drivers: imx: mxc_usdhc: Add USDHC driver to support boot EMMC

Add USDHC driver to support boot EMMC. Only initialization
and single/multiple block read are tested.

[bod: fixed checkpatch.pl complaints]
[bod: changed name to imx_usdhc for namespace consistency]
[bod: squashed antecedent fixes into this one patch]
Signed-off-by: Jun Nie <jun.nie@linaro.org>
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>

drivers/imx/usdhc/imx_usdhc.c

+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch.h>
+#include <arch_helpers.h>
+#include <assert.h>
+#include <debug.h>
+#include <delay_timer.h>
+#include <imx_usdhc.h>
+#include <mmc.h>
+#include <errno.h>
+#include <mmio.h>
+#include <string.h>
+
+static void imx_usdhc_initialize(void);
+static int imx_usdhc_send_cmd(struct mmc_cmd *cmd);
+static int imx_usdhc_set_ios(unsigned int clk, unsigned int width);
+static int imx_usdhc_prepare(int lba, uintptr_t buf, size_t size);
+static int imx_usdhc_read(int lba, uintptr_t buf, size_t size);
+static int imx_usdhc_write(int lba, uintptr_t buf, size_t size);
+
+static const struct mmc_ops imx_usdhc_ops = {
+	.init		= imx_usdhc_initialize,
+	.send_cmd	= imx_usdhc_send_cmd,
+	.set_ios	= imx_usdhc_set_ios,
+	.prepare	= imx_usdhc_prepare,
+	.read		= imx_usdhc_read,
+	.write		= imx_usdhc_write,
+};
+
+static imx_usdhc_params_t imx_usdhc_params;
+
+#define IMX7_MMC_SRC_CLK_RATE (200 * 1000 * 1000)
+static void imx_usdhc_set_clk(int clk)
+{
+	int div = 1;
+	int pre_div = 1;
+	unsigned int sdhc_clk = IMX7_MMC_SRC_CLK_RATE;
+	uintptr_t reg_base = imx_usdhc_params.reg_base;
+
+	assert(clk > 0);
+
+	while (sdhc_clk / (16 * pre_div) > clk && pre_div < 256)
+		pre_div *= 2;
+
+	while (sdhc_clk / div > clk && div < 16)
+		div++;
+
+	pre_div >>= 1;
+	div -= 1;
+	clk = (pre_div << 8) | (div << 4);
+
+	mmio_clrbits32(reg_base + VENDSPEC, VENDSPEC_CARD_CLKEN);
+	mmio_clrsetbits32(reg_base + SYSCTRL, SYSCTRL_CLOCK_MASK, clk);
+	udelay(10000);
+
+	mmio_setbits32(reg_base + VENDSPEC, VENDSPEC_PER_CLKEN | VENDSPEC_CARD_CLKEN);
+}
+
+static void imx_usdhc_initialize(void)
+{
+	unsigned int timeout = 10000;
+	uintptr_t reg_base = imx_usdhc_params.reg_base;
+
+	assert((imx_usdhc_params.reg_base & MMC_BLOCK_MASK) == 0);
+
+	/* reset the controller */
+	mmio_setbits32(reg_base + SYSCTRL, SYSCTRL_RSTA);
+
+	/* wait for reset done */
+	while ((mmio_read_32(reg_base + SYSCTRL) & SYSCTRL_RSTA)) {
+		if (!timeout)
+			ERROR("IMX MMC reset timeout.\n");
+		timeout--;
+	}
+
