[PATCH] fix u32 vs. pm_message_t in drivers/mmc,mtd,scsi

[linux-2.6/linux-mips.git] / drivers / mmc / wbsd.c

/*
 *  linux/drivers/mmc/wbsd.c - Winbond W83L51xD SD/MMC driver
 *
 *  Copyright (C) 2004-2005 Pierre Ossman, All Rights Reserved.
 *
 * 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.
 *
 *
 * Warning!
 *
 * Changes to the FIFO system should be done with extreme care since
 * the hardware is full of bugs related to the FIFO. Known issues are:
 *
 * - FIFO size field in FSR is always zero.
 *
 * - FIFO interrupts tend not to work as they should. Interrupts are
 *   triggered only for full/empty events, not for threshold values.
 *
 * - On APIC systems the FIFO empty interrupt is sometimes lost.
 */

#include <linux/config.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/highmem.h>
#include <linux/mmc/host.h>
#include <linux/mmc/protocol.h>

#include <asm/io.h>
#include <asm/dma.h>
#include <asm/scatterlist.h>

#include "wbsd.h"

#define DRIVER_NAME "wbsd"
#define DRIVER_VERSION "1.1"

#ifdef CONFIG_MMC_DEBUG
#define DBG(x...) \
        printk(KERN_DEBUG DRIVER_NAME ": " x)
#define DBGF(f, x...) \
        printk(KERN_DEBUG DRIVER_NAME " [%s()]: " f, __func__ , ##x)
#else
#define DBG(x...)       do { } while (0)
#define DBGF(x...)      do { } while (0)
#endif

static unsigned int io = 0x248;
static unsigned int irq = 6;
static int dma = 2;

#ifdef CONFIG_MMC_DEBUG
void DBG_REG(int reg, u8 value)
{
        int i;
        
        printk(KERN_DEBUG "wbsd: Register %d: 0x%02X %3d '%c' ",
                reg, (int)value, (int)value, (value < 0x20)?'.':value);
        
        for (i = 7;i >= 0;i--)
        {
                if (value & (1 << i))
                        printk("x");
                else
                        printk(".");
        }
        
        printk("\n");
}
#else
#define DBG_REG(r, v) do {}  while (0)
#endif

/*
 * Basic functions
 */

static inline void wbsd_unlock_config(struct wbsd_host* host)
{
        outb(host->unlock_code, host->config);
        outb(host->unlock_code, host->config);
}

static inline void wbsd_lock_config(struct wbsd_host* host)
{
        outb(LOCK_CODE, host->config);
}

static inline void wbsd_write_config(struct wbsd_host* host, u8 reg, u8 value)
{
        outb(reg, host->config);
        outb(value, host->config + 1);
}

static inline u8 wbsd_read_config(struct wbsd_host* host, u8 reg)
{
        outb(reg, host->config);
        return inb(host->config + 1);
}

static inline void wbsd_write_index(struct wbsd_host* host, u8 index, u8 value)
{
        outb(index, host->base + WBSD_IDXR);
        outb(value, host->base + WBSD_DATAR);
}

static inline u8 wbsd_read_index(struct wbsd_host* host, u8 index)
{
        outb(index, host->base + WBSD_IDXR);
        return inb(host->base + WBSD_DATAR);
}

/*
 * Common routines
 */

static void wbsd_init_device(struct wbsd_host* host)
{
        u8 setup, ier;
        
        /*
         * Reset chip (SD/MMC part) and fifo.
         */
        setup = wbsd_read_index(host, WBSD_IDX_SETUP);
        setup |= WBSD_FIFO_RESET | WBSD_SOFT_RESET;
        wbsd_write_index(host, WBSD_IDX_SETUP, setup);
        
        /*
         * Read back default clock.
         */
        host->clk = wbsd_read_index(host, WBSD_IDX_CLK);

        /*
         * Power down port.
         */
        outb(WBSD_POWER_N, host->base + WBSD_CSR);
        
        /*
         * Set maximum timeout.
         */
        wbsd_write_index(host, WBSD_IDX_TAAC, 0x7F);
        
        /*
         * Enable interesting interrupts.
         */
        ier = 0;
        ier |= WBSD_EINT_CARD;
        ier |= WBSD_EINT_FIFO_THRE;
        ier |= WBSD_EINT_CCRC;
        ier |= WBSD_EINT_TIMEOUT;
        ier |= WBSD_EINT_CRC;
        ier |= WBSD_EINT_TC;

        outb(ier, host->base + WBSD_EIR);

        /*
         * Clear interrupts.
         */
        inb(host->base + WBSD_ISR);
}

static void wbsd_reset(struct wbsd_host* host)
{
        u8 setup;
        
        printk(KERN_ERR DRIVER_NAME ": Resetting chip\n");
        
        /*
         * Soft reset of chip (SD/MMC part).
         */
        setup = wbsd_read_index(host, WBSD_IDX_SETUP);
        setup |= WBSD_SOFT_RESET;
        wbsd_write_index(host, WBSD_IDX_SETUP, setup);
}

static void wbsd_request_end(struct wbsd_host* host, struct mmc_request* mrq)
{
        unsigned long dmaflags;
        
        DBGF("Ending request, cmd (%x)\n", mrq->cmd->opcode);
        
        if (host->dma >= 0)
        {
                /*
                 * Release ISA DMA controller.
                 */
                dmaflags = claim_dma_lock();
                disable_dma(host->dma);
                clear_dma_ff(host->dma);
                release_dma_lock(dmaflags);

