spi-bfin-sport.c

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/*
 * SPI bus via the Blackfin SPORT peripheral
 *
 * Enter bugs at http://blackfin.uclinux.org/
 *
 * Copyright 2009-2011 Analog Devices Inc.
 *
 * Licensed under the GPL-2 or later.
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/workqueue.h>

#include <asm/portmux.h>
#include <asm/bfin5xx_spi.h>
#include <asm/blackfin.h>
#include <asm/bfin_sport.h>
#include <asm/cacheflush.h>

#define DRV_NAME    "bfin-sport-spi"
#define DRV_DESC    "SPI bus via the Blackfin SPORT"

MODULE_AUTHOR("Cliff Cai");
MODULE_DESCRIPTION(DRV_DESC);
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:bfin-sport-spi");

enum bfin_sport_spi_state {
    START_STATE,
    RUNNING_STATE,
    DONE_STATE,
    ERROR_STATE,
};

struct bfin_sport_spi_master_data;

struct bfin_sport_transfer_ops {
    void (*write) (struct bfin_sport_spi_master_data *);
    void (*read) (struct bfin_sport_spi_master_data *);
    void (*duplex) (struct bfin_sport_spi_master_data *);
};

struct bfin_sport_spi_master_data {
    /* Driver model hookup */
    struct device *dev;

    /* SPI framework hookup */
    struct spi_master *master;

    /* Regs base of SPI controller */
    struct sport_register __iomem *regs;
    int err_irq;

    /* Pin request list */
    u16 *pin_req;

    /* Driver message queue */
    struct workqueue_struct *workqueue;
    struct work_struct pump_messages;
    spinlock_t lock;
    struct list_head queue;
    int busy;
    bool run;

    /* Message Transfer pump */
    struct tasklet_struct pump_transfers;

    /* Current message transfer state info */
    enum bfin_sport_spi_state state;
    struct spi_message *cur_msg;
    struct spi_transfer *cur_transfer;
    struct bfin_sport_spi_slave_data *cur_chip;
    union {
        void *tx;
        u8 *tx8;
        u16 *tx16;
    };
    void *tx_end;
    union {
        void *rx;
        u8 *rx8;
        u16 *rx16;
    };
    void *rx_end;

    int cs_change;
    struct bfin_sport_transfer_ops *ops;
};

struct bfin_sport_spi_slave_data {
    u16 ctl_reg;
    u16 baud;
    u16 cs_chg_udelay;  /* Some devices require > 255usec delay */
    u32 cs_gpio;
    u16 idle_tx_val;
    struct bfin_sport_transfer_ops *ops;
};

static void
bfin_sport_spi_enable(struct bfin_sport_spi_master_data *drv_data)
{
    bfin_write_or(&drv_data->regs->tcr1, TSPEN);
    bfin_write_or(&drv_data->regs->rcr1, TSPEN);
    SSYNC();
}

static void
bfin_sport_spi_disable(struct bfin_sport_spi_master_data *drv_data)
{
    bfin_write_and(&drv_data->regs->tcr1, ~TSPEN);
    bfin_write_and(&drv_data->regs->rcr1, ~TSPEN);
    SSYNC();
}

/* Caculate the SPI_BAUD register value based on input HZ */
static u16
bfin_sport_hz_to_spi_baud(u32 speed_hz)
{
    u_long clk, sclk = get_sclk();
    int div = (sclk / (2 * speed_hz)) - 1;

    if (div < 0)
        div = 0;

    clk = sclk / (2 * (div + 1));

    if (clk > speed_hz)
        div++;

    return div;
}

/* Chip select operation functions for cs_change flag */
static void
bfin_sport_spi_cs_active(struct bfin_sport_spi_slave_data *chip)
{
    gpio_direction_output(chip->cs_gpio, 0);
}

static void
bfin_sport_spi_cs_deactive(struct bfin_sport_spi_slave_data *chip)
{
    gpio_direction_output(chip->cs_gpio, 1);
    /* Move delay here for consistency */
    if (chip->cs_chg_udelay)
        udelay(chip->cs_chg_udelay);
}