+	mmio_write_32(reg_base + MMCBOOT, 0);
+	mmio_write_32(reg_base + MIXCTRL, 0);
+	mmio_write_32(reg_base + CLKTUNECTRLSTS, 0);
+
+	mmio_write_32(reg_base + VENDSPEC, VENDSPEC_INIT);
+	mmio_write_32(reg_base + DLLCTRL, 0);
+	mmio_setbits32(reg_base + VENDSPEC, VENDSPEC_IPG_CLKEN | VENDSPEC_PER_CLKEN);
+
+	/* Set the initial boot clock rate */
+	imx_usdhc_set_clk(MMC_BOOT_CLK_RATE);
+	udelay(100);
+
+	/* Clear read/write ready status */
+	mmio_clrbits32(reg_base + INTSTATEN, INTSTATEN_BRR | INTSTATEN_BWR);
+
+	/* configure as little endian */
+	mmio_write_32(reg_base + PROTCTRL, PROTCTRL_LE);
+
+	/* Set timeout to the maximum value */
+	mmio_clrsetbits32(reg_base + SYSCTRL, SYSCTRL_TIMEOUT_MASK,
+			  SYSCTRL_TIMEOUT(15));
+
+	/* set wartermark level as 16 for safe for MMC */
+	mmio_clrsetbits32(reg_base + WATERMARKLEV, WMKLV_MASK, 16 | (16 << 16));
+}
+
+#define FSL_CMD_RETRIES	1000
+
+static int imx_usdhc_send_cmd(struct mmc_cmd *cmd)
+{
+	uintptr_t reg_base = imx_usdhc_params.reg_base;
+	unsigned int xfertype = 0, mixctl = 0, multiple = 0, data = 0, err = 0;
+	unsigned int state, flags = INTSTATEN_CC | INTSTATEN_CTOE;
+	unsigned int cmd_retries = 0;
+
+	assert(cmd);
+
+	/* clear all irq status */
+	mmio_write_32(reg_base + INTSTAT, 0xffffffff);
+
+	/* Wait for the bus to be idle */
+	do {
+		state = mmio_read_32(reg_base + PSTATE);
+	} while (state & (PSTATE_CDIHB | PSTATE_CIHB));
+
+	while (mmio_read_32(reg_base + PSTATE) & PSTATE_DLA)
+		;
+
+	mmio_write_32(reg_base + INTSIGEN, 0);
+	udelay(1000);
+
+	switch (cmd->cmd_idx) {
+	case MMC_CMD(12):
+		xfertype |= XFERTYPE_CMDTYP_ABORT;
+		break;
+	case MMC_CMD(18):
+		multiple = 1;
+		/* fall thru for read op */
+	case MMC_CMD(17):
+	case MMC_CMD(8):
+		mixctl |= MIXCTRL_DTDSEL;
+		data = 1;
+		break;
+	case MMC_CMD(25):
+		multiple = 1;
+		/* fall thru for data op flag */
+	case MMC_CMD(24):
+		data = 1;
+		break;
+	default:
+		break;
+	}
+
+	if (multiple) {
+		mixctl |= MIXCTRL_MSBSEL;
+		mixctl |= MIXCTRL_BCEN;
+	}
+
+	if (data) {
+		xfertype |= XFERTYPE_DPSEL;
+		mixctl |= MIXCTRL_DMAEN;
+	}
+
+	if (cmd->resp_type & MMC_RSP_48)
+		xfertype |= XFERTYPE_RSPTYP_48;
+	else if (cmd->resp_type & MMC_RSP_136)
+		xfertype |= XFERTYPE_RSPTYP_136;
+	else if (cmd->resp_type & MMC_RSP_BUSY)
+		xfertype |= XFERTYPE_RSPTYP_48_BUSY;
+
+	if (cmd->resp_type & MMC_RSP_CMD_IDX)
+		xfertype |= XFERTYPE_CICEN;
+
+	if (cmd->resp_type & MMC_RSP_CRC)
+		xfertype |= XFERTYPE_CCCEN;
+
+	xfertype |= XFERTYPE_CMD(cmd->cmd_idx);
+
