mxc-mmc: sdhc host driver for MX2 and MX3 proccessor

This is a port of Linux driver for SDHC host controller hardware
found on Freescale's MX2 and MX3 processors. Uses new generic MMC
framework (CONFIG_GENERIC_MMC) and it looks like there are some
problems with a framework (at least on LE cpus). Some of these
problems are addressed in the following patches.

Signed-off-by: Ilya Yanok <yanok@emcraft.com>

cpu/arm926ejs/mx27/generic.c

@@ -23,6 +23,9 @@
 #include <netdev.h>
 #include <asm/io.h>
 #include <asm/arch/imx-regs.h>
+#ifdef CONFIG_MXC_MMC
+#include <asm/arch/mxcmmc.h>
+#endif
 
 /*
  *  get the system pll clock in Hz
@@ -169,6 +172,19 @@ int cpu_eth_init(bd_t *bis)
 #endif
 }
 
+/*
+ * Initializes on-chip MMC controllers.
+ * to override, implement board_mmc_init()
+ */
+int cpu_mmc_init(bd_t *bis)
+{
+#ifdef CONFIG_MXC_MMC
+	return mxc_mmc_init(bis);
+#else
+	return 0;
+#endif
+}
+
 void imx_gpio_mode(int gpio_mode)
 {
 	struct gpio_regs *regs = (struct gpio_regs *)IMX_GPIO_BASE;

drivers/mmc/Makefile

@@ -30,6 +30,7 @@ COBJS-$(CONFIG_ATMEL_MCI) += atmel_mci.o
 COBJS-$(CONFIG_BFIN_SDH) += bfin_sdh.o
 COBJS-$(CONFIG_OMAP3_MMC) += omap3_mmc.o
 COBJS-$(CONFIG_FSL_ESDHC) += fsl_esdhc.o
+COBJS-$(CONFIG_MXC_MMC) += mxcmmc.o
 COBJS-$(CONFIG_PXA_MMC) += pxa_mmc.o
 
 COBJS	:= $(COBJS-y)

