diff mbox series

[v1,5/9] mmc: sdhci: add Black Sesame Technologies BST C1200 controller driver

Message ID 20250528085453.481320-1-yangzh0906@thundersoft.com
State New
Headers show
Series None | expand

Commit Message

Albert Yang May 28, 2025, 8:54 a.m. UTC
Add a driver for the DesignWare Mobile Storage Host Controller (DWCMSHC)
SDHCI controller found in Black Sesame Technologies C1200 SoCs.

The driver provides specialized clock configuration, tuning, voltage
switching, and power management for the BST DWCMSHC controller. It also
includes support for eMMC boot and memory-mapped I/O for CRM registers.

Signed-off-by: Ge Gordon <gordon.ge@bst.ai>
Signed-off-by: Albert Yang <yangzh0906@thundersoft.com>
---
 drivers/mmc/host/Kconfig              |  11 +
 drivers/mmc/host/Makefile             |   1 +
 drivers/mmc/host/sdhci-of-bst-c1200.c | 920 ++++++++++++++++++++++++++
 3 files changed, 932 insertions(+)
 create mode 100644 drivers/mmc/host/sdhci-of-bst-c1200.c
diff mbox series

Patch

diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
index 264e11fa58ea..a5b3c0beeb78 100644
--- a/drivers/mmc/host/Kconfig
+++ b/drivers/mmc/host/Kconfig
@@ -1112,3 +1112,14 @@  config MMC_LITEX
 	  module will be called litex_mmc.
 
 	  If unsure, say N.
+
+config MMC_SDHCI_BST
+	tristate "SDHCI OF support for the BST DWC MSHC"
+	depends on MMC_SDHCI_PLTFM
+	depends on OF
+	depends on COMMON_CLK
+	help
+	  This selects Synopsys DesignWare Cores Mobile Storage Controller
+	  support.
+	  If you have a controller with this interface, say Y or M here.
+	  If unsure, say N.
diff --git a/drivers/mmc/host/Makefile b/drivers/mmc/host/Makefile
index 5147467ec825..08a281009d1d 100644
--- a/drivers/mmc/host/Makefile
+++ b/drivers/mmc/host/Makefile
@@ -13,6 +13,7 @@  obj-$(CONFIG_MMC_MXS)		+= mxs-mmc.o
 obj-$(CONFIG_MMC_SDHCI)		+= sdhci.o
 obj-$(CONFIG_MMC_SDHCI_UHS2)	+= sdhci-uhs2.o
 obj-$(CONFIG_MMC_SDHCI_PCI)	+= sdhci-pci.o
+obj-$(CONFIG_MMC_SDHCI_BST)	        += sdhci-of-bst-c1200.o
 sdhci-pci-y			+= sdhci-pci-core.o sdhci-pci-o2micro.o sdhci-pci-arasan.o \
 				   sdhci-pci-dwc-mshc.o sdhci-pci-gli.o
 obj-$(CONFIG_MMC_SDHCI_ACPI)	+= sdhci-acpi.o
diff --git a/drivers/mmc/host/sdhci-of-bst-c1200.c b/drivers/mmc/host/sdhci-of-bst-c1200.c
new file mode 100644
index 000000000000..c6d2e6273e96
--- /dev/null
+++ b/drivers/mmc/host/sdhci-of-bst-c1200.c
@@ -0,0 +1,920 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Black Sesame Technologies SDHCI driver
+ *
+ * Copyright (C) 2024 Black Sesame Technologies. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/ktime.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/regulator/consumer.h>
+#include "sdhci.h"
+#include "sdhci-pltfm.h"
+
+struct dwcmshc_priv {
+	u32 phy_crm_reg_base;
+	u32 phy_crm_reg_size;
+};
+
+#define SDHCI_CLOCK_PLL_EN		0x0008
+#define SDHCI_TUNING_COUNT		0x20
+#define SDHCI_VENDOR_PTR_R		0xE8
+#define MBIU_CTRL			0x510
+#define BURST_INCR16_EN			BIT(3)
+#define BURST_INCR8_EN			BIT(2)
+#define BURST_INCR4_EN			BIT(1)
+#define BURST_EN			(BURST_INCR16_EN | BURST_INCR8_EN | BURST_INCR4_EN)
+
+/* Synopsys vendor specific registers */
+#define reg_offset_addr_vendor		(sdhci_readw(host, SDHCI_VENDOR_PTR_R))
+#define SDHC_MHSC_VER_ID_R		(reg_offset_addr_vendor)
+#define SDHC_MHSC_VER_TPYE_R		(reg_offset_addr_vendor + 0x4)
+#define SDHC_MHSC_CTRL_R		(reg_offset_addr_vendor + 0x8)
+#define SDHC_MBIU_CTRL_R		(reg_offset_addr_vendor + 0x10)
+#define SDHC_EMMC_CTRL_R		(reg_offset_addr_vendor + 0x2C)
+#define SDHC_BOOT_CTRL_R		(reg_offset_addr_vendor + 0x2E)
+#define SDHC_GP_IN_R			(reg_offset_addr_vendor + 0x30)
+#define SDHC_GP_OUT_R			(reg_offset_addr_vendor + 0x34)
