad short to gnd!", sdmmc->id + 1);
#endif

	// In case auto calibration fails, we load suggested standard values.
	if (!timeout)
	{
		sdmmc->regs->autocalcfg &= ~SDHCI_TEGRA_AUTOCAL_ENABLE;
		_sdmmc_pad_config_fallback(sdmmc, power);
#ifdef ERROR_EXTRA_PRINTING
		EPRINTFARGS("SDMMC%d: Comp Pad cal timeout!", sdmmc->id + 1);
#endif
	}

	// Disable E_INPUT (SD) or enable E_PWRD (eMMC) to conserve power.
	sdmmc->regs->sdmemcmppadctl &= ~SDHCI_TEGRA_PADCTRL_E_INPUT_PWRD;

	if (should_enable_sd_clock)
		sdmmc->regs->clkcon |= SDHCI_CLOCK_CARD_EN;
}

static int _sdmmc_dll_cal_execute(sdmmc_t *sdmmc)
{
	int res = 0, should_disable_sd_clock = 0;

	if (!(sdmmc->regs->clkcon & SDHCI_CLOCK_CARD_EN))
	{
		should_disable_sd_clock = 1;
		sdmmc->regs->clkcon |= SDHCI_CLOCK_CARD_EN;
	}

	 // Add -4 TX_DLY_CODE_OFFSET if HS533/HS667.
	 // if (sdmmc->id == SDMMC_4 && sdmmc->card_clock > 208000)
	 //	sdmmc->regs->vendllctl0 = sdmmc->regs->vendllctl0 &= 0xFFFFC07F | (0x7C << 7);

	sdmmc->regs->vendllcalcfg |= SDHCI_TEGRA_DLLCAL_CALIBRATE;
	_sdmmc_commit_changes(sdmmc);

	u32 timeout = get_tmr_ms() + 5;
	while (sdmmc->regs->vendllcalcfg & SDHCI_TEGRA_DLLCAL_CALIBRATE)
	{
		if (get_tmr_ms() > timeout)
		{
			res = 1;
			goto out;
		}
	}

	timeout = get_tmr_ms() + 10;
	while (sdmmc->regs->vendllcalcfgsts & SDHCI_TEGRA_DLLCAL_ACTIVE)
	{
		if (get_tmr_ms() > timeout)
		{
			res = 1;
			goto out;
		}
	}

out:
	if (should_disable_sd_clock)
		sdmmc->regs->clkcon &= ~SDHCI_CLOCK_CARD_EN;

	return res;
}

static void _sdmmc_reset_cmd_data(sdmmc_t *sdmmc)
{
	sdmmc->regs->swrst |= SDHCI_RESET_CMD | SDHCI_RESET_DATA;
	_sdmmc_commit_changes(sdmmc);
	u32 timeout = get_tmr_ms() + 2000;
	while ((sdmmc->regs->swrst & (SDHCI_RESET_CMD | SDHCI_RESET_DATA)) && get_tmr_ms() < timeout)
		;
}

static void _sdmmc_reset_all(sdmmc_t *sdmmc)
{
	sdmmc->regs->swrst |= SDHCI_RESET_ALL;
	_sdmmc_commit_changes(sdmmc);
	u32 timeout = get_tmr_ms() + 2000;//100ms
	while ((sdmmc->regs->swrst & SDHCI_RESET_ALL) && get_tmr_ms() < timeout)
		;
}

void sdmmc_setup_drv_type(sdmmc_t *sdmmc, u32 type)
{
	sdmmc->regs->hostctl2  = (sdmmc->regs->hostctl2 & (~SDHCI_CTRL_DRV_TYPE_MASK)) | SDHCI_CTRL_DRV_TYPE(type);

	_sdmmc_commit_changes(sdmmc);
}

int sdmmc_setup_clock(sdmmc_t *sdmmc, u32 type)
{
	// Disable the SD clock if it was enabled, and reenable it later.
	bool should_enable_sd_clock = false;
	if (sdmmc->regs->clkcon & SDHCI_CLOCK_CARD_EN)
	{
		should_enable_sd_clock = true;
		sdmmc->regs->clkcon &= ~SDHCI_CLOCK_CARD_EN;
	}

	_sdmmc_config_tap_val(sdmmc, type);

	_sdmmc_reset_cmd_data(sdmmc);

	switch (type)
	{
	case SDHCI_TIMING_MMC_ID:
	case SDHCI_TIMING_MMC_LS26:
	case SDHCI_TIMING_SD_ID:
	case SDHCI_TIMING_SD_DS12:
		sdmmc->regs->hostctl  &= ~SDHCI_CTRL_HISPD;
		sdmmc->regs->hostctl2 &= ~SDHCI_CTRL_VDD_180;
		break;

	case SDHCI_TIMING_MMC_HS52:
	case SDHCI_TIMING_SD_HS25:
		sdmmc->regs->hostctl  |= SDHCI_CTRL_HISPD;
		sdmmc->regs->hostctl2 &= ~SDHCI_CTRL_VDD_180;
		break;

	case SDHCI_TIMING_MMC_HS200:
	case SDHCI_TIMING_UHS_SDR50: // T210 Errata: the host must be set to SDR104 to WAR a CRC issue.
	case SDHCI_TIMING_UHS_SDR104:
	case SDHCI_TIMING_UHS_SDR82:
	case SDHCI_TIMING_MMC_HS100:
		sdmmc->regs->hostctl2  = (sdmmc->regs->hostctl2 & (~SDHCI_CTRL_UHS_MASK)) | UHS_SDR104_BUS_SPEED;
		sdmmc->regs->hostctl2 |= SDHCI_CTRL_VDD_180;
		break;

	case SDHCI_TIMING_MMC_HS400:
		// Non standard.
		sdmmc->regs->hostctl2  = (sdmmc->regs->hostctl2 & (~SDHCI_CTRL_UHS_MASK)) | HS400_BUS_SPEED;
		sdmmc->regs->hostctl2 |= SDHCI_CTRL_VDD_180;
		break;

	case SDHCI_TIMING_UHS_SDR25:
		sdmmc->regs->hostctl2  = (sdmmc->regs->hostctl2 & (~SDHCI_CTRL_UHS_MASK)) | UHS_SDR25_BUS_SPEED;
		sdmmc->regs->hostctl2 |= SDHCI_CTRL_VDD_180;
		break;

	case SDHCI_TIMING_UHS_SDR12:
		sdmmc->regs->hostctl2  = (sdmmc->regs->hostctl2 & (~SDHCI_CTRL_UHS_MASK)) | UHS_SDR12_BUS_SPEED;
		sdmmc->regs->hostctl2 |= SDHCI_CTRL_VDD_180;
		break;

	case SDHCI_TIMING_UHS_DDR50:
#ifdef BDK_SDMMC_UHS_DDR200_SUPPORT
	case SDHCI_TIMING_UHS_DDR200:
#endif
		sdmmc->regs->hostctl2  = (sdmmc->regs->hostctl2 & (~SDHCI_CTRL_UHS_MASK)) | UHS_DDR50_BUS_SPEED;
		sdmmc->regs->hostctl2 |= SDHCI_CTRL_VDD_180;
		break;
	}

