Davinci MMCSD Support

Added support for MMC/SD cards for Davinci.  This feature is enabled by
CONFIG_DAVINCI_MMC and is dependant on CONFIG_MMC and CONFIG_GENERIC_MMC
options. This is tested on DM355 and DM365 EVMs with both the available mmc
controllers.

Signed-off-by: Alagu Sankar <alagusankar@embwise.com>
Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>

2 files changed, 405 insertions, 0 deletions

diff --git a/drivers/mmc/Makefile b/drivers/mmc/Makefile
index 68afd30..3496f0a 100644
--- a/drivers/mmc/Makefile
+++ b/drivers/mmc/Makefile
@@ -27,6 +27,7 @@ LIB	:= $(obj)libmmc.o
 
 COBJS-$(CONFIG_ATMEL_MCI) += atmel_mci.o
 COBJS-$(CONFIG_BFIN_SDH) += bfin_sdh.o
+COBJS-$(CONFIG_DAVINCI_MMC) += davinci_mmc.o
 COBJS-$(CONFIG_FSL_ESDHC) += fsl_esdhc.o
 COBJS-$(CONFIG_GENERIC_MMC) += mmc.o
 COBJS-$(CONFIG_GENERIC_ATMEL_MCI) += gen_atmel_mci.o
diff --git a/drivers/mmc/davinci_mmc.c b/drivers/mmc/davinci_mmc.c
new file mode 100644
index 0000000..4e572dc
--- /dev/null
+++ b/drivers/mmc/davinci_mmc.c
@@ -0,0 +1,404 @@
+/*
+ * Davinci MMC Controller Driver
+ *
+ * Copyright (C) 2010 Texas Instruments Incorporated
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+#include <common.h>
+#include <command.h>
+#include <mmc.h>
+#include <part.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <asm/arch/sdmmc_defs.h>
+
+#define DAVINCI_MAX_BLOCKS	(32)
+#define WATCHDOG_COUNT		(100000)
+
+#define get_val(addr)		REG(addr)
+#define set_val(addr, val)	REG(addr) = (val)
+#define set_bit(addr, val)	set_val((addr), (get_val(addr) | (val)))
+#define clear_bit(addr, val)	set_val((addr), (get_val(addr) & ~(val)))
+
+/* Set davinci clock prescalar value based on the required clock in HZ */
+static void dmmc_set_clock(struct mmc *mmc, uint clock)
+{
+	struct davinci_mmc *host = mmc->priv;
+	struct davinci_mmc_regs *regs = host->reg_base;
+	uint clkrt, sysclk2, act_clock;
+
+	if (clock < mmc->f_min)
+		clock = mmc->f_min;
+	if (clock > mmc->f_max)
+		clock = mmc->f_max;
+
+	set_val(&regs->mmcclk, 0);
+	sysclk2 = host->input_clk;
+	clkrt = (sysclk2 / (2 * clock)) - 1;
+
+	/* Calculate the actual clock for the divider used */
+	act_clock = (sysclk2 / (2 * (clkrt + 1)));
+
+	/* Adjust divider if actual clock exceeds the required clock */
+	if (act_clock > clock)
+		clkrt++;
+
+	/* check clock divider boundary and correct it */
+	if (clkrt > 0xFF)
+		clkrt = 0xFF;
+
+	set_val(&regs->mmcclk, (clkrt | MMCCLK_CLKEN));
+}
+
+/* Status bit wait loop for MMCST1 */
+static int
+dmmc_wait_fifo_status(volatile struct davinci_mmc_regs *regs, uint status)
+{
+	uint mmcstatus1, wdog = WATCHDOG_COUNT;
+	mmcstatus1 = get_val(&regs->mmcst1);
+	while (--wdog && ((get_val(&regs->mmcst1) & status) != status))
+		udelay(10);
+
+	if (!(get_val(&regs->mmcctl) & MMCCTL_WIDTH_4_BIT))
+		udelay(100);
+
+	if (wdog == 0)
