at91_mci.c

/*
 * File      : at91_mci.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006, RT-Thread Development Team
 *
 *  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.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Change Logs:
 * Date           Author		Notes
 * 2011-07-25     weety		first version
 */

#include <rtthread.h>
#include <rthw.h>
#include <drivers/mmcsd_core.h>
#include <at91sam926x.h>
#include "at91_mci.h"

#define USE_SLOT_B
//#define RT_MCI_DBG

#ifdef RT_MCI_DBG
#define mci_dbg(fmt, ...)  rt_kprintf(fmt, ##__VA_ARGS__)
#else
#define mci_dbg(fmt, ...)
#endif

#define MMU_NOCACHE_ADDR(a)      	((rt_uint32_t)a | (1UL<<31))

extern void mmu_clean_dcache(rt_uint32_t buffer, rt_uint32_t size);
extern void mmu_invalidate_dcache(rt_uint32_t buffer, rt_uint32_t size);


#define AT91_MCI_ERRORS	(AT91_MCI_RINDE | AT91_MCI_RDIRE | AT91_MCI_RCRCE	\
		| AT91_MCI_RENDE | AT91_MCI_RTOE | AT91_MCI_DCRCE		\
		| AT91_MCI_DTOE | AT91_MCI_OVRE | AT91_MCI_UNRE)

#define at91_mci_read(reg)	readl(AT91SAM9260_BASE_MCI + (reg))
#define at91_mci_write(reg, val)	writel((val), AT91SAM9260_BASE_MCI + (reg))


#define REQ_ST_INIT	(1U << 0)
#define REQ_ST_CMD	(1U << 1)
#define REQ_ST_STOP	(1U << 2)

struct at91_mci {
	struct rt_mmcsd_host *host;
	struct rt_mmcsd_req *req;
	struct rt_mmcsd_cmd *cmd;
	struct rt_timer timer;
	//struct rt_semaphore sem_ack;
	rt_uint32_t *buf;
	rt_uint32_t current_status;
};

/*
 * Reset the controller and restore most of the state
 */
static void at91_reset_host()
{
	rt_uint32_t mr;
	rt_uint32_t sdcr;
	rt_uint32_t dtor;
	rt_uint32_t imr;
	rt_uint32_t level;

	level = rt_hw_interrupt_disable();

	imr = at91_mci_read(AT91_MCI_IMR);

	at91_mci_write(AT91_MCI_IDR, 0xffffffff);

	/* save current state */
	mr = at91_mci_read(AT91_MCI_MR) & 0x7fff;
	sdcr = at91_mci_read(AT91_MCI_SDCR);
	dtor = at91_mci_read(AT91_MCI_DTOR);

	/* reset the controller */
	at91_mci_write(AT91_MCI_CR, AT91_MCI_MCIDIS | AT91_MCI_SWRST);

	/* restore state */
	at91_mci_write(AT91_MCI_CR, AT91_MCI_MCIEN);
	at91_mci_write(AT91_MCI_MR, mr);
	at91_mci_write(AT91_MCI_SDCR, sdcr);
	at91_mci_write(AT91_MCI_DTOR, dtor);
	at91_mci_write(AT91_MCI_IER, imr);

	/* make sure sdio interrupts will fire */
	at91_mci_read(AT91_MCI_SR);
	rt_hw_interrupt_enable(level);

}


/*
 * Enable the controller
 */
static void at91_mci_enable()
{
	rt_uint32_t mr;

	at91_mci_write(AT91_MCI_CR, AT91_MCI_MCIEN);
	at91_mci_write(AT91_MCI_IDR, 0xffffffff);
	at91_mci_write(AT91_MCI_DTOR, AT91_MCI_DTOMUL_1M | AT91_MCI_DTOCYC);
	mr = AT91_MCI_PDCMODE | 0x34a;

	mr |= AT91_MCI_RDPROOF | AT91_MCI_WRPROOF;

	at91_mci_write(AT91_MCI_MR, mr);

	/* use Slot A or B (only one at same time) */
	at91_mci_write(AT91_MCI_SDCR, 1); /* use slot b */
}