+#define SDHC_AT_CTRL_R			(reg_offset_addr_vendor + 0x40)
+#define SDHC_AT_STAT_R			(reg_offset_addr_vendor + 0x44)
+
+#define SDEMMC_CRM_BCLK_DIV_CTRL	0x08
+#define SDEMMC_CRM_RX_CLK_CTRL		0x14
+#define SDEMMC_CRM_TIMER_DIV_CTRL	0x0C
+#define SDEMMC_CRM_VOL_CTRL		0x1C
+#define DRIVER_NAME			"sdhci_bst"
+#define BST_VOL_STABLE_ON		(0x1 << 7)
+#define SDHCI_DUMP_BST(f, x...)		\
+	pr_info("%s: " DRIVER_NAME ": " f, mmc_hostname(host->mmc), ##x)
+#define SD_3_3V				0
+#define SD_1_8V				1
+#define default_max_freq		200000ul
+
+void sdhci_bst_print_vendor(struct sdhci_host *host)
+{
+	SDHCI_DUMP_BST("============ SDHCI VENDOR REGISTER DUMP ===========\n");
+
+	SDHCI_DUMP_BST("VER_ID:  0x%08x | VER_TPYE:  0x%08x\n",
+		       sdhci_readl(host, SDHC_MHSC_VER_ID_R),
+		       sdhci_readl(host, SDHC_MHSC_VER_TPYE_R));
+	SDHCI_DUMP_BST("MHSC_CTRL:  0x%08x | MBIU_CTRL:  0x%08x\n",
+		       sdhci_readw(host, SDHC_MHSC_CTRL_R),
+		       sdhci_readw(host, SDHC_MBIU_CTRL_R));
+	SDHCI_DUMP_BST("EMMC_CTRL:  0x%08x | BOOT_CTRL: 0x%08x\n",
+		       sdhci_readl(host, SDHC_EMMC_CTRL_R),
+		       sdhci_readw(host, SDHC_BOOT_CTRL_R));
+	SDHCI_DUMP_BST("GP_IN:   0x%08x | GP_OUT: 0x%08x\n",
+		       sdhci_readl(host, SDHC_GP_IN_R),
+		       sdhci_readb(host, SDHC_GP_OUT_R));
+	SDHCI_DUMP_BST("AT_CTRL:     0x%08x | AT_STAT:  0x%08x\n",
+		       sdhci_readb(host, SDHC_AT_CTRL_R),
+		       sdhci_readb(host, SDHC_AT_STAT_R));
+}
+EXPORT_SYMBOL_GPL(sdhci_bst_print_vendor);
+
+static u32 bst_read_phys_bst(u32 phys_addr)
+{
+	u32 phys_addr_page = phys_addr & 0xFFFFE000;
+	u32 phys_offset = phys_addr & 0x00001FFF;
+	u32 map_size = phys_offset + sizeof(u32);
+	u32 ret = 0xDEADBEEF;
+	void *mem_mapped = ioremap(phys_addr_page, map_size);
+
+	if (mem_mapped) {
+		ret = (u32)ioread32(((u8 *)mem_mapped) + phys_offset);
+		iounmap(mem_mapped);
+	}
+
+	return ret;
+}
+
+static void bst_write_phys_bst(u32 phys_addr, u32 value)
+{
+	u32 phys_addr_page = phys_addr & 0xFFFFE000;
+	u32 phys_offset = phys_addr & 0x00001FFF;
+	u32 map_size = phys_offset + sizeof(u32);
+	void *mem_mapped = ioremap(phys_addr_page, map_size);
+
+	if (mem_mapped) {
+		iowrite32(value, ((u8 *)mem_mapped) + phys_offset);
+		iounmap(mem_mapped);
+	}
+}
+
+static unsigned int bst_get_max_clock(struct sdhci_host *host)
+{
+	return host->mmc->f_max;
+}
+
+static unsigned int bst_get_min_clock(struct sdhci_host *host)
+{
+	return host->mmc->f_min;
+}
+
+struct rx_ctrl {
+	struct {
+		u32 rx_revert:1;
+		u32 rx_clk_sel_sec:1;
+		u32 rx_clk_div:4;
+		u32 rx_clk_phase_inner:2;
+		u32 rx_clk_sel_first:1;
+		u32 rx_clk_phase_out:2;
+		u32 rx_clk_en:1;
+		u32 res0:20;
+	} bit;
+	u32 reg;
+};
+
+struct sdmmc_iocfg {
+	struct {
+		u32 res0:16;
+		u32 SC_SDMMC0_PVDD18POCSD0:2;
+		u32 SC_SDMMC0_PVDD18POCSD1:2;
+		u32 SC_SDMMC0_PVDD18POCSD2:2;
+		u32 SC_SDMMC1_PVDD18POCSD0:2;
+		u32 SC_SDMMC1_PVDD18POCSD1:2;
+		u32 SC_SDMMC1_PVDD18POCSD2:2;
+		u32 res1:4;
+	} bit;
+	u32 reg;
+};
+
+void sdhci_enable_bst_clk(struct sdhci_host *host, unsigned int clk)
+{
+	struct sdhci_pltfm_host *pltfm_host;
+	struct dwcmshc_priv *priv;
+	unsigned int div;
+	u32 val;
+	struct rx_ctrl rx_reg;
+
+	pltfm_host = sdhci_priv(host);
+	priv = sdhci_pltfm_priv(pltfm_host);
+	if (clk == 0) {
+		div = clk;
+	} else if (clk > default_max_freq) {
+		div = clk / 1000;
+		div = default_max_freq / div;
+	} else if (clk < 1500) {
+		div = clk;
+	} else {
+		div = default_max_freq * 100;
+		div = div / clk;
+		div /= 100;
+	}
+
+	clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+	clk &= ~SDHCI_CLOCK_CARD_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+	clk &= ~SDHCI_CLOCK_PLL_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+	val = bst_read_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_TIMER_DIV_CTRL);
