drivers/mmc/host/mmci_stm32_sdmmc.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) STMicroelectronics 2018 - All Rights Reserved
  * Author: Ludovic.barre@st.com for STMicroelectronics.
  */
 #include <linux/bitfield.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/iopoll.h>
 #include <linux/mmc/host.h>
 #include <linux/mmc/card.h>
 #include <linux/of_address.h>
 #include <linux/reset.h>
 #include <linux/scatterlist.h>
 #include "mmci.h"

 #define SDMMC_LLI_BUF_LEN	PAGE_SIZE

 #define DLYB_CR			0x0
 #define DLYB_CR_DEN		BIT(0)
 #define DLYB_CR_SEN		BIT(1)

 #define DLYB_CFGR		0x4
 #define DLYB_CFGR_SEL_MASK	GENMASK(3, 0)
 #define DLYB_CFGR_UNIT_MASK	GENMASK(14, 8)
 #define DLYB_CFGR_LNG_MASK	GENMASK(27, 16)
 #define DLYB_CFGR_LNGF		BIT(31)

 #define DLYB_NB_DELAY		11
 #define DLYB_CFGR_SEL_MAX	(DLYB_NB_DELAY + 1)
 #define DLYB_CFGR_UNIT_MAX	127

 #define DLYB_LNG_TIMEOUT_US	1000
 #define SDMMC_VSWEND_TIMEOUT_US 10000

 #define SYSCFG_DLYBSD_CR	0x0
 #define DLYBSD_CR_EN		BIT(0)
 #define DLYBSD_CR_RXTAPSEL_MASK	GENMASK(6, 1)
 #define DLYBSD_TAPSEL_NB	32
 #define DLYBSD_BYP_EN		BIT(16)
 #define DLYBSD_BYP_CMD		GENMASK(21, 17)
 #define DLYBSD_ANTIGLITCH_EN	BIT(22)

 #define SYSCFG_DLYBSD_SR	0x4
 #define DLYBSD_SR_LOCK		BIT(0)
 #define DLYBSD_SR_RXTAPSEL_ACK	BIT(1)

 #define DLYBSD_TIMEOUT_1S_IN_US	1000000

 struct sdmmc_lli_desc {
 	u32 idmalar;
 	u32 idmabase;
 	u32 idmasize;
 };

 struct sdmmc_idma {
 	dma_addr_t sg_dma;
 	void *sg_cpu;
 	dma_addr_t bounce_dma_addr;
 	void *bounce_buf;
 	bool use_bounce_buffer;
 };

 struct sdmmc_dlyb;

 struct sdmmc_tuning_ops {
 	int (*dlyb_enable)(struct sdmmc_dlyb *dlyb);
 	void (*set_input_ck)(struct sdmmc_dlyb *dlyb);
 	int (*tuning_prepare)(struct mmci_host *host);
 	int (*set_cfg)(struct sdmmc_dlyb *dlyb, int unit __maybe_unused,
 		       int phase, bool sampler __maybe_unused);
 };

 struct sdmmc_dlyb {
 	void __iomem *base;
 	u32 unit;
 	u32 max;
 	struct sdmmc_tuning_ops *ops;
 };

 static int sdmmc_idma_validate_data(struct mmci_host *host,
 				    struct mmc_data *data)
 {
 	struct sdmmc_idma *idma = host->dma_priv;
 	struct device *dev = mmc_dev(host->mmc);
 	struct scatterlist *sg;
 	int i;

 	/*
 	 * idma has constraints on idmabase & idmasize for each element
 	 * excepted the last element which has no constraint on idmasize
 	 */
 	idma->use_bounce_buffer = false;
 	for_each_sg(data->sg, sg, data->sg_len - 1, i) {
 		if (!IS_ALIGNED(sg->offset, sizeof(u32)) ||
 		    !IS_ALIGNED(sg->length,
 				host->variant->stm32_idmabsize_align)) {
 			dev_dbg(mmc_dev(host->mmc),
 				"unaligned scatterlist: ofst:%x length:%d\n",
 				data->sg->offset, data->sg->length);
 			goto use_bounce_buffer;
 		}
 	}

 	if (!IS_ALIGNED(sg->offset, sizeof(u32))) {
 		dev_dbg(mmc_dev(host->mmc),
 			"unaligned last scatterlist: ofst:%x length:%d\n",
 			data->sg->offset, data->sg->length);
 		goto use_bounce_buffer;
 	}

 	return 0;

 use_bounce_buffer:
 	if (!idma->bounce_buf) {
 		idma->bounce_buf = dmam_alloc_coherent(dev,
 						       host->mmc->max_req_size,
 						       &idma->bounce_dma_addr,
 						       GFP_KERNEL);
 		if (!idma->bounce_buf) {
 			dev_err(dev, "Unable to map allocate DMA bounce buffer.\n");
 			return -ENOMEM;
 		}
 	}

 	idma->use_bounce_buffer = true;

 	return 0;
 }

 static int _sdmmc_idma_prep_data(struct mmci_host *host,
 				 struct mmc_data *data)
 {
 	struct sdmmc_idma *idma = host->dma_priv;

 	if (idma->use_bounce_buffer) {
 		if (data->flags & MMC_DATA_WRITE) {
 			unsigned int xfer_bytes = data->blksz * data->blocks;

 			sg_copy_to_buffer(data->sg, data->sg_len,
 					  idma->bounce_buf, xfer_bytes);
 			dma_wmb();
 		}
 	} else {
 		int n_elem;

 		n_elem = dma_map_sg(mmc_dev(host->mmc),
 				    data->sg,
 				    data->sg_len,
 				    mmc_get_dma_dir(data));

 		if (!n_elem) {
 			dev_err(mmc_dev(host->mmc), "dma_map_sg failed\n");
 			return -EINVAL;
 		}
 	}
 	return 0;
 }

 static int sdmmc_idma_prep_data(struct mmci_host *host,
 				struct mmc_data *data, bool next)
 {
 	/* Check if job is already prepared. */
 	if (!next && data->host_cookie == host->next_cookie)
 		return 0;

 	return _sdmmc_idma_prep_data(host, data);
 }

 static void sdmmc_idma_unprep_data(struct mmci_host *host,
 				   struct mmc_data *data, int err)
 {
 	struct sdmmc_idma *idma = host->dma_priv;

 	if (idma->use_bounce_buffer) {
 		if (data->flags & MMC_DATA_READ) {
 			unsigned int xfer_bytes = data->blksz * data->blocks;

 			sg_copy_from_buffer(data->sg, data->sg_len,
 					    idma->bounce_buf, xfer_bytes);
 		}
 	} else {
 		dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
 			     mmc_get_dma_dir(data));
 	}
 }

 static int sdmmc_idma_setup(struct mmci_host *host)
 {
 	struct sdmmc_idma *idma;
 	struct device *dev = mmc_dev(host->mmc);

 	idma = devm_kzalloc(dev, sizeof(*idma), GFP_KERNEL);
 	if (!idma)
 		return -ENOMEM;

 	host->dma_priv = idma;

 	if (host->variant->dma_lli) {
 		idma->sg_cpu = dmam_alloc_coherent(dev, SDMMC_LLI_BUF_LEN,
 						   &idma->sg_dma, GFP_KERNEL);
 		if (!idma->sg_cpu) {
 			dev_err(dev, "Failed to alloc IDMA descriptor\n");
 			return -ENOMEM;
 		}
 		host->mmc->max_segs = SDMMC_LLI_BUF_LEN /
 			sizeof(struct sdmmc_lli_desc);
 		host->mmc->max_seg_size = host->variant->stm32_idmabsize_mask;

 		host->mmc->max_req_size = SZ_1M;
 	} else {
 		host->mmc->max_segs = 1;
 		host->mmc->max_seg_size = host->mmc->max_req_size;
 	}

 	return dma_set_max_seg_size(dev, host->mmc->max_seg_size);
 }

 static int sdmmc_idma_start(struct mmci_host *host, unsigned int *datactrl)