	_sdmmc_commit_changes(sdmmc);

	u32 clock;
	u16 divisor;
	clock_sdmmc_get_card_clock_div(&clock, &divisor, type);
	clock_sdmmc_config_clock_source(&clock, sdmmc->id, clock);
	sdmmc->card_clock = (clock + divisor - 1) / divisor;

	// (divisor != 1) && (divisor & 1) -> error

	u16 div_lo = divisor >> 1;
	u16 div_hi = div_lo  >> 8;

	sdmmc->regs->clkcon = (sdmmc->regs->clkcon & ~(SDHCI_DIV_MASK | SDHCI_DIV_HI_MASK)) |
						  (div_lo << SDHCI_DIV_LO_SHIFT) | (div_hi << SDHCI_DIV_HI_SHIFT);

	// Enable the SD clock again.
	if (should_enable_sd_clock)
		sdmmc->regs->clkcon |= SDHCI_CLOCK_CARD_EN;

	if (type == SDHCI_TIMING_MMC_HS400)
		return _sdmmc_dll_cal_execute(sdmmc);

	return 0;
}

static void _sdmmc_card_clock_enable(sdmmc_t *sdmmc)
{
	// Recalibrate periodically if needed.
	if (sdmmc->periodic_calibration && !sdmmc->powersave_enabled)
		_sdmmc_autocal_execute(sdmmc, sdmmc_get_io_power(sdmmc));

	if (!sdmmc->powersave_enabled)
	{
		if (!(sdmmc->regs->clkcon & SDHCI_CLOCK_CARD_EN))
			sdmmc->regs->clkcon |= SDHCI_CLOCK_CARD_EN;
	}
	sdmmc->card_clock_enabled = 1;
}

static void _sdmmc_card_clock_disable(sdmmc_t *sdmmc)
{
	sdmmc->card_clock_enabled = 0;
	sdmmc->regs->clkcon &= ~SDHCI_CLOCK_CARD_EN;
}

void sdmmc_card_clock_powersave(sdmmc_t *sdmmc, int powersave_enable)
{
	// Recalibrate periodically if needed.
	if (sdmmc->periodic_calibration && !powersave_enable && sdmmc->card_clock_enabled)
		_sdmmc_autocal_execute(sdmmc, sdmmc_get_io_power(sdmmc));

	sdmmc->powersave_enabled = powersave_enable;
	if (powersave_enable)
	{
		if (sdmmc->regs->clkcon & SDHCI_CLOCK_CARD_EN)
			sdmmc->regs->clkcon &= ~SDHCI_CLOCK_CARD_EN;
		return;
	}

	if (sdmmc->card_clock_enabled)
		if (!(sdmmc->regs->clkcon & SDHCI_CLOCK_CARD_EN))
			sdmmc->regs->clkcon |= SDHCI_CLOCK_CARD_EN;
}

static int _sdmmc_cache_rsp(sdmmc_t *sdmmc, u32 *rsp, u32 type)
{
	switch (type)
	{
	case SDMMC_RSP_TYPE_1:
	case SDMMC_RSP_TYPE_3:
	case SDMMC_RSP_TYPE_6:
	case SDMMC_RSP_TYPE_7:
		rsp[0] = sdmmc->regs->rspreg[0];
		break;

	case SDMMC_RSP_TYPE_2:
		// CRC is stripped, so shifting is needed.
		for (u32 i = 0; i < 4; i++)
		{
			u32 tempreg = sdmmc->regs->rspreg[3 - i];
			rsp[i] = tempreg << 8;

			if (i != 0)
				rsp[i - 1] |= (tempreg >> 24) & 0xFF;
		}
		break;

	default:
		return 1;
	}

	return 0;
}

int sdmmc_get_cached_rsp(sdmmc_t *sdmmc, u32 *rsp, u32 type)
{
	if (sdmmc->expected_rsp_type != type)
		return 1;

	switch (type)
	{
	case SDMMC_RSP_TYPE_1:
	case SDMMC_RSP_TYPE_3:
	case SDMMC_RSP_TYPE_6:
	case SDMMC_RSP_TYPE_7:
		rsp[0] = sdmmc->rsp[0];
		break;

	case SDMMC_RSP_TYPE_2:
		for (u32 i = 0; i < 4; i++)
			rsp[i] = sdmmc->rsp[i];
		break;

	default:
		return 1;
	}

	return 0;
}

static int _sdmmc_wait_cmd_data_inhibit(sdmmc_t *sdmmc, bool wait_dat)
{
	_sdmmc_commit_changes(sdmmc);

	u32 timeout = get_tmr_ms() + 2000;
	while (sdmmc->regs->prnsts & SDHCI_CMD_INHIBIT)
		if (get_tmr_ms() > timeout)
		{
			_sdmmc_reset_cmd_data(sdmmc);
			return 1;
		}

	if (wait_dat)
	{
		timeout = get_tmr_ms() + 2000;
		while (sdmmc->regs->prnsts & SDHCI_DATA_INHIBIT)
			if (get_tmr_ms() > timeout)
			{
				_sdmmc_reset_cmd_data(sdmmc);
				return 1;
			}
	}

	return 0;
}

static int _sdmmc_wait_card_busy(sdmmc_t *sdmmc)
{
	_sdmmc_commit_changes(sdmmc);

	u32 timeout = get_tmr_ms() + 2000;
	while (!(sdmmc->regs->prnsts & SDHCI_DATA_0_LVL))
		if (get_tmr_ms() > timeout)
		{
			_sdmmc_reset_cmd_data(sdmmc);
			return 1;
		}

	return 0;
}

static int _sdmmc_setup_read_small_block(sdmmc_t *sdmmc)
{
	switch (sdmmc_get_bus_width(sdmmc))
	{
	case SDMMC_BUS_WIDTH_1:
		return 1;

	case SDMMC_BUS_WIDTH_4:
		sdmmc->regs->blksize = 64;
		break;

	case SDMMC_BUS_WIDTH_8:
		sdmmc->regs->blksize = 128;
		break;
	}

	sdmmc->regs->blkcnt = 1;
	sdmmc->regs->trnmod = SDHCI_TRNS_READ;

	return 0;
}

static int _sdmmc_send_cmd(sdmmc_t *sdmmc, const sdmmc_cmd_t *cmd, bool is_data_present)
{
	u16 cmdflags = 0;