+	val &= ~(1 << 8);
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_TIMER_DIV_CTRL, val);
+
+	val = bst_read_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_TIMER_DIV_CTRL);
+	val &= ~(0xff);
+	val |= 0x20;
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_TIMER_DIV_CTRL, val);
+
+	val = bst_read_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_TIMER_DIV_CTRL);
+	val |= 1 << 8;
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_TIMER_DIV_CTRL, val);
+
+	val = bst_read_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_RX_CLK_CTRL);
+	val &= ~(1 << 11);
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_RX_CLK_CTRL, val);
+
+	rx_reg.reg = bst_read_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_RX_CLK_CTRL);
+
+	rx_reg.bit.rx_revert = 0;
+	rx_reg.bit.rx_clk_sel_sec = 1;
+	rx_reg.bit.rx_clk_div = 4;
+	rx_reg.bit.rx_clk_phase_inner = 2;
+	rx_reg.bit.rx_clk_sel_first = 0;
+	rx_reg.bit.rx_clk_phase_out = 2;
+
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_RX_CLK_CTRL, rx_reg.reg);
+
+	val = bst_read_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_RX_CLK_CTRL);
+	val |= 1 << 11;
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_RX_CLK_CTRL, val);
+
+	/* Disable clock first */
+	val = bst_read_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_BCLK_DIV_CTRL);
+	val &= ~0x0400;
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_BCLK_DIV_CTRL, val);
+
+	/* Setup clock divider */
+	val = bst_read_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_BCLK_DIV_CTRL);
+	val &= ~0x03ff;
+	val |= div;
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_BCLK_DIV_CTRL, val);
+
+	/* Enable clock */
+	val = bst_read_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_BCLK_DIV_CTRL);
+	val |= 0x0400;
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_BCLK_DIV_CTRL, val);
+
+	sdhci_writew(host, (div & 0xff) << 8, SDHCI_CLOCK_CONTROL);
+
+	sdhci_writew(host, (div & 0xff) << 8, SDHCI_CLOCK_CONTROL);
+	clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+	clk |= SDHCI_CLOCK_PLL_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+	clk |= SDHCI_CLOCK_CARD_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+	clk |= SDHCI_CLOCK_INT_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+}
+
+void sdhci_set_bst_clock(struct sdhci_host *host, unsigned int clock)
+{
+	if (clock == 0)
+		return;
+	sdhci_enable_bst_clk(host, clock);
+}
+
+/**
+ * sdhci_bst_reset - Reset the SDHCI host controller
+ * @host: SDHCI host controller
+ * @mask: Reset mask
+ *
+ * Performs a reset of the SDHCI host controller with special handling for eMMC.
+ */
+static void sdhci_bst_reset(struct sdhci_host *host, u8 mask)
+{
+	if (host->mmc->caps2 & MMC_CAP2_NO_SD) {
+		sdhci_writew(host,
+			     sdhci_readw(host, SDHC_EMMC_CTRL_R) & (~BIT(2)),
+			     SDHC_EMMC_CTRL_R);
+		sdhci_reset(host, mask);
+		usleep_range(10, 20);
+		sdhci_writew(host,
+			     sdhci_readw(host, SDHC_EMMC_CTRL_R) | BIT(2),
+			     SDHC_EMMC_CTRL_R);
+	} else {
+		sdhci_reset(host, mask);
+	}
+}
+
+/**
+ * sdhci_bst_timeout - Set timeout value for commands
+ * @host: SDHCI host controller
+ * @cmd: MMC command
+ *
+ * Sets the timeout control register to maximum value (0xE).
+ */
+static void sdhci_bst_timeout(struct sdhci_host *host, struct mmc_command *cmd)
+{
+	sdhci_writeb(host, 0xE, SDHCI_TIMEOUT_CONTROL);
+}
+
+/**
+ * sdhci_bst_set_power - Set power mode and voltage
+ * @host: SDHCI host controller
+ * @mode: Power mode to set
+ * @vdd: Voltage to set
+ *
+ * Sets power mode and voltage, also configures MBIU control register.