static void
bfin_sport_spi_stat_poll_complete(struct bfin_sport_spi_master_data *drv_data)
{
    unsigned long timeout = jiffies + HZ;
    while (!(bfin_read(&drv_data->regs->stat) & RXNE)) {
        if (!time_before(jiffies, timeout))
            break;
    }
}

static void
bfin_sport_spi_u8_writer(struct bfin_sport_spi_master_data *drv_data)
{
    u16 dummy;

    while (drv_data->tx < drv_data->tx_end) {
        bfin_write(&drv_data->regs->tx16, *drv_data->tx8++);
        bfin_sport_spi_stat_poll_complete(drv_data);
        dummy = bfin_read(&drv_data->regs->rx16);
    }
}

static void
bfin_sport_spi_u8_reader(struct bfin_sport_spi_master_data *drv_data)
{
    u16 tx_val = drv_data->cur_chip->idle_tx_val;

    while (drv_data->rx < drv_data->rx_end) {
        bfin_write(&drv_data->regs->tx16, tx_val);
        bfin_sport_spi_stat_poll_complete(drv_data);
        *drv_data->rx8++ = bfin_read(&drv_data->regs->rx16);
    }
}

static void
bfin_sport_spi_u8_duplex(struct bfin_sport_spi_master_data *drv_data)
{
    while (drv_data->rx < drv_data->rx_end) {
        bfin_write(&drv_data->regs->tx16, *drv_data->tx8++);
        bfin_sport_spi_stat_poll_complete(drv_data);
        *drv_data->rx8++ = bfin_read(&drv_data->regs->rx16);
    }
}

static struct bfin_sport_transfer_ops bfin_sport_transfer_ops_u8 = {
    .write  = bfin_sport_spi_u8_writer,
    .read   = bfin_sport_spi_u8_reader,
    .duplex = bfin_sport_spi_u8_duplex,
};

static void
bfin_sport_spi_u16_writer(struct bfin_sport_spi_master_data *drv_data)
{
    u16 dummy;

    while (drv_data->tx < drv_data->tx_end) {
        bfin_write(&drv_data->regs->tx16, *drv_data->tx16++);
        bfin_sport_spi_stat_poll_complete(drv_data);
        dummy = bfin_read(&drv_data->regs->rx16);
    }
}

static void
bfin_sport_spi_u16_reader(struct bfin_sport_spi_master_data *drv_data)
{
    u16 tx_val = drv_data->cur_chip->idle_tx_val;

    while (drv_data->rx < drv_data->rx_end) {
        bfin_write(&drv_data->regs->tx16, tx_val);
        bfin_sport_spi_stat_poll_complete(drv_data);
        *drv_data->rx16++ = bfin_read(&drv_data->regs->rx16);
    }
}

static void
bfin_sport_spi_u16_duplex(struct bfin_sport_spi_master_data *drv_data)
{
    while (drv_data->rx < drv_data->rx_end) {
        bfin_write(&drv_data->regs->tx16, *drv_data->tx16++);
        bfin_sport_spi_stat_poll_complete(drv_data);
        *drv_data->rx16++ = bfin_read(&drv_data->regs->rx16);
    }
}

static struct bfin_sport_transfer_ops bfin_sport_transfer_ops_u16 = {
    .write  = bfin_sport_spi_u16_writer,
    .read   = bfin_sport_spi_u16_reader,
    .duplex = bfin_sport_spi_u16_duplex,
};

/* stop controller and re-config current chip */
static void
bfin_sport_spi_restore_state(struct bfin_sport_spi_master_data *drv_data)
{
    struct bfin_sport_spi_slave_data *chip = drv_data->cur_chip;

    bfin_sport_spi_disable(drv_data);
    dev_dbg(drv_data->dev, "restoring spi ctl state\n");

    bfin_write(&drv_data->regs->tcr1, chip->ctl_reg);
    bfin_write(&drv_data->regs->tclkdiv, chip->baud);
    SSYNC();

    bfin_write(&drv_data->regs->rcr1, chip->ctl_reg & ~(ITCLK | ITFS));
    SSYNC();

    bfin_sport_spi_cs_active(chip);
}

/* test if there is more transfer to be done */
static enum bfin_sport_spi_state
bfin_sport_spi_next_transfer(struct bfin_sport_spi_master_data *drv_data)
{
    struct spi_message *msg = drv_data->cur_msg;
    struct spi_transfer *trans = drv_data->cur_transfer;