	switch (cmd->rsp_type)
	{
	case SDMMC_RSP_TYPE_0:
		break;

	case SDMMC_RSP_TYPE_1:
	case SDMMC_RSP_TYPE_6:
	case SDMMC_RSP_TYPE_7:
		if (cmd->check_busy)
			cmdflags = SDHCI_CMD_RESP_LEN48_BUSY | SDHCI_CMD_INDEX | SDHCI_CMD_CRC;
		else
			cmdflags = SDHCI_CMD_RESP_LEN48      | SDHCI_CMD_INDEX | SDHCI_CMD_CRC;
		break;

	case SDMMC_RSP_TYPE_2:
		cmdflags = SDHCI_CMD_RESP_LEN136 | SDHCI_CMD_CRC;
		break;

	case SDMMC_RSP_TYPE_3:
		cmdflags = SDHCI_CMD_RESP_LEN48;
		break;

	default:
		return 1;
	}

	if (is_data_present)
		cmdflags |= SDHCI_CMD_DATA;

	sdmmc->regs->argument = cmd->arg;
	sdmmc->regs->cmdreg   = SDHCI_CMD_IDX(cmd->cmd) | cmdflags;

	return 0;
}

static void _sdmmc_send_tuning_cmd(sdmmc_t *sdmmc, u32 cmd)
{
	sdmmc_cmd_t cmdbuf;
	cmdbuf.cmd = cmd;
	cmdbuf.arg = 0;
	cmdbuf.rsp_type = SDMMC_RSP_TYPE_1;
	cmdbuf.check_busy = 0;
	_sdmmc_send_cmd(sdmmc, &cmdbuf, true);
}

static int _sdmmc_tuning_execute_once(sdmmc_t *sdmmc, u32 cmd, u32 tap)
{
	if (_sdmmc_wait_cmd_data_inhibit(sdmmc, true))
		return 1;

	_sdmmc_setup_read_small_block(sdmmc);

	sdmmc->regs->norintstsen |= SDHCI_INT_DATA_AVAIL;
	sdmmc->regs->norintsts = sdmmc->regs->norintsts;
	sdmmc->regs->clkcon &= ~SDHCI_CLOCK_CARD_EN;

#ifdef BDK_SDMMC_UHS_DDR200_SUPPORT
	// Set tap if manual tuning.
	if (tap != SDMMC_HW_TAP_TUNING)
	{
		sdmmc->regs->ventunctl0 &= ~SDHCI_TEGRA_TUNING_TAP_HW_UPDATED;
		sdmmc->regs->venclkctl   = (sdmmc->regs->venclkctl & 0xFF00FFFF) | (tap << 16);
		sdmmc->regs->ventunctl0 |=  SDHCI_TEGRA_TUNING_TAP_HW_UPDATED;
	}
#endif

	_sdmmc_send_tuning_cmd(sdmmc, cmd);
	_sdmmc_commit_changes(sdmmc);
	usleep(1);

	_sdmmc_reset_cmd_data(sdmmc);

	sdmmc->regs->clkcon |= SDHCI_CLOCK_CARD_EN;
	_sdmmc_commit_changes(sdmmc);

	u32 timeout = get_tmr_us() + 5000;
	while (get_tmr_us() < timeout)
	{
		// Check if we got valid data.
		if (sdmmc->regs->norintsts & SDHCI_INT_DATA_AVAIL)
		{
			sdmmc->regs->norintsts = SDHCI_INT_DATA_AVAIL;
			sdmmc->regs->norintstsen &= ~SDHCI_INT_DATA_AVAIL;
			_sdmmc_commit_changes(sdmmc);
			usleep((8 * 1000 + sdmmc->card_clock - 1) / sdmmc->card_clock); // Wait 8 cycles.

			return 0;
		}
	}

	_sdmmc_reset_cmd_data(sdmmc);

	sdmmc->regs->norintstsen &= ~SDHCI_INT_DATA_AVAIL;
	_sdmmc_commit_changes(sdmmc);
	usleep((8 * 1000 + sdmmc->card_clock - 1) / sdmmc->card_clock); // Wait 8 cycles.

	return 1;
}

#ifdef BDK_SDMMC_UHS_DDR200_SUPPORT
typedef struct _sdmmc_manual_tuning_t
{
	u32 result[8];
	u32 num_iter;
	u32 tap_start;
	u32 tap_end;
} sdmmc_manual_tuning_t;

static int _sdmmc_manual_tuning_set_tap(sdmmc_t *sdmmc, sdmmc_manual_tuning_t *tuning)
{
	u32 tap_start = SDMMC_INVALID_TAP;
	u32 win_size  = 0;
	u32 best_tap  = 0;
	u32 best_size = 0;

	for (u32 i = 0; i < tuning->num_iter; i++)
	{
		u32 iter_end = i == (tuning->num_iter - 1) ? 1 : 0;
		u32 stable = tuning->result[i / 32] & BIT(i % 32);
		if (stable && !iter_end)
		{
			if (tap_start == SDMMC_INVALID_TAP)
				tap_start = i;

			win_size++;
		}
		else
		{
			if (tap_start != SDMMC_INVALID_TAP)
			{
				u32 tap_end = !iter_end ? (i - 1) : i;

				// Check if window is wider.
				if (win_size > best_size)
				{
					best_tap  = (tap_start + tap_end) / 2;
					best_size = win_size + iter_end;
				}

				tap_start = SDMMC_INVALID_TAP;
				win_size  = 0;
			}
		}
	}


	// Check if failed or window too small.
	if (!best_tap || best_size < SDMMC_SAMPLE_WIN_SIZE_MIN)
		return 1;

	sdmmc->regs->clkcon     &= ~SDHCI_CLOCK_CARD_EN;
	sdmmc->regs->ventunctl0 &= ~SDHCI_TEGRA_TUNING_TAP_HW_UPDATED;

	// Set tap.
	sdmmc->regs->venclkctl   = (sdmmc->regs->venclkctl & 0xFF00FFFF) | (best_tap << 16);

	sdmmc->regs->ventunctl0 |=  SDHCI_TEGRA_TUNING_TAP_HW_UPDATED;
	sdmmc->regs->clkcon     |= SDHCI_CLOCK_CARD_EN;

	return 0;
}

/*
 * SD Card DDR200 (DDR208) support
 *
 * On Tegra X1, that can be done with DDR50 host mode.
 * That's because HS400 4-bit or HS400 generally, is not supported on SDMMC1/3.
 * And also, tuning can't be done automatically on any DDR mode.
 * So it needs to be done manually and selected tap will be applied from the biggest
 * sampling window.
 * That allows DDR200 support on every DDR200 sd card, other than the original maker
 * of DDR200, Sandisk. Since Sandisk cards mandate DLL syncing.
 */
static int sdmmc_tuning_execute_ddr200(sdmmc_t *sdmmc)
{
	sdmmc_manual_tuning_t manual_tuning = { 0 };
	manual_tuning.num_iter = 128;

	sdmmc->regs->ventunctl1  = 0; // step_size 1.
	sdmmc->regs->ventunctl0  = (sdmmc->regs->ventunctl0 & 0xFFFF1FFF) | (2 << 13); // 128 Tries.
	sdmmc->regs->ventunctl0  = (sdmmc->regs->ventunctl0 & 0xFFFFE03F) | (1 << 6);  // 1x Multiplier.
	sdmmc->regs->ventunctl0 |= SDHCI_TEGRA_TUNING_TAP_HW_UPDATED;

	sdmmc->regs->hostctl2   |= SDHCI_CTRL_EXEC_TUNING;

	for (u32 i = 0; i < manual_tuning.num_iter; i++)
	{
		_sdmmc_tuning_execute_once(sdmmc, MMC_SEND_TUNING_BLOCK, i);