+ */
+static void sdhci_bst_set_power(struct sdhci_host *host, unsigned char mode,
+				unsigned short vdd)
+{
+	sdhci_set_power(host, mode, vdd);
+	sdhci_writeb(host, 0xF, SDHCI_POWER_CONTROL);
+	sdhci_writew(host,
+		     (sdhci_readw(host, MBIU_CTRL) & (~0xf)) | BURST_EN,
+		     MBIU_CTRL);
+}
+
+/**
+ * bst_sdhci_execute_tuning - Execute tuning procedure
+ * @host: SDHCI host controller
+ * @opcode: Opcode to use for tuning
+ *
+ * Performs tuning procedure by trying different values and selecting the best one.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static int bst_sdhci_execute_tuning(struct sdhci_host *host, u32 opcode)
+{
+	struct sdhci_pltfm_host *pltfm_host;
+	struct dwcmshc_priv *priv;
+	unsigned int clk = 0, timeout;
+	int ret = 0, error;
+	int start0 = -1, end0 = -1, best = 0;
+	int start1 = -1, end1 = -1, flag = 0;
+	int i;
+	u32 val;
+
+	pltfm_host = sdhci_priv(host);
+	priv = sdhci_pltfm_priv(pltfm_host);
+
+	for (i = 0; i < SDHCI_TUNING_COUNT; i++) {
+		/* Protected write */
+		bst_write_phys_bst(priv->phy_crm_reg_base + 0x88, 0x1234abcd);
+		/* Write tuning value */
+		bst_write_phys_bst(priv->phy_crm_reg_base + 0x94,
+				   (1ul << i) - 1);
+
+		timeout = 20;
+		while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL)) &
+			SDHCI_CLOCK_INT_STABLE)) {
+			if (timeout == 0) {
+				pr_err("%s: Internal clock never stabilised.\n",
+				       __func__);
+				return -EBUSY;
+			}
+			timeout--;
+			usleep_range(1000, 1100);
+		}
+
+		ret = mmc_send_tuning(host->mmc, opcode, &error);
+		if (ret != 0) {
+			flag = 1;
+		} else {
+			if (flag == 0) {
+				if (start0 == -1)
+					start0 = i;
+				end0 = i;
+			} else {
+				if (start1 == -1)
+					start1 = i;
+				end1 = i;
+			}
+		}
+	}
+
+	/* Calculate best tuning value */
+	if (end0 - start0 >= end1 - start1)
+		best = ((end0 - start0) >> 1) + start0;
+	else
+		best = ((end1 - start1) >> 1) + start1;
+
+	if (best < 0)
+		best = 0;
+
+	bst_write_phys_bst(priv->phy_crm_reg_base + 0x94, (1ul << best) - 1);
+	timeout = 20;
+
+	while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL)) &
+		SDHCI_CLOCK_INT_STABLE)) {
+		if (timeout == 0) {
+			pr_err("%s: Internal clock never stabilised.\n",
+			       __func__);
+			return -EBUSY;
+		}
+		timeout--;
+		usleep_range(1000, 1100);
+	}
+
+	return 0;
+}
+
+/**
+ * sdhci_bst_voltage_switch - Perform voltage switch
+ * @host: SDHCI host controller
+ *
+ * Enables voltage stable power.
+ */
+static void sdhci_bst_voltage_switch(struct sdhci_host *host)
+{
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct dwcmshc_priv *priv = sdhci_pltfm_priv(pltfm_host);
+
+	/* vol stable power on */
+	bst_write_phys_bst(priv->phy_crm_reg_base + SDEMMC_CRM_VOL_CTRL,
+			   BST_VOL_STABLE_ON);
+}
+
+static const struct sdhci_ops sdhci_dwcmshc_ops = {
+	.set_clock		= sdhci_set_bst_clock,
+	.set_bus_width		= sdhci_set_bus_width,
+	.set_uhs_signaling	= sdhci_set_uhs_signaling,
+	.get_min_clock		= bst_get_min_clock,
+	.get_max_clock		= bst_get_max_clock,
+	.reset			= sdhci_bst_reset,
+	.set_power		= sdhci_bst_set_power,
+	.set_timeout		= sdhci_bst_timeout,
+	.platform_execute_tuning = bst_sdhci_execute_tuning,
+	.voltage_switch		= sdhci_bst_voltage_switch,
+};
+
+static const struct sdhci_pltfm_data sdhci_dwcmshc_pdata = {
+	.ops = &sdhci_dwcmshc_ops,
+	.quirks = SDHCI_QUIRK_DELAY_AFTER_POWER |
+		  SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN |
+		  SDHCI_QUIRK_INVERTED_WRITE_PROTECT,
+	.quirks2 = SDHCI_QUIRK2_BROKEN_DDR50 |
+		   SDHCI_QUIRK2_TUNING_WORK_AROUND |
+		   SDHCI_QUIRK2_ACMD23_BROKEN,
+};
+
+static void bst_sdhci_allocate_bounce_buffer(struct sdhci_host *host)
+{
+	struct mmc_host *mmc = host->mmc;
+	unsigned int max_blocks;
+	unsigned int bounce_size;
+	int ret;
+
+	/*
+	 * Cap the bounce buffer at 64KB. Using a bigger bounce buffer
+	 * has diminishing returns, this is probably because SD/MMC
+	 * cards are usually optimized to handle this size of requests.