                /*
                 * Disable DMA on host.
                 */
                wbsd_write_index(host, WBSD_IDX_DMA, 0);
        }
        
        host->mrq = NULL;

        /*
         * MMC layer might call back into the driver so first unlock.
         */
        spin_unlock(&host->lock);
        mmc_request_done(host->mmc, mrq);
        spin_lock(&host->lock);
}

/*
 * Scatter/gather functions
 */

static inline void wbsd_init_sg(struct wbsd_host* host, struct mmc_data* data)
{
        /*
         * Get info. about SG list from data structure.
         */
        host->cur_sg = data->sg;
        host->num_sg = data->sg_len;

        host->offset = 0;
        host->remain = host->cur_sg->length;
}

static inline int wbsd_next_sg(struct wbsd_host* host)
{
        /*
         * Skip to next SG entry.
         */
        host->cur_sg++;
        host->num_sg--;

        /*
         * Any entries left?
         */
        if (host->num_sg > 0)
          {
            host->offset = 0;
            host->remain = host->cur_sg->length;
          }
        
        return host->num_sg;
}

static inline char* wbsd_kmap_sg(struct wbsd_host* host)
{
        host->mapped_sg = kmap_atomic(host->cur_sg->page, KM_BIO_SRC_IRQ) +
                host->cur_sg->offset;
        return host->mapped_sg;
}

static inline void wbsd_kunmap_sg(struct wbsd_host* host)
{
        kunmap_atomic(host->mapped_sg, KM_BIO_SRC_IRQ);
}

static inline void wbsd_sg_to_dma(struct wbsd_host* host, struct mmc_data* data)
{
        unsigned int len, i, size;
        struct scatterlist* sg;
        char* dmabuf = host->dma_buffer;
        char* sgbuf;
        
        size = host->size;
        
        sg = data->sg;
        len = data->sg_len;
        
        /*
         * Just loop through all entries. Size might not
         * be the entire list though so make sure that
         * we do not transfer too much.
         */
        for (i = 0;i < len;i++)
        {
                sgbuf = kmap_atomic(sg[i].page, KM_BIO_SRC_IRQ) + sg[i].offset;
                if (size < sg[i].length)
                        memcpy(dmabuf, sgbuf, size);
                else
                        memcpy(dmabuf, sgbuf, sg[i].length);
                kunmap_atomic(sgbuf, KM_BIO_SRC_IRQ);
                dmabuf += sg[i].length;
                
                if (size < sg[i].length)
                        size = 0;
                else
                        size -= sg[i].length;
        
                if (size == 0)
                        break;
        }
        
        /*
         * Check that we didn't get a request to transfer
         * more data than can fit into the SG list.
         */
        
        BUG_ON(size != 0);
        
        host->size -= size;
}

static inline void wbsd_dma_to_sg(struct wbsd_host* host, struct mmc_data* data)
{
        unsigned int len, i, size;
        struct scatterlist* sg;
        char* dmabuf = host->dma_buffer;
        char* sgbuf;
        
        size = host->size;
        
        sg = data->sg;
        len = data->sg_len;
        
        /*
         * Just loop through all entries. Size might not
         * be the entire list though so make sure that
         * we do not transfer too much.
         */
        for (i = 0;i < len;i++)
        {
                sgbuf = kmap_atomic(sg[i].page, KM_BIO_SRC_IRQ) + sg[i].offset;
                if (size < sg[i].length)
                        memcpy(sgbuf, dmabuf, size);
                else
                        memcpy(sgbuf, dmabuf, sg[i].length);
                kunmap_atomic(sgbuf, KM_BIO_SRC_IRQ);
                dmabuf += sg[i].length;
                
                if (size < sg[i].length)
                        size = 0;
                else
                        size -= sg[i].length;
                
                if (size == 0)
                        break;
        }
        
        /*
         * Check that we didn't get a request to transfer
         * more data than can fit into the SG list.
         */
        
        BUG_ON(size != 0);
        
        host->size -= size;
}

/*
 * Command handling
 */
 
static inline void wbsd_get_short_reply(struct wbsd_host* host,
        struct mmc_command* cmd)
{
        /*
         * Correct response type?
         */
        if (wbsd_read_index(host, WBSD_IDX_RSPLEN) != WBSD_RSP_SHORT)
        {
                cmd->error = MMC_ERR_INVALID;
                return;
        }
        
        cmd->resp[0] =
                wbsd_read_index(host, WBSD_IDX_RESP12) << 24;
        cmd->resp[0] |=
                wbsd_read_index(host, WBSD_IDX_RESP13) << 16;
        cmd->resp[0] |=
                wbsd_read_index(host, WBSD_IDX_RESP14) << 8;
        cmd->resp[0] |=
                wbsd_read_index(host, WBSD_IDX_RESP15) << 0;
        cmd->resp[1] =
                wbsd_read_index(host, WBSD_IDX_RESP16) << 24;
}

static inline void wbsd_get_long_reply(struct wbsd_host* host,
        struct mmc_command* cmd)
{
        int i;
        