/*
 * Disable the controller
 */
static void at91_mci_disable()
{
	at91_mci_write(AT91_MCI_CR, AT91_MCI_MCIDIS | AT91_MCI_SWRST);
}

static void at91_timeout_timer(void *data)
{
	struct at91_mci *mci;

	mci = (struct at91_mci *)data;

	if (mci->req) 
	{
		rt_kprintf("Timeout waiting end of packet\n");

		if (mci->current_status == REQ_ST_CMD) 
		{
			if (mci->req->cmd && mci->req->data) 
			{
				mci->req->data->err = -RT_ETIMEOUT;
			} 
			else 
			{
				if (mci->req->cmd)
					mci->req->cmd->err = -RT_ETIMEOUT;
			}
		}
		else if (mci->current_status == REQ_ST_STOP) 
		{
			mci->req->stop->err = -RT_ETIMEOUT;
		}

		at91_reset_host();
		mmcsd_req_complete(mci->host);
	}
}

/*
 * Prepare a dma read
 */
static void at91_mci_init_dma_read(struct at91_mci *mci)
{
	rt_uint8_t i;
	struct rt_mmcsd_cmd *cmd;
	struct rt_mmcsd_data *data;
	rt_uint32_t length;

	mci_dbg("pre dma read\n");

	cmd = mci->cmd;
	if (!cmd)
	{
		mci_dbg("no command\n");
		return;
	}

	data = cmd->data;
	if (!data)
	{
		mci_dbg("no data\n");
		return;
	}

	for (i = 0; i < 1; i++) 
	{
		/* Check to see if this needs filling */
		if (i == 0) 
		{
			if (at91_mci_read(AT91_PDC_RCR) != 0) 
			{
				mci_dbg("Transfer active in current\n");
				continue;
			}
		}
		else {
			if (at91_mci_read(AT91_PDC_RNCR) != 0)
			{
				mci_dbg("Transfer active in next\n");
				continue;
			}
		}

		length = data->blksize * data->blks;
		mci_dbg("dma address = %08X, length = %d\n", data->buf, length);

		if (i == 0) 
		{
			at91_mci_write(AT91_PDC_RPR, (rt_uint32_t)(data->buf));
			at91_mci_write(AT91_PDC_RCR, (data->blksize & 0x3) ? length : length / 4);
		}
		else 
		{
			at91_mci_write(AT91_PDC_RNPR, (rt_uint32_t)(data->buf));
			at91_mci_write(AT91_PDC_RNCR, (data->blksize & 0x3) ? length : length / 4);
		}
	}

	mci_dbg("pre dma read done\n");
}

/*
 * Send a command
 */
static void at91_mci_send_command(struct at91_mci *mci, struct rt_mmcsd_cmd *cmd)
{
	rt_uint32_t cmdr, mr;
	rt_uint32_t block_length;
	struct rt_mmcsd_data *data = cmd->data;
	struct rt_mmcsd_host *host = mci->host;

	rt_uint32_t blocks;
	rt_uint32_t ier = 0;
	rt_uint32_t length;

	mci->cmd = cmd;

	/* Needed for leaving busy state before CMD1 */
	if ((at91_mci_read(AT91_MCI_SR) & AT91_MCI_RTOE) && (cmd->cmd_code == 1)) 
	{
		mci_dbg("Clearing timeout\n");
		at91_mci_write(AT91_MCI_ARGR, 0);
		at91_mci_write(AT91_MCI_CMDR, AT91_MCI_OPDCMD);
		while (!(at91_mci_read(AT91_MCI_SR) & AT91_MCI_CMDRDY)) 
		{
			/* spin */
			mci_dbg("Clearing: SR = %08X\n", at91_mci_read(AT91_MCI_SR));
		}
	}

	cmdr = cmd->cmd_code;

	if (resp_type(cmd) == RESP_NONE)
		cmdr |= AT91_MCI_RSPTYP_NONE;
	else 
	{
		/* if a response is expected then allow maximum response latancy */
		cmdr |= AT91_MCI_MAXLAT;
		/* set 136 bit response for R2, 48 bit response otherwise */
		if (resp_type(cmd) == RESP_R2)
			cmdr |= AT91_MCI_RSPTYP_136;
		else
			cmdr |= AT91_MCI_RSPTYP_48;
	}

	if (data) 
	{

		block_length = data->blksize;
		blocks = data->blks;

