iMX28: Add SSP MMC driver

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Andy Fleming <afleming@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
Acked-by: Andy Fleming <afleming@gmail.com>

1 files changed, 351 insertions, 0 deletions

diff --git a/drivers/mmc/mxsmmc.c b/drivers/mmc/mxsmmc.c
new file mode 100644
index 0000000000..2a9949eb94
--- /dev/null
+++ b/drivers/mmc/mxsmmc.c
@@ -0,0 +1,351 @@
+/*
+ * Freescale i.MX28 SSP MMC driver
+ *
+ * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
+ * on behalf of DENX Software Engineering GmbH
+ *
+ * Based on code from LTIB:
+ * (C) Copyright 2008-2010 Freescale Semiconductor, Inc.
+ * Terry Lv
+ *
+ * Copyright 2007, Freescale Semiconductor, Inc
+ * Andy Fleming
+ *
+ * Based vaguely on the pxa mmc code:
+ * (C) Copyright 2003
+ * Kyle Harris, Nexus Technologies, Inc. kharris@nexus-tech.net
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#include <common.h>
+#include <malloc.h>
+#include <mmc.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/arch/sys_proto.h>
+
+struct mxsmmc_priv {
+	int			id;
+	struct mx28_ssp_regs	*regs;
+	uint32_t		clkseq_bypass;
+	uint32_t		*clkctrl_ssp;
+	uint32_t		buswidth;
+	int			(*mmc_is_wp)(int);
+};
+
+#define	MXSMMC_MAX_TIMEOUT	10000
+
+/*
+ * Sends a command out on the bus.  Takes the mmc pointer,
+ * a command pointer, and an optional data pointer.
+ */
+static int
+mxsmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
+{
+	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
+	struct mx28_ssp_regs *ssp_regs = priv->regs;
+	uint32_t reg;
+	int timeout;
+	uint32_t data_count;
+	uint32_t *data_ptr;
+	uint32_t ctrl0;
+
+	debug("MMC%d: CMD%d\n", mmc->block_dev.dev, cmd->cmdidx);
+
+	/* Check bus busy */
+	timeout = MXSMMC_MAX_TIMEOUT;
+	while (--timeout) {
+		udelay(1000);
+		reg = readl(&ssp_regs->hw_ssp_status);
+		if (!(reg &
+			(SSP_STATUS_BUSY | SSP_STATUS_DATA_BUSY |
+			SSP_STATUS_CMD_BUSY))) {
+			break;
+		}
+	}
+
+	if (!timeout) {
+		printf("MMC%d: Bus busy timeout!\n", mmc->block_dev.dev);
+		return TIMEOUT;
+	}
+
+	/* See if card is present */
+	if (readl(&ssp_regs->hw_ssp_status) & SSP_STATUS_CARD_DETECT) {
+		printf("MMC%d: No card detected!\n", mmc->block_dev.dev);
+		return NO_CARD_ERR;
+	}
+
+	/* Start building CTRL0 contents */
+	ctrl0 = priv->buswidth;
+
+	/* Set up command */
+	if (!(cmd->resp_type & MMC_RSP_CRC))
+		ctrl0 |= SSP_CTRL0_IGNORE_CRC;
+	if (cmd->resp_type & MMC_RSP_PRESENT)	/* Need to get response */
+		ctrl0 |= SSP_CTRL0_GET_RESP;
+	if (cmd->resp_type & MMC_RSP_136)	/* It's a 136 bits response */
+		ctrl0 |= SSP_CTRL0_LONG_RESP;
+
+	/* Command index */
+	reg = readl(&ssp_regs->hw_ssp_cmd0);
+	reg &= ~(SSP_CMD0_CMD_MASK | SSP_CMD0_APPEND_8CYC);
+	reg |= cmd->cmdidx << SSP_CMD0_CMD_OFFSET;
+	if (cmd->cmdidx == MMC_CMD_STOP_TRANSMISSION)
+		reg |= SSP_CMD0_APPEND_8CYC;
+	writel(reg, &ssp_regs->hw_ssp_cmd0);
+
+	/* Command argument */
+	writel(cmd->cmdarg, &ssp_regs->hw_ssp_cmd1);
+
+	/* Set up data */
+	if (data) {
+		/* READ or WRITE */
+		if (data->flags & MMC_DATA_READ) {
+			ctrl0 |= SSP_CTRL0_READ;
+		} else if (priv->mmc_is_wp(mmc->block_dev.dev)) {