+		return COMM_ERR;
+
+	return 0;
+}
+
+/* Busy bit wait loop for MMCST1 */
+static int dmmc_busy_wait(volatile struct davinci_mmc_regs *regs)
+{
+	uint mmcstatus1, wdog = WATCHDOG_COUNT;
+
+	mmcstatus1 = get_val(&regs->mmcst1);
+	while (--wdog && (get_val(&regs->mmcst1) & MMCST1_BUSY))
+		udelay(10);
+
+	if (wdog == 0)
+		return COMM_ERR;
+
+	return 0;
+}
+
+/* Status bit wait loop for MMCST0 - Checks for error bits as well */
+static int dmmc_check_status(volatile struct davinci_mmc_regs *regs,
+		uint *cur_st, uint st_ready, uint st_error)
+{
+	uint wdog = WATCHDOG_COUNT;
+	uint mmcstatus = *cur_st;
+
+	while (wdog--) {
+		if (mmcstatus & st_ready) {
+			*cur_st = mmcstatus;
+			mmcstatus = get_val(&regs->mmcst1);
+			return 0;
+		} else if (mmcstatus & st_error) {
+			if (mmcstatus & MMCST0_TOUTRS)
+				return TIMEOUT;
+			printf("[ ST0 ERROR %x]\n", mmcstatus);
+			/*
+			 * Ignore CRC errors as some MMC cards fail to
+			 * initialize on DM365-EVM on the SD1 slot
+			 */
+			if (mmcstatus & MMCST0_CRCRS)
+				return 0;
+			return COMM_ERR;
+		}
+		udelay(10);
+
+		mmcstatus = get_val(&regs->mmcst0);
+	}
+
+	printf("Status %x Timeout ST0:%x ST1:%x\n", st_ready, mmcstatus,
+			get_val(&regs->mmcst1));
+	return COMM_ERR;
+}
+
+/*
+ * Sends a command out on the bus.  Takes the mmc pointer,
+ * a command pointer, and an optional data pointer.
+ */
+static int
+dmmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
+{
+	struct davinci_mmc *host = mmc->priv;
+	volatile struct davinci_mmc_regs *regs = host->reg_base;
+	uint mmcstatus, status_rdy, status_err;
+	uint i, cmddata, bytes_left = 0;
+	int fifo_words, fifo_bytes, err;
+	char *data_buf = NULL;
+
+	/* Clear status registers */
+	mmcstatus = get_val(&regs->mmcst0);
+	fifo_words = (host->version == MMC_CTLR_VERSION_2) ? 16 : 8;
+	fifo_bytes = fifo_words << 2;
+
+	/* Wait for any previous busy signal to be cleared */
+	dmmc_busy_wait(regs);
+
+	cmddata = cmd->cmdidx;
+	cmddata |= MMCCMD_PPLEN;
+
+	/* Send init clock for CMD0 */
+	if (cmd->cmdidx == MMC_CMD_GO_IDLE_STATE)
+		cmddata |= MMCCMD_INITCK;
+
+	switch (cmd->resp_type) {
+	case MMC_RSP_R1b:
+		cmddata |= MMCCMD_BSYEXP;
+		/* Fall-through */
+	case MMC_RSP_R1:    /* R1, R1b, R5, R6, R7 */
+		cmddata |= MMCCMD_RSPFMT_R1567;
+		break;
+	case MMC_RSP_R2:
+		cmddata |= MMCCMD_RSPFMT_R2;
+		break;
+	case MMC_RSP_R3: /* R3, R4 */
+		cmddata |= MMCCMD_RSPFMT_R3;
+		break;
+	}
+
+	set_val(&regs->mmcim, 0);
+
+	if (data) {
+		/* clear previous data transfer if any and set new one */
+		bytes_left = (data->blocksize * data->blocks);
+
+		/* Reset FIFO - Always use 32 byte fifo threshold */
+		set_val(&regs->mmcfifoctl,
+				(MMCFIFOCTL_FIFOLEV | MMCFIFOCTL_FIFORST));
+
+		if (host->version == MMC_CTLR_VERSION_2)
+			cmddata |= MMCCMD_DMATRIG;
+
+		cmddata |= MMCCMD_WDATX;