		/* always set data start - also set direction flag for read */
		if (data->flags & DATA_DIR_READ)
			cmdr |= (AT91_MCI_TRDIR | AT91_MCI_TRCMD_START);
		else if (data->flags & DATA_DIR_WRITE)
			cmdr |= AT91_MCI_TRCMD_START;

		if (data->flags & DATA_STREAM)
			cmdr |= AT91_MCI_TRTYP_STREAM;
		if (data->blks > 1)
			cmdr |= AT91_MCI_TRTYP_MULTIPLE;
	}
	else 
	{
		block_length = 0;
		blocks = 0;
	}

	/*if (cmd->cmd_code == GO_IDLE_STATE) 
	{
		cmdr |= AT91_MCI_SPCMD_INIT;
	}*/

	if (cmd->cmd_code == STOP_TRANSMISSION)
		cmdr |= AT91_MCI_TRCMD_STOP;

	if (host->io_cfg.bus_mode == MMCSD_BUSMODE_OPENDRAIN)
		cmdr |= AT91_MCI_OPDCMD;

	/*
	 * Set the arguments and send the command
	 */
	mci_dbg("Sending command %d as %08X, arg = %08X, blocks = %d, length = %d (MR = %08X)\n",
		cmd->cmd_code, cmdr, cmd->arg, blocks, block_length, at91_mci_read(AT91_MCI_MR));

	if (!data) 
	{
		at91_mci_write(AT91_PDC_PTCR, AT91_PDC_TXTDIS | AT91_PDC_RXTDIS);
		at91_mci_write(AT91_PDC_RPR, 0);
		at91_mci_write(AT91_PDC_RCR, 0);
		at91_mci_write(AT91_PDC_RNPR, 0);
		at91_mci_write(AT91_PDC_RNCR, 0);
		at91_mci_write(AT91_PDC_TPR, 0);
		at91_mci_write(AT91_PDC_TCR, 0);
		at91_mci_write(AT91_PDC_TNPR, 0);
		at91_mci_write(AT91_PDC_TNCR, 0);
		ier = AT91_MCI_CMDRDY;
	} 
	else 
	{
		/* zero block length and PDC mode */
		mr = at91_mci_read(AT91_MCI_MR) & 0x5fff;
		mr |= (data->blksize & 0x3) ? AT91_MCI_PDCFBYTE : 0;
		mr |= (block_length << 16);
		mr |= AT91_MCI_PDCMODE;
		at91_mci_write(AT91_MCI_MR, mr);

		at91_mci_write(AT91_MCI_BLKR,
			AT91_MCI_BLKR_BCNT(blocks) |
			AT91_MCI_BLKR_BLKLEN(block_length));

		/*
		 * Disable the PDC controller
		 */
		at91_mci_write(AT91_PDC_PTCR, AT91_PDC_RXTDIS | AT91_PDC_TXTDIS);

		if (cmdr & AT91_MCI_TRCMD_START) 
		{
			if (cmdr & AT91_MCI_TRDIR) 
			{
				/*
				 * Handle a read
				 */