        /*
         * Correct response type?
         */
        if (wbsd_read_index(host, WBSD_IDX_RSPLEN) != WBSD_RSP_LONG)
        {
                cmd->error = MMC_ERR_INVALID;
                return;
        }
        
        for (i = 0;i < 4;i++)
        {
                cmd->resp[i] =
                        wbsd_read_index(host, WBSD_IDX_RESP1 + i * 4) << 24;
                cmd->resp[i] |=
                        wbsd_read_index(host, WBSD_IDX_RESP2 + i * 4) << 16;
                cmd->resp[i] |=
                        wbsd_read_index(host, WBSD_IDX_RESP3 + i * 4) << 8;
                cmd->resp[i] |=
                        wbsd_read_index(host, WBSD_IDX_RESP4 + i * 4) << 0;
        }
}

static irqreturn_t wbsd_irq(int irq, void *dev_id, struct pt_regs *regs);

static void wbsd_send_command(struct wbsd_host* host, struct mmc_command* cmd)
{
        int i;
        u8 status, isr;
        
        DBGF("Sending cmd (%x)\n", cmd->opcode);

        /*
         * Clear accumulated ISR. The interrupt routine
         * will fill this one with events that occur during
         * transfer.
         */
        host->isr = 0;
        
        /*
         * Send the command (CRC calculated by host).
         */
        outb(cmd->opcode, host->base + WBSD_CMDR);
        for (i = 3;i >= 0;i--)
                outb((cmd->arg >> (i * 8)) & 0xff, host->base + WBSD_CMDR);
        
        cmd->error = MMC_ERR_NONE;
        
        /*
         * Wait for the request to complete.
         */
        do {
                status = wbsd_read_index(host, WBSD_IDX_STATUS);
        } while (status & WBSD_CARDTRAFFIC);

        /*
         * Do we expect a reply?
         */
        if ((cmd->flags & MMC_RSP_MASK) != MMC_RSP_NONE)
        {
                /*
                 * Read back status.
                 */
                isr = host->isr;
                
                /* Card removed? */
                if (isr & WBSD_INT_CARD)
                        cmd->error = MMC_ERR_TIMEOUT;
                /* Timeout? */
                else if (isr & WBSD_INT_TIMEOUT)
                        cmd->error = MMC_ERR_TIMEOUT;
                /* CRC? */
                else if ((cmd->flags & MMC_RSP_CRC) && (isr & WBSD_INT_CRC))
                        cmd->error = MMC_ERR_BADCRC;
                /* All ok */
                else
                {
                        if ((cmd->flags & MMC_RSP_MASK) == MMC_RSP_SHORT)
                                wbsd_get_short_reply(host, cmd);
                        else
                                wbsd_get_long_reply(host, cmd);
                }
        }

        DBGF("Sent cmd (%x), res %d\n", cmd->opcode, cmd->error);
}

/*
 * Data functions
 */

static void wbsd_empty_fifo(struct wbsd_host* host)
{
        struct mmc_data* data = host->mrq->cmd->data;
        char* buffer;
        int i, fsr, fifo;
        
        /*
         * Handle excessive data.
         */
        if (data->bytes_xfered == host->size)
                return;
        
        buffer = wbsd_kmap_sg(host) + host->offset;

        /*
         * Drain the fifo. This has a tendency to loop longer
         * than the FIFO length (usually one block).
         */
        while (!((fsr = inb(host->base + WBSD_FSR)) & WBSD_FIFO_EMPTY))
        {
                /*
                 * The size field in the FSR is broken so we have to
                 * do some guessing.
                 */             
                if (fsr & WBSD_FIFO_FULL)
                        fifo = 16;
                else if (fsr & WBSD_FIFO_FUTHRE)
                        fifo = 8;
                else
                        fifo = 1;
                
                for (i = 0;i < fifo;i++)
                {
                        *buffer = inb(host->base + WBSD_DFR);
                        buffer++;
                        host->offset++;
                        host->remain--;

                        data->bytes_xfered++;
                        
                        /*
                         * Transfer done?
                         */
                        if (data->bytes_xfered == host->size)
                        {
                                wbsd_kunmap_sg(host);                           
                                return;
                        }
                        
                        /*
                         * End of scatter list entry?
                         */
                        if (host->remain == 0)
                        {
                                wbsd_kunmap_sg(host);
                                
                                /*
                                 * Get next entry. Check if last.
                                 */
                                if (!wbsd_next_sg(host))
                                {
                                        /*
                                         * We should never reach this point.
                                         * It means that we're trying to
                                         * transfer more blocks than can fit
                                         * into the scatter list.
                                         */
                                        BUG_ON(1);
                                        
                                        host->size = data->bytes_xfered;
                                        
                                        return;
                                }
                                
                                buffer = wbsd_kmap_sg(host);
                        }
                }
        }
        
        wbsd_kunmap_sg(host);

        /*
         * This is a very dirty hack to solve a
         * hardware problem. The chip doesn't trigger
         * FIFO threshold interrupts properly.
         */
        if ((host->size - data->bytes_xfered) < 16)
                tasklet_schedule(&host->fifo_tasklet);
}

static void wbsd_fill_fifo(struct wbsd_host* host)
{
        struct mmc_data* data = host->mrq->cmd->data;
        char* buffer;
        int i, fsr, fifo;
        
        /*
         * Check that we aren't being called after the
         * entire buffer has been transfered.
         */
        if (data->bytes_xfered == host->size)
                return;

        buffer = wbsd_kmap_sg(host) + host->offset;

        /*
         * Fill the fifo. This has a tendency to loop longer
         * than the FIFO length (usually one block).
         */
        while (!((fsr = inb(host->base + WBSD_FSR)) & WBSD_FIFO_FULL))
        {
                /*
                 * The size field in the FSR is broken so we have to
                 * do some guessing.
                 */             
                if (fsr & WBSD_FIFO_EMPTY)
                        fifo = 0;
                else if (fsr & WBSD_FIFO_EMTHRE)
                        fifo = 8;
                else
                        fifo = 15;

                for (i = 16;i > fifo;i--)
                {
                        outb(*buffer, host->base + WBSD_DFR);
                        buffer++;
                        host->offset++;
                        host->remain--;
                        