drivers/mmc/mxcmmc.c

@@ -0,0 +1,523 @@
+/*
+ *  This is a driver for the SDHC controller found in Freescale MX2/MX3
+ *  SoCs. It is basically the same hardware as found on MX1 (imxmmc.c).
+ *  Unlike the hardware found on MX1, this hardware just works and does
+ *  not need all the quirks found in imxmmc.c, hence the seperate driver.
+ *
+ *  Copyright (C) 2009 Ilya Yanok, <yanok@emcraft.com>
+ *  Copyright (C) 2008 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
+ *  Copyright (C) 2006 Pavel Pisa, PiKRON <ppisa@pikron.com>
+ *
+ *  derived from pxamci.c by Russell King
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <config.h>
+#include <common.h>
+#include <command.h>
+#include <mmc.h>
+#include <part.h>
+#include <malloc.h>
+#include <mmc.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+#ifdef CONFIG_MX27
+#include <asm/arch/clock.h>
+#endif
+
+#define DRIVER_NAME "mxc-mmc"
+
+struct mxcmci_regs {
+	u32 str_stp_clk;
+	u32 status;
+	u32 clk_rate;
+	u32 cmd_dat_cont;
+	u32 res_to;
+	u32 read_to;
+	u32 blk_len;
+	u32 nob;
+	u32 rev_no;
+	u32 int_cntr;
+	u32 cmd;
+	u32 arg;
+	u32 pad;
+	u32 res_fifo;
+	u32 buffer_access;
+};
+
+#define STR_STP_CLK_RESET               (1 << 3)
+#define STR_STP_CLK_START_CLK           (1 << 1)
+#define STR_STP_CLK_STOP_CLK            (1 << 0)
+
+#define STATUS_CARD_INSERTION		(1 << 31)
+#define STATUS_CARD_REMOVAL		(1 << 30)
+#define STATUS_YBUF_EMPTY		(1 << 29)
+#define STATUS_XBUF_EMPTY		(1 << 28)
+#define STATUS_YBUF_FULL		(1 << 27)
+#define STATUS_XBUF_FULL		(1 << 26)
+#define STATUS_BUF_UND_RUN		(1 << 25)
+#define STATUS_BUF_OVFL			(1 << 24)
+#define STATUS_SDIO_INT_ACTIVE		(1 << 14)
+#define STATUS_END_CMD_RESP		(1 << 13)
+#define STATUS_WRITE_OP_DONE		(1 << 12)
+#define STATUS_DATA_TRANS_DONE		(1 << 11)
+#define STATUS_READ_OP_DONE		(1 << 11)
+#define STATUS_WR_CRC_ERROR_CODE_MASK	(3 << 10)
+#define STATUS_CARD_BUS_CLK_RUN		(1 << 8)
+#define STATUS_BUF_READ_RDY		(1 << 7)
+#define STATUS_BUF_WRITE_RDY		(1 << 6)
+#define STATUS_RESP_CRC_ERR		(1 << 5)
+#define STATUS_CRC_READ_ERR		(1 << 3)
+#define STATUS_CRC_WRITE_ERR		(1 << 2)
+#define STATUS_TIME_OUT_RESP		(1 << 1)
+#define STATUS_TIME_OUT_READ		(1 << 0)
+#define STATUS_ERR_MASK			0x2f
+
+#define CMD_DAT_CONT_CMD_RESP_LONG_OFF	(1 << 12)
+#define CMD_DAT_CONT_STOP_READWAIT	(1 << 11)
+#define CMD_DAT_CONT_START_READWAIT	(1 << 10)
+#define CMD_DAT_CONT_BUS_WIDTH_4	(2 << 8)
+#define CMD_DAT_CONT_INIT		(1 << 7)
+#define CMD_DAT_CONT_WRITE		(1 << 4)
+#define CMD_DAT_CONT_DATA_ENABLE	(1 << 3)
+#define CMD_DAT_CONT_RESPONSE_48BIT_CRC	(1 << 0)
+#define CMD_DAT_CONT_RESPONSE_136BIT	(2 << 0)
+#define CMD_DAT_CONT_RESPONSE_48BIT	(3 << 0)
+
+#define INT_SDIO_INT_WKP_EN		(1 << 18)
+#define INT_CARD_INSERTION_WKP_EN	(1 << 17)
+#define INT_CARD_REMOVAL_WKP_EN		(1 << 16)
+#define INT_CARD_INSERTION_EN		(1 << 15)
+#define INT_CARD_REMOVAL_EN		(1 << 14)
+#define INT_SDIO_IRQ_EN			(1 << 13)
+#define INT_DAT0_EN			(1 << 12)
+#define INT_BUF_READ_EN			(1 << 4)
+#define INT_BUF_WRITE_EN		(1 << 3)
+#define INT_END_CMD_RES_EN		(1 << 2)
+#define INT_WRITE_OP_DONE_EN		(1 << 1)
+#define INT_READ_OP_EN			(1 << 0)