+	 */
+	bounce_size = SZ_32K;
+	/*
+	 * Adjust downwards to maximum request size if this is less
+	 * than our segment size, else hammer down the maximum
+	 * request size to the maximum buffer size.
+	 */
+	if (mmc->max_req_size < bounce_size)
+		bounce_size = mmc->max_req_size;
+	max_blocks = bounce_size / 512;
+
+	ret = of_reserved_mem_device_init_by_idx(mmc_dev(mmc), mmc_dev(mmc)->of_node, 0);
+	if (ret) {
+		dev_err(mmc_dev(mmc), "of_reserved_mem_device_init error\n");
+		return;
+	}
+	host->bounce_buffer = dma_alloc_coherent(mmc_dev(mmc), bounce_size,
+						 &host->bounce_addr, GFP_KERNEL);
+
+	ret = dma_mapping_error(mmc_dev(mmc), host->bounce_addr);
+	if (ret) {
+		devm_kfree(mmc_dev(mmc), host->bounce_buffer);
+		host->bounce_buffer = NULL;
+		/* Again fall back to max_segs == 1 */
+		return;
+	}
+
+	host->bounce_buffer_size = bounce_size;
+
+	/* Lie about this since we're bouncing */
+	mmc->max_segs = max_blocks;
+	mmc->max_seg_size = bounce_size;
+	mmc->max_req_size = bounce_size;
+
+	pr_info("BST reallocate %s bounce up to %u segments into one, max segment size %u bytes\n",
+		mmc_hostname(mmc), max_blocks, bounce_size);
+}
+
+static int bst_sdhci_set_dma_mask(struct sdhci_host *host)
+{
+	struct mmc_host *mmc = host->mmc;
+	struct device *dev = mmc_dev(mmc);
+	int ret = -EINVAL;
+
+	if (host->quirks2 & SDHCI_QUIRK2_BROKEN_64_BIT_DMA)
+		host->flags &= ~SDHCI_USE_64_BIT_DMA;
+
+	/* Try 64-bit mask if hardware is capable  of it */
+	if (host->flags & SDHCI_USE_64_BIT_DMA) {
+		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+		if (ret) {
+			pr_warn("%s: Failed to set 64-bit DMA mask.\n",
+				mmc_hostname(mmc));
+			host->flags &= ~SDHCI_USE_64_BIT_DMA;
+		}
+	}
+
+	/* 32-bit mask as default & fallback */
+	if (ret) {
+		ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
+		if (ret)
+			pr_warn("%s: Failed to set 32-bit DMA mask.\n",
+				mmc_hostname(mmc));
+	}
+
+	return ret;
+}
+
+int bst_sdhci_setup_host(struct sdhci_host *host)
+{
+	struct mmc_host *mmc;
+	u32 max_current_caps;
+	unsigned int ocr_avail;
+	unsigned int override_timeout_clk;
+	u32 max_clk;
+	int ret = 0;
+	bool enable_vqmmc = false;
+
+	WARN_ON(!host);
+	if (!host)
+		return -EINVAL;
+
+	mmc = host->mmc;
+
+	/*
+	 * If there are external regulators, get them. Note this must be done
+	 * early before resetting the host and reading the capabilities so that
+	 * the host can take the appropriate action if regulators are not
+	 * available.