+	/* Send the command */
+	mmio_write_32(reg_base + CMDARG, cmd->cmd_arg);
+	mmio_clrsetbits32(reg_base + MIXCTRL, MIXCTRL_DATMASK, mixctl);
+	mmio_write_32(reg_base + XFERTYPE, xfertype);
+
+	/* Wait for the command done */
+	do {
+		state = mmio_read_32(reg_base + INTSTAT);
+		if (cmd_retries)
+			udelay(1);
+	} while ((!(state & flags)) && ++cmd_retries < FSL_CMD_RETRIES);
+
+	if ((state & (INTSTATEN_CTOE | CMD_ERR)) || cmd_retries == FSL_CMD_RETRIES) {
+		if (cmd_retries == FSL_CMD_RETRIES)
+			err = -ETIMEDOUT;
+		else
+			err = -EIO;
+		ERROR("imx_usdhc mmc cmd %d state 0x%x errno=%d\n",
+		      cmd->cmd_idx, state, err);
+		goto out;
+	}
+
+	/* Copy the response to the response buffer */
+	if (cmd->resp_type & MMC_RSP_136) {
+		unsigned int cmdrsp3, cmdrsp2, cmdrsp1, cmdrsp0;
+
+		cmdrsp3 = mmio_read_32(reg_base + CMDRSP3);
+		cmdrsp2 = mmio_read_32(reg_base + CMDRSP2);
+		cmdrsp1 = mmio_read_32(reg_base + CMDRSP1);
+		cmdrsp0 = mmio_read_32(reg_base + CMDRSP0);
+		cmd->resp_data[3] = (cmdrsp3 << 8) | (cmdrsp2 >> 24);
+		cmd->resp_data[2] = (cmdrsp2 << 8) | (cmdrsp1 >> 24);
+		cmd->resp_data[1] = (cmdrsp1 << 8) | (cmdrsp0 >> 24);
+		cmd->resp_data[0] = (cmdrsp0 << 8);
+	} else {
+		cmd->resp_data[0] = mmio_read_32(reg_base + CMDRSP0);
+	}
+
+	/* Wait until all of the blocks are transferred */
+	if (data) {
+		flags = DATA_COMPLETE;
+		do {
+			state = mmio_read_32(reg_base + INTSTAT);
+
+			if (state & (INTSTATEN_DTOE | DATA_ERR)) {
+				err = -EIO;
+				ERROR("imx_usdhc mmc data state 0x%x\n", state);
+				goto out;
+			}
+		} while ((state & flags) != flags);
+	}
+
+out:
+	/* Reset CMD and DATA on error */
+	if (err) {
+		mmio_setbits32(reg_base + SYSCTRL, SYSCTRL_RSTC);
+		while (mmio_read_32(reg_base + SYSCTRL) & SYSCTRL_RSTC)
+			;
+
+		if (data) {
+			mmio_setbits32(reg_base + SYSCTRL, SYSCTRL_RSTD);
+			while (mmio_read_32(reg_base + SYSCTRL) & SYSCTRL_RSTD)
+				;
+		}
+	}
+
+	/* clear all irq status */
+	mmio_write_32(reg_base + INTSTAT, 0xffffffff);
+
+	return err;
+}
+
+static int imx_usdhc_set_ios(unsigned int clk, unsigned int width)
+{
+	uintptr_t reg_base = imx_usdhc_params.reg_base;
+
+	imx_usdhc_set_clk(clk);
+
+	if (width == MMC_BUS_WIDTH_4)
+		mmio_clrsetbits32(reg_base + PROTCTRL, PROTCTRL_WIDTH_MASK,
+				  PROTCTRL_WIDTH_4);
+	else if (width == MMC_BUS_WIDTH_8)
+		mmio_clrsetbits32(reg_base + PROTCTRL, PROTCTRL_WIDTH_MASK,
+				  PROTCTRL_WIDTH_8);
+
+	return 0;
+}
+
+static int imx_usdhc_prepare(int lba, uintptr_t buf, size_t size)