				mmu_invalidate_dcache((rt_uint32_t)data->buf, data->blksize*data->blks);
				at91_mci_init_dma_read(mci);
				ier = AT91_MCI_ENDRX /* | AT91_MCI_RXBUFF */;
			}
			else 
			{
				/*
				 * Handle a write
				 */
				length = block_length * blocks;
				/*
				 * at91mci MCI1 rev2xx Data Write Operation and
				 * number of bytes erratum
				 */
				if (length < 12)
				{
					length = 12;
					mci->buf = rt_malloc(length);
					if (!mci->buf)
					{
						rt_kprintf("rt alloc tx buffer failed\n");
						cmd->err = -RT_ENOMEM;
						mmcsd_req_complete(mci->host);
						return;
					}
					rt_memset(mci->buf, 0, 12);
					rt_memcpy(mci->buf, data->buf, length);
					mmu_clean_dcache((rt_uint32_t)mci->buf, length);
					at91_mci_write(AT91_PDC_TPR, (rt_uint32_t)(mci->buf));
					at91_mci_write(AT91_PDC_TCR, (data->blksize & 0x3) ?
							length : length / 4);
				}
				else
				{
					mmu_clean_dcache((rt_uint32_t)data->buf, data->blksize*data->blks);
					at91_mci_write(AT91_PDC_TPR, (rt_uint32_t)(data->buf));
					at91_mci_write(AT91_PDC_TCR, (data->blksize & 0x3) ?
							length : length / 4);
				}
				mci_dbg("Transmitting %d bytes\n", length);
				ier = AT91_MCI_CMDRDY;
			}
		}
	}

	/*
	 * Send the command and then enable the PDC - not the other way round as
	 * the data sheet says
	 */

	at91_mci_write(AT91_MCI_ARGR, cmd->arg);
	at91_mci_write(AT91_MCI_CMDR, cmdr);

	if (cmdr & AT91_MCI_TRCMD_START) 
	{
		if (cmdr & AT91_MCI_TRDIR)
			at91_mci_write(AT91_PDC_PTCR, AT91_PDC_RXTEN);
	}

	/* Enable selected interrupts */
	at91_mci_write(AT91_MCI_IER, AT91_MCI_ERRORS | ier);
}

/*
 * Process the next step in the request
 */
static void at91_mci_process_next(struct at91_mci *mci)
{
	if (mci->current_status == REQ_ST_INIT) 
	{
		mci->current_status = REQ_ST_CMD;
		at91_mci_send_command(mci, mci->req->cmd);
	}
	else if ((mci->current_status == REQ_ST_CMD) && mci->req->stop) 
	{
		mci->current_status = REQ_ST_STOP;
		at91_mci_send_command(mci, mci->req->stop);
	} 
	else 
	{
		rt_timer_stop(&mci->timer);
		/* the mci controller hangs after some transfers,
		 * and the workaround is to reset it after each transfer.
		 */
		at91_reset_host();
		mmcsd_req_complete(mci->host);
	}
}

/*
 * Handle an MMC request
 */
static void at91_mci_request(struct rt_mmcsd_host *host, struct rt_mmcsd_req *req)
{
	rt_uint32_t timeout = RT_TICK_PER_SECOND;
	struct at91_mci *mci = host->private_data;
	mci->req = req;
	mci->current_status = REQ_ST_INIT;

	rt_timer_control(&mci->timer, RT_TIMER_CTRL_SET_TIME, (void*)&timeout);
	rt_timer_start(&mci->timer);

	at91_mci_process_next(mci);
}

/*
 * Handle transmitted data
 */
static void at91_mci_handle_transmitted(struct at91_mci *mci)
{
	struct rt_mmcsd_cmd *cmd;
	struct rt_mmcsd_data *data;

	mci_dbg("Handling the transmit\n");

	/* Disable the transfer */
	at91_mci_write(AT91_PDC_PTCR, AT91_PDC_RXTDIS | AT91_PDC_TXTDIS);

	/* Now wait for cmd ready */
	at91_mci_write(AT91_MCI_IDR, AT91_MCI_TXBUFE);

	cmd = mci->cmd;
	if (!cmd) return;

	data = cmd->data;
	if (!data) return;

	if (data->blks > 1) 
	{
		mci_dbg("multiple write : wait for BLKE...\n");
		at91_mci_write(AT91_MCI_IER, AT91_MCI_BLKE);
	} else
		at91_mci_write(AT91_MCI_IER, AT91_MCI_NOTBUSY);
}