    /* Move to next transfer */
    if (trans->transfer_list.next != &msg->transfers) {
        drv_data->cur_transfer =
            list_entry(trans->transfer_list.next,
                   struct spi_transfer, transfer_list);
        return RUNNING_STATE;
    }

    return DONE_STATE;
}

/*
 * caller already set message->status;
 * dma and pio irqs are blocked give finished message back
 */
static void
bfin_sport_spi_giveback(struct bfin_sport_spi_master_data *drv_data)
{
    struct bfin_sport_spi_slave_data *chip = drv_data->cur_chip;
    unsigned long flags;
    struct spi_message *msg;

    spin_lock_irqsave(&drv_data->lock, flags);
    msg = drv_data->cur_msg;
    drv_data->state = START_STATE;
    drv_data->cur_msg = NULL;
    drv_data->cur_transfer = NULL;
    drv_data->cur_chip = NULL;
    queue_work(drv_data->workqueue, &drv_data->pump_messages);
    spin_unlock_irqrestore(&drv_data->lock, flags);

    if (!drv_data->cs_change)
        bfin_sport_spi_cs_deactive(chip);

    if (msg->complete)
        msg->complete(msg->context);
}

static irqreturn_t
sport_err_handler(int irq, void *dev_id)
{
    struct bfin_sport_spi_master_data *drv_data = dev_id;
    u16 status;

    dev_dbg(drv_data->dev, "%s enter\n", __func__);
    status = bfin_read(&drv_data->regs->stat) & (TOVF | TUVF | ROVF | RUVF);

    if (status) {
        bfin_write(&drv_data->regs->stat, status);
        SSYNC();

        bfin_sport_spi_disable(drv_data);
        dev_err(drv_data->dev, "status error:%s%s%s%s\n",
            status & TOVF ? " TOVF" : "",
            status & TUVF ? " TUVF" : "",
            status & ROVF ? " ROVF" : "",
            status & RUVF ? " RUVF" : "");
    }

    return IRQ_HANDLED;
}

static void
bfin_sport_spi_pump_transfers(unsigned long data)
{
    struct bfin_sport_spi_master_data *drv_data = (void *)data;
    struct spi_message *message = NULL;
    struct spi_transfer *transfer = NULL;
    struct spi_transfer *previous = NULL;
    struct bfin_sport_spi_slave_data *chip = NULL;
    unsigned int bits_per_word;
    u32 tranf_success = 1;
    u32 transfer_speed;
    u8 full_duplex = 0;

    /* Get current state information */
    message = drv_data->cur_msg;
    transfer = drv_data->cur_transfer;
    chip = drv_data->cur_chip;

    if (transfer->speed_hz)
        transfer_speed = bfin_sport_hz_to_spi_baud(transfer->speed_hz);
    else
        transfer_speed = chip->baud;
    bfin_write(&drv_data->regs->tclkdiv, transfer_speed);
    SSYNC();

    /*
     * if msg is error or done, report it back using complete() callback
     */

     /* Handle for abort */
    if (drv_data->state == ERROR_STATE) {
        dev_dbg(drv_data->dev, "transfer: we've hit an error\n");
        message->status = -EIO;
        bfin_sport_spi_giveback(drv_data);
        return;
    }

    /* Handle end of message */
    if (drv_data->state == DONE_STATE) {
        dev_dbg(drv_data->dev, "transfer: all done!\n");
        message->status = 0;
        bfin_sport_spi_giveback(drv_data);
        return;
    }

    /* Delay if requested at end of transfer */
    if (drv_data->state == RUNNING_STATE) {
        dev_dbg(drv_data->dev, "transfer: still running ...\n");
        previous = list_entry(transfer->transfer_list.prev,
                      struct spi_transfer, transfer_list);
        if (previous->delay_usecs)
            udelay(previous->delay_usecs);
    }

    if (transfer->len == 0) {
        /* Move to next transfer of this msg */
        drv_data->state = bfin_sport_spi_next_transfer(drv_data);
        /* Schedule next transfer tasklet */
        tasklet_schedule(&drv_data->pump_transfers);
    }