+	 */
+	if (!mmc->supply.vqmmc) {
+		ret = mmc_regulator_get_supply(mmc);
+		if (ret)
+			return ret;
+		enable_vqmmc  = true;
+	}
+
+	pr_info("Version:   0x%08x | Present:  0x%08x\n",
+		sdhci_readw(host, SDHCI_HOST_VERSION),
+		sdhci_readl(host, SDHCI_PRESENT_STATE));
+	pr_info("Caps:      0x%08x | Caps_1:   0x%08x\n",
+		sdhci_readl(host, SDHCI_CAPABILITIES),
+		sdhci_readl(host, SDHCI_CAPABILITIES_1));
+
+	sdhci_read_caps(host);
+
+	override_timeout_clk = host->timeout_clk;
+
+	host->flags |= SDHCI_USE_SDMA;
+
+	if (host->flags & (SDHCI_USE_SDMA | SDHCI_USE_ADMA)) {
+		if (host->ops->set_dma_mask)
+			ret = host->ops->set_dma_mask(host);
+		else
+			ret = bst_sdhci_set_dma_mask(host);
+
+		if (!ret && host->ops->enable_dma)
+			ret = host->ops->enable_dma(host);
+
+		if (ret) {
+			pr_warn("%s: No suitable DMA available - falling back to PIO\n",
+				mmc_hostname(mmc));
+			host->flags &= ~(SDHCI_USE_SDMA | SDHCI_USE_ADMA);
+
+			ret = 0;
+		}
+	}
+
+	if (host->flags & SDHCI_USE_ADMA) {
+		dma_addr_t dma;
+		void *buf;
+
+		if (!(host->flags & SDHCI_USE_64_BIT_DMA))
+			host->alloc_desc_sz = SDHCI_ADMA2_32_DESC_SZ;
+		else if (!host->alloc_desc_sz)
+			host->alloc_desc_sz = SDHCI_ADMA2_64_DESC_SZ(host);
+
+		host->desc_sz = host->alloc_desc_sz;
+		host->adma_table_sz = host->adma_table_cnt * host->desc_sz;
+
+		host->align_buffer_sz = SDHCI_MAX_SEGS * SDHCI_ADMA2_ALIGN;
+		/*
+		 * Use zalloc to zero the reserved high 32-bits of 128-bit
+		 * descriptors so that they never need to be written.
+		 */
+		buf = dma_alloc_coherent(mmc_dev(mmc),
+					 host->align_buffer_sz + host->adma_table_sz,
+					 &dma, GFP_KERNEL);
+		if (!buf) {
+			pr_warn("%s: Unable to allocate ADMA buffers - falling back to standard DMA\n",
+				mmc_hostname(mmc));
+			host->flags &= ~SDHCI_USE_ADMA;
+		} else if ((dma + host->align_buffer_sz) &
+			   (SDHCI_ADMA2_DESC_ALIGN - 1)) {
+			pr_warn("%s: unable to allocate aligned ADMA descriptor\n",
+				mmc_hostname(mmc));
+			host->flags &= ~SDHCI_USE_ADMA;
+			dma_free_coherent(mmc_dev(mmc), host->align_buffer_sz +
+					  host->adma_table_sz, buf, dma);
+		} else {
+			host->align_buffer = buf;
+			host->align_addr = dma;
+
+			host->adma_table = buf + host->align_buffer_sz;
+			host->adma_addr = dma + host->align_buffer_sz;
+		}
+	}
+
+	host->max_clk = FIELD_GET(SDHCI_CLOCK_V3_BASE_MASK, host->caps);
+
+	host->max_clk *= 1000000;
+	if (host->max_clk == 0 || host->quirks &
+			SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN) {
+		if (!host->ops->get_max_clock) {
+			pr_err("%s: Hardware doesn't specify base clock frequency.\n",
+			       mmc_hostname(mmc));
+			ret = -ENODEV;
+			goto undma;
+		}
+		host->max_clk = host->ops->get_max_clock(host);
+	}
+
+	/*
+	 * Set host parameters.
+	 */
+	max_clk = host->max_clk;
+
+	if (host->ops->get_min_clock)
+		mmc->f_min = host->ops->get_min_clock(host);
+
+	if (!(host->quirks & SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK)) {
+		host->timeout_clk = FIELD_GET(SDHCI_TIMEOUT_CLK_MASK, host->caps);
+
+		if (host->caps & SDHCI_TIMEOUT_CLK_UNIT)
+			host->timeout_clk *= 1000;
+
+		if (host->timeout_clk == 0) {
+			if (!host->ops->get_timeout_clock) {
+				pr_err("%s: Hardware doesn't specify timeout clock frequency.\n",
+				       mmc_hostname(mmc));
+				ret = -ENODEV;
+				goto undma;
+			}
+
+			host->timeout_clk =
+				DIV_ROUND_UP(host->ops->get_timeout_clock(host),
+					     1000);
+		}
+
+		if (override_timeout_clk)
+			host->timeout_clk = override_timeout_clk;
+
+		mmc->max_busy_timeout = host->ops->get_max_timeout_count ?
+			host->ops->get_max_timeout_count(host) : 1 << 27;
+		mmc->max_busy_timeout /= host->timeout_clk;
+	}
+
+	mmc->caps |= MMC_CAP_SDIO_IRQ | MMC_CAP_CMD23;
+	mmc->caps2 |= MMC_CAP2_SDIO_IRQ_NOTHREAD;
+
+	if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12)
+		host->flags |= SDHCI_AUTO_CMD12;
+
+	/*
+	 * A controller may support 8-bit width, but the board itself
+	 * might not have the pins brought out.  Boards that support
+	 * 8-bit width must set "mmc->caps |= MMC_CAP_8_BIT_DATA;" in
+	 * their platform code before calling sdhci_add_host(), and we
+	 * won't assume 8-bit width for hosts without that CAP.