+
+struct mxcmci_host {
+	struct mmc		*mmc;
+	struct mxcmci_regs	*base;
+	int			irq;
+	int			detect_irq;
+	int			dma;
+	int			do_dma;
+	unsigned int		power_mode;
+
+	struct mmc_cmd		*cmd;
+	struct mmc_data		*data;
+
+	unsigned int		dma_nents;
+	unsigned int		datasize;
+	unsigned int		dma_dir;
+
+	u16			rev_no;
+	unsigned int		cmdat;
+
+	int			clock;
+};
+
+static struct mxcmci_host mxcmci_host;
+static struct mxcmci_host *host = &mxcmci_host;
+
+static inline int mxcmci_use_dma(struct mxcmci_host *host)
+{
+	return host->do_dma;
+}
+
+static void mxcmci_softreset(struct mxcmci_host *host)
+{
+	int i;
+
+	/* reset sequence */
+	writew(STR_STP_CLK_RESET, &host->base->str_stp_clk);
+	writew(STR_STP_CLK_RESET | STR_STP_CLK_START_CLK,
+			&host->base->str_stp_clk);
+
+	for (i = 0; i < 8; i++)
+		writew(STR_STP_CLK_START_CLK, &host->base->str_stp_clk);
+
+	writew(0xff, &host->base->res_to);
+}
+
+static void mxcmci_setup_data(struct mxcmci_host *host, struct mmc_data *data)
+{
+	unsigned int nob = data->blocks;
+	unsigned int blksz = data->blocksize;
+	unsigned int datasize = nob * blksz;
+
+	host->data = data;
+
+	writew(nob, &host->base->nob);
+	writew(blksz, &host->base->blk_len);
+	host->datasize = datasize;
+}
+
+static int mxcmci_start_cmd(struct mxcmci_host *host, struct mmc_cmd *cmd,
+		unsigned int cmdat)
+{
+	if (host->cmd != NULL)
+		printf("mxcmci: error!\n");
+	host->cmd = cmd;
+
+	switch (cmd->resp_type) {
+	case MMC_RSP_R1: /* short CRC, OPCODE */
+	case MMC_RSP_R1b:/* short CRC, OPCODE, BUSY */
+		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT_CRC;
+		break;
+	case MMC_RSP_R2: /* long 136 bit + CRC */
+		cmdat |= CMD_DAT_CONT_RESPONSE_136BIT;
+		break;
+	case MMC_RSP_R3: /* short */
+		cmdat |= CMD_DAT_CONT_RESPONSE_48BIT;
+		break;
+	case MMC_RSP_NONE:
+		break;
+	default:
+		printf("mxcmci: unhandled response type 0x%x\n",
+				cmd->resp_type);
+		return -EINVAL;
+	}
+
+	writew(cmd->cmdidx, &host->base->cmd);
+	writel(cmd->cmdarg, &host->base->arg);
+	writew(cmdat, &host->base->cmd_dat_cont);
+
+	return 0;
+}
+
+static void mxcmci_finish_request(struct mxcmci_host *host,
+		struct mmc_cmd *cmd, struct mmc_data *data)
+{
+	host->cmd = NULL;
+	host->data = NULL;
+}
+
+static int mxcmci_finish_data(struct mxcmci_host *host, unsigned int stat)
+{
+	int data_error = 0;
+
+	if (stat & STATUS_ERR_MASK) {
+		printf("request failed. status: 0x%08x\n",
+				stat);
+		if (stat & STATUS_CRC_READ_ERR) {
+			data_error = -EILSEQ;
+		} else if (stat & STATUS_CRC_WRITE_ERR) {
+			u32 err_code = (stat >> 9) & 0x3;
+			if (err_code == 2) /* No CRC response */
+				data_error = TIMEOUT;
+			else
+				data_error = -EILSEQ;
+		} else if (stat & STATUS_TIME_OUT_READ) {
+			data_error = TIMEOUT;
+		} else {
+			data_error = -EIO;
+		}
+	}
+
+	host->data = NULL;
+
+	return data_error;
+}
+
+static int mxcmci_read_response(struct mxcmci_host *host, unsigned int stat)
+{
+	struct mmc_cmd *cmd = host->cmd;
+	int i;
+	u32 a, b, c;
+	u32 *resp = (u32 *)cmd->response;
+
+	if (!cmd)
+		return 0;
+
+	if (stat & STATUS_TIME_OUT_RESP) {
+		printf("CMD TIMEOUT\n");
+		return TIMEOUT;