		// Save result for manual tuning.
		int sampled = (sdmmc->regs->hostctl2 >> SDHCI_CTRL_TUNED_CLK_SHIFT) & 1;
		manual_tuning.result[i / 32] |= sampled << (i % 32);

		if (!(sdmmc->regs->hostctl2 & SDHCI_CTRL_EXEC_TUNING))
			break;
	}

	return _sdmmc_manual_tuning_set_tap(sdmmc, &manual_tuning);
}
#endif

int sdmmc_tuning_execute(sdmmc_t *sdmmc, u32 type, u32 cmd)
{
	u32 num_iter, flag;

	if (sdmmc->powersave_enabled)
		return 1;

	switch (type)
	{
	case SDHCI_TIMING_MMC_HS200:
	case SDHCI_TIMING_UHS_SDR104:
	case SDHCI_TIMING_UHS_SDR82:
		num_iter = 128;
		flag = (2 << 13); // 128 iterations.
		break;

	case SDHCI_TIMING_UHS_SDR50:
	case SDHCI_TIMING_UHS_DDR50: // HW tuning is not supported on DDR modes. But it sets tap to 0 which is proper.
	case SDHCI_TIMING_MMC_HS100:
		num_iter = 256;
		flag = (4 << 13); // 256 iterations.
		break;

	case SDHCI_TIMING_MMC_HS400:
	case SDHCI_TIMING_UHS_SDR12:
	case SDHCI_TIMING_UHS_SDR25:
		return 0;

#ifdef BDK_SDMMC_UHS_DDR200_SUPPORT
	case SDHCI_TIMING_UHS_DDR200:
		return sdmmc_tuning_execute_ddr200(sdmmc);
#endif

	default:
		return 1;
	}

	sdmmc->regs->ventunctl1  = 0; // step_size 1.
	sdmmc->regs->ventunctl0  = (sdmmc->regs->ventunctl0 & 0xFFFF1FFF) | flag;     // Tries.
	sdmmc->regs->ventunctl0  = (sdmmc->regs->ventunctl0 & 0xFFFFE03F) | (1 << 6); // 1x Multiplier.
	sdmmc->regs->ventunctl0 |= SDHCI_TEGRA_TUNING_TAP_HW_UPDATED;

	sdmmc->regs->hostctl2   |= SDHCI_CTRL_EXEC_TUNING;

	for (u32 i = 0; i < num_iter; i++)
	{
		_sdmmc_tuning_execute_once(sdmmc, cmd, SDMMC_HW_TAP_TUNING);

		if (!(sdmmc->regs->hostctl2 & SDHCI_CTRL_EXEC_TUNING))
			break;
	}

	if (sdmmc->regs->hostctl2 & SDHCI_CTRL_TUNED_CLK)
		return 0;

	return 1;
}

static int _sdmmc_enable_internal_clock(sdmmc_t *sdmmc)
{
	//Enable internal clock and wait till it is stable.
	sdmmc->regs->clkcon |= SDHCI_CLOCK_INT_EN;
	_sdmmc_commit_changes(sdmmc);
	u32 timeout = get_tmr_ms() + 2000;
	while (!(sdmmc->regs->clkcon & SDHCI_CLOCK_INT_STABLE))
	{
		if (get_tmr_ms() > timeout)
			return 1;
	}

	sdmmc->regs->hostctl2 &= ~SDHCI_CTRL_PRESET_VAL_EN;
	sdmmc->regs->clkcon   &= ~SDHCI_PROG_CLOCK_MODE;
	// Enable 32/64bit addressing if used (sysad. if blkcnt it fallbacks to 16bit).
	sdmmc->regs->hostctl2 |= SDHCI_HOST_VERSION_4_EN;

	if (!(sdmmc->regs->capareg & SDHCI_CAP_64BIT))
		return 1;

	sdmmc->regs->hostctl2  |= SDHCI_ADDRESSING_64BIT_EN;
	sdmmc->regs->hostctl   &= ~SDHCI_CTRL_DMA_MASK; // Use SDMA. Host V4 enabled so adma address regs in use.
	sdmmc->regs->timeoutcon = (sdmmc->regs->timeoutcon & 0xF0) | 14; // TMCLK * 2^27.

	return 0;
}

static int _sdmmc_autocal_config_offset(sdmmc_t *sdmmc, u32 power)
{
	u32 off_pd = 0;
	u32 off_pu = 0;

	switch (sdmmc->id)
	{
	case SDMMC_2:
	case SDMMC_4:
		if (power != SDMMC_POWER_1_8)
			return 1;
		off_pd = 5;
		off_pu = 5;
		break;

	case SDMMC_1:
		if (power == SDMMC_POWER_1_8)
		{
			if (!sdmmc->t210b01)
			{
				off_pd = 0x7B; // -5.
				off_pu = 0x7B; // -5.
			}
			else
			{
				off_pd = 6;
				off_pu = 6;
			}
		}
		else if (power == SDMMC_POWER_3_3)
		{
			if (!sdmmc->t210b01)
			{
				off_pd = 0x7D; // -3.
				off_pu = 0;
			}
		}
		else
			return 1;
		break;
	}

	sdmmc->regs->autocalcfg = (sdmmc->regs->autocalcfg & 0xFFFF8080) | (off_pd << 8) | off_pu;
	return 0;
}

static void _sdmmc_enable_interrupts(sdmmc_t *sdmmc)
{
	sdmmc->regs->norintstsen |= SDHCI_INT_DMA_END | SDHCI_INT_DATA_END | SDHCI_INT_RESPONSE;
	sdmmc->regs->errintstsen |= SDHCI_ERR_INT_ALL_EXCEPT_ADMA_BUSPWR;
	sdmmc->regs->norintsts = sdmmc->regs->norintsts;
	sdmmc->regs->errintsts = sdmmc->regs->errintsts;
	sdmmc->error_sts = 0;
}

static void _sdmmc_mask_interrupts(sdmmc_t *sdmmc)
{
	sdmmc->regs->errintstsen &= ~SDHCI_ERR_INT_ALL_EXCEPT_ADMA_BUSPWR;
	sdmmc->regs->norintstsen &= ~(SDHCI_INT_DMA_END | SDHCI_INT_DATA_END | SDHCI_INT_RESPONSE);
}

static u32 _sdmmc_check_mask_interrupt(sdmmc_t *sdmmc, u16 *pout, u16 mask)
{
	u16 norintsts = sdmmc->regs->norintsts;
	u16 errintsts = sdmmc->regs->errintsts;