/*
 * Handle after a dma read
 */
static void at91_mci_post_dma_read(struct at91_mci *mci)
{
	struct rt_mmcsd_cmd *cmd;
	struct rt_mmcsd_data *data;

	mci_dbg("post dma read\n");

	cmd = mci->cmd;
	if (!cmd)
	{
		mci_dbg("no command\n");
		return;
	}

	data = cmd->data;
	if (!data)
	{
		mci_dbg("no data\n");
		return;
	}

	at91_mci_write(AT91_MCI_IDR, AT91_MCI_ENDRX);
	at91_mci_write(AT91_MCI_IER, AT91_MCI_RXBUFF);

	mci_dbg("post dma read done\n");
}

/*Handle after command sent ready*/
static int at91_mci_handle_cmdrdy(struct at91_mci *mci)
{
	if (!mci->cmd)
		return 1;
	else if (!mci->cmd->data) 
	{
		if (mci->current_status == REQ_ST_STOP) 
		{
			/*After multi block write, we must wait for NOTBUSY*/
			at91_mci_write(AT91_MCI_IER, AT91_MCI_NOTBUSY);
		}
		else return 1;
	}
	else if (mci->cmd->data->flags & DATA_DIR_WRITE)
	{
		/*After sendding multi-block-write command, start DMA transfer*/
		at91_mci_write(AT91_MCI_IER, AT91_MCI_TXBUFE | AT91_MCI_BLKE);
		at91_mci_write(AT91_PDC_PTCR, AT91_PDC_TXTEN);
	}

	/* command not completed, have to wait */
	return 0;
}

/*
 * Handle a command that has been completed
 */
static void at91_mci_completed_command(struct at91_mci *mci, rt_uint32_t status)
{
	struct rt_mmcsd_cmd *cmd = mci->cmd;
	struct rt_mmcsd_data *data = cmd->data;

	at91_mci_write(AT91_MCI_IDR, 0xffffffff & ~(AT91_MCI_SDIOIRQA | AT91_MCI_SDIOIRQB));

	cmd->resp[0] = at91_mci_read(AT91_MCI_RSPR(0));
	cmd->resp[1] = at91_mci_read(AT91_MCI_RSPR(1));
	cmd->resp[2] = at91_mci_read(AT91_MCI_RSPR(2));
	cmd->resp[3] = at91_mci_read(AT91_MCI_RSPR(3));

	if (mci->buf) 
	{
		//rt_memcpy(data->buf, mci->buf, data->blksize*data->blks);
		rt_free(mci->buf);
		mci->buf = RT_NULL;
	}

	mci_dbg("Status = %08X/%08x [%08X %08X %08X %08X]\n",
		 status, at91_mci_read(AT91_MCI_SR),
		 cmd->resp[0], cmd->resp[1], cmd->resp[2], cmd->resp[3]);

	if (status & AT91_MCI_ERRORS) 
	{
		if ((status & AT91_MCI_RCRCE) && (resp_type(cmd) & (RESP_R3|RESP_R4))) 
		{
			cmd->err = 0;
		}
		else 
		{
			if (status & (AT91_MCI_DTOE | AT91_MCI_DCRCE)) 
			{
				if (data) 
				{
					if (status & AT91_MCI_DTOE)
						data->err = -RT_ETIMEOUT;
					else if (status & AT91_MCI_DCRCE)
						data->err = -RT_ERROR;
				}
			} 
			else 
			{
				if (status & AT91_MCI_RTOE)
					cmd->err = -RT_ETIMEOUT;
				else if (status & AT91_MCI_RCRCE)
					cmd->err = -RT_ERROR;
				else
					cmd->err = -RT_ERROR;
			}

			rt_kprintf("error detected and set to %d/%d (cmd = %d)\n",
				cmd->err, data ? data->err : 0,
				 cmd->cmd_code);
		}
	}
	else
		cmd->err = 0;

	at91_mci_process_next(mci);
}

/*
 * Handle an interrupt
 */
static void at91_mci_irq(int irq, void *param)
{
	struct at91_mci *mci = (struct at91_mci *)param;
	rt_int32_t completed = 0;
	rt_uint32_t int_status, int_mask;

	int_status = at91_mci_read(AT91_MCI_SR);
	int_mask = at91_mci_read(AT91_MCI_IMR);