 {
 	struct sdmmc_idma *idma = host->dma_priv;
 	struct sdmmc_lli_desc *desc = (struct sdmmc_lli_desc *)idma->sg_cpu;
 	struct mmc_data *data = host->data;
 	struct scatterlist *sg;
 	int i;

 	host->dma_in_progress = true;

 	if (!host->variant->dma_lli || data->sg_len == 1 ||
 	    idma->use_bounce_buffer) {
 		u32 dma_addr;

 		if (idma->use_bounce_buffer)
 			dma_addr = idma->bounce_dma_addr;
 		else
 			dma_addr = sg_dma_address(data->sg);

 		writel_relaxed(dma_addr,
 			       host->base + MMCI_STM32_IDMABASE0R);
 		writel_relaxed(MMCI_STM32_IDMAEN,
 			       host->base + MMCI_STM32_IDMACTRLR);
 		return 0;
 	}

 	for_each_sg(data->sg, sg, data->sg_len, i) {
 		desc[i].idmalar = (i + 1) * sizeof(struct sdmmc_lli_desc);
 		desc[i].idmalar |= MMCI_STM32_ULA | MMCI_STM32_ULS
 			| MMCI_STM32_ABR;
 		desc[i].idmabase = sg_dma_address(sg);
 		desc[i].idmasize = sg_dma_len(sg);
 	}

 	/* notice the end of link list */
 	desc[data->sg_len - 1].idmalar &= ~MMCI_STM32_ULA;

 	dma_wmb();
 	writel_relaxed(idma->sg_dma, host->base + MMCI_STM32_IDMABAR);
 	writel_relaxed(desc[0].idmalar, host->base + MMCI_STM32_IDMALAR);
 	writel_relaxed(desc[0].idmabase, host->base + MMCI_STM32_IDMABASE0R);
 	writel_relaxed(desc[0].idmasize, host->base + MMCI_STM32_IDMABSIZER);
 	writel_relaxed(MMCI_STM32_IDMAEN | MMCI_STM32_IDMALLIEN,
 		       host->base + MMCI_STM32_IDMACTRLR);

 	return 0;
 }

 static void sdmmc_idma_error(struct mmci_host *host)
 {
 	struct mmc_data *data = host->data;
 	struct sdmmc_idma *idma = host->dma_priv;

 	if (!dma_inprogress(host))
 		return;

 	writel_relaxed(0, host->base + MMCI_STM32_IDMACTRLR);
 	host->dma_in_progress = false;
 	data->host_cookie = 0;

 	if (!idma->use_bounce_buffer)
 		dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
 			     mmc_get_dma_dir(data));
 }

 static void sdmmc_idma_finalize(struct mmci_host *host, struct mmc_data *data)
 {
 	if (!dma_inprogress(host))
 		return;

 	writel_relaxed(0, host->base + MMCI_STM32_IDMACTRLR);
 	host->dma_in_progress = false;

 	if (!data->host_cookie)
 		sdmmc_idma_unprep_data(host, data, 0);
 }

 static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired)
 {
 	unsigned int clk = 0, ddr = 0;

 	if (host->mmc->ios.timing == MMC_TIMING_MMC_DDR52 ||
 	    host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
 		ddr = MCI_STM32_CLK_DDR;

 	/*
 	 * cclk = mclk / (2 * clkdiv)
 	 * clkdiv 0 => bypass
 	 * in ddr mode bypass is not possible
 	 */
 	if (desired) {
 		if (desired >= host->mclk && !ddr) {
 			host->cclk = host->mclk;
 		} else {
 			clk = DIV_ROUND_UP(host->mclk, 2 * desired);
 			if (clk > MCI_STM32_CLK_CLKDIV_MSK)
 				clk = MCI_STM32_CLK_CLKDIV_MSK;
 			host->cclk = host->mclk / (2 * clk);
 		}
 	} else {
 		/*
 		 * while power-on phase the clock can't be define to 0,
 		 * Only power-off and power-cyc deactivate the clock.
 		 * if desired clock is 0, set max divider
 		 */
 		clk = MCI_STM32_CLK_CLKDIV_MSK;
 		host->cclk = host->mclk / (2 * clk);
 	}

 	/* Set actual clock for debug */
 	if (host->mmc->ios.power_mode == MMC_POWER_ON)
 		host->mmc->actual_clock = host->cclk;
 	else
 		host->mmc->actual_clock = 0;

 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
 		clk |= MCI_STM32_CLK_WIDEBUS_4;
 	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
 		clk |= MCI_STM32_CLK_WIDEBUS_8;

 	clk |= MCI_STM32_CLK_HWFCEN;
 	clk |= host->clk_reg_add;
 	clk |= ddr;

 	if (host->mmc->ios.timing >= MMC_TIMING_UHS_SDR50)
 		clk |= MCI_STM32_CLK_BUSSPEED;

 	mmci_write_clkreg(host, clk);
 }

 static void sdmmc_dlyb_mp15_input_ck(struct sdmmc_dlyb *dlyb)
 {
 	if (!dlyb || !dlyb->base)
 		return;

 	/* Output clock = Input clock */
 	writel_relaxed(0, dlyb->base + DLYB_CR);
 }

 static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr)
 {
 	struct mmc_ios ios = host->mmc->ios;
 	struct sdmmc_dlyb *dlyb = host->variant_priv;

 	/* adds OF options */
 	pwr = host->pwr_reg_add;

 	if (dlyb && dlyb->ops->set_input_ck)
 		dlyb->ops->set_input_ck(dlyb);

 	if (ios.power_mode == MMC_POWER_OFF) {
 		/* Only a reset could power-off sdmmc */
 		reset_control_assert(host->rst);
 		udelay(2);
 		reset_control_deassert(host->rst);

 		/*
 		 * Set the SDMMC in Power-cycle state.
 		 * This will make that the SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK
 		 * are driven low, to prevent the Card from being supplied
 		 * through the signal lines.
 		 */
 		mmci_write_pwrreg(host, MCI_STM32_PWR_CYC | pwr);
 	} else if (ios.power_mode == MMC_POWER_ON) {
 		/*
 		 * After power-off (reset): the irq mask defined in probe
 		 * functionis lost
 		 * ault irq mask (probe) must be activated
 		 */
 		writel(MCI_IRQENABLE | host->variant->start_err,
 		       host->base + MMCIMASK0);