    if (transfer->tx_buf != NULL) {
        drv_data->tx = (void *)transfer->tx_buf;
        drv_data->tx_end = drv_data->tx + transfer->len;
        dev_dbg(drv_data->dev, "tx_buf is %p, tx_end is %p\n",
            transfer->tx_buf, drv_data->tx_end);
    } else
        drv_data->tx = NULL;

    if (transfer->rx_buf != NULL) {
        full_duplex = transfer->tx_buf != NULL;
        drv_data->rx = transfer->rx_buf;
        drv_data->rx_end = drv_data->rx + transfer->len;
        dev_dbg(drv_data->dev, "rx_buf is %p, rx_end is %p\n",
            transfer->rx_buf, drv_data->rx_end);
    } else
        drv_data->rx = NULL;

    drv_data->cs_change = transfer->cs_change;

    /* Bits per word setup */
    bits_per_word = transfer->bits_per_word ? :
        message->spi->bits_per_word ? : 8;
    if (bits_per_word % 16 == 0)
        drv_data->ops = &bfin_sport_transfer_ops_u16;
    else
        drv_data->ops = &bfin_sport_transfer_ops_u8;
    bfin_write(&drv_data->regs->tcr2, bits_per_word - 1);
    bfin_write(&drv_data->regs->tfsdiv, bits_per_word - 1);
    bfin_write(&drv_data->regs->rcr2, bits_per_word - 1);

    drv_data->state = RUNNING_STATE;

    if (drv_data->cs_change)
        bfin_sport_spi_cs_active(chip);

    dev_dbg(drv_data->dev,
        "now pumping a transfer: width is %d, len is %d\n",
        bits_per_word, transfer->len);

    /* PIO mode write then read */
    dev_dbg(drv_data->dev, "doing IO transfer\n");

    bfin_sport_spi_enable(drv_data);
    if (full_duplex) {
        /* full duplex mode */
        BUG_ON((drv_data->tx_end - drv_data->tx) !=
               (drv_data->rx_end - drv_data->rx));
        drv_data->ops->duplex(drv_data);

        if (drv_data->tx != drv_data->tx_end)
            tranf_success = 0;
    } else if (drv_data->tx != NULL) {
        /* write only half duplex */

        drv_data->ops->write(drv_data);

        if (drv_data->tx != drv_data->tx_end)
            tranf_success = 0;
    } else if (drv_data->rx != NULL) {
        /* read only half duplex */

        drv_data->ops->read(drv_data);
        if (drv_data->rx != drv_data->rx_end)
            tranf_success = 0;
    }
    bfin_sport_spi_disable(drv_data);

    if (!tranf_success) {
        dev_dbg(drv_data->dev, "IO write error!\n");
        drv_data->state = ERROR_STATE;
    } else {
        /* Update total byte transferred */
        message->actual_length += transfer->len;
        /* Move to next transfer of this msg */
        drv_data->state = bfin_sport_spi_next_transfer(drv_data);
        if (drv_data->cs_change)
            bfin_sport_spi_cs_deactive(chip);
    }

    /* Schedule next transfer tasklet */
    tasklet_schedule(&drv_data->pump_transfers);
}

/* pop a msg from queue and kick off real transfer */
static void
bfin_sport_spi_pump_messages(struct work_struct *work)
{
    struct bfin_sport_spi_master_data *drv_data;
    unsigned long flags;
    struct spi_message *next_msg;

    drv_data = container_of(work, struct bfin_sport_spi_master_data, pump_messages);

    /* Lock queue and check for queue work */
    spin_lock_irqsave(&drv_data->lock, flags);
    if (list_empty(&drv_data->queue) || !drv_data->run) {
        /* pumper kicked off but no work to do */
        drv_data->busy = 0;
        spin_unlock_irqrestore(&drv_data->lock, flags);
        return;
    }

    /* Make sure we are not already running a message */
    if (drv_data->cur_msg) {
        spin_unlock_irqrestore(&drv_data->lock, flags);
        return;
    }

    /* Extract head of queue */
    next_msg = list_entry(drv_data->queue.next,
        struct spi_message, queue);

    drv_data->cur_msg = next_msg;

    /* Setup the SSP using the per chip configuration */
    drv_data->cur_chip = spi_get_ctldata(drv_data->cur_msg->spi);

    list_del_init(&drv_data->cur_msg->queue);