                        data->bytes_xfered++;
                        
                        /*
                         * Transfer done?
                         */
                        if (data->bytes_xfered == host->size)
                        {
                                wbsd_kunmap_sg(host);
                                return;
                        }

                        /*
                         * End of scatter list entry?
                         */
                        if (host->remain == 0)
                        {
                                wbsd_kunmap_sg(host);
                                
                                /*
                                 * Get next entry. Check if last.
                                 */
                                if (!wbsd_next_sg(host))
                                {
                                        /*
                                         * We should never reach this point.
                                         * It means that we're trying to
                                         * transfer more blocks than can fit
                                         * into the scatter list.
                                         */
                                        BUG_ON(1);
                                        
                                        host->size = data->bytes_xfered;
                                        
                                        return;
                                }
                                
                                buffer = wbsd_kmap_sg(host);
                        }
                }
        }
        
        wbsd_kunmap_sg(host);
}

static void wbsd_prepare_data(struct wbsd_host* host, struct mmc_data* data)
{
        u16 blksize;
        u8 setup;
        unsigned long dmaflags;

        DBGF("blksz %04x blks %04x flags %08x\n",
                1 << data->blksz_bits, data->blocks, data->flags);
        DBGF("tsac %d ms nsac %d clk\n",
                data->timeout_ns / 1000000, data->timeout_clks);
        
        /*
         * Calculate size.
         */
        host->size = data->blocks << data->blksz_bits;

        /*
         * Check timeout values for overflow.
         * (Yes, some cards cause this value to overflow).
         */
        if (data->timeout_ns > 127000000)
                wbsd_write_index(host, WBSD_IDX_TAAC, 127);
        else
                wbsd_write_index(host, WBSD_IDX_TAAC, data->timeout_ns/1000000);
        
        if (data->timeout_clks > 255)
                wbsd_write_index(host, WBSD_IDX_NSAC, 255);
        else
                wbsd_write_index(host, WBSD_IDX_NSAC, data->timeout_clks);
        
        /*
         * Inform the chip of how large blocks will be
         * sent. It needs this to determine when to
         * calculate CRC.
         *
         * Space for CRC must be included in the size.
         */
        blksize = (1 << data->blksz_bits) + 2;
        
        wbsd_write_index(host, WBSD_IDX_PBSMSB, (blksize >> 4) & 0xF0);
        wbsd_write_index(host, WBSD_IDX_PBSLSB, blksize & 0xFF);

        /*
         * Clear the FIFO. This is needed even for DMA
         * transfers since the chip still uses the FIFO
         * internally.
         */
        setup = wbsd_read_index(host, WBSD_IDX_SETUP);
        setup |= WBSD_FIFO_RESET;
        wbsd_write_index(host, WBSD_IDX_SETUP, setup);
        
        /*
         * DMA transfer?
         */
        if (host->dma >= 0)
        {       
                /*
                 * The buffer for DMA is only 64 kB.
                 */
                BUG_ON(host->size > 0x10000);
                if (host->size > 0x10000)
                {
                        data->error = MMC_ERR_INVALID;
                        return;
                }
                
                /*
                 * Transfer data from the SG list to
                 * the DMA buffer.
                 */
                if (data->flags & MMC_DATA_WRITE)
                        wbsd_sg_to_dma(host, data);
                
                /*
                 * Initialise the ISA DMA controller.
                 */     
                dmaflags = claim_dma_lock();
                disable_dma(host->dma);
                clear_dma_ff(host->dma);
                if (data->flags & MMC_DATA_READ)
                        set_dma_mode(host->dma, DMA_MODE_READ & ~0x40);
                else
                        set_dma_mode(host->dma, DMA_MODE_WRITE & ~0x40);
                set_dma_addr(host->dma, host->dma_addr);
                set_dma_count(host->dma, host->size);

                enable_dma(host->dma);
                release_dma_lock(dmaflags);

                /*
                 * Enable DMA on the host.
                 */
                wbsd_write_index(host, WBSD_IDX_DMA, WBSD_DMA_ENABLE);
        }
        else
        {
                /*
                 * This flag is used to keep printk
                 * output to a minimum.
                 */
                host->firsterr = 1;
                
                /*
                 * Initialise the SG list.
                 */
                wbsd_init_sg(host, data);
        
                /*
                 * Turn off DMA.
                 */
                wbsd_write_index(host, WBSD_IDX_DMA, 0);
        
                /*
                 * Set up FIFO threshold levels (and fill
                 * buffer if doing a write).
                 */
                if (data->flags & MMC_DATA_READ)
                {
                        wbsd_write_index(host, WBSD_IDX_FIFOEN,
                                WBSD_FIFOEN_FULL | 8);
                }
                else
                {
                        wbsd_write_index(host, WBSD_IDX_FIFOEN,
                                WBSD_FIFOEN_EMPTY | 8);
                        wbsd_fill_fifo(host);
                }
        }       
                
        data->error = MMC_ERR_NONE;
}

static void wbsd_finish_data(struct wbsd_host* host, struct mmc_data* data)
{
        unsigned long dmaflags;
        int count;
        u8 status;
        
        WARN_ON(host->mrq == NULL);