 		/* preserves voltage switch bits */
 		pwr |= host->pwr_reg & (MCI_STM32_VSWITCHEN |
 					MCI_STM32_VSWITCH);

 		/*
 		 * After a power-cycle state, we must set the SDMMC in
 		 * Power-off. The SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK are
 		 * driven high. Then we can set the SDMMC to Power-on state
 		 */
 		mmci_write_pwrreg(host, MCI_PWR_OFF | pwr);
 		mdelay(1);
 		mmci_write_pwrreg(host, MCI_PWR_ON | pwr);
 	}
 }

 static u32 sdmmc_get_dctrl_cfg(struct mmci_host *host)
 {
 	u32 datactrl;

 	datactrl = mmci_dctrl_blksz(host);

 	if (host->hw_revision >= 3) {
 		u32 thr = 0;

 		if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104 ||
 		    host->mmc->ios.timing == MMC_TIMING_MMC_HS200) {
 			thr = ffs(min_t(unsigned int, host->data->blksz,
 					host->variant->fifosize));
 			thr = min_t(u32, thr, MMCI_STM32_THR_MASK);
 		}

 		writel_relaxed(thr, host->base + MMCI_STM32_FIFOTHRR);
 	}

 	if (host->mmc->card && mmc_card_sdio(host->mmc->card) &&
 	    host->data->blocks == 1)
 		datactrl |= MCI_DPSM_STM32_MODE_SDIO;
 	else if (host->data->stop && !host->mrq->sbc)
 		datactrl |= MCI_DPSM_STM32_MODE_BLOCK_STOP;
 	else
 		datactrl |= MCI_DPSM_STM32_MODE_BLOCK;

 	return datactrl;
 }

 static bool sdmmc_busy_complete(struct mmci_host *host, struct mmc_command *cmd,
 				u32 status, u32 err_msk)
 {
 	void __iomem *base = host->base;
 	u32 busy_d0, busy_d0end, mask, sdmmc_status;

 	mask = readl_relaxed(base + MMCIMASK0);
 	sdmmc_status = readl_relaxed(base + MMCISTATUS);
 	busy_d0end = sdmmc_status & MCI_STM32_BUSYD0END;
 	busy_d0 = sdmmc_status & MCI_STM32_BUSYD0;

 	/* complete if there is an error or busy_d0end */
 	if ((status & err_msk) || busy_d0end)
 		goto complete;

 	/*
 	 * On response the busy signaling is reflected in the BUSYD0 flag.
 	 * if busy_d0 is in-progress we must activate busyd0end interrupt
 	 * to wait this completion. Else this request has no busy step.
 	 */
 	if (busy_d0) {
 		if (!host->busy_status) {
 			writel_relaxed(mask | host->variant->busy_detect_mask,
 				       base + MMCIMASK0);
 			host->busy_status = status &
 				(MCI_CMDSENT | MCI_CMDRESPEND);
 		}
 		return false;
 	}

 complete:
 	if (host->busy_status) {
 		writel_relaxed(mask & ~host->variant->busy_detect_mask,
 			       base + MMCIMASK0);
 		host->busy_status = 0;
 	}

 	writel_relaxed(host->variant->busy_detect_mask, base + MMCICLEAR);

 	return true;
 }

 static int sdmmc_dlyb_mp15_enable(struct sdmmc_dlyb *dlyb)
 {
 	writel_relaxed(DLYB_CR_DEN, dlyb->base + DLYB_CR);

 	return 0;
 }

 static int sdmmc_dlyb_mp15_set_cfg(struct sdmmc_dlyb *dlyb,
 				   int unit, int phase, bool sampler)
 {
 	u32 cfgr;

 	writel_relaxed(DLYB_CR_SEN | DLYB_CR_DEN, dlyb->base + DLYB_CR);

 	cfgr = FIELD_PREP(DLYB_CFGR_UNIT_MASK, unit) |
 	       FIELD_PREP(DLYB_CFGR_SEL_MASK, phase);
 	writel_relaxed(cfgr, dlyb->base + DLYB_CFGR);

 	if (!sampler)
 		writel_relaxed(DLYB_CR_DEN, dlyb->base + DLYB_CR);

 	return 0;
 }

 static int sdmmc_dlyb_mp15_prepare(struct mmci_host *host)
 {
 	struct sdmmc_dlyb *dlyb = host->variant_priv;
 	u32 cfgr;
 	int i, lng, ret;

 	for (i = 0; i <= DLYB_CFGR_UNIT_MAX; i++) {
 		dlyb->ops->set_cfg(dlyb, i, DLYB_CFGR_SEL_MAX, true);

 		ret = readl_relaxed_poll_timeout(dlyb->base + DLYB_CFGR, cfgr,
 						 (cfgr & DLYB_CFGR_LNGF),
 						 1, DLYB_LNG_TIMEOUT_US);
 		if (ret) {
 			dev_warn(mmc_dev(host->mmc),
 				 "delay line cfg timeout unit:%d cfgr:%d\n",
 				 i, cfgr);
 			continue;
 		}

 		lng = FIELD_GET(DLYB_CFGR_LNG_MASK, cfgr);
 		if (lng < BIT(DLYB_NB_DELAY) && lng > 0)
 			break;
 	}

 	if (i > DLYB_CFGR_UNIT_MAX)
 		return -EINVAL;

 	dlyb->unit = i;
 	dlyb->max = __fls(lng);

 	return 0;
 }

 static int sdmmc_dlyb_mp25_enable(struct sdmmc_dlyb *dlyb)
 {
 	u32 cr, sr;

 	cr = readl_relaxed(dlyb->base + SYSCFG_DLYBSD_CR);
 	cr |= DLYBSD_CR_EN;

 	writel_relaxed(cr, dlyb->base + SYSCFG_DLYBSD_CR);

 	return readl_relaxed_poll_timeout(dlyb->base + SYSCFG_DLYBSD_SR,
 					   sr, sr & DLYBSD_SR_LOCK, 1,
 					   DLYBSD_TIMEOUT_1S_IN_US);
 }

 static int sdmmc_dlyb_mp25_set_cfg(struct sdmmc_dlyb *dlyb,
 				   int unit __maybe_unused, int phase,
 				   bool sampler __maybe_unused)
 {
 	u32 cr, sr;

 	cr = readl_relaxed(dlyb->base + SYSCFG_DLYBSD_CR);
 	cr &= ~DLYBSD_CR_RXTAPSEL_MASK;
 	cr |= FIELD_PREP(DLYBSD_CR_RXTAPSEL_MASK, phase);

 	writel_relaxed(cr, dlyb->base + SYSCFG_DLYBSD_CR);

 	return readl_relaxed_poll_timeout(dlyb->base + SYSCFG_DLYBSD_SR,
 					  sr, sr & DLYBSD_SR_RXTAPSEL_ACK, 1,
 					  DLYBSD_TIMEOUT_1S_IN_US);
 }