    /* Initialize message state */
    drv_data->cur_msg->state = START_STATE;
    drv_data->cur_transfer = list_entry(drv_data->cur_msg->transfers.next,
                        struct spi_transfer, transfer_list);
    bfin_sport_spi_restore_state(drv_data);
    dev_dbg(drv_data->dev, "got a message to pump, "
        "state is set to: baud %d, cs_gpio %i, ctl 0x%x\n",
        drv_data->cur_chip->baud, drv_data->cur_chip->cs_gpio,
        drv_data->cur_chip->ctl_reg);

    dev_dbg(drv_data->dev,
        "the first transfer len is %d\n",
        drv_data->cur_transfer->len);

    /* Mark as busy and launch transfers */
    tasklet_schedule(&drv_data->pump_transfers);

    drv_data->busy = 1;
    spin_unlock_irqrestore(&drv_data->lock, flags);
}

/*
 * got a msg to transfer, queue it in drv_data->queue.
 * And kick off message pumper
 */
static int
bfin_sport_spi_transfer(struct spi_device *spi, struct spi_message *msg)
{
    struct bfin_sport_spi_master_data *drv_data = spi_master_get_devdata(spi->master);
    unsigned long flags;

    spin_lock_irqsave(&drv_data->lock, flags);

    if (!drv_data->run) {
        spin_unlock_irqrestore(&drv_data->lock, flags);
        return -ESHUTDOWN;
    }

    msg->actual_length = 0;
    msg->status = -EINPROGRESS;
    msg->state = START_STATE;

    dev_dbg(&spi->dev, "adding an msg in transfer()\n");
    list_add_tail(&msg->queue, &drv_data->queue);

    if (drv_data->run && !drv_data->busy)
        queue_work(drv_data->workqueue, &drv_data->pump_messages);

    spin_unlock_irqrestore(&drv_data->lock, flags);

    return 0;
}

/* Called every time common spi devices change state */
static int
bfin_sport_spi_setup(struct spi_device *spi)
{
    struct bfin_sport_spi_slave_data *chip, *first = NULL;
    int ret;

    /* Only alloc (or use chip_info) on first setup */
    chip = spi_get_ctldata(spi);
    if (chip == NULL) {
        struct bfin5xx_spi_chip *chip_info;

        chip = first = kzalloc(sizeof(*chip), GFP_KERNEL);
        if (!chip)
            return -ENOMEM;

        /* platform chip_info isn't required */
        chip_info = spi->controller_data;
        if (chip_info) {
            /*
             * DITFS and TDTYPE are only thing we don't set, but
             * they probably shouldn't be changed by people.
             */
            if (chip_info->ctl_reg || chip_info->enable_dma) {
                ret = -EINVAL;
                dev_err(&spi->dev, "don't set ctl_reg/enable_dma fields");
                goto error;
            }
            chip->cs_chg_udelay = chip_info->cs_chg_udelay;
            chip->idle_tx_val = chip_info->idle_tx_val;
        }
    }

    if (spi->bits_per_word % 8) {
        dev_err(&spi->dev, "%d bits_per_word is not supported\n",
                spi->bits_per_word);
        ret = -EINVAL;
        goto error;
    }

    /* translate common spi framework into our register
     * following configure contents are same for tx and rx.
     */

    if (spi->mode & SPI_CPHA)
        chip->ctl_reg &= ~TCKFE;
    else
        chip->ctl_reg |= TCKFE;

    if (spi->mode & SPI_LSB_FIRST)
        chip->ctl_reg |= TLSBIT;
    else
        chip->ctl_reg &= ~TLSBIT;