        /*
         * Send a stop command if needed.
         */
        if (data->stop)
                wbsd_send_command(host, data->stop);

        /*
         * Wait for the controller to leave data
         * transfer state.
         */
        do
        {
                status = wbsd_read_index(host, WBSD_IDX_STATUS);
        } while (status & (WBSD_BLOCK_READ | WBSD_BLOCK_WRITE));
        
        /*
         * DMA transfer?
         */
        if (host->dma >= 0)
        {
                /*
                 * Disable DMA on the host.
                 */
                wbsd_write_index(host, WBSD_IDX_DMA, 0);
                
                /*
                 * Turn of ISA DMA controller.
                 */
                dmaflags = claim_dma_lock();
                disable_dma(host->dma);
                clear_dma_ff(host->dma);
                count = get_dma_residue(host->dma);
                release_dma_lock(dmaflags);
                
                /*
                 * Any leftover data?
                 */
                if (count)
                {
                        printk(KERN_ERR DRIVER_NAME ": Incomplete DMA "
                                "transfer. %d bytes left.\n", count);
                        
                        data->error = MMC_ERR_FAILED;
                }
                else
                {
                        /*
                         * Transfer data from DMA buffer to
                         * SG list.
                         */
                        if (data->flags & MMC_DATA_READ)
                                wbsd_dma_to_sg(host, data);
                        
                        data->bytes_xfered = host->size;
                }
        }
        
        DBGF("Ending data transfer (%d bytes)\n", data->bytes_xfered);
        
        wbsd_request_end(host, host->mrq);
}

/*
 * MMC Callbacks
 */

static void wbsd_request(struct mmc_host* mmc, struct mmc_request* mrq)
{
        struct wbsd_host* host = mmc_priv(mmc);
        struct mmc_command* cmd;

        /*
         * Disable tasklets to avoid a deadlock.
         */
        spin_lock_bh(&host->lock);

        BUG_ON(host->mrq != NULL);

        cmd = mrq->cmd;

        host->mrq = mrq;
        
        /*
         * If there is no card in the slot then
         * timeout immediatly.
         */
        if (!(inb(host->base + WBSD_CSR) & WBSD_CARDPRESENT))
        {
                cmd->error = MMC_ERR_TIMEOUT;
                goto done;
        }

        /*
         * Does the request include data?
         */
        if (cmd->data)
        {
                wbsd_prepare_data(host, cmd->data);
                
                if (cmd->data->error != MMC_ERR_NONE)
                        goto done;
        }
        
        wbsd_send_command(host, cmd);

        /*
         * If this is a data transfer the request
         * will be finished after the data has
         * transfered.
         */     
        if (cmd->data && (cmd->error == MMC_ERR_NONE))
        {
                /*
                 * Dirty fix for hardware bug.
                 */
                if (host->dma == -1)
                        tasklet_schedule(&host->fifo_tasklet);

                spin_unlock_bh(&host->lock);

                return;
        }
                
done:
        wbsd_request_end(host, mrq);

        spin_unlock_bh(&host->lock);
}

static void wbsd_set_ios(struct mmc_host* mmc, struct mmc_ios* ios)
{
        struct wbsd_host* host = mmc_priv(mmc);
        u8 clk, setup, pwr;
        
        DBGF("clock %uHz busmode %u powermode %u Vdd %u\n",
                ios->clock, ios->bus_mode, ios->power_mode, ios->vdd);

        spin_lock_bh(&host->lock);

        /*
         * Reset the chip on each power off.
         * Should clear out any weird states.
         */
        if (ios->power_mode == MMC_POWER_OFF)
                wbsd_init_device(host);
        
        if (ios->clock >= 24000000)
                clk = WBSD_CLK_24M;
        else if (ios->clock >= 16000000)
                clk = WBSD_CLK_16M;
        else if (ios->clock >= 12000000)
                clk = WBSD_CLK_12M;
        else
                clk = WBSD_CLK_375K;

        /*
         * Only write to the clock register when
         * there is an actual change.
         */
        if (clk != host->clk)
        {
                wbsd_write_index(host, WBSD_IDX_CLK, clk);
                host->clk = clk;
        }

        if (ios->power_mode != MMC_POWER_OFF)
        {
                /*
                 * Power up card.
                 */
                pwr = inb(host->base + WBSD_CSR);
                pwr &= ~WBSD_POWER_N;
                outb(pwr, host->base + WBSD_CSR);

                /*
                 * This behaviour is stolen from the
                 * Windows driver. Don't know why, but
                 * it is needed.
                 */
                setup = wbsd_read_index(host, WBSD_IDX_SETUP);
                if (ios->bus_mode == MMC_BUSMODE_OPENDRAIN)
                        setup |= WBSD_DAT3_H;
                else
                        setup &= ~WBSD_DAT3_H;
                wbsd_write_index(host, WBSD_IDX_SETUP, setup);

                mdelay(1);
        }

        spin_unlock_bh(&host->lock);
}

/*
 * Tasklets
 */

inline static struct mmc_data* wbsd_get_data(struct wbsd_host* host)
{
        WARN_ON(!host->mrq);
        if (!host->mrq)
                return NULL;

        WARN_ON(!host->mrq->cmd);
        if (!host->mrq->cmd)
                return NULL;