+{
+	uintptr_t reg_base = imx_usdhc_params.reg_base;
+
+	mmio_write_32(reg_base + DSADDR, buf);
+	mmio_write_32(reg_base + BLKATT,
+		      (size / MMC_BLOCK_SIZE) << 16 | MMC_BLOCK_SIZE);
+
+	return 0;
+}
+
+static int imx_usdhc_read(int lba, uintptr_t buf, size_t size)
+{
+	return 0;
+}
+
+static int imx_usdhc_write(int lba, uintptr_t buf, size_t size)
+{
+	return 0;
+}
+
+void imx_usdhc_init(imx_usdhc_params_t *params,
+		    struct mmc_device_info *mmc_dev_info)
+{
+	assert((params != 0) &&
+	       ((params->reg_base & MMC_BLOCK_MASK) == 0) &&
+	       (params->clk_rate > 0) &&
+	       ((params->bus_width == MMC_BUS_WIDTH_1) ||
+		(params->bus_width == MMC_BUS_WIDTH_4) ||
+		(params->bus_width == MMC_BUS_WIDTH_8)));
+
+	memcpy(&imx_usdhc_params, params, sizeof(imx_usdhc_params_t));
+	mmc_init(&imx_usdhc_ops, params->clk_rate, params->bus_width,
+		 params->flags, mmc_dev_info);
+}

drivers/imx/usdhc/imx_usdhc.h

+/*
+ * Copyright (c) 2018, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef __IMX_USDHC_H__
+#define	__IMX_USDHC_H__
+
+#include <mmc.h>
+
+typedef struct imx_usdhc_params {
+	uintptr_t	reg_base;
+	int		clk_rate;
+	int		bus_width;
+	unsigned int	flags;
+} imx_usdhc_params_t;
+
+void imx_usdhc_init(imx_usdhc_params_t *params,
+		    struct mmc_device_info *mmc_dev_info);
+
+/* iMX MMC registers definition */
+#define DSADDR			0x000
+#define BLKATT			0x004
+#define CMDARG			0x008
+#define CMDRSP0			0x010
+#define CMDRSP1			0x014
+#define CMDRSP2			0x018
+#define CMDRSP3			0x01c
+
+#define XFERTYPE		0x00c
+#define XFERTYPE_CMD(x)		(((x) & 0x3f) << 24)
+#define XFERTYPE_CMDTYP_ABORT	(3 << 22)
+#define XFERTYPE_DPSEL		BIT(21)
+#define XFERTYPE_CICEN		BIT(20)
+#define XFERTYPE_CCCEN		BIT(19)
+#define XFERTYPE_RSPTYP_136	BIT(16)
+#define XFERTYPE_RSPTYP_48	BIT(17)
+#define XFERTYPE_RSPTYP_48_BUSY	(BIT(16) | BIT(17))
+
+#define PSTATE			0x024
+#define PSTATE_DAT0		BIT(24)
+#define PSTATE_DLA		BIT(2)
+#define PSTATE_CDIHB		BIT(1)
+#define PSTATE_CIHB		BIT(0)
+
+#define PROTCTRL		0x028
+#define PROTCTRL_LE		BIT(5)
+#define PROTCTRL_WIDTH_4	BIT(1)
+#define PROTCTRL_WIDTH_8	BIT(2)
+#define PROTCTRL_WIDTH_MASK	0x6
+
+#define SYSCTRL			0x02c
+#define SYSCTRL_RSTD		BIT(26)
+#define SYSCTRL_RSTC		BIT(25)
+#define SYSCTRL_RSTA		BIT(24)
+#define SYSCTRL_CLOCK_MASK	0x0000fff0
+#define SYSCTRL_TIMEOUT_MASK	0x000f0000
+#define SYSCTRL_TIMEOUT(x)	((0xf & (x)) << 16)
+
+#define INTSTAT			0x030
+#define INTSTAT_DMAE		BIT(28)