 static int sdmmc_dlyb_mp25_prepare(struct mmci_host *host)
 {
 	struct sdmmc_dlyb *dlyb = host->variant_priv;

 	dlyb->max = DLYBSD_TAPSEL_NB;

 	return 0;
 }

 static int sdmmc_dlyb_phase_tuning(struct mmci_host *host, u32 opcode)
 {
 	struct sdmmc_dlyb *dlyb = host->variant_priv;
 	int cur_len = 0, max_len = 0, end_of_len = 0;
 	int phase, ret;

 	for (phase = 0; phase <= dlyb->max; phase++) {
 		ret = dlyb->ops->set_cfg(dlyb, dlyb->unit, phase, false);
 		if (ret) {
 			dev_err(mmc_dev(host->mmc), "tuning config failed\n");
 			return ret;
 		}

 		if (mmc_send_tuning(host->mmc, opcode, NULL)) {
 			cur_len = 0;
 		} else {
 			cur_len++;
 			if (cur_len > max_len) {
 				max_len = cur_len;
 				end_of_len = phase;
 			}
 		}
 	}

 	if (!max_len) {
 		dev_err(mmc_dev(host->mmc), "no tuning point found\n");
 		return -EINVAL;
 	}

 	if (dlyb->ops->set_input_ck)
 		dlyb->ops->set_input_ck(dlyb);

 	phase = end_of_len - max_len / 2;
 	ret = dlyb->ops->set_cfg(dlyb, dlyb->unit, phase, false);
 	if (ret) {
 		dev_err(mmc_dev(host->mmc), "tuning reconfig failed\n");
 		return ret;
 	}

 	dev_dbg(mmc_dev(host->mmc), "unit:%d max_dly:%d phase:%d\n",
 		dlyb->unit, dlyb->max, phase);

 	return 0;
 }

 static int sdmmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
 {
 	struct mmci_host *host = mmc_priv(mmc);
 	struct sdmmc_dlyb *dlyb = host->variant_priv;
 	u32 clk;
 	int ret;

 	if ((host->mmc->ios.timing != MMC_TIMING_UHS_SDR104 &&
 	     host->mmc->ios.timing != MMC_TIMING_MMC_HS200) ||
 	    host->mmc->actual_clock <= 50000000)
 		return 0;

 	if (!dlyb || !dlyb->base)
 		return -EINVAL;

 	ret = dlyb->ops->dlyb_enable(dlyb);
 	if (ret)
 		return ret;

 	/*
 	 * SDMMC_FBCK is selected when an external Delay Block is needed
 	 * with SDR104 or HS200.
 	 */
 	clk = host->clk_reg;
 	clk &= ~MCI_STM32_CLK_SEL_MSK;
 	clk |= MCI_STM32_CLK_SELFBCK;
 	mmci_write_clkreg(host, clk);

 	ret = dlyb->ops->tuning_prepare(host);
 	if (ret)
 		return ret;

 	return sdmmc_dlyb_phase_tuning(host, opcode);
 }

 static void sdmmc_pre_sig_volt_vswitch(struct mmci_host *host)
 {
 	/* clear the voltage switch completion flag */
 	writel_relaxed(MCI_STM32_VSWENDC, host->base + MMCICLEAR);
 	/* enable Voltage switch procedure */
 	mmci_write_pwrreg(host, host->pwr_reg | MCI_STM32_VSWITCHEN);
 }

 static int sdmmc_post_sig_volt_switch(struct mmci_host *host,
 				      struct mmc_ios *ios)
 {
 	unsigned long flags;
 	u32 status;
 	int ret = 0;

 	spin_lock_irqsave(&host->lock, flags);
 	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180 &&
 	    host->pwr_reg & MCI_STM32_VSWITCHEN) {
 		mmci_write_pwrreg(host, host->pwr_reg | MCI_STM32_VSWITCH);
 		spin_unlock_irqrestore(&host->lock, flags);

 		/* wait voltage switch completion while 10ms */
 		ret = readl_relaxed_poll_timeout(host->base + MMCISTATUS,
 						 status,
 						 (status & MCI_STM32_VSWEND),
 						 10, SDMMC_VSWEND_TIMEOUT_US);

 		writel_relaxed(MCI_STM32_VSWENDC | MCI_STM32_CKSTOPC,
 			       host->base + MMCICLEAR);
 		spin_lock_irqsave(&host->lock, flags);
 		mmci_write_pwrreg(host, host->pwr_reg &
 				  ~(MCI_STM32_VSWITCHEN | MCI_STM32_VSWITCH));
 	}
 	spin_unlock_irqrestore(&host->lock, flags);

 	return ret;
 }

 static struct mmci_host_ops sdmmc_variant_ops = {
 	.validate_data = sdmmc_idma_validate_data,
 	.prep_data = sdmmc_idma_prep_data,
 	.unprep_data = sdmmc_idma_unprep_data,
 	.get_datactrl_cfg = sdmmc_get_dctrl_cfg,
 	.dma_setup = sdmmc_idma_setup,
 	.dma_start = sdmmc_idma_start,
 	.dma_finalize = sdmmc_idma_finalize,
 	.dma_error = sdmmc_idma_error,
 	.set_clkreg = mmci_sdmmc_set_clkreg,
 	.set_pwrreg = mmci_sdmmc_set_pwrreg,
 	.busy_complete = sdmmc_busy_complete,
 	.pre_sig_volt_switch = sdmmc_pre_sig_volt_vswitch,
 	.post_sig_volt_switch = sdmmc_post_sig_volt_switch,
 };

 static struct sdmmc_tuning_ops dlyb_tuning_mp15_ops = {
 	.dlyb_enable = sdmmc_dlyb_mp15_enable,
 	.set_input_ck = sdmmc_dlyb_mp15_input_ck,
 	.tuning_prepare = sdmmc_dlyb_mp15_prepare,
 	.set_cfg = sdmmc_dlyb_mp15_set_cfg,
 };

 static struct sdmmc_tuning_ops dlyb_tuning_mp25_ops = {
 	.dlyb_enable = sdmmc_dlyb_mp25_enable,
 	.tuning_prepare = sdmmc_dlyb_mp25_prepare,
 	.set_cfg = sdmmc_dlyb_mp25_set_cfg,
 };

 void sdmmc_variant_init(struct mmci_host *host)
 {
 	struct device_node *np = host->mmc->parent->of_node;
 	void __iomem *base_dlyb;
 	struct sdmmc_dlyb *dlyb;

 	host->ops = &sdmmc_variant_ops;
 	host->pwr_reg = readl_relaxed(host->base + MMCIPOWER);

 	base_dlyb = devm_of_iomap(mmc_dev(host->mmc), np, 1, NULL);
 	if (IS_ERR(base_dlyb))
 		return;

 	dlyb = devm_kzalloc(mmc_dev(host->mmc), sizeof(*dlyb), GFP_KERNEL);
 	if (!dlyb)
 		return;

 	dlyb->base = base_dlyb;
 	if (of_device_is_compatible(np, "st,stm32mp25-sdmmc2"))
 		dlyb->ops = &dlyb_tuning_mp25_ops;
 	else
 		dlyb->ops = &dlyb_tuning_mp15_ops;

 	host->variant_priv = dlyb;
 	host->mmc_ops->execute_tuning = sdmmc_execute_tuning;
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* Copyright (C) STMicroelectronics 2018 - All Rights Reserved
	* Author: Ludovic.barre@st.com for STMicroelectronics.
	*/
	#include <linux/bitfield.h>
	#include <linux/delay.h>
	#include <linux/dma-mapping.h>
	#include <linux/iopoll.h>
	#include <linux/mmc/host.h>
	#include <linux/mmc/card.h>
	#include <linux/of_address.h>
	#include <linux/reset.h>
	#include <linux/scatterlist.h>
	#include "mmci.h"