+		if (data->flags == MMC_DATA_READ) {
+			set_val(&regs->mmcfifoctl, MMCFIFOCTL_FIFOLEV);
+		} else if (data->flags == MMC_DATA_WRITE) {
+			set_val(&regs->mmcfifoctl,
+					(MMCFIFOCTL_FIFOLEV |
+					 MMCFIFOCTL_FIFODIR));
+			cmddata |= MMCCMD_DTRW;
+		}
+
+		set_val(&regs->mmctod, 0xFFFF);
+		set_val(&regs->mmcnblk, (data->blocks & MMCNBLK_NBLK_MASK));
+		set_val(&regs->mmcblen, (data->blocksize & MMCBLEN_BLEN_MASK));
+
+		if (data->flags == MMC_DATA_WRITE) {
+			uint val;
+			data_buf = (char *)data->src;
+			/* For write, fill FIFO with data before issue of CMD */
+			for (i = 0; (i < fifo_words) && bytes_left; i++) {
+				memcpy((char *)&val, data_buf, 4);
+				set_val(&regs->mmcdxr, val);
+				data_buf += 4;
+				bytes_left -= 4;
+			}
+		}
+	} else {
+		set_val(&regs->mmcblen, 0);
+		set_val(&regs->mmcnblk, 0);
+	}
+
+	set_val(&regs->mmctor, 0x1FFF);
+
+	/* Send the command */
+	set_val(&regs->mmcarghl, cmd->cmdarg);
+	set_val(&regs->mmccmd, cmddata);
+
+	status_rdy = MMCST0_RSPDNE;
+	status_err = (MMCST0_TOUTRS | MMCST0_TOUTRD |
+			MMCST0_CRCWR | MMCST0_CRCRD);
+	if (cmd->resp_type & MMC_RSP_CRC)
+		status_err |= MMCST0_CRCRS;
+
+	mmcstatus = get_val(&regs->mmcst0);
+	err = dmmc_check_status(regs, &mmcstatus, status_rdy, status_err);
+	if (err)
+		return err;
+
+	/* For R1b wait for busy done */
+	if (cmd->resp_type == MMC_RSP_R1b)
+		dmmc_busy_wait(regs);
+
+	/* Collect response from controller for specific commands */
+	if (mmcstatus & MMCST0_RSPDNE) {
+		/* Copy the response to the response buffer */
+		if (cmd->resp_type & MMC_RSP_136) {
+			cmd->response[0] = get_val(&regs->mmcrsp67);
+			cmd->response[1] = get_val(&regs->mmcrsp45);
+			cmd->response[2] = get_val(&regs->mmcrsp23);
+			cmd->response[3] = get_val(&regs->mmcrsp01);
+		} else if (cmd->resp_type & MMC_RSP_PRESENT) {
+			cmd->response[0] = get_val(&regs->mmcrsp67);
+		}
+	}
+
+	if (data == NULL)
+		return 0;
+
+	if (data->flags == MMC_DATA_READ) {
+		/* check for DATDNE along with DRRDY as the controller might
+		 * set the DATDNE without DRRDY for smaller transfers with
+		 * less than FIFO threshold bytes
+		 */
+		status_rdy = MMCST0_DRRDY | MMCST0_DATDNE;
+		status_err = MMCST0_TOUTRD | MMCST0_CRCRD;
+		data_buf = data->dest;
+	} else {
+		status_rdy = MMCST0_DXRDY | MMCST0_DATDNE;
+		status_err = MMCST0_CRCWR;
+	}
+
+	/* Wait until all of the blocks are transferred */
+	while (bytes_left) {
+		err = dmmc_check_status(regs, &mmcstatus, status_rdy,
+				status_err);
+		if (err)
+			return err;
+
+		if (data->flags == MMC_DATA_READ) {
+			/*
+			 * MMC controller sets the Data receive ready bit
+			 * (DRRDY) in MMCST0 even before the entire FIFO is
+			 * full. This results in erratic behavior if we start
+			 * reading the FIFO soon after DRRDY.  Wait for the
+			 * FIFO full bit in MMCST1 for proper FIFO clearing.