+	 */
+	if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA))
+		mmc->caps |= MMC_CAP_4_BIT_DATA;
+
+	if (host->quirks2 & SDHCI_QUIRK2_HOST_NO_CMD23)
+		mmc->caps &= ~MMC_CAP_CMD23;
+
+	if (host->caps & SDHCI_CAN_DO_HISPD)
+		mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
+
+	/* Any UHS-I mode in caps implies SDR12 and SDR25 support. */
+	if (host->caps1 & (SDHCI_SUPPORT_SDR104 | SDHCI_SUPPORT_SDR50 |
+			   SDHCI_SUPPORT_DDR50))
+		mmc->caps |= MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25;
+
+	/* SDR104 supports also implies SDR50 support */
+	if (host->caps1 & SDHCI_SUPPORT_SDR104) {
+		mmc->caps |= MMC_CAP_UHS_SDR104 | MMC_CAP_UHS_SDR50;
+		/* SD3.0: SDR104 is supported so (for eMMC) the caps2
+		 * field can be promoted to support HS200.
+		 */
+		if (!(host->quirks2 & SDHCI_QUIRK2_BROKEN_HS200))
+			mmc->caps2 |= MMC_CAP2_HS200;
+	}
+
+	if ((mmc->caps2 & MMC_CAP2_HSX00_1_2V) &&
+	    (IS_ERR(mmc->supply.vqmmc) ||
+	     !regulator_is_supported_voltage(mmc->supply.vqmmc, 1100000,
+					     1300000)))
+		mmc->caps2 &= ~MMC_CAP2_HSX00_1_2V;
+
+	/* Does the host need tuning for SDR50? */
+	if (host->caps1 & SDHCI_USE_SDR50_TUNING)
+		host->flags |= SDHCI_SDR50_NEEDS_TUNING;
+
+	/* Driver Type(s) (A, C, D) supported by the host */
+	if (host->caps1 & SDHCI_DRIVER_TYPE_A)
+		mmc->caps |= MMC_CAP_DRIVER_TYPE_A;
+	if (host->caps1 & SDHCI_DRIVER_TYPE_C)
+		mmc->caps |= MMC_CAP_DRIVER_TYPE_C;
+	if (host->caps1 & SDHCI_DRIVER_TYPE_D)
+		mmc->caps |= MMC_CAP_DRIVER_TYPE_D;
+
+	/* Initial value for re-tuning timer count */
+	host->tuning_count = FIELD_GET(SDHCI_RETUNING_TIMER_COUNT_MASK,
+				       host->caps1);
+
+	/*
+	 * In case Re-tuning Timer is not disabled, the actual value of
+	 * re-tuning timer will be 2 ^ (n - 1).
+	 */
+	if (host->tuning_count)
+		host->tuning_count = 1 << (host->tuning_count - 1);
+
+	/* Re-tuning mode supported by the Host Controller */
+	host->tuning_mode = FIELD_GET(SDHCI_RETUNING_MODE_MASK, host->caps1);
+
+	ocr_avail = 0;
+
+	if (host->caps & SDHCI_CAN_VDD_330) {
+		ocr_avail |= MMC_VDD_32_33 | MMC_VDD_33_34;
+
+		mmc->max_current_330 = FIELD_GET(SDHCI_MAX_CURRENT_330_MASK,
+						 max_current_caps) *
+						SDHCI_MAX_CURRENT_MULTIPLIER;
+	}
+	if (host->caps & SDHCI_CAN_VDD_300) {
+		ocr_avail |= MMC_VDD_29_30 | MMC_VDD_30_31;
+
+		mmc->max_current_300 = FIELD_GET(SDHCI_MAX_CURRENT_300_MASK,
+						 max_current_caps) *
+						SDHCI_MAX_CURRENT_MULTIPLIER;
+	}
+	if (host->caps & SDHCI_CAN_VDD_180) {
+		ocr_avail |= MMC_VDD_165_195;
+
+		mmc->max_current_180 = FIELD_GET(SDHCI_MAX_CURRENT_180_MASK,
+						 max_current_caps) *
+						SDHCI_MAX_CURRENT_MULTIPLIER;
+	}
+
+	/* If OCR set by host, use it instead. */
+	if (host->ocr_mask)
+		ocr_avail = host->ocr_mask;
+
+	/* If OCR set by external regulators, give it highest prio. */
+	if (mmc->ocr_avail)
+		ocr_avail = mmc->ocr_avail;
+
+	mmc->ocr_avail = ocr_avail;
+	mmc->ocr_avail_sdio = ocr_avail;
+	if (host->ocr_avail_sdio)
+		mmc->ocr_avail_sdio &= host->ocr_avail_sdio;
+	mmc->ocr_avail_sd = ocr_avail;
+	if (host->ocr_avail_sd)
+		mmc->ocr_avail_sd &= host->ocr_avail_sd;
+	else /* normal SD controllers don't support 1.8V */
+		mmc->ocr_avail_sd &= ~MMC_VDD_165_195;
+	mmc->ocr_avail_mmc = ocr_avail;
+	if (host->ocr_avail_mmc)
+		mmc->ocr_avail_mmc &= host->ocr_avail_mmc;
+
+	if ((mmc->caps & (MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 |
+			  MMC_CAP_UHS_SDR50 | MMC_CAP_UHS_SDR104 |
+			  MMC_CAP_UHS_DDR50 | MMC_CAP_1_8V_DDR)) ||
+	    (mmc->caps2 & (MMC_CAP2_HS200_1_8V_SDR | MMC_CAP2_HS400_1_8V)))
+		host->flags |= SDHCI_SIGNALING_180;
+
+	spin_lock_init(&host->lock);
+
+	/*
+	 * Maximum number of sectors in one transfer. Limited by SDMA boundary
+	 * size (512KiB). Note some tuning modes impose a 4MiB limit, but this
+	 * is less anyway.