	mci_dbg("MCI irq: status = %08X, %08X, %08X\n", int_status, int_mask,
		int_status & int_mask);

	int_status = int_status & int_mask;

	if (int_status & AT91_MCI_ERRORS) 
	{
		completed = 1;

		if (int_status & AT91_MCI_UNRE)
			mci_dbg("MMC: Underrun error\n");
		if (int_status & AT91_MCI_OVRE)
			mci_dbg("MMC: Overrun error\n");
		if (int_status & AT91_MCI_DTOE)
			mci_dbg("MMC: Data timeout\n");
		if (int_status & AT91_MCI_DCRCE)
			mci_dbg("MMC: CRC error in data\n");
		if (int_status & AT91_MCI_RTOE)
			mci_dbg("MMC: Response timeout\n");
		if (int_status & AT91_MCI_RENDE)
			mci_dbg("MMC: Response end bit error\n");
		if (int_status & AT91_MCI_RCRCE)
			mci_dbg("MMC: Response CRC error\n");
		if (int_status & AT91_MCI_RDIRE)
			mci_dbg("MMC: Response direction error\n");
		if (int_status & AT91_MCI_RINDE)
			mci_dbg("MMC: Response index error\n");
	} 
	else 
	{
		/* Only continue processing if no errors */

		if (int_status & AT91_MCI_TXBUFE) 
		{
			mci_dbg("TX buffer empty\n");
			at91_mci_handle_transmitted(mci);
		}

		if (int_status & AT91_MCI_ENDRX) 
		{
			mci_dbg("ENDRX\n");
			at91_mci_post_dma_read(mci);
		}

		if (int_status & AT91_MCI_RXBUFF) 
		{
			mci_dbg("RX buffer full\n");
			at91_mci_write(AT91_PDC_PTCR, AT91_PDC_RXTDIS | AT91_PDC_TXTDIS);
			at91_mci_write(AT91_MCI_IDR, AT91_MCI_RXBUFF | AT91_MCI_ENDRX);
			completed = 1;
		}

		if (int_status & AT91_MCI_ENDTX)
			mci_dbg("Transmit has ended\n");

		if (int_status & AT91_MCI_NOTBUSY) 
		{
			mci_dbg("Card is ready\n");
			//at91_mci_update_bytes_xfered(host);
			completed = 1;
		}

		if (int_status & AT91_MCI_DTIP)
			mci_dbg("Data transfer in progress\n");

		if (int_status & AT91_MCI_BLKE) 
		{
			mci_dbg("Block transfer has ended\n");
			if (mci->req->data && mci->req->data->blks > 1) 
			{
				/* multi block write : complete multi write
				 * command and send stop */
				completed = 1;
			} 
			else 
			{
				at91_mci_write(AT91_MCI_IER, AT91_MCI_NOTBUSY);
			}
		}

		/*if (int_status & AT91_MCI_SDIOIRQA)
			rt_mmcsd_signal_sdio_irq(host->mmc);*/

		if (int_status & AT91_MCI_SDIOIRQB)
			sdio_irq_wakeup(mci->host);

		if (int_status & AT91_MCI_TXRDY)
			mci_dbg("Ready to transmit\n");

		if (int_status & AT91_MCI_RXRDY)
			mci_dbg("Ready to receive\n");

		if (int_status & AT91_MCI_CMDRDY) 
		{
			mci_dbg("Command ready\n");
			completed = at91_mci_handle_cmdrdy(mci);
		}
	}

	if (completed) 
	{
		mci_dbg("Completed command\n");
		at91_mci_write(AT91_MCI_IDR, 0xffffffff & ~(AT91_MCI_SDIOIRQA | AT91_MCI_SDIOIRQB));
		at91_mci_completed_command(mci, int_status);
	} 
	else
		at91_mci_write(AT91_MCI_IDR, int_status & ~(AT91_MCI_SDIOIRQA | AT91_MCI_SDIOIRQB));