+			printf("MMC%d: Can not write a locked card!\n",
+				mmc->block_dev.dev);
+			return UNUSABLE_ERR;
+		}
+
+		ctrl0 |= SSP_CTRL0_DATA_XFER;
+		reg = ((data->blocks - 1) <<
+			SSP_BLOCK_SIZE_BLOCK_COUNT_OFFSET) |
+			((ffs(data->blocksize) - 1) <<
+			SSP_BLOCK_SIZE_BLOCK_SIZE_OFFSET);
+		writel(reg, &ssp_regs->hw_ssp_block_size);
+
+		reg = data->blocksize * data->blocks;
+		writel(reg, &ssp_regs->hw_ssp_xfer_size);
+	}
+
+	/* Kick off the command */
+	ctrl0 |= SSP_CTRL0_WAIT_FOR_IRQ | SSP_CTRL0_ENABLE | SSP_CTRL0_RUN;
+	writel(ctrl0, &ssp_regs->hw_ssp_ctrl0);
+
+	/* Wait for the command to complete */
+	timeout = MXSMMC_MAX_TIMEOUT;
+	while (--timeout) {
+		udelay(1000);
+		reg = readl(&ssp_regs->hw_ssp_status);
+		if (!(reg & SSP_STATUS_CMD_BUSY))
+			break;
+	}
+
+	if (!timeout) {
+		printf("MMC%d: Command %d busy\n",
+			mmc->block_dev.dev, cmd->cmdidx);
+		return TIMEOUT;
+	}
+
+	/* Check command timeout */
+	if (reg & SSP_STATUS_RESP_TIMEOUT) {
+		printf("MMC%d: Command %d timeout (status 0x%08x)\n",
+			mmc->block_dev.dev, cmd->cmdidx, reg);
+		return TIMEOUT;
+	}
+
+	/* Check command errors */
+	if (reg & (SSP_STATUS_RESP_CRC_ERR | SSP_STATUS_RESP_ERR)) {
+		printf("MMC%d: Command %d error (status 0x%08x)!\n",
+			mmc->block_dev.dev, cmd->cmdidx, reg);
+		return COMM_ERR;
+	}
+
+	/* Copy response to response buffer */
+	if (cmd->resp_type & MMC_RSP_136) {
+		cmd->response[3] = readl(&ssp_regs->hw_ssp_sdresp0);
+		cmd->response[2] = readl(&ssp_regs->hw_ssp_sdresp1);
+		cmd->response[1] = readl(&ssp_regs->hw_ssp_sdresp2);
+		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp3);
+	} else
+		cmd->response[0] = readl(&ssp_regs->hw_ssp_sdresp0);
+
+	/* Return if no data to process */
+	if (!data)
+		return 0;
+
+	/* Process the data */
+	data_count = data->blocksize * data->blocks;
+	timeout = MXSMMC_MAX_TIMEOUT;
+	if (data->flags & MMC_DATA_READ) {
+		data_ptr = (uint32_t *)data->dest;
+		while (data_count && --timeout) {
+			reg = readl(&ssp_regs->hw_ssp_status);
+			if (!(reg & SSP_STATUS_FIFO_EMPTY)) {
+				*data_ptr++ = readl(&ssp_regs->hw_ssp_data);
+				data_count -= 4;
+				timeout = MXSMMC_MAX_TIMEOUT;
+			} else
+				udelay(1000);
+		}
+	} else {
+		data_ptr = (uint32_t *)data->src;
+		timeout *= 100;
+		while (data_count && --timeout) {
+			reg = readl(&ssp_regs->hw_ssp_status);
+			if (!(reg & SSP_STATUS_FIFO_FULL)) {
+				writel(*data_ptr++, &ssp_regs->hw_ssp_data);
+				data_count -= 4;
+				timeout = MXSMMC_MAX_TIMEOUT;
+			} else
+				udelay(1000);
+		}
+	}
+
+	if (!timeout) {
+		printf("MMC%d: Data timeout with command %d (status 0x%08x)!\n",
+			mmc->block_dev.dev, cmd->cmdidx, reg);
+		return COMM_ERR;
+	}
+
+	/* Check data errors */
+	reg = readl(&ssp_regs->hw_ssp_status);
+	if (reg &
+		(SSP_STATUS_TIMEOUT | SSP_STATUS_DATA_CRC_ERR |
+		SSP_STATUS_FIFO_OVRFLW | SSP_STATUS_FIFO_UNDRFLW)) {
+		printf("MMC%d: Data error with command %d (status 0x%08x)!\n",
+			mmc->block_dev.dev, cmd->cmdidx, reg);
+		return COMM_ERR;
+	}
+
+	return 0;
+}
+
+static void mxsmmc_set_ios(struct mmc *mmc)
+{
+	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
+	struct mx28_ssp_regs *ssp_regs = priv->regs;