+	 */
+	mmc->max_req_size = 524288;
+	/*
+	 * Maximum number of segments. Depends on if the hardware
+	 * can do scatter/gather or not.
+	 */
+	mmc->max_segs = 1;
+	mmc->max_req_size = min_t(size_t, mmc->max_req_size,
+				  dma_max_mapping_size(mmc_dev(mmc)));
+
+	mmc->max_seg_size = mmc->max_req_size;
+
+	mmc->max_blk_size = (host->caps & SDHCI_MAX_BLOCK_MASK) >>
+			SDHCI_MAX_BLOCK_SHIFT;
+
+	mmc->max_blk_size = 512 << mmc->max_blk_size;
+
+	/*
+	 * Maximum block count.
+	 */
+	mmc->max_blk_count = (host->quirks & SDHCI_QUIRK_NO_MULTIBLOCK) ? 1 : 65535;
+
+	if (mmc->max_segs == 1)
+		/* This may alter mmc->*_blk_* parameters */
+		// bst sdhci must reallocate bounce buffer
+		bst_sdhci_allocate_bounce_buffer(host);
+
+	return 0;
+
+undma:
+	if (host->align_buffer)
+		dma_free_coherent(mmc_dev(mmc), host->align_buffer_sz +
+				  host->adma_table_sz, host->align_buffer,
+				  host->align_addr);
+	host->adma_table = NULL;
+	host->align_buffer = NULL;
+
+	return ret;
+}
+
+static int bst_sdhci_add_host(struct sdhci_host *host)
+{
+	int ret;
+
+	ret = bst_sdhci_setup_host(host);
+	if (ret)
+		return ret;
+
+	ret = __sdhci_add_host(host);
+	if (ret)
+		goto cleanup;
+
+	return 0;
+
+cleanup:
+	sdhci_cleanup_host(host);
+
+	return ret;
+}
+
+/**
+ * dwcmshc_probe - Platform driver probe
+ * @pdev: Platform device
+ *
+ * Initializes the SDHCI host controller and registers it.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static int dwcmshc_probe(struct platform_device *pdev)
+{
+	struct sdhci_pltfm_host *pltfm_host;
+	struct sdhci_host *host;
+	struct dwcmshc_priv *priv;
+	int err;
+
+	host = sdhci_pltfm_init(pdev, &sdhci_dwcmshc_pdata,
+				sizeof(struct dwcmshc_priv));
+	if (IS_ERR(host))
+		return PTR_ERR(host);
+
+	pltfm_host = sdhci_priv(host);
+	priv = sdhci_pltfm_priv(pltfm_host);
+
+	err = mmc_of_parse(host->mmc);
+	if (err)
+		goto err_clk;
+
+	sdhci_get_of_property(pdev);
+	device_property_read_u32(&pdev->dev, "mmc_crm_base",
+				 &priv->phy_crm_reg_base);
+	device_property_read_u32(&pdev->dev, "mmc_crm_size",
+				 &priv->phy_crm_reg_size);
+
+	err = bst_sdhci_add_host(host);
+	if (err)
+		goto err_clk;
+
+	return 0;
+
+err_clk:
+	sdhci_pltfm_free(pdev);
+	return err;
+}
+
+/**
+ * dwcmshc_remove - Platform driver remove
+ * @pdev: Platform device
+ *
+ * Removes the SDHCI host controller.
+ *
+ * Return: 0 on success
+ */
+static void dwcmshc_remove(struct platform_device *pdev)
+{
+	struct sdhci_host *host = platform_get_drvdata(pdev);
+
+	sdhci_remove_host(host, 0);
+	sdhci_pltfm_free(pdev);
+}
+
+static const struct of_device_id sdhci_dwcmshc_dt_ids[] = {
+	{ .compatible = "bst,dwcmshc-sdhci" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sdhci_dwcmshc_dt_ids);
+
+static struct platform_driver sdhci_dwcmshc_driver = {
+	.driver = {
+		.name = "sdhci-dwcmshc",
+		.of_match_table = sdhci_dwcmshc_dt_ids,
+	},
+	.probe = dwcmshc_probe,
+	.remove = dwcmshc_remove,
+};
+module_platform_driver(sdhci_dwcmshc_driver);
+
+MODULE_DESCRIPTION("SDHCI platform driver for BST DWC MSHC");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("BST Ltd.");