	#define SDMMC_LLI_BUF_LEN PAGE_SIZE

	#define DLYB_CR 0x0
	#define DLYB_CR_DEN BIT(0)
	#define DLYB_CR_SEN BIT(1)

	#define DLYB_CFGR 0x4
	#define DLYB_CFGR_SEL_MASK GENMASK(3, 0)
	#define DLYB_CFGR_UNIT_MASK GENMASK(14, 8)
	#define DLYB_CFGR_LNG_MASK GENMASK(27, 16)
	#define DLYB_CFGR_LNGF BIT(31)

	#define DLYB_NB_DELAY 11
	#define DLYB_CFGR_SEL_MAX (DLYB_NB_DELAY + 1)
	#define DLYB_CFGR_UNIT_MAX 127

	#define DLYB_LNG_TIMEOUT_US 1000
	#define SDMMC_VSWEND_TIMEOUT_US 10000

	#define SYSCFG_DLYBSD_CR 0x0
	#define DLYBSD_CR_EN BIT(0)
	#define DLYBSD_CR_RXTAPSEL_MASK GENMASK(6, 1)
	#define DLYBSD_TAPSEL_NB 32
	#define DLYBSD_BYP_EN BIT(16)
	#define DLYBSD_BYP_CMD GENMASK(21, 17)
	#define DLYBSD_ANTIGLITCH_EN BIT(22)

	#define SYSCFG_DLYBSD_SR 0x4
	#define DLYBSD_SR_LOCK BIT(0)
	#define DLYBSD_SR_RXTAPSEL_ACK BIT(1)

	#define DLYBSD_TIMEOUT_1S_IN_US 1000000

	struct sdmmc_lli_desc {
	u32 idmalar;
	u32 idmabase;
	u32 idmasize;
	};

	struct sdmmc_idma {
	dma_addr_t sg_dma;
	void *sg_cpu;
	dma_addr_t bounce_dma_addr;
	void *bounce_buf;
	bool use_bounce_buffer;
	};

	struct sdmmc_dlyb;

	struct sdmmc_tuning_ops {
	int (dlyb_enable)(struct sdmmc_dlyb dlyb);
	void (set_input_ck)(struct sdmmc_dlyb dlyb);
	int (tuning_prepare)(struct mmci_host host);
	int (set_cfg)(struct sdmmc_dlyb dlyb, int unit __maybe_unused,
	int phase, bool sampler __maybe_unused);
	};

	struct sdmmc_dlyb {
	void __iomem *base;
	u32 unit;
	u32 max;
	struct sdmmc_tuning_ops *ops;
	};

	static int sdmmc_idma_validate_data(struct mmci_host *host,
	struct mmc_data *data)
	{
	struct sdmmc_idma *idma = host->dma_priv;
	struct device *dev = mmc_dev(host->mmc);
	struct scatterlist *sg;
	int i;

	/*
	* idma has constraints on idmabase & idmasize for each element
	* excepted the last element which has no constraint on idmasize
	*/
	idma->use_bounce_buffer = false;
	for_each_sg(data->sg, sg, data->sg_len - 1, i) {
	if (!IS_ALIGNED(sg->offset, sizeof(u32)) \|\|
	!IS_ALIGNED(sg->length,
	host->variant->stm32_idmabsize_align)) {
	dev_dbg(mmc_dev(host->mmc),
	"unaligned scatterlist: ofst:%x length:%d\n",
	data->sg->offset, data->sg->length);
	goto use_bounce_buffer;
	}
	}

	if (!IS_ALIGNED(sg->offset, sizeof(u32))) {
	dev_dbg(mmc_dev(host->mmc),
	"unaligned last scatterlist: ofst:%x length:%d\n",
	data->sg->offset, data->sg->length);
	goto use_bounce_buffer;
	}

	return 0;

	use_bounce_buffer:
	if (!idma->bounce_buf) {
	idma->bounce_buf = dmam_alloc_coherent(dev,
	host->mmc->max_req_size,
	&idma->bounce_dma_addr,
	GFP_KERNEL);
	if (!idma->bounce_buf) {
	dev_err(dev, "Unable to map allocate DMA bounce buffer.\n");
	return -ENOMEM;
	}
	}

	idma->use_bounce_buffer = true;

	return 0;
	}

	static int _sdmmc_idma_prep_data(struct mmci_host *host,
	struct mmc_data *data)
	{
	struct sdmmc_idma *idma = host->dma_priv;

	if (idma->use_bounce_buffer) {
	if (data->flags & MMC_DATA_WRITE) {
	unsigned int xfer_bytes = data->blksz * data->blocks;

	sg_copy_to_buffer(data->sg, data->sg_len,
	idma->bounce_buf, xfer_bytes);
	dma_wmb();
	}
	} else {
	int n_elem;

	n_elem = dma_map_sg(mmc_dev(host->mmc),
	data->sg,
	data->sg_len,
	mmc_get_dma_dir(data));

	if (!n_elem) {
	dev_err(mmc_dev(host->mmc), "dma_map_sg failed\n");
	return -EINVAL;
	}
	}
	return 0;
	}

	static int sdmmc_idma_prep_data(struct mmci_host *host,
	struct mmc_data *data, bool next)
	{
	/* Check if job is already prepared. */
	if (!next && data->host_cookie == host->next_cookie)
	return 0;

	return _sdmmc_idma_prep_data(host, data);
	}

	static void sdmmc_idma_unprep_data(struct mmci_host *host,
	struct mmc_data *data, int err)
	{
	struct sdmmc_idma *idma = host->dma_priv;

	if (idma->use_bounce_buffer) {
	if (data->flags & MMC_DATA_READ) {
	unsigned int xfer_bytes = data->blksz * data->blocks;

	sg_copy_from_buffer(data->sg, data->sg_len,
	idma->bounce_buf, xfer_bytes);
	}
	} else {
	dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
	mmc_get_dma_dir(data));
	}
	}

	static int sdmmc_idma_setup(struct mmci_host *host)
	{
	struct sdmmc_idma *idma;
	struct device *dev = mmc_dev(host->mmc);

	idma = devm_kzalloc(dev, sizeof(*idma), GFP_KERNEL);
	if (!idma)
	return -ENOMEM;

	host->dma_priv = idma;

	if (host->variant->dma_lli) {
	idma->sg_cpu = dmam_alloc_coherent(dev, SDMMC_LLI_BUF_LEN,
	&idma->sg_dma, GFP_KERNEL);
	if (!idma->sg_cpu) {
	dev_err(dev, "Failed to alloc IDMA descriptor\n");
	return -ENOMEM;
	}
	host->mmc->max_segs = SDMMC_LLI_BUF_LEN /
	sizeof(struct sdmmc_lli_desc);
	host->mmc->max_seg_size = host->variant->stm32_idmabsize_mask;

	host->mmc->max_req_size = SZ_1M;
	} else {
	host->mmc->max_segs = 1;
	host->mmc->max_seg_size = host->mmc->max_req_size;
	}

	return dma_set_max_seg_size(dev, host->mmc->max_seg_size);
	}

	static int sdmmc_idma_start(struct mmci_host host, unsigned int datactrl)