	DPRINTF("norintsts %08X, errintsts %08X\n", norintsts, errintsts);

	if (pout)
		*pout = norintsts;

	// Check for error interrupt.
	if (norintsts & SDHCI_INT_ERROR)
	{
#ifdef ERROR_EXTRA_PRINTING
		EPRINTFARGS("SDMMC%d: intsts %08X, errintsts %08X", sdmmc->id + 1, norintsts, errintsts);
#endif
		sdmmc->error_sts = errintsts;
		sdmmc->regs->errintsts = errintsts;
		return SDMMC_MASKINT_ERROR;
	}
	else if (norintsts & mask)
	{
		sdmmc->regs->norintsts = norintsts & mask;
		return SDMMC_MASKINT_MASKED;
	}

	return SDMMC_MASKINT_NOERROR;
}

static int _sdmmc_wait_response(sdmmc_t *sdmmc)
{
	_sdmmc_commit_changes(sdmmc);

	u32 timeout = get_tmr_ms() + 2000;
	while (true)
	{
		u32 res = _sdmmc_check_mask_interrupt(sdmmc, NULL, SDHCI_INT_RESPONSE);
		if (res == SDMMC_MASKINT_MASKED)
			break;
		if (res != SDMMC_MASKINT_NOERROR || get_tmr_ms() > timeout)
		{
			_sdmmc_reset_cmd_data(sdmmc);
			return 1;
		}
	}

	return 0;
}

static int _sdmmc_stop_transmission_inner(sdmmc_t *sdmmc, u32 *rsp)
{
	sdmmc_cmd_t cmd;

	if (_sdmmc_wait_cmd_data_inhibit(sdmmc, false))
		return 1;

	_sdmmc_enable_interrupts(sdmmc);

	cmd.cmd = MMC_STOP_TRANSMISSION;
	cmd.arg = 0;
	cmd.rsp_type = SDMMC_RSP_TYPE_1;
	cmd.check_busy = 1;

	_sdmmc_send_cmd(sdmmc, &cmd, false);

	int res = _sdmmc_wait_response(sdmmc);
	_sdmmc_mask_interrupts(sdmmc);

	if (res)
		return 1;

	_sdmmc_cache_rsp(sdmmc, rsp, SDMMC_RSP_TYPE_1);

	return _sdmmc_wait_card_busy(sdmmc);
}

int sdmmc_stop_transmission(sdmmc_t *sdmmc, u32 *rsp)
{
	if (!sdmmc->card_clock_enabled)
		return 1;

	// Recalibrate periodically if needed.
	if (sdmmc->periodic_calibration && sdmmc->powersave_enabled)
		_sdmmc_autocal_execute(sdmmc, sdmmc_get_io_power(sdmmc));

	bool should_disable_sd_clock = false;
	if (!(sdmmc->regs->clkcon & SDHCI_CLOCK_CARD_EN))
	{
		should_disable_sd_clock = true;
		sdmmc->regs->clkcon |= SDHCI_CLOCK_CARD_EN;
		_sdmmc_commit_changes(sdmmc);
		usleep((8 * 1000 + sdmmc->card_clock - 1) / sdmmc->card_clock); // Wait 8 cycles.
	}

	int res = _sdmmc_stop_transmission_inner(sdmmc, rsp);
	usleep((8 * 1000 + sdmmc->card_clock - 1) / sdmmc->card_clock); // Wait 8 cycles.

	if (should_disable_sd_clock)
		sdmmc->regs->clkcon &= ~SDHCI_CLOCK_CARD_EN;

	return res;
}

static int _sdmmc_config_sdma(sdmmc_t *sdmmc, u32 *blkcnt_out, const sdmmc_req_t *request)
{
	if (!request->blksize || !request->num_sectors)
		return 1;

	u32 blkcnt = request->num_sectors;
	if (blkcnt >= SDMMC_HMAX_BLOCKNUM)
		blkcnt = SDMMC_HMAX_BLOCKNUM;
	u32 admaaddr = (u32)request->buf;

	// Check alignment.
	if (admaaddr & 7)
		return 1;

	sdmmc->regs->admaaddr = admaaddr;
	sdmmc->regs->admaaddr_hi = 0;

	sdmmc->dma_addr_next = ALIGN_DOWN((admaaddr + SZ_512K), SZ_512K);

	sdmmc->regs->blksize = request->blksize | (7u << 12); // SDMA DMA 512KB Boundary (Detects A18 carry out).
	sdmmc->regs->blkcnt  = blkcnt;

	if (blkcnt_out)
		*blkcnt_out = blkcnt;

	u32 trnmode = SDHCI_TRNS_DMA | SDHCI_TRNS_RTYPE_R1;

	// Set multiblock request.
	if (request->is_multi_block)
		trnmode |= SDHCI_TRNS_MULTI | SDHCI_TRNS_BLK_CNT_EN;

	// Set request direction.
	if (!request->is_write)
		trnmode |= SDHCI_TRNS_READ;

	// Automatic send of stop transmission or set block count cmd.
	if (request->is_auto_stop_trn)
		trnmode |= SDHCI_TRNS_AUTO_CMD12;
	//else if (request->is_auto_set_blkcnt)
	//	trnmode |= SDHCI_TRNS_AUTO_CMD23;

	sdmmc->regs->trnmod = trnmode;

	return 0;
}

static int _sdmmc_update_sdma(sdmmc_t *sdmmc)
{
	u16 blkcnt = 0;
	do
	{
		blkcnt = sdmmc->regs->blkcnt;
		u32 timeout = get_tmr_ms() + 1500;
		do
		{
			u32 res = SDMMC_MASKINT_MASKED;
			while (true)
			{
				u16 intr = 0;
				res = _sdmmc_check_mask_interrupt(sdmmc, &intr,
					SDHCI_INT_DATA_END | SDHCI_INT_DMA_END);
				if (res != SDMMC_MASKINT_MASKED)
					break;

				if (intr & SDHCI_INT_DATA_END)
					return 0; // Transfer complete.