+
+	/* Set the clock speed */
+	if (mmc->clock)
+		mx28_set_ssp_busclock(priv->id, mmc->clock / 1000);
+
+	switch (mmc->bus_width) {
+	case 1:
+		priv->buswidth = SSP_CTRL0_BUS_WIDTH_ONE_BIT;
+		break;
+	case 4:
+		priv->buswidth = SSP_CTRL0_BUS_WIDTH_FOUR_BIT;
+		break;
+	case 8:
+		priv->buswidth = SSP_CTRL0_BUS_WIDTH_EIGHT_BIT;
+		break;
+	}
+
+	/* Set the bus width */
+	clrsetbits_le32(&ssp_regs->hw_ssp_ctrl0,
+			SSP_CTRL0_BUS_WIDTH_MASK, priv->buswidth);
+
+	debug("MMC%d: Set %d bits bus width\n",
+		mmc->block_dev.dev, mmc->bus_width);
+}
+
+static int mxsmmc_init(struct mmc *mmc)
+{
+	struct mxsmmc_priv *priv = (struct mxsmmc_priv *)mmc->priv;
+	struct mx28_ssp_regs *ssp_regs = priv->regs;
+
+	/* Reset SSP */
+	mx28_reset_block(&ssp_regs->hw_ssp_ctrl0_reg);
+
+	/* 8 bits word length in MMC mode */
+	clrsetbits_le32(&ssp_regs->hw_ssp_ctrl1,
+		SSP_CTRL1_SSP_MODE_MASK | SSP_CTRL1_WORD_LENGTH_MASK,
+		SSP_CTRL1_SSP_MODE_SD_MMC | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS);
+
+	/* Set initial bit clock 400 KHz */
+	mx28_set_ssp_busclock(priv->id, 400);
+
+	/* Send initial 74 clock cycles (185 us @ 400 KHz)*/
+	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_set);
+	udelay(200);
+	writel(SSP_CMD0_CONT_CLKING_EN, &ssp_regs->hw_ssp_cmd0_clr);
+
+	return 0;
+}
+
+int mxsmmc_initialize(bd_t *bis, int id, int (*wp)(int))
+{
+	struct mx28_clkctrl_regs *clkctrl_regs =
+		(struct mx28_clkctrl_regs *)MXS_CLKCTRL_BASE;
+	struct mmc *mmc = NULL;
+	struct mxsmmc_priv *priv = NULL;
+
+	mmc = malloc(sizeof(struct mmc));
+	if (!mmc)
+		return -ENOMEM;
+
+	priv = malloc(sizeof(struct mxsmmc_priv));
+	if (!priv) {
+		free(mmc);
+		return -ENOMEM;
+	}
+
+	priv->mmc_is_wp = wp;
+	priv->id = id;
+	switch (id) {
+	case 0:
+		priv->regs = (struct mx28_ssp_regs *)MXS_SSP0_BASE;
+		priv->clkseq_bypass = CLKCTRL_CLKSEQ_BYPASS_SSP0;
+		priv->clkctrl_ssp = &clkctrl_regs->hw_clkctrl_ssp0;
+		break;
+	case 1:
+		priv->regs = (struct mx28_ssp_regs *)MXS_SSP1_BASE;
+		priv->clkseq_bypass = CLKCTRL_CLKSEQ_BYPASS_SSP1;
+		priv->clkctrl_ssp = &clkctrl_regs->hw_clkctrl_ssp1;
+		break;
+	case 2:
+		priv->regs = (struct mx28_ssp_regs *)MXS_SSP2_BASE;
+		priv->clkseq_bypass = CLKCTRL_CLKSEQ_BYPASS_SSP2;
+		priv->clkctrl_ssp = &clkctrl_regs->hw_clkctrl_ssp2;
+		break;
+	case 3:
+		priv->regs = (struct mx28_ssp_regs *)MXS_SSP3_BASE;
+		priv->clkseq_bypass = CLKCTRL_CLKSEQ_BYPASS_SSP3;
+		priv->clkctrl_ssp = &clkctrl_regs->hw_clkctrl_ssp3;
+		break;
+	}
+
+	sprintf(mmc->name, "MXS MMC");
+	mmc->send_cmd = mxsmmc_send_cmd;
+	mmc->set_ios = mxsmmc_set_ios;
+	mmc->init = mxsmmc_init;
+	mmc->priv = priv;
+
+	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
+
+	mmc->host_caps = MMC_MODE_4BIT | MMC_MODE_8BIT |
+			 MMC_MODE_HS_52MHz | MMC_MODE_HS;
+
+	/*
+	 * SSPCLK = 480 * 18 / 29 / 1 = 297.731 MHz
+	 * SSP bit rate = SSPCLK / (CLOCK_DIVIDE * (1 + CLOCK_RATE)),
+	 * CLOCK_DIVIDE has to be an even value from 2 to 254, and
+	 * CLOCK_RATE could be any integer from 0 to 255.
+	 */
+	mmc->f_min = 400000;
+	mmc->f_max = mxc_get_clock(MXC_SSP0_CLK + id) * 1000 / 2;
+	mmc->b_max = 0;
+
+	mmc_register(mmc);
+	return 0;
+}