	{
	struct sdmmc_idma *idma = host->dma_priv;
	struct sdmmc_lli_desc desc = (struct sdmmc_lli_desc )idma->sg_cpu;
	struct mmc_data *data = host->data;
	struct scatterlist *sg;
	int i;

	host->dma_in_progress = true;

	if (!host->variant->dma_lli \|\| data->sg_len == 1 \|\|
	idma->use_bounce_buffer) {
	u32 dma_addr;

	if (idma->use_bounce_buffer)
	dma_addr = idma->bounce_dma_addr;
	else
	dma_addr = sg_dma_address(data->sg);

	writel_relaxed(dma_addr,
	host->base + MMCI_STM32_IDMABASE0R);
	writel_relaxed(MMCI_STM32_IDMAEN,
	host->base + MMCI_STM32_IDMACTRLR);
	return 0;
	}

	for_each_sg(data->sg, sg, data->sg_len, i) {
	desc[i].idmalar = (i + 1) * sizeof(struct sdmmc_lli_desc);
	desc[i].idmalar \|= MMCI_STM32_ULA \| MMCI_STM32_ULS
	\| MMCI_STM32_ABR;
	desc[i].idmabase = sg_dma_address(sg);
	desc[i].idmasize = sg_dma_len(sg);
	}

	/* notice the end of link list */
	desc[data->sg_len - 1].idmalar &= ~MMCI_STM32_ULA;

	dma_wmb();
	writel_relaxed(idma->sg_dma, host->base + MMCI_STM32_IDMABAR);
	writel_relaxed(desc[0].idmalar, host->base + MMCI_STM32_IDMALAR);
	writel_relaxed(desc[0].idmabase, host->base + MMCI_STM32_IDMABASE0R);
	writel_relaxed(desc[0].idmasize, host->base + MMCI_STM32_IDMABSIZER);
	writel_relaxed(MMCI_STM32_IDMAEN \| MMCI_STM32_IDMALLIEN,
	host->base + MMCI_STM32_IDMACTRLR);

	return 0;
	}

	static void sdmmc_idma_error(struct mmci_host *host)
	{
	struct mmc_data *data = host->data;
	struct sdmmc_idma *idma = host->dma_priv;

	if (!dma_inprogress(host))
	return;

	writel_relaxed(0, host->base + MMCI_STM32_IDMACTRLR);
	host->dma_in_progress = false;
	data->host_cookie = 0;

	if (!idma->use_bounce_buffer)
	dma_unmap_sg(mmc_dev(host->mmc), data->sg, data->sg_len,
	mmc_get_dma_dir(data));
	}

	static void sdmmc_idma_finalize(struct mmci_host host, struct mmc_data data)
	{
	if (!dma_inprogress(host))
	return;

	writel_relaxed(0, host->base + MMCI_STM32_IDMACTRLR);
	host->dma_in_progress = false;

	if (!data->host_cookie)
	sdmmc_idma_unprep_data(host, data, 0);
	}

	static void mmci_sdmmc_set_clkreg(struct mmci_host *host, unsigned int desired)
	{
	unsigned int clk = 0, ddr = 0;

	if (host->mmc->ios.timing == MMC_TIMING_MMC_DDR52 \|\|
	host->mmc->ios.timing == MMC_TIMING_UHS_DDR50)
	ddr = MCI_STM32_CLK_DDR;

	/*
	* cclk = mclk / (2 * clkdiv)
	* clkdiv 0 => bypass
	* in ddr mode bypass is not possible
	*/
	if (desired) {
	if (desired >= host->mclk && !ddr) {
	host->cclk = host->mclk;
	} else {
	clk = DIV_ROUND_UP(host->mclk, 2 * desired);
	if (clk > MCI_STM32_CLK_CLKDIV_MSK)
	clk = MCI_STM32_CLK_CLKDIV_MSK;
	host->cclk = host->mclk / (2 * clk);
	}
	} else {
	/*
	* while power-on phase the clock can't be define to 0,
	* Only power-off and power-cyc deactivate the clock.
	* if desired clock is 0, set max divider
	*/
	clk = MCI_STM32_CLK_CLKDIV_MSK;
	host->cclk = host->mclk / (2 * clk);
	}

	/* Set actual clock for debug */
	if (host->mmc->ios.power_mode == MMC_POWER_ON)
	host->mmc->actual_clock = host->cclk;
	else
	host->mmc->actual_clock = 0;

	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
	clk \|= MCI_STM32_CLK_WIDEBUS_4;
	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
	clk \|= MCI_STM32_CLK_WIDEBUS_8;

	clk \|= MCI_STM32_CLK_HWFCEN;
	clk \|= host->clk_reg_add;
	clk \|= ddr;

	if (host->mmc->ios.timing >= MMC_TIMING_UHS_SDR50)
	clk \|= MCI_STM32_CLK_BUSSPEED;

	mmci_write_clkreg(host, clk);
	}

	static void sdmmc_dlyb_mp15_input_ck(struct sdmmc_dlyb *dlyb)
	{
	if (!dlyb \|\| !dlyb->base)
	return;

	/* Output clock = Input clock */
	writel_relaxed(0, dlyb->base + DLYB_CR);
	}

	static void mmci_sdmmc_set_pwrreg(struct mmci_host *host, unsigned int pwr)
	{
	struct mmc_ios ios = host->mmc->ios;
	struct sdmmc_dlyb *dlyb = host->variant_priv;

	/* adds OF options */
	pwr = host->pwr_reg_add;

	if (dlyb && dlyb->ops->set_input_ck)
	dlyb->ops->set_input_ck(dlyb);

	if (ios.power_mode == MMC_POWER_OFF) {
	/* Only a reset could power-off sdmmc */
	reset_control_assert(host->rst);
	udelay(2);
	reset_control_deassert(host->rst);