+	} else if (stat & STATUS_RESP_CRC_ERR && cmd->resp_type & MMC_RSP_CRC) {
+		printf("cmd crc error\n");
+		return -EILSEQ;
+	}
+
+	if (cmd->resp_type & MMC_RSP_PRESENT) {
+		if (cmd->resp_type & MMC_RSP_136) {
+			for (i = 0; i < 4; i++) {
+				a = readw(&host->base->res_fifo);
+				b = readw(&host->base->res_fifo);
+				resp[i] = a << 16 | b;
+			}
+		} else {
+			a = readw(&host->base->res_fifo);
+			b = readw(&host->base->res_fifo);
+			c = readw(&host->base->res_fifo);
+			resp[0] = a << 24 | b << 8 | c >> 8;
+		}
+	}
+	return 0;
+}
+
+static int mxcmci_poll_status(struct mxcmci_host *host, u32 mask)
+{
+	u32 stat;
+	unsigned long timeout = get_ticks() + CONFIG_SYS_HZ;
+
+	do {
+		stat = readl(&host->base->status);
+		if (stat & STATUS_ERR_MASK)
+			return stat;
+		if (timeout < get_ticks())
+			return STATUS_TIME_OUT_READ;
+		if (stat & mask)
+			return 0;
+	} while (1);
+}
+
+static int mxcmci_pull(struct mxcmci_host *host, void *_buf, int bytes)
+{
+	unsigned int stat;
+	u32 *buf = _buf;
+
+	while (bytes > 3) {
+		stat = mxcmci_poll_status(host,
+				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
+		if (stat)
+			return stat;
+		*buf++ = readl(&host->base->buffer_access);
+		bytes -= 4;
+	}
+
+	if (bytes) {
+		u8 *b = (u8 *)buf;
+		u32 tmp;
+
+		stat = mxcmci_poll_status(host,
+				STATUS_BUF_READ_RDY | STATUS_READ_OP_DONE);
+		if (stat)
+			return stat;
+		tmp = readl(&host->base->buffer_access);
+		memcpy(b, &tmp, bytes);
+	}
+
+	return 0;
+}
+
+static int mxcmci_push(struct mxcmci_host *host, const void *_buf, int bytes)
+{
+	unsigned int stat;
+	const u32 *buf = _buf;
+
+	while (bytes > 3) {
+		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
+		if (stat)
+			return stat;
+		writel(*buf++, &host->base->buffer_access);
+		bytes -= 4;
+	}
+
+	if (bytes) {
+		const u8 *b = (u8 *)buf;
+		u32 tmp;
+
+		stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
+		if (stat)
+			return stat;
+
+		memcpy(&tmp, b, bytes);
+		writel(tmp, &host->base->buffer_access);
+	}
+
+	stat = mxcmci_poll_status(host, STATUS_BUF_WRITE_RDY);
+	if (stat)
+		return stat;
+
+	return 0;
+}
+
+static int mxcmci_transfer_data(struct mxcmci_host *host)
+{
+	struct mmc_data *data = host->data;
+	int stat;
+	unsigned long length;
+
+	length = data->blocks * data->blocksize;
+	host->datasize = 0;
+
+	if (data->flags & MMC_DATA_READ) {
+		stat = mxcmci_pull(host, data->dest, length);
+		if (stat)
+			return stat;
+		host->datasize += length;
+	} else {
+		stat = mxcmci_push(host, (const void *)(data->src), length);
+		if (stat)
+			return stat;
+		host->datasize += length;
+		stat = mxcmci_poll_status(host, STATUS_WRITE_OP_DONE);
+		if (stat)
+			return stat;
+	}
+	return 0;
+}
+
+static int mxcmci_cmd_done(struct mxcmci_host *host, unsigned int stat)
+{
+	int datastat;
+	int ret;
+
+	ret = mxcmci_read_response(host, stat);
+
+	if (ret) {
+		mxcmci_finish_request(host, host->cmd, host->data);
+		return ret;
+	}
+
+	if (!host->data) {
+		mxcmci_finish_request(host, host->cmd, host->data);
+		return 0;
+	}
+
+	datastat = mxcmci_transfer_data(host);
+	ret = mxcmci_finish_data(host, datastat);