        WARN_ON(!host->mrq->cmd->data);
        if (!host->mrq->cmd->data)
                return NULL;
        
        return host->mrq->cmd->data;
}

static void wbsd_tasklet_card(unsigned long param)
{
        struct wbsd_host* host = (struct wbsd_host*)param;
        u8 csr;
        
        spin_lock(&host->lock);
        
        csr = inb(host->base + WBSD_CSR);
        WARN_ON(csr == 0xff);
        
        if (csr & WBSD_CARDPRESENT)
                DBG("Card inserted\n");
        else
        {
                DBG("Card removed\n");
                
                if (host->mrq)
                {
                        printk(KERN_ERR DRIVER_NAME
                                ": Card removed during transfer!\n");
                        wbsd_reset(host);
                        
                        host->mrq->cmd->error = MMC_ERR_FAILED;
                        tasklet_schedule(&host->finish_tasklet);
                }
        }
        
        /*
         * Unlock first since we might get a call back.
         */
        spin_unlock(&host->lock);

        mmc_detect_change(host->mmc);
}

static void wbsd_tasklet_fifo(unsigned long param)
{
        struct wbsd_host* host = (struct wbsd_host*)param;
        struct mmc_data* data;
        
        spin_lock(&host->lock);
                
        if (!host->mrq)
                goto end;
        
        data = wbsd_get_data(host);
        if (!data)
                goto end;

        if (data->flags & MMC_DATA_WRITE)
                wbsd_fill_fifo(host);
        else
                wbsd_empty_fifo(host);

        /*
         * Done?
         */
        if (host->size == data->bytes_xfered)
        {
                wbsd_write_index(host, WBSD_IDX_FIFOEN, 0);
                tasklet_schedule(&host->finish_tasklet);
        }

end:    
        spin_unlock(&host->lock);
}

static void wbsd_tasklet_crc(unsigned long param)
{
        struct wbsd_host* host = (struct wbsd_host*)param;
        struct mmc_data* data;
        
        spin_lock(&host->lock);
        
        if (!host->mrq)
                goto end;
        
        data = wbsd_get_data(host);
        if (!data)
                goto end;
        
        DBGF("CRC error\n");

        data->error = MMC_ERR_BADCRC;
        
        tasklet_schedule(&host->finish_tasklet);

end:            
        spin_unlock(&host->lock);
}

static void wbsd_tasklet_timeout(unsigned long param)
{
        struct wbsd_host* host = (struct wbsd_host*)param;
        struct mmc_data* data;
        
        spin_lock(&host->lock);
        
        if (!host->mrq)
                goto end;
        
        data = wbsd_get_data(host);
        if (!data)
                goto end;
        
        DBGF("Timeout\n");

        data->error = MMC_ERR_TIMEOUT;
        
        tasklet_schedule(&host->finish_tasklet);

end:    
        spin_unlock(&host->lock);
}

static void wbsd_tasklet_finish(unsigned long param)
{
        struct wbsd_host* host = (struct wbsd_host*)param;
        struct mmc_data* data;
        
        spin_lock(&host->lock);
        
        WARN_ON(!host->mrq);
        if (!host->mrq)
                goto end;
        
        data = wbsd_get_data(host);
        if (!data)
                goto end;

        wbsd_finish_data(host, data);
        
end:    
        spin_unlock(&host->lock);
}

static void wbsd_tasklet_block(unsigned long param)
{
        struct wbsd_host* host = (struct wbsd_host*)param;
        struct mmc_data* data;
        
        spin_lock(&host->lock);

        if ((wbsd_read_index(host, WBSD_IDX_CRCSTATUS) & WBSD_CRC_MASK) !=
                WBSD_CRC_OK)
        {
                data = wbsd_get_data(host);
                if (!data)
                        goto end;
                
                DBGF("CRC error\n");

                data->error = MMC_ERR_BADCRC;
        
                tasklet_schedule(&host->finish_tasklet);
        }

end:    
        spin_unlock(&host->lock);
}

/*
 * Interrupt handling
 */

static irqreturn_t wbsd_irq(int irq, void *dev_id, struct pt_regs *regs)
{
        struct wbsd_host* host = dev_id;
        int isr;
        
        isr = inb(host->base + WBSD_ISR);

        /*
         * Was it actually our hardware that caused the interrupt?
         */
        if (isr == 0xff || isr == 0x00)
                return IRQ_NONE;
        
        host->isr |= isr;

        /*
         * Schedule tasklets as needed.
         */
        if (isr & WBSD_INT_CARD)
                tasklet_schedule(&host->card_tasklet);
        if (isr & WBSD_INT_FIFO_THRE)
                tasklet_schedule(&host->fifo_tasklet);
        if (isr & WBSD_INT_CRC)
                tasklet_hi_schedule(&host->crc_tasklet);
        if (isr & WBSD_INT_TIMEOUT)
                tasklet_hi_schedule(&host->timeout_tasklet);
        if (isr & WBSD_INT_BUSYEND)
                tasklet_hi_schedule(&host->block_tasklet);
        if (isr & WBSD_INT_TC)
                tasklet_schedule(&host->finish_tasklet);
        
        return IRQ_HANDLED;
}

/*
 * Support functions for probe
 */

static int wbsd_scan(struct wbsd_host* host)
{
        int i, j, k;
        int id;
        
        /*
         * Iterate through all ports, all codes to
         * find hardware that is in our known list.
         */
        for (i = 0;i < sizeof(config_ports)/sizeof(int);i++)
        {
                if (!request_region(config_ports[i], 2, DRIVER_NAME))
                        continue;
                        
                for (j = 0;j < sizeof(unlock_codes)/sizeof(int);j++)
                {
                        id = 0xFFFF;
                        
                        outb(unlock_codes[j], config_ports[i]);
                        outb(unlock_codes[j], config_ports[i]);
                        