    /* Sport in master mode */
    chip->ctl_reg |= ITCLK | ITFS | TFSR | LATFS | LTFS;

    chip->baud = bfin_sport_hz_to_spi_baud(spi->max_speed_hz);

    chip->cs_gpio = spi->chip_select;
    ret = gpio_request(chip->cs_gpio, spi->modalias);
    if (ret)
        goto error;

    dev_dbg(&spi->dev, "setup spi chip %s, width is %d\n",
            spi->modalias, spi->bits_per_word);
    dev_dbg(&spi->dev, "ctl_reg is 0x%x, GPIO is %i\n",
            chip->ctl_reg, spi->chip_select);

    spi_set_ctldata(spi, chip);

    bfin_sport_spi_cs_deactive(chip);

    return ret;

 error:
    kfree(first);
    return ret;
}

/*
 * callback for spi framework.
 * clean driver specific data
 */
static void
bfin_sport_spi_cleanup(struct spi_device *spi)
{
    struct bfin_sport_spi_slave_data *chip = spi_get_ctldata(spi);

    if (!chip)
        return;

    gpio_free(chip->cs_gpio);

    kfree(chip);
}

static int
bfin_sport_spi_init_queue(struct bfin_sport_spi_master_data *drv_data)
{
    INIT_LIST_HEAD(&drv_data->queue);
    spin_lock_init(&drv_data->lock);

    drv_data->run = false;
    drv_data->busy = 0;

    /* init transfer tasklet */
    tasklet_init(&drv_data->pump_transfers,
             bfin_sport_spi_pump_transfers, (unsigned long)drv_data);

    /* init messages workqueue */
    INIT_WORK(&drv_data->pump_messages, bfin_sport_spi_pump_messages);
    drv_data->workqueue =
        create_singlethread_workqueue(dev_name(drv_data->master->dev.parent));
    if (drv_data->workqueue == NULL)
        return -EBUSY;

    return 0;
}

static int
bfin_sport_spi_start_queue(struct bfin_sport_spi_master_data *drv_data)
{
    unsigned long flags;

    spin_lock_irqsave(&drv_data->lock, flags);

    if (drv_data->run || drv_data->busy) {
        spin_unlock_irqrestore(&drv_data->lock, flags);
        return -EBUSY;
    }

    drv_data->run = true;
    drv_data->cur_msg = NULL;
    drv_data->cur_transfer = NULL;
    drv_data->cur_chip = NULL;
    spin_unlock_irqrestore(&drv_data->lock, flags);

    queue_work(drv_data->workqueue, &drv_data->pump_messages);

    return 0;
}

static inline int
bfin_sport_spi_stop_queue(struct bfin_sport_spi_master_data *drv_data)
{
    unsigned long flags;
    unsigned limit = 500;
    int status = 0;

    spin_lock_irqsave(&drv_data->lock, flags);

    /*
     * This is a bit lame, but is optimized for the common execution path.
     * A wait_queue on the drv_data->busy could be used, but then the common
     * execution path (pump_messages) would be required to call wake_up or
     * friends on every SPI message. Do this instead
     */
    drv_data->run = false;
    while (!list_empty(&drv_data->queue) && drv_data->busy && limit--) {
        spin_unlock_irqrestore(&drv_data->lock, flags);
        msleep(10);
        spin_lock_irqsave(&drv_data->lock, flags);
    }

    if (!list_empty(&drv_data->queue) || drv_data->busy)
        status = -EBUSY;

    spin_unlock_irqrestore(&drv_data->lock, flags);

    return status;
}

static inline int
bfin_sport_spi_destroy_queue(struct bfin_sport_spi_master_data *drv_data)
{
    int status;

    status = bfin_sport_spi_stop_queue(drv_data);
    if (status)
        return status;

    destroy_workqueue(drv_data->workqueue);

    return 0;
}

static int __devinit
bfin_sport_spi_probe(struct platform_device *pdev)
{
    struct device *dev = &pdev->dev;
    struct bfin5xx_spi_master *platform_info;
    struct spi_master *master;
    struct resource *res, *ires;
    struct bfin_sport_spi_master_data *drv_data;
    int status;

    platform_info = dev->platform_data;

    /* Allocate master with space for drv_data */
    master = spi_alloc_master(dev, sizeof(*master) + 16);
    if (!master) {
        dev_err(dev, "cannot alloc spi_master\n");
        return -ENOMEM;
    }

    drv_data = spi_master_get_devdata(master);
    drv_data->master = master;
    drv_data->dev = dev;
    drv_data->pin_req = platform_info->pin_req;

    master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
    master->bus_num = pdev->id;
    master->num_chipselect = platform_info->num_chipselect;
    master->cleanup = bfin_sport_spi_cleanup;
    master->setup = bfin_sport_spi_setup;
    master->transfer = bfin_sport_spi_transfer;