	/*
	* Set the SDMMC in Power-cycle state.
	* This will make that the SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK
	* are driven low, to prevent the Card from being supplied
	* through the signal lines.
	*/
	mmci_write_pwrreg(host, MCI_STM32_PWR_CYC \| pwr);
	} else if (ios.power_mode == MMC_POWER_ON) {
	/*
	* After power-off (reset): the irq mask defined in probe
	* functionis lost
	* ault irq mask (probe) must be activated
	*/
	writel(MCI_IRQENABLE \| host->variant->start_err,
	host->base + MMCIMASK0);

	/* preserves voltage switch bits */
	pwr \|= host->pwr_reg & (MCI_STM32_VSWITCHEN \|
	MCI_STM32_VSWITCH);

	/*
	* After a power-cycle state, we must set the SDMMC in
	* Power-off. The SDMMC_D[7:0], SDMMC_CMD and SDMMC_CK are
	* driven high. Then we can set the SDMMC to Power-on state
	*/
	mmci_write_pwrreg(host, MCI_PWR_OFF \| pwr);
	mdelay(1);
	mmci_write_pwrreg(host, MCI_PWR_ON \| pwr);
	}
	}

	static u32 sdmmc_get_dctrl_cfg(struct mmci_host *host)
	{
	u32 datactrl;

	datactrl = mmci_dctrl_blksz(host);

	if (host->hw_revision >= 3) {
	u32 thr = 0;

	if (host->mmc->ios.timing == MMC_TIMING_UHS_SDR104 \|\|
	host->mmc->ios.timing == MMC_TIMING_MMC_HS200) {
	thr = ffs(min_t(unsigned int, host->data->blksz,
	host->variant->fifosize));
	thr = min_t(u32, thr, MMCI_STM32_THR_MASK);
	}

	writel_relaxed(thr, host->base + MMCI_STM32_FIFOTHRR);
	}

	if (host->mmc->card && mmc_card_sdio(host->mmc->card) &&
	host->data->blocks == 1)
	datactrl \|= MCI_DPSM_STM32_MODE_SDIO;
	else if (host->data->stop && !host->mrq->sbc)
	datactrl \|= MCI_DPSM_STM32_MODE_BLOCK_STOP;
	else
	datactrl \|= MCI_DPSM_STM32_MODE_BLOCK;

	return datactrl;
	}

	static bool sdmmc_busy_complete(struct mmci_host host, struct mmc_command cmd,
	u32 status, u32 err_msk)
	{
	void __iomem *base = host->base;
	u32 busy_d0, busy_d0end, mask, sdmmc_status;

	mask = readl_relaxed(base + MMCIMASK0);
	sdmmc_status = readl_relaxed(base + MMCISTATUS);
	busy_d0end = sdmmc_status & MCI_STM32_BUSYD0END;
	busy_d0 = sdmmc_status & MCI_STM32_BUSYD0;

	/* complete if there is an error or busy_d0end */
	if ((status & err_msk) \|\| busy_d0end)
	goto complete;

	/*
	* On response the busy signaling is reflected in the BUSYD0 flag.
	* if busy_d0 is in-progress we must activate busyd0end interrupt
	* to wait this completion. Else this request has no busy step.
	*/
	if (busy_d0) {
	if (!host->busy_status) {
	writel_relaxed(mask \| host->variant->busy_detect_mask,
	base + MMCIMASK0);
	host->busy_status = status &
	(MCI_CMDSENT \| MCI_CMDRESPEND);
	}
	return false;
	}

	complete:
	if (host->busy_status) {
	writel_relaxed(mask & ~host->variant->busy_detect_mask,
	base + MMCIMASK0);
	host->busy_status = 0;
	}

	writel_relaxed(host->variant->busy_detect_mask, base + MMCICLEAR);

	return true;
	}

	static int sdmmc_dlyb_mp15_enable(struct sdmmc_dlyb *dlyb)
	{
	writel_relaxed(DLYB_CR_DEN, dlyb->base + DLYB_CR);

	return 0;
	}

	static int sdmmc_dlyb_mp15_set_cfg(struct sdmmc_dlyb *dlyb,
	int unit, int phase, bool sampler)
	{
	u32 cfgr;

	writel_relaxed(DLYB_CR_SEN \| DLYB_CR_DEN, dlyb->base + DLYB_CR);

	cfgr = FIELD_PREP(DLYB_CFGR_UNIT_MASK, unit) \|
	FIELD_PREP(DLYB_CFGR_SEL_MASK, phase);
	writel_relaxed(cfgr, dlyb->base + DLYB_CFGR);

	if (!sampler)
	writel_relaxed(DLYB_CR_DEN, dlyb->base + DLYB_CR);

	return 0;
	}

	static int sdmmc_dlyb_mp15_prepare(struct mmci_host *host)
	{
	struct sdmmc_dlyb *dlyb = host->variant_priv;
	u32 cfgr;
	int i, lng, ret;

	for (i = 0; i <= DLYB_CFGR_UNIT_MAX; i++) {
	dlyb->ops->set_cfg(dlyb, i, DLYB_CFGR_SEL_MAX, true);

	ret = readl_relaxed_poll_timeout(dlyb->base + DLYB_CFGR, cfgr,
	(cfgr & DLYB_CFGR_LNGF),
	1, DLYB_LNG_TIMEOUT_US);
	if (ret) {
	dev_warn(mmc_dev(host->mmc),
	"delay line cfg timeout unit:%d cfgr:%d\n",
	i, cfgr);
	continue;
	}

	lng = FIELD_GET(DLYB_CFGR_LNG_MASK, cfgr);
	if (lng < BIT(DLYB_NB_DELAY) && lng > 0)
	break;
	}

	if (i > DLYB_CFGR_UNIT_MAX)
	return -EINVAL;

	dlyb->unit = i;
	dlyb->max = __fls(lng);

	return 0;
	}

	static int sdmmc_dlyb_mp25_enable(struct sdmmc_dlyb *dlyb)
	{
	u32 cr, sr;

	cr = readl_relaxed(dlyb->base + SYSCFG_DLYBSD_CR);
	cr \|= DLYBSD_CR_EN;

	writel_relaxed(cr, dlyb->base + SYSCFG_DLYBSD_CR);

	return readl_relaxed_poll_timeout(dlyb->base + SYSCFG_DLYBSD_SR,
	sr, sr & DLYBSD_SR_LOCK, 1,
	DLYBSD_TIMEOUT_1S_IN_US);
	}

	static int sdmmc_dlyb_mp25_set_cfg(struct sdmmc_dlyb *dlyb,
	int unit __maybe_unused, int phase,
	bool sampler __maybe_unused)
	{
	u32 cr, sr;

	cr = readl_relaxed(dlyb->base + SYSCFG_DLYBSD_CR);
	cr &= ~DLYBSD_CR_RXTAPSEL_MASK;
	cr \|= FIELD_PREP(DLYBSD_CR_RXTAPSEL_MASK, phase);

	writel_relaxed(cr, dlyb->base + SYSCFG_DLYBSD_CR);

	return readl_relaxed_poll_timeout(dlyb->base + SYSCFG_DLYBSD_SR,
	sr, sr & DLYBSD_SR_RXTAPSEL_ACK, 1,
	DLYBSD_TIMEOUT_1S_IN_US);
	}