				if (intr & SDHCI_INT_DMA_END)
				{
					// Update DMA.
					sdmmc->regs->admaaddr = sdmmc->dma_addr_next;
					sdmmc->regs->admaaddr_hi = 0;
					sdmmc->dma_addr_next += SZ_512K;
				}
			}

			if (res != SDMMC_MASKINT_NOERROR)
			{
#ifdef ERROR_EXTRA_PRINTING
				EPRINTFARGS("SDMMC%d: int error!", sdmmc->id + 1);
#endif
				_sdmmc_reset_cmd_data(sdmmc);

				return 1;
			}
		} while (get_tmr_ms() < timeout);
	} while (sdmmc->regs->blkcnt != blkcnt);

	_sdmmc_reset_cmd_data(sdmmc);

	return 1;
}

static int _sdmmc_execute_cmd_inner(sdmmc_t *sdmmc, sdmmc_cmd_t *cmd, sdmmc_req_t *request, u32 *blkcnt_out)
{
	bool has_req_or_check_busy = request || cmd->check_busy;
	if (_sdmmc_wait_cmd_data_inhibit(sdmmc, has_req_or_check_busy))
		return 1;

	u32 blkcnt = 0;
	bool is_data_present = false;
	if (request)
	{
		if (_sdmmc_config_sdma(sdmmc, &blkcnt, request))
		{
#ifdef ERROR_EXTRA_PRINTING
			EPRINTFARGS("SDMMC%d: DMA Wrong cfg!", sdmmc->id + 1);
#endif
			return 1;
		}

		// Flush cache before starting the transfer.
		bpmp_mmu_maintenance(BPMP_MMU_MAINT_CLEAN_WAY, false);

		is_data_present = true;
	}

	_sdmmc_enable_interrupts(sdmmc);

	if (_sdmmc_send_cmd(sdmmc, cmd, is_data_present))
	{
#ifdef ERROR_EXTRA_PRINTING
		EPRINTFARGS("SDMMC%d: Wrong Response type %08X!", sdmmc->id + 1, cmd->rsp_type);
#endif
		return 1;
	}

	int res = _sdmmc_wait_response(sdmmc);
#ifdef ERROR_EXTRA_PRINTING
	if (res)
		EPRINTFARGS("SDMMC%d: Transfer error!", sdmmc->id + 1);
#endif
	DPRINTF("rsp(%d): %08X, %08X, %08X, %08X\n", res,
		sdmmc->regs->rspreg[0], sdmmc->regs->rspreg[1], sdmmc->regs->rspreg[2], sdmmc->regs->rspreg[3]);

	if (!res)
	{
		if (cmd->rsp_type)
		{
			sdmmc->expected_rsp_type = cmd->rsp_type;
			res = _sdmmc_cache_rsp(sdmmc, sdmmc->rsp, cmd->rsp_type);
		}
		if (request && !res)
		{
			res = _sdmmc_update_sdma(sdmmc);
#ifdef ERROR_EXTRA_PRINTING
			if (res)
				EPRINTFARGS("SDMMC%d: DMA Update failed!", sdmmc->id + 1);
#endif
		}
	}

	_sdmmc_mask_interrupts(sdmmc);

	if (!res)
	{
		if (request)
		{
			// Invalidate cache after transfer.
			bpmp_mmu_maintenance(BPMP_MMU_MAINT_INVALID_WAY, false);

			if (blkcnt_out)
				*blkcnt_out = blkcnt;

			if (request->is_auto_stop_trn)
				sdmmc->stop_trn_rsp = sdmmc->regs->rspreg[3];
		}

		if (has_req_or_check_busy)
		{
			res = _sdmmc_wait_card_busy(sdmmc);
#ifdef ERROR_EXTRA_PRINTING
			if (res)
				EPRINTFARGS("SDMMC%d: Busy timeout!", sdmmc->id + 1);
#endif
		}
	}

	return res;
}

bool sdmmc_get_sd_inserted()
{
	return (!gpio_read(GPIO_PORT_Z, GPIO_PIN_1));
}

static void _sdmmc_config_sdmmc1_schmitt()
{
	PINMUX_AUX(PINMUX_AUX_SDMMC1_CLK)  |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC1_CMD)  |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC1_DAT3) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC1_DAT2) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC1_DAT1) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC1_DAT0) |= PINMUX_SCHMT;
}

static void _sdmmc_config_sdmmc2_schmitt()
{
	PINMUX_AUX(PINMUX_AUX_SDMMC2_CLK)  |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC2_CMD)  |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC2_DAT7) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC2_DAT6) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC2_DAT5) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC2_DAT4) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC2_DAT3) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC2_DAT2) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC2_DAT1) |= PINMUX_SCHMT;
	PINMUX_AUX(PINMUX_AUX_SDMMC2_DAT0) |= PINMUX_SCHMT;
}

static void _sdmmc_config_sdmmc1_pads(bool discharge)
{
	u32 sdmmc1_pin_mask = GPIO_PIN_0 | GPIO_PIN_1 | GPIO_PIN_2 | GPIO_PIN_3 | GPIO_PIN_4 | GPIO_PIN_5;

	// Set values for Reset state.
	u32 function = GPIO_MODE_SPIO;
	u32 level    = GPIO_LOW;
	u32 output   = GPIO_OUTPUT_DISABLE;

	// Set values for discharging.
	if (discharge)
	{
		function = GPIO_MODE_GPIO;
		level    = GPIO_HIGH;
		output   = GPIO_OUTPUT_ENABLE;
	}

	// Set all pads function.
	gpio_config(GPIO_PORT_M, sdmmc1_pin_mask, function);
	// Set all pads output level.
	gpio_write(GPIO_PORT_M, sdmmc1_pin_mask, level);
	// Set all pads output.
	gpio_output_enable(GPIO_PORT_M, sdmmc1_pin_mask, output);
}

static int _sdmmc_config_sdmmc1(bool t210b01)
{
	// Configure SD card detect.
	PINMUX_AUX(PINMUX_AUX_GPIO_PZ1) = PINMUX_INPUT_ENABLE | PINMUX_PULL_UP | 2; // GPIO control, pull up.
	APB_MISC(APB_MISC_GP_VGPIO_GPIO_MUX_SEL) = 0;
	gpio_direction_input(GPIO_PORT_Z, GPIO_PIN_1);
	usleep(100);

	// Check if SD card is inserted.
	if (!sdmmc_get_sd_inserted())
		return 1;

	// Enable deep loopback for SDMMC1 CLK pad so reads work.
	APB_MISC(APB_MISC_GP_SDMMC1_CLK_LPBK_CONTROL) = 1;