}


/*
 * Set the IOCFG
 */
static void at91_mci_set_iocfg(struct rt_mmcsd_host *host, struct rt_mmcsd_io_cfg *io_cfg)
{
	rt_uint32_t clkdiv;
	//struct at91_mci *mci = host->private_data;
	rt_uint32_t at91_master_clock = clk_get_rate(clk_get("mck"));

	if (io_cfg->clock == 0) 
	{
		/* Disable the MCI controller */
		at91_mci_write(AT91_MCI_CR, AT91_MCI_MCIDIS);
		clkdiv = 0;
	}
	else 
	{
		/* Enable the MCI controller */
		at91_mci_write(AT91_MCI_CR, AT91_MCI_MCIEN);

		if ((at91_master_clock % (io_cfg->clock * 2)) == 0)
			clkdiv = ((at91_master_clock / io_cfg->clock) / 2) - 1;
		else
			clkdiv = (at91_master_clock / io_cfg->clock) / 2;

		mci_dbg("clkdiv = %d. mcck = %ld\n", clkdiv,
			at91_master_clock / (2 * (clkdiv + 1)));
	}
	if (io_cfg->bus_width == MMCSD_BUS_WIDTH_4) 
	{
		mci_dbg("MMC: Setting controller bus width to 4\n");
		at91_mci_write(AT91_MCI_SDCR, at91_mci_read(AT91_MCI_SDCR) | AT91_MCI_SDCBUS);
	}
	else 
	{
		mci_dbg("MMC: Setting controller bus width to 1\n");
		at91_mci_write(AT91_MCI_SDCR, at91_mci_read(AT91_MCI_SDCR) & ~AT91_MCI_SDCBUS);
	}

	/* Set the clock divider */
	at91_mci_write(AT91_MCI_MR, (at91_mci_read(AT91_MCI_MR) & ~AT91_MCI_CLKDIV) | clkdiv);

	/* maybe switch power to the card */
	switch (io_cfg->power_mode) 
	{
		case MMCSD_POWER_OFF:
			break;
		case MMCSD_POWER_UP:
			break;
		case MMCSD_POWER_ON:
			/*at91_mci_write(AT91_MCI_ARGR, 0);
			at91_mci_write(AT91_MCI_CMDR, 0|AT91_MCI_SPCMD_INIT|AT91_MCI_OPDCMD);
			mci_dbg("MCI_SR=0x%08x\n", at91_mci_read(AT91_MCI_SR));
			while (!(at91_mci_read(AT91_MCI_SR) & AT91_MCI_CMDRDY)) 
			{
				
			}
			mci_dbg("at91 mci power on\n");*/
			break;
		default:
			rt_kprintf("unknown power_mode %d\n", io_cfg->power_mode);
			break;
	}

}


static void at91_mci_enable_sdio_irq(struct rt_mmcsd_host *host, rt_int32_t enable)
{
	at91_mci_write(enable ? AT91_MCI_IER : AT91_MCI_IDR, AT91_MCI_SDIOIRQB);
}


static const struct rt_mmcsd_host_ops ops = {
	at91_mci_request,
	at91_mci_set_iocfg,
        RT_NULL,
	at91_mci_enable_sdio_irq,
};

void at91_mci_detect(int irq, void *param)
{
	rt_kprintf("mmcsd gpio detected\n");
}

static void mci_gpio_init()
{
#ifdef USE_SLOT_B
	at91_sys_write(AT91_PIOA + PIO_PUER, (1 << 0)|(1 << 1)|(1 << 3)|(1 << 4)|(1 << 5));
	at91_sys_write(AT91_PIOA + PIO_PUDR, (1 << 8));
	at91_sys_write(AT91_PIOA + PIO_BSR, (1 << 0)|(1 << 1)|(1 << 3)|(1 << 4)|(1 << 5));
	at91_sys_write(AT91_PIOA + PIO_ASR, (1 << 8));
	at91_sys_write(AT91_PIOA + PIO_PDR, (1 << 0)|(1 << 1)|(1 << 3)|(1 << 4)|(1 << 5)|(1 << 8));