	static int sdmmc_dlyb_mp25_prepare(struct mmci_host *host)
	{
	struct sdmmc_dlyb *dlyb = host->variant_priv;

	dlyb->max = DLYBSD_TAPSEL_NB;

	return 0;
	}

	static int sdmmc_dlyb_phase_tuning(struct mmci_host *host, u32 opcode)
	{
	struct sdmmc_dlyb *dlyb = host->variant_priv;
	int cur_len = 0, max_len = 0, end_of_len = 0;
	int phase, ret;

	for (phase = 0; phase <= dlyb->max; phase++) {
	ret = dlyb->ops->set_cfg(dlyb, dlyb->unit, phase, false);
	if (ret) {
	dev_err(mmc_dev(host->mmc), "tuning config failed\n");
	return ret;
	}

	if (mmc_send_tuning(host->mmc, opcode, NULL)) {
	cur_len = 0;
	} else {
	cur_len++;
	if (cur_len > max_len) {
	max_len = cur_len;
	end_of_len = phase;
	}
	}
	}

	if (!max_len) {
	dev_err(mmc_dev(host->mmc), "no tuning point found\n");
	return -EINVAL;
	}

	if (dlyb->ops->set_input_ck)
	dlyb->ops->set_input_ck(dlyb);

	phase = end_of_len - max_len / 2;
	ret = dlyb->ops->set_cfg(dlyb, dlyb->unit, phase, false);
	if (ret) {
	dev_err(mmc_dev(host->mmc), "tuning reconfig failed\n");
	return ret;
	}

	dev_dbg(mmc_dev(host->mmc), "unit:%d max_dly:%d phase:%d\n",
	dlyb->unit, dlyb->max, phase);

	return 0;
	}

	static int sdmmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
	{
	struct mmci_host *host = mmc_priv(mmc);
	struct sdmmc_dlyb *dlyb = host->variant_priv;
	u32 clk;
	int ret;

	if ((host->mmc->ios.timing != MMC_TIMING_UHS_SDR104 &&
	host->mmc->ios.timing != MMC_TIMING_MMC_HS200) \|\|
	host->mmc->actual_clock <= 50000000)
	return 0;

	if (!dlyb \|\| !dlyb->base)
	return -EINVAL;

	ret = dlyb->ops->dlyb_enable(dlyb);
	if (ret)
	return ret;

	/*
	* SDMMC_FBCK is selected when an external Delay Block is needed
	* with SDR104 or HS200.
	*/
	clk = host->clk_reg;
	clk &= ~MCI_STM32_CLK_SEL_MSK;
	clk \|= MCI_STM32_CLK_SELFBCK;
	mmci_write_clkreg(host, clk);

	ret = dlyb->ops->tuning_prepare(host);
	if (ret)
	return ret;

	return sdmmc_dlyb_phase_tuning(host, opcode);
	}

	static void sdmmc_pre_sig_volt_vswitch(struct mmci_host *host)
	{
	/* clear the voltage switch completion flag */
	writel_relaxed(MCI_STM32_VSWENDC, host->base + MMCICLEAR);
	/* enable Voltage switch procedure */
	mmci_write_pwrreg(host, host->pwr_reg \| MCI_STM32_VSWITCHEN);
	}

	static int sdmmc_post_sig_volt_switch(struct mmci_host *host,
	struct mmc_ios *ios)
	{
	unsigned long flags;
	u32 status;
	int ret = 0;

	spin_lock_irqsave(&host->lock, flags);
	if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_180 &&
	host->pwr_reg & MCI_STM32_VSWITCHEN) {
	mmci_write_pwrreg(host, host->pwr_reg \| MCI_STM32_VSWITCH);
	spin_unlock_irqrestore(&host->lock, flags);

	/* wait voltage switch completion while 10ms */
	ret = readl_relaxed_poll_timeout(host->base + MMCISTATUS,
	status,
	(status & MCI_STM32_VSWEND),
	10, SDMMC_VSWEND_TIMEOUT_US);

	writel_relaxed(MCI_STM32_VSWENDC \| MCI_STM32_CKSTOPC,
	host->base + MMCICLEAR);
	spin_lock_irqsave(&host->lock, flags);
	mmci_write_pwrreg(host, host->pwr_reg &
	~(MCI_STM32_VSWITCHEN \| MCI_STM32_VSWITCH));
	}
	spin_unlock_irqrestore(&host->lock, flags);

	return ret;
	}

	static struct mmci_host_ops sdmmc_variant_ops = {
	.validate_data = sdmmc_idma_validate_data,
	.prep_data = sdmmc_idma_prep_data,
	.unprep_data = sdmmc_idma_unprep_data,
	.get_datactrl_cfg = sdmmc_get_dctrl_cfg,
	.dma_setup = sdmmc_idma_setup,
	.dma_start = sdmmc_idma_start,
	.dma_finalize = sdmmc_idma_finalize,
	.dma_error = sdmmc_idma_error,
	.set_clkreg = mmci_sdmmc_set_clkreg,
	.set_pwrreg = mmci_sdmmc_set_pwrreg,
	.busy_complete = sdmmc_busy_complete,
	.pre_sig_volt_switch = sdmmc_pre_sig_volt_vswitch,
	.post_sig_volt_switch = sdmmc_post_sig_volt_switch,
	};

	static struct sdmmc_tuning_ops dlyb_tuning_mp15_ops = {
	.dlyb_enable = sdmmc_dlyb_mp15_enable,
	.set_input_ck = sdmmc_dlyb_mp15_input_ck,
	.tuning_prepare = sdmmc_dlyb_mp15_prepare,
	.set_cfg = sdmmc_dlyb_mp15_set_cfg,
	};

	static struct sdmmc_tuning_ops dlyb_tuning_mp25_ops = {
	.dlyb_enable = sdmmc_dlyb_mp25_enable,
	.tuning_prepare = sdmmc_dlyb_mp25_prepare,
	.set_cfg = sdmmc_dlyb_mp25_set_cfg,
	};

	void sdmmc_variant_init(struct mmci_host *host)
	{
	struct device_node *np = host->mmc->parent->of_node;
	void __iomem *base_dlyb;
	struct sdmmc_dlyb *dlyb;

	host->ops = &sdmmc_variant_ops;
	host->pwr_reg = readl_relaxed(host->base + MMCIPOWER);

	base_dlyb = devm_of_iomap(mmc_dev(host->mmc), np, 1, NULL);
	if (IS_ERR(base_dlyb))
	return;

	dlyb = devm_kzalloc(mmc_dev(host->mmc), sizeof(*dlyb), GFP_KERNEL);
	if (!dlyb)
	return;

	dlyb->base = base_dlyb;
	if (of_device_is_compatible(np, "st,stm32mp25-sdmmc2"))
	dlyb->ops = &dlyb_tuning_mp25_ops;
	else
	dlyb->ops = &dlyb_tuning_mp15_ops;

	host->variant_priv = dlyb;
	host->mmc_ops->execute_tuning = sdmmc_execute_tuning;
	}