+			 */
+			if (bytes_left > fifo_bytes)
+				dmmc_wait_fifo_status(regs, 0x4a);
+			else if (bytes_left == fifo_bytes)
+				dmmc_wait_fifo_status(regs, 0x40);
+
+			for (i = 0; bytes_left && (i < fifo_words); i++) {
+				cmddata = get_val(&regs->mmcdrr);
+				memcpy(data_buf, (char *)&cmddata, 4);
+				data_buf += 4;
+				bytes_left -= 4;
+			}
+		} else {
+			/*
+			 * MMC controller sets the Data transmit ready bit
+			 * (DXRDY) in MMCST0 even before the entire FIFO is
+			 * empty. This results in erratic behavior if we start
+			 * writing the FIFO soon after DXRDY.  Wait for the
+			 * FIFO empty bit in MMCST1 for proper FIFO clearing.
+			 */
+			dmmc_wait_fifo_status(regs, MMCST1_FIFOEMP);
+			for (i = 0; bytes_left && (i < fifo_words); i++) {
+				memcpy((char *)&cmddata, data_buf, 4);
+				set_val(&regs->mmcdxr, cmddata);
+				data_buf += 4;
+				bytes_left -= 4;
+			}
+			dmmc_busy_wait(regs);
+		}
+	}
+
+	err = dmmc_check_status(regs, &mmcstatus, MMCST0_DATDNE, status_err);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+/* Initialize Davinci MMC controller */
+static int dmmc_init(struct mmc *mmc)
+{
+	struct davinci_mmc *host = mmc->priv;
+	struct davinci_mmc_regs *regs = host->reg_base;
+
+	/* Clear status registers explicitly - soft reset doesn't clear it
+	 * If Uboot is invoked from UBL with SDMMC Support, the status
+	 * registers can have uncleared bits
+	 */
+	get_val(&regs->mmcst0);
+	get_val(&regs->mmcst1);
+
+	/* Hold software reset */
+	set_bit(&regs->mmcctl, MMCCTL_DATRST);
+	set_bit(&regs->mmcctl, MMCCTL_CMDRST);
+	udelay(10);
+
+	set_val(&regs->mmcclk, 0x0);
+	set_val(&regs->mmctor, 0x1FFF);
+	set_val(&regs->mmctod, 0xFFFF);
+
+	/* Clear software reset */
+	clear_bit(&regs->mmcctl, MMCCTL_DATRST);
+	clear_bit(&regs->mmcctl, MMCCTL_CMDRST);
+
+	udelay(10);
+
+	/* Reset FIFO - Always use the maximum fifo threshold */
+	set_val(&regs->mmcfifoctl, (MMCFIFOCTL_FIFOLEV | MMCFIFOCTL_FIFORST));
+	set_val(&regs->mmcfifoctl, MMCFIFOCTL_FIFOLEV);
+
+	return 0;
+}
+
+/* Set buswidth or clock as indicated by the GENERIC_MMC framework */
+static void dmmc_set_ios(struct mmc *mmc)
+{
+	struct davinci_mmc *host = mmc->priv;
+	struct davinci_mmc_regs *regs = host->reg_base;
+
+	/* Set the bus width */
+	if (mmc->bus_width == 4)
+		set_bit(&regs->mmcctl, MMCCTL_WIDTH_4_BIT);
+	else
+		clear_bit(&regs->mmcctl, MMCCTL_WIDTH_4_BIT);
+
+	/* Set clock speed */
+	if (mmc->clock)
+		dmmc_set_clock(mmc, mmc->clock);
+}
+
+/* Called from board_mmc_init during startup. Can be called multiple times
+ * depending on the number of slots available on board and controller
+ */
+int davinci_mmc_init(bd_t *bis, struct davinci_mmc *host)
+{
+	struct mmc *mmc;
+
+	mmc = malloc(sizeof(struct mmc));
+	memset(mmc, 0, sizeof(struct mmc));
+
+	sprintf(mmc->name, "davinci");
+	mmc->priv = host;
+	mmc->send_cmd = dmmc_send_cmd;
+	mmc->set_ios = dmmc_set_ios;
+	mmc->init = dmmc_init;
+
+	mmc->f_min = 200000;
+	mmc->f_max = 25000000;
+	mmc->voltages = host->voltages;
+	mmc->host_caps = host->host_caps;
+
+#ifdef CONFIG_MMC_MBLOCK
+	mmc->b_max = DAVINCI_MAX_BLOCKS;
+#endif
+	mmc_register(mmc);
+
+	return 0;
+}
+