                        outb(WBSD_CONF_ID_HI, config_ports[i]);
                        id = inb(config_ports[i] + 1) << 8;

                        outb(WBSD_CONF_ID_LO, config_ports[i]);
                        id |= inb(config_ports[i] + 1);
                        
                        for (k = 0;k < sizeof(valid_ids)/sizeof(int);k++)
                        {
                                if (id == valid_ids[k])
                                {                               
                                        host->chip_id = id;
                                        host->config = config_ports[i];
                                        host->unlock_code = unlock_codes[i];
                                
                                        return 0;
                                }
                        }
                        
                        if (id != 0xFFFF)
                        {
                                DBG("Unknown hardware (id %x) found at %x\n",
                                        id, config_ports[i]);
                        }

                        outb(LOCK_CODE, config_ports[i]);
                }
                
                release_region(config_ports[i], 2);
        }
        
        return -ENODEV;
}

static int wbsd_request_regions(struct wbsd_host* host)
{
        if (io & 0x7)
                return -EINVAL;
        
        if (!request_region(io, 8, DRIVER_NAME))
                return -EIO;
        
        host->base = io;
                
        return 0;
}

static void wbsd_release_regions(struct wbsd_host* host)
{
        if (host->base)
                release_region(host->base, 8);

        if (host->config)
                release_region(host->config, 2);
}

static void wbsd_init_dma(struct wbsd_host* host)
{
        host->dma = -1;
        
        if (dma < 0)
                return;
        
        if (request_dma(dma, DRIVER_NAME))
                goto err;
        
        /*
         * We need to allocate a special buffer in
         * order for ISA to be able to DMA to it.
         */
        host->dma_buffer = kmalloc(65536,
                GFP_NOIO | GFP_DMA | __GFP_REPEAT | __GFP_NOWARN);
        if (!host->dma_buffer)
                goto free;

        /*
         * Translate the address to a physical address.
         */
        host->dma_addr = isa_virt_to_bus(host->dma_buffer);
                        
        /*
         * ISA DMA must be aligned on a 64k basis.
         */
        if ((host->dma_addr & 0xffff) != 0)
                goto kfree;
        /*
         * ISA cannot access memory above 16 MB.
         */
        else if (host->dma_addr >= 0x1000000)
                goto kfree;

        host->dma = dma;
        
        return;
        
kfree:
        /*
         * If we've gotten here then there is some kind of alignment bug
         */
        BUG_ON(1);
        
        kfree(host->dma_buffer);
        host->dma_buffer = NULL;

free:
        free_dma(dma);

err:
        printk(KERN_WARNING DRIVER_NAME ": Unable to allocate DMA %d. "
                "Falling back on FIFO.\n", dma);
}

static struct mmc_host_ops wbsd_ops = {
        .request        = wbsd_request,
        .set_ios        = wbsd_set_ios,
};

/*
 * Device probe
 */

static int wbsd_probe(struct device* dev)
{
        struct wbsd_host* host = NULL;
        struct mmc_host* mmc = NULL;
        int ret;
        
        /*
         * Allocate MMC structure.
         */
        mmc = mmc_alloc_host(sizeof(struct wbsd_host), dev);
        if (!mmc)
                return -ENOMEM;
        
        host = mmc_priv(mmc);
        host->mmc = mmc;
        
        /*
         * Scan for hardware.
         */
        ret = wbsd_scan(host);
        if (ret)
                goto freemmc;

        /*
         * Reset the chip.
         */     
        wbsd_write_config(host, WBSD_CONF_SWRST, 1);
        wbsd_write_config(host, WBSD_CONF_SWRST, 0);

        /*
         * Allocate I/O ports.
         */
        ret = wbsd_request_regions(host);
        if (ret)
                goto release;

        /*
         * Set host parameters.
         */
        mmc->ops = &wbsd_ops;
        mmc->f_min = 375000;
        mmc->f_max = 24000000;
        mmc->ocr_avail = MMC_VDD_32_33|MMC_VDD_33_34;
        
        spin_lock_init(&host->lock);

        /*
         * Select SD/MMC function.
         */
        wbsd_write_config(host, WBSD_CONF_DEVICE, DEVICE_SD);
        
        /*
         * Set up card detection.
         */
        wbsd_write_config(host, WBSD_CONF_PINS, 0x02);
        
        /*
         * Configure I/O port.
         */
        wbsd_write_config(host, WBSD_CONF_PORT_HI, host->base >> 8);
        wbsd_write_config(host, WBSD_CONF_PORT_LO, host->base & 0xff);

        /*
         * Allocate interrupt.
         */
        ret = request_irq(irq, wbsd_irq, SA_SHIRQ, DRIVER_NAME, host);
        if (ret)
                goto release;
        
        host->irq = irq;
        
        /*
         * Set up tasklets.
         */
        tasklet_init(&host->card_tasklet, wbsd_tasklet_card, (unsigned long)host);
        tasklet_init(&host->fifo_tasklet, wbsd_tasklet_fifo, (unsigned long)host);
        tasklet_init(&host->crc_tasklet, wbsd_tasklet_crc, (unsigned long)host);
        tasklet_init(&host->timeout_tasklet, wbsd_tasklet_timeout, (unsigned long)host);
        tasklet_init(&host->finish_tasklet, wbsd_tasklet_finish, (unsigned long)host);
        tasklet_init(&host->block_tasklet, wbsd_tasklet_block, (unsigned long)host);
        