+	mxcmci_finish_request(host, host->cmd, host->data);
+	return ret;
+}
+
+static int mxcmci_request(struct mmc *mmc, struct mmc_cmd *cmd,
+		struct mmc_data *data)
+{
+	struct mxcmci_host *host = mmc->priv;
+	unsigned int cmdat = host->cmdat;
+	u32 stat;
+	int ret;
+
+	host->cmdat &= ~CMD_DAT_CONT_INIT;
+	if (data) {
+		mxcmci_setup_data(host, data);
+
+		cmdat |= CMD_DAT_CONT_DATA_ENABLE;
+
+		if (data->flags & MMC_DATA_WRITE)
+			cmdat |= CMD_DAT_CONT_WRITE;
+	}
+
+	if ((ret = mxcmci_start_cmd(host, cmd, cmdat))) {
+		mxcmci_finish_request(host, cmd, data);
+		return ret;
+	}
+
+	do {
+		stat = readl(&host->base->status);
+		writel(stat, &host->base->status);
+	} while (!(stat & STATUS_END_CMD_RESP));
+
+	return mxcmci_cmd_done(host, stat);
+}
+
+static void mxcmci_set_clk_rate(struct mxcmci_host *host, unsigned int clk_ios)
+{
+	unsigned int divider;
+	int prescaler = 0;
+	unsigned long clk_in = imx_get_perclk2();
+
+	while (prescaler <= 0x800) {
+		for (divider = 1; divider <= 0xF; divider++) {
+			int x;
+
+			x = (clk_in / (divider + 1));
+
+			if (prescaler)
+				x /= (prescaler * 2);
+
+			if (x <= clk_ios)
+				break;
+		}
+		if (divider < 0x10)
+			break;
+
+		if (prescaler == 0)
+			prescaler = 1;
+		else
+			prescaler <<= 1;
+	}
+
+	writew((prescaler << 4) | divider, &host->base->clk_rate);
+}
+
+static void mxcmci_set_ios(struct mmc *mmc)
+{
+	struct mxcmci_host *host = mmc->priv;
+	if (mmc->bus_width == 4)
+		host->cmdat |= CMD_DAT_CONT_BUS_WIDTH_4;
+	else
+		host->cmdat &= ~CMD_DAT_CONT_BUS_WIDTH_4;
+
+	if (mmc->clock) {
+		mxcmci_set_clk_rate(host, mmc->clock);
+		writew(STR_STP_CLK_START_CLK, &host->base->str_stp_clk);
+	} else {
+		writew(STR_STP_CLK_STOP_CLK, &host->base->str_stp_clk);
+	}
+
+	host->clock = mmc->clock;
+}
+
+static int mxcmci_init(struct mmc *mmc)
+{
+	struct mxcmci_host *host = mmc->priv;
+
+	mxcmci_softreset(host);
+
+	host->rev_no = readw(&host->base->rev_no);
+	if (host->rev_no != 0x400) {
+		printf("wrong rev.no. 0x%08x. aborting.\n",
+			host->rev_no);
+		return -ENODEV;
+	}
+
+	/* recommended in data sheet */
+	writew(0x2db4, &host->base->read_to);
+
+	writel(0, &host->base->int_cntr);
+
+	return 0;
+}
+
+static int mxcmci_initialize(bd_t *bis)
+{
+	struct mmc *mmc = NULL;
+
+	mmc = malloc(sizeof(struct mmc));
+
+	if (!mmc)
+		return -ENOMEM;
+
+	sprintf(mmc->name, "MXC MCI");
+	mmc->send_cmd = mxcmci_request;
+	mmc->set_ios = mxcmci_set_ios;
+	mmc->init = mxcmci_init;
+	mmc->host_caps = MMC_MODE_4BIT;
+
+	host->base = (struct mxcmci_regs *)CONFIG_MXC_MCI_REGS_BASE;
+	mmc->priv = host;
+	host->mmc = mmc;
+
+	mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34;
+
+	mmc->f_min = imx_get_perclk2() >> 7;
+	mmc->f_max = imx_get_perclk2() >> 1;
+
+	mmc_register(mmc);
+
+	return 0;
+}
+
+int mxc_mmc_init(bd_t *bis)
+{
+	return mxcmci_initialize(bis);
+}
+

include/asm-arm/arch-mx27/mxcmmc.h

@@ -0,0 +1,25 @@
+/*
+ *  Copyright (c) 2009 Ilya Yanok <yanok@emcraft.com>
+ *
+ * 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
+ */
+
+#ifndef ASM_ARCH_MXCMMC_H
+#define ASM_ARCH_MXCMMC_H
+
+int mxc_mmc_init(bd_t *bis);
+
+#endif