    /* Find and map our resources */
    res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
    if (res == NULL) {
        dev_err(dev, "cannot get IORESOURCE_MEM\n");
        status = -ENOENT;
        goto out_error_get_res;
    }

    drv_data->regs = ioremap(res->start, resource_size(res));
    if (drv_data->regs == NULL) {
        dev_err(dev, "cannot map registers\n");
        status = -ENXIO;
        goto out_error_ioremap;
    }

    ires = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
    if (!ires) {
        dev_err(dev, "cannot get IORESOURCE_IRQ\n");
        status = -ENODEV;
        goto out_error_get_ires;
    }
    drv_data->err_irq = ires->start;

    /* Initial and start queue */
    status = bfin_sport_spi_init_queue(drv_data);
    if (status) {
        dev_err(dev, "problem initializing queue\n");
        goto out_error_queue_alloc;
    }

    status = bfin_sport_spi_start_queue(drv_data);
    if (status) {
        dev_err(dev, "problem starting queue\n");
        goto out_error_queue_alloc;
    }

    status = request_irq(drv_data->err_irq, sport_err_handler,
        0, "sport_spi_err", drv_data);
    if (status) {
        dev_err(dev, "unable to request sport err irq\n");
        goto out_error_irq;
    }

    status = peripheral_request_list(drv_data->pin_req, DRV_NAME);
    if (status) {
        dev_err(dev, "requesting peripherals failed\n");
        goto out_error_peripheral;
    }

    /* Register with the SPI framework */
    platform_set_drvdata(pdev, drv_data);
    status = spi_register_master(master);
    if (status) {
        dev_err(dev, "problem registering spi master\n");
        goto out_error_master;
    }

    dev_info(dev, "%s, regs_base@%p\n", DRV_DESC, drv_data->regs);
    return 0;

 out_error_master:
    peripheral_free_list(drv_data->pin_req);
 out_error_peripheral:
    free_irq(drv_data->err_irq, drv_data);
 out_error_irq:
 out_error_queue_alloc:
    bfin_sport_spi_destroy_queue(drv_data);
 out_error_get_ires:
    iounmap(drv_data->regs);
 out_error_ioremap:
 out_error_get_res:
    spi_master_put(master);

    return status;
}

/* stop hardware and remove the driver */
static int __devexit
bfin_sport_spi_remove(struct platform_device *pdev)
{
    struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
    int status = 0;

    if (!drv_data)
        return 0;

    /* Remove the queue */
    status = bfin_sport_spi_destroy_queue(drv_data);
    if (status)
        return status;

    /* Disable the SSP at the peripheral and SOC level */
    bfin_sport_spi_disable(drv_data);

    /* Disconnect from the SPI framework */
    spi_unregister_master(drv_data->master);

    peripheral_free_list(drv_data->pin_req);

    /* Prevent double remove */
    platform_set_drvdata(pdev, NULL);

    return 0;
}

#ifdef CONFIG_PM
static int
bfin_sport_spi_suspend(struct platform_device *pdev, pm_message_t state)
{
    struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
    int status;

    status = bfin_sport_spi_stop_queue(drv_data);
    if (status)
        return status;

    /* stop hardware */
    bfin_sport_spi_disable(drv_data);

    return status;
}

static int
bfin_sport_spi_resume(struct platform_device *pdev)
{
    struct bfin_sport_spi_master_data *drv_data = platform_get_drvdata(pdev);
    int status;

    /* Enable the SPI interface */
    bfin_sport_spi_enable(drv_data);

    /* Start the queue running */
    status = bfin_sport_spi_start_queue(drv_data);
    if (status)
        dev_err(drv_data->dev, "problem resuming queue\n");

    return status;
}
#else
# define bfin_sport_spi_suspend NULL
# define bfin_sport_spi_resume  NULL
#endif

static struct platform_driver bfin_sport_spi_driver = {
    .driver = {
        .name = DRV_NAME,
        .owner = THIS_MODULE,
    },
    .probe   = bfin_sport_spi_probe,
    .remove  = __devexit_p(bfin_sport_spi_remove),
    .suspend = bfin_sport_spi_suspend,
    .resume  = bfin_sport_spi_resume,
};
module_platform_driver(bfin_sport_spi_driver);