+#define INTSTAT_DEBE		BIT(22)
+#define INTSTAT_DCE		BIT(21)
+#define INTSTAT_DTOE		BIT(20)
+#define INTSTAT_CIE		BIT(19)
+#define INTSTAT_CEBE		BIT(18)
+#define INTSTAT_CCE		BIT(17)
+#define INTSTAT_DINT		BIT(3)
+#define INTSTAT_BGE		BIT(2)
+#define INTSTAT_TC		BIT(1)
+#define INTSTAT_CC		BIT(0)
+#define CMD_ERR			(INTSTAT_CIE | INTSTAT_CEBE | INTSTAT_CCE)
+#define DATA_ERR		(INTSTAT_DMAE | INTSTAT_DEBE | INTSTAT_DCE | \
+				 INTSTAT_DTOE)
+#define DATA_COMPLETE		(INTSTAT_DINT | INTSTAT_TC)
+
+#define INTSTATEN		0x034
+#define INTSTATEN_DEBE		BIT(22)
+#define INTSTATEN_DCE		BIT(21)
+#define INTSTATEN_DTOE		BIT(20)
+#define INTSTATEN_CIE		BIT(19)
+#define INTSTATEN_CEBE		BIT(18)
+#define INTSTATEN_CCE		BIT(17)
+#define INTSTATEN_CTOE		BIT(16)
+#define INTSTATEN_CINT		BIT(8)
+#define INTSTATEN_BRR		BIT(5)
+#define INTSTATEN_BWR		BIT(4)
+#define INTSTATEN_DINT		BIT(3)
+#define INTSTATEN_TC		BIT(1)
+#define INTSTATEN_CC		BIT(0)
+#define EMMC_INTSTATEN_BITS	(INTSTATEN_CC | INTSTATEN_TC | INTSTATEN_DINT | \
+				 INTSTATEN_BWR | INTSTATEN_BRR | INTSTATEN_CINT | \
+				 INTSTATEN_CTOE | INTSTATEN_CCE | INTSTATEN_CEBE | \
+				 INTSTATEN_CIE | INTSTATEN_DTOE | INTSTATEN_DCE | \
+				 INTSTATEN_DEBE)
+
+#define INTSIGEN		0x038
+
+#define WATERMARKLEV		0x044
+#define WMKLV_RD_MASK		0xff
+#define WMKLV_WR_MASK		0x00ff0000
+#define WMKLV_MASK		(WMKLV_RD_MASK | WMKLV_WR_MASK)
+
+#define MIXCTRL			0x048
+#define MIXCTRL_MSBSEL		BIT(5)
+#define MIXCTRL_DTDSEL		BIT(4)
+#define MIXCTRL_DDREN		BIT(3)
+#define MIXCTRL_AC12EN		BIT(2)
+#define MIXCTRL_BCEN		BIT(1)
+#define MIXCTRL_DMAEN		BIT(0)
+#define MIXCTRL_DATMASK		0x7f
+
+#define DLLCTRL			0x060
+
+#define CLKTUNECTRLSTS		0x068
+
+#define VENDSPEC		0x0c0
+#define VENDSPEC_RSRV1		BIT(29)
+#define VENDSPEC_CARD_CLKEN	BIT(14)
+#define VENDSPEC_PER_CLKEN	BIT(13)
+#define VENDSPEC_AHB_CLKEN	BIT(12)
+#define VENDSPEC_IPG_CLKEN	BIT(11)
+#define VENDSPEC_AC12_CHKBUSY	BIT(3)
+#define VENDSPEC_EXTDMA		BIT(0)
+#define VENDSPEC_INIT		(VENDSPEC_RSRV1	| VENDSPEC_CARD_CLKEN | \
+				 VENDSPEC_PER_CLKEN | VENDSPEC_AHB_CLKEN | \
+				 VENDSPEC_IPG_CLKEN | VENDSPEC_AC12_CHKBUSY | \
+				 VENDSPEC_EXTDMA)
+
+#define MMCBOOT			0x0c4
+
+#define mmio_clrsetbits32(addr, clear, set)	mmio_write_32(addr, (mmio_read_32(addr) & ~(clear)) | (set))
+#define mmio_clrbits32(addr, clear)		mmio_write_32(addr, mmio_read_32(addr) & ~(clear))
+#define mmio_setbits32(addr, set)		mmio_write_32(addr, mmio_read_32(addr) | (set))
+
+#endif  /* __IMX_USDHC_H__ */