        /*
         * Configure interrupt.
         */
        wbsd_write_config(host, WBSD_CONF_IRQ, host->irq);
        
        /*
         * Allocate DMA.
         */
        wbsd_init_dma(host);
        
        /*
         * If all went well, then configure DMA.
         */
        if (host->dma >= 0)
                wbsd_write_config(host, WBSD_CONF_DRQ, host->dma);
        
        /*
         * Maximum number of segments. Worst case is one sector per segment
         * so this will be 64kB/512.
         */
        mmc->max_hw_segs = 128;
        mmc->max_phys_segs = 128;
        
        /*
         * Maximum number of sectors in one transfer. Also limited by 64kB
         * buffer.
         */
        mmc->max_sectors = 128;
        
        /*
         * Maximum segment size. Could be one segment with the maximum number
         * of segments.
         */
        mmc->max_seg_size = mmc->max_sectors * 512;
        
        /*
         * Enable chip.
         */
        wbsd_write_config(host, WBSD_CONF_ENABLE, 1);
        
        /*
         * Power up chip.
         */
        wbsd_write_config(host, WBSD_CONF_POWER, 0x20);
        
        /*
         * Power Management stuff. No idea how this works.
         * Not tested.
         */
#ifdef CONFIG_PM
        wbsd_write_config(host, WBSD_CONF_PME, 0xA0);
#endif

        /*
         * Reset the chip into a known state.
         */
        wbsd_init_device(host);
        
        dev_set_drvdata(dev, mmc);
        
        /*
         * Add host to MMC layer.
         */
        mmc_add_host(mmc);

        printk(KERN_INFO "%s: W83L51xD id %x at 0x%x irq %d dma %d\n",
                mmc->host_name, (int)host->chip_id, (int)host->base,
                (int)host->irq, (int)host->dma);

        return 0;

release:
        wbsd_release_regions(host);

freemmc:
        mmc_free_host(mmc);

        return ret;
}

/*
 * Device remove
 */

static int wbsd_remove(struct device* dev)
{
        struct mmc_host* mmc = dev_get_drvdata(dev);
        struct wbsd_host* host;
        
        if (!mmc)
                return 0;

        host = mmc_priv(mmc);
        
        /*
         * Unregister host with MMC layer.
         */
        mmc_remove_host(mmc);

        /*
         * Power down the SD/MMC function.
         */
        wbsd_unlock_config(host);
        wbsd_write_config(host, WBSD_CONF_DEVICE, DEVICE_SD);
        wbsd_write_config(host, WBSD_CONF_ENABLE, 0);
        wbsd_lock_config(host);
        
        /*
         * Free resources.
         */
        if (host->dma_buffer)
                kfree(host->dma_buffer);
        
        if (host->dma >= 0)
                free_dma(host->dma);

        free_irq(host->irq, host);
        
        tasklet_kill(&host->card_tasklet);
        tasklet_kill(&host->fifo_tasklet);
        tasklet_kill(&host->crc_tasklet);
        tasklet_kill(&host->timeout_tasklet);
        tasklet_kill(&host->finish_tasklet);
        tasklet_kill(&host->block_tasklet);
        
        wbsd_release_regions(host);
        
        mmc_free_host(mmc);

        return 0;
}

/*
 * Power management
 */

#ifdef CONFIG_PM
static int wbsd_suspend(struct device *dev, pm_message_t state, u32 level)
{
        DBGF("Not yet supported\n");

        return 0;
}

static int wbsd_resume(struct device *dev, u32 level)
{
        DBGF("Not yet supported\n");

        return 0;
}
#else
#define wbsd_suspend NULL
#define wbsd_resume NULL
#endif

static void wbsd_release(struct device *dev)
{
}

static struct platform_device wbsd_device = {
        .name           = DRIVER_NAME,
        .id                     = -1,
        .dev            = {
                .release = wbsd_release,
        },
};

static struct device_driver wbsd_driver = {
        .name           = DRIVER_NAME,
        .bus            = &platform_bus_type,
        .probe          = wbsd_probe,
        .remove         = wbsd_remove,
        
        .suspend        = wbsd_suspend,
        .resume         = wbsd_resume,
};

/*
 * Module loading/unloading
 */

static int __init wbsd_drv_init(void)
{
        int result;
        
        printk(KERN_INFO DRIVER_NAME
                ": Winbond W83L51xD SD/MMC card interface driver, "
                DRIVER_VERSION "\n");
        printk(KERN_INFO DRIVER_NAME ": Copyright(c) Pierre Ossman\n");
        
        result = driver_register(&wbsd_driver);
        if (result < 0)
                return result;

        result = platform_device_register(&wbsd_device);
        if (result < 0)
                return result;

        return 0;
}

static void __exit wbsd_drv_exit(void)
{
        platform_device_unregister(&wbsd_device);
        
        driver_unregister(&wbsd_driver);

        DBG("unloaded\n");
}

module_init(wbsd_drv_init);
module_exit(wbsd_drv_exit);
module_param(io, uint, 0444);
module_param(irq, uint, 0444);
module_param(dma, int, 0444);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Winbond W83L51xD SD/MMC card interface driver");
MODULE_VERSION(DRIVER_VERSION);

MODULE_PARM_DESC(io, "I/O base to allocate. Must be 8 byte aligned. (default 0x248)");
MODULE_PARM_DESC(irq, "IRQ to allocate. (default 6)");
MODULE_PARM_DESC(dma, "DMA channel to allocate. -1 for no DMA. (default 2)");