	// Configure SDMMC1 CLK pinmux, based on state and SoC type.
	PINMUX_AUX(PINMUX_AUX_SDMMC1_CLK) &= ~PINMUX_SCHMT;
	if (PINMUX_AUX(PINMUX_AUX_SDMMC1_CLK) != (PINMUX_DRIVE_2X | PINMUX_INPUT_ENABLE | PINMUX_PULL_DOWN)) // Check if CLK pad is already configured.
		PINMUX_AUX(PINMUX_AUX_SDMMC1_CLK) = PINMUX_DRIVE_2X | PINMUX_INPUT_ENABLE | (t210b01 ? PINMUX_PULL_NONE : PINMUX_PULL_DOWN);

	// Configure reset state of SDMMC1 pins pinmux.
	PINMUX_AUX(PINMUX_AUX_SDMMC1_CMD)  = PINMUX_DRIVE_2X | PINMUX_INPUT_ENABLE | PINMUX_PULL_UP;
	PINMUX_AUX(PINMUX_AUX_SDMMC1_DAT3) = PINMUX_DRIVE_2X | PINMUX_INPUT_ENABLE | PINMUX_PULL_UP;
	PINMUX_AUX(PINMUX_AUX_SDMMC1_DAT2) = PINMUX_DRIVE_2X | PINMUX_INPUT_ENABLE | PINMUX_PULL_UP;
	PINMUX_AUX(PINMUX_AUX_SDMMC1_DAT1) = PINMUX_DRIVE_2X | PINMUX_INPUT_ENABLE | PINMUX_PULL_UP;
	PINMUX_AUX(PINMUX_AUX_SDMMC1_DAT0) = PINMUX_DRIVE_2X | PINMUX_INPUT_ENABLE | PINMUX_PULL_UP;

	// Force schmitt trigger for T210B01.
	if (t210b01)
		_sdmmc_config_sdmmc1_schmitt();

	// Make sure the SDMMC1 controller is powered.
	PMC(APBDEV_PMC_NO_IOPOWER) |=  PMC_NO_IOPOWER_SDMMC1;
	usleep(1000);
	PMC(APBDEV_PMC_NO_IOPOWER) &= ~PMC_NO_IOPOWER_SDMMC1;
	(void)PMC(APBDEV_PMC_NO_IOPOWER); // Commit write.

	// Enable SD card power. Powers LDO2 also.
	PINMUX_AUX(PINMUX_AUX_DMIC3_CLK) = PINMUX_PULL_DOWN | 2;
	gpio_direction_output(GPIO_PORT_E, GPIO_PIN_4, GPIO_HIGH);
	usleep(10000); // Minimum 3 to 10 ms.

	// Inform IO pads that voltage is gonna be 3.3V.
	PMC(APBDEV_PMC_PWR_DET_VAL) |= PMC_PWR_DET_33V_SDMMC1;
	(void)PMC(APBDEV_PMC_PWR_DET_VAL); // Commit write.

	// Enable SD card IO power.
	max7762x_regulator_set_voltage(REGULATOR_LDO2, 3300000);
	max7762x_regulator_enable(REGULATOR_LDO2, true);
	usleep(1000);

	// Set pad slew codes to get good quality clock.
	if (!t210b01)
	{
		APB_MISC(APB_MISC_GP_SDMMC1_PAD_CFGPADCTRL) = (APB_MISC(APB_MISC_GP_SDMMC1_PAD_CFGPADCTRL) & 0xFFFFFFF) | 0x50000000;
		(void)APB_MISC(APB_MISC_GP_SDMMC1_PAD_CFGPADCTRL); // Commit write.
		usleep(1000);
	}

	return 0;
}

static void _sdmmc_config_emmc(u32 id, bool t210b01)
{
	switch (id)
	{
	case SDMMC_2:
		if (!t210b01)
		{
			// Unset park for pads.
			APB_MISC(APB_MISC_GP_EMMC2_PAD_CFGPADCTRL) &= 0xF8003FFF;
			(void)APB_MISC(APB_MISC_GP_EMMC2_PAD_CFGPADCTRL); // Commit write.
		}
		else // Enable schmitt trigger for T210B01.
			_sdmmc_config_sdmmc2_schmitt();
		break;

	case SDMMC_4:
		// Unset park for pads.
		APB_MISC(APB_MISC_GP_EMMC4_PAD_CFGPADCTRL) &= 0xF8003FFF;
		// Set default pad cfg.
		if (t210b01)
			APB_MISC(APB_MISC_GP_EMMC4_PAD_PUPD_CFGPADCTRL) &= 0xFFBFFFF9; // Unset CMD/CLK/DQS weak pull up/down.
		// Enable schmitt trigger.
		APB_MISC(APB_MISC_GP_EMMC4_PAD_CFGPADCTRL) |= 1;
		(void)APB_MISC(APB_MISC_GP_EMMC4_PAD_CFGPADCTRL); // Commit write.
		break;
	}
}

int sdmmc_init(sdmmc_t *sdmmc, u32 id, u32 power, u32 bus_width, u32 type)
{
	u32 clock;
	u16 divisor;
	u8 vref_sel = 7;

	static const u8 trim_values_t210[4]    = {  2,  8,  3,  8 };
	static const u8 trim_values_t210b01[4] = { 14, 13, 15, 13 };
	const u8 *trim_values;

	if (id > SDMMC_4 || id == SDMMC_3)
		return 1;

	memset(sdmmc, 0, sizeof(sdmmc_t));

	sdmmc->regs = (t210_sdmmc_t *)(SDMMC_BASE + (u32)_sdmmc_base_offsets[id]);
	sdmmc->id = id;
	sdmmc->clock_stopped = 1;
	sdmmc->t210b01 = hw_get_chip_id() == GP_HIDREV_MAJOR_T210B01;

	trim_values = sdmmc->t210b01 ? trim_values_t210b01 : trim_values_t210;

	// Do specific SDMMC HW configuration.
	switch (id)
	{
	case SDMMC_1:
		if (_sdmmc_config_sdmmc1(sdmmc->t210b01))
			return 1;
		if (sdmmc->t210b01)
			vref_sel = 0;
		else
			sdmmc->periodic_calibration = 1;
		break;

	case SDMMC_2:
	case SDMMC_4:
		_sdmmc_config_emmc(id, sdmmc->t210b01);
		break;
	}

	// Disable clock if enabled.
	if (clock_sdmmc_is_active(id))
	{
		_sdmmc_card_clock_disable(sdmmc);
		_sdmmc_commit_changes(sdmmc);
	}

	// Configure and enable selected clock.
	clock_sdmmc_get_card_clock_div(&clock, &divisor, type);
	clock_sdmmc_enable(id, clock);
	sdmmc->clock_stopped = 0;

	// Make sure all sdmmc registers are reset.
	_sdmmc_reset_all(sdmmc);