	at91_sys_write(AT91_PIOA + PIO_IDR, (1 << 6)|(1 << 7));
	at91_sys_write(AT91_PIOA + PIO_PUER, (1 << 6)|(1 << 7));
	at91_sys_write(AT91_PIOA + PIO_ODR, (1 << 6)|(1 << 7));
	at91_sys_write(AT91_PIOA + PIO_PER, (1 << 6)|(1 << 7));
#else
	at91_sys_write(AT91_PIOA + PIO_PUER, (1 << 6)|(1 << 7)|(1 << 9)|(1 << 10)|(1 << 11));
	at91_sys_write(AT91_PIOA + PIO_ASR, (1 << 6)|(1 << 7)|(1 << 9)|(1 << 10)|(1 << 11)|(1 << 8));
	at91_sys_write(AT91_PIOA + PIO_PDR, (1 << 6)|(1 << 7)|(1 << 9)|(1 << 10)|(1 << 11)|(1 << 8));
#endif
}

rt_int32_t at91_mci_init(void)
{
	struct rt_mmcsd_host *host;
	struct at91_mci *mci;

	host = mmcsd_alloc_host();
	if (!host) 
	{
		return -RT_ERROR;
	}

	mci = rt_malloc(sizeof(struct at91_mci));
	if (!mci) 
	{
		rt_kprintf("alloc mci failed\n");
		goto err;
	}

	rt_memset(mci, 0, sizeof(struct at91_mci));

	host->ops = &ops;
	host->freq_min = 375000;
	host->freq_max = 25000000;
	host->valid_ocr = VDD_32_33 | VDD_33_34;
	host->flags = MMCSD_BUSWIDTH_4 | MMCSD_MUTBLKWRITE | \
				MMCSD_SUP_HIGHSPEED | MMCSD_SUP_SDIO_IRQ;
	host->max_seg_size = 65535;
	host->max_dma_segs = 2;
	host->max_blk_size = 512;
	host->max_blk_count = 4096;

	mci->host = host;

	mci_gpio_init();
	at91_sys_write(AT91_PMC_PCER, 1 << AT91SAM9260_ID_MCI); //enable MCI clock
	
	at91_mci_disable();
	at91_mci_enable();

	/* instal interrupt */
	rt_hw_interrupt_install(AT91SAM9260_ID_MCI, at91_mci_irq, 
							(void *)mci, "MMC");
	rt_hw_interrupt_umask(AT91SAM9260_ID_MCI);
	rt_hw_interrupt_install(gpio_to_irq(AT91_PIN_PA7), 
							at91_mci_detect, RT_NULL, "MMC_DETECT");
	rt_hw_interrupt_umask(gpio_to_irq(AT91_PIN_PA7));

	rt_timer_init(&mci->timer, "mci_timer", 
		at91_timeout_timer, 
		mci, 
		RT_TICK_PER_SECOND, 
		RT_TIMER_FLAG_PERIODIC);

	//rt_timer_start(&mci->timer);

	//rt_sem_init(&mci->sem_ack, "sd_ack", 0, RT_IPC_FLAG_FIFO);

	host->private_data = mci;

	mmcsd_change(host);

	return 0;

err:
	mmcsd_free_host(host);

	return -RT_ENOMEM;
}


#include "finsh.h"
FINSH_FUNCTION_EXPORT(at91_mci_init, at91sam9260 sd init);

void mci_dump(void)
{
	rt_uint32_t i;

	rt_kprintf("PIOA_PSR=0x%08x\n", at91_sys_read(AT91_PIOA+PIO_PSR));
	rt_kprintf("PIOA_ABSR=0x%08x\n", at91_sys_read(AT91_PIOA+PIO_ABSR));
	rt_kprintf("PIOA_PUSR=0x%08x\n", at91_sys_read(AT91_PIOA+PIO_PUSR));

	for (i = 0; i <= 0x4c; i += 4) {
		rt_kprintf("0x%08x:0x%08x\n", AT91SAM9260_BASE_MCI+i, at91_mci_read(i));
	}
}

FINSH_FUNCTION_EXPORT(mci_dump, dump register for mci);