	// Set default pad IO trimming configuration.
	sdmmc->regs->iospare |= BIT(19);      // Enable 1 cycle delayed cmd_oen.
	sdmmc->regs->veniotrimctl &= ~BIT(2); // Set Band Gap VREG to supply DLL.
	sdmmc->regs->venclkctl = (sdmmc->regs->venclkctl & 0xE0FFFFFB) | ((u32)trim_values[sdmmc->id] << 24);
	sdmmc->regs->sdmemcmppadctl = (sdmmc->regs->sdmemcmppadctl & ~SDHCI_TEGRA_PADCTRL_VREF_SEL_MASK) | vref_sel;

	// Configure auto calibration values.
	if (_sdmmc_autocal_config_offset(sdmmc, power))
		return 1;

	_sdmmc_commit_changes(sdmmc);

	// Calibrate pads.
	_sdmmc_autocal_execute(sdmmc, power);

	// Enable internal clock and power.
	if (!_sdmmc_enable_internal_clock(sdmmc))
	{
		sdmmc_set_bus_width(sdmmc, bus_width);
		_sdmmc_set_io_power(sdmmc, power);

		if (!sdmmc_setup_clock(sdmmc, type))
		{
			sdmmc_card_clock_powersave(sdmmc, SDMMC_POWER_SAVE_DISABLE);
			_sdmmc_card_clock_enable(sdmmc);
			_sdmmc_commit_changes(sdmmc);

			return 0;
		}
	}

	// Failed to enable clock.
	return 1;
}

void sdmmc1_disable_power()
{
	// T210B01 WAR: Clear pull down from CLK pad.
	PINMUX_AUX(PINMUX_AUX_SDMMC1_CLK) &= ~PINMUX_PULL_MASK;

	// T210B01 WAR: Set pads to discharge state.
	_sdmmc_config_sdmmc1_pads(true);

	// Disable SD card IO power.
	max7762x_regulator_enable(REGULATOR_LDO2, false);
	usleep(4000);

	// Disable SD card power.
	gpio_write(GPIO_PORT_E, GPIO_PIN_4, GPIO_LOW);

	// T210/T210B01 WAR: Set start timer for IO and Controller power discharge.
	sd_power_cycle_time_start = get_tmr_ms();
	usleep(10000); // To power cycle, min 1ms without power is needed.

	// Disable SDMMC1 controller power.
	PMC(APBDEV_PMC_NO_IOPOWER) |= PMC_NO_IOPOWER_SDMMC1;
	(void)PMC(APBDEV_PMC_NO_IOPOWER); // Commit write.

	// Inform IO pads that next voltage might be 3.3V.
	PMC(APBDEV_PMC_PWR_DET_VAL) |= PMC_PWR_DET_33V_SDMMC1;
	(void)PMC(APBDEV_PMC_PWR_DET_VAL); // Commit write.

	// T210B01 WAR: Restore pads to reset state.
	_sdmmc_config_sdmmc1_pads(false);

	// T210B01 WAR: Restore pull down to CLK pad.
	PINMUX_AUX(PINMUX_AUX_SDMMC1_CLK) |= PINMUX_PULL_DOWN;
}

void sdmmc_end(sdmmc_t *sdmmc)
{
	if (!sdmmc->clock_stopped)
	{
		_sdmmc_card_clock_disable(sdmmc);
		// Disable SDMMC power.
		_sdmmc_set_io_power(sdmmc, SDMMC_POWER_OFF);
		_sdmmc_commit_changes(sdmmc);

		// Disable SD card power.
		if (sdmmc->id == SDMMC_1)
			sdmmc1_disable_power();

		clock_sdmmc_disable(sdmmc->id);
		sdmmc->clock_stopped = 1;
	}
}

void sdmmc_init_cmd(sdmmc_cmd_t *cmdbuf, u16 cmd, u32 arg, u32 rsp_type, u32 check_busy)
{
	cmdbuf->cmd = cmd;
	cmdbuf->arg = arg;
	cmdbuf->rsp_type = rsp_type;
	cmdbuf->check_busy = check_busy;
}

int sdmmc_execute_cmd(sdmmc_t *sdmmc, sdmmc_cmd_t *cmd, sdmmc_req_t *request, u32 *blkcnt_out)
{
	if (!sdmmc->card_clock_enabled)
		return 1;

	// Recalibrate periodically if needed.
	if (sdmmc->periodic_calibration && sdmmc->powersave_enabled)
		_sdmmc_autocal_execute(sdmmc, sdmmc_get_io_power(sdmmc));

	int should_disable_sd_clock = 0;
	if (!(sdmmc->regs->clkcon & SDHCI_CLOCK_CARD_EN))
	{
		should_disable_sd_clock = 1;
		sdmmc->regs->clkcon |= SDHCI_CLOCK_CARD_EN;
		_sdmmc_commit_changes(sdmmc);
		usleep((8 * 1000 + sdmmc->card_clock - 1) / sdmmc->card_clock); // Wait 8 cycles.
	}

	int res = _sdmmc_execute_cmd_inner(sdmmc, cmd, request, blkcnt_out);
	usleep((8 * 1000 + sdmmc->card_clock - 1) / sdmmc->card_clock); // Wait 8 cycles.

	if (should_disable_sd_clock)
		sdmmc->regs->clkcon &= ~SDHCI_CLOCK_CARD_EN;

	return res;
}

int sdmmc_enable_low_voltage(sdmmc_t *sdmmc)
{
	if (sdmmc->id != SDMMC_1)
		return 1;

	_sdmmc_commit_changes(sdmmc);

	// Switch to 1.8V and wait for regulator to stabilize. Assume max possible wait needed.
	max7762x_regulator_set_voltage(REGULATOR_LDO2, 1800000);
	usleep(150);

	// Inform IO pads that we switched to 1.8V.
	PMC(APBDEV_PMC_PWR_DET_VAL) &= ~PMC_PWR_DET_33V_SDMMC1;
	(void)PMC(APBDEV_PMC_PWR_DET_VAL); // Commit write.

	// Enable schmitt trigger for better duty cycle and low jitter clock.
	_sdmmc_config_sdmmc1_schmitt();

	_sdmmc_autocal_config_offset(sdmmc, SDMMC_POWER_1_8);
	_sdmmc_autocal_execute(sdmmc, SDMMC_POWER_1_8);
	_sdmmc_set_io_power(sdmmc, SDMMC_POWER_1_8);
	_sdmmc_commit_changes(sdmmc);
	msleep(5); // Wait minimum 5ms before turning on the card clock.

	// Turn on SDCLK.
	if (sdmmc->regs->hostctl2 & SDHCI_CTRL_VDD_180)
	{
		sdmmc->regs->clkcon |= SDHCI_CLOCK_CARD_EN;
		_sdmmc_commit_changes(sdmmc);
		usleep(1000);
		if ((sdmmc->regs->prnsts & SDHCI_DATA_LVL_MASK) == SDHCI_DATA_LVL_MASK)
			return 0;
	}

	return 1;
}