spi: Add Freescale/Motorola Coldfire QSPI driver

Add support for the QSPI controller found some on Freescale/Motorola
Coldfire MCUs.

Full duplex, active high cs, spi modes 0-3 and word sizes 8-16 bits are
supported.  The hardware drives the MISO, MOSI and SCLK lines, but the chip
selects are managed via GPIO and must be configured by the board code.

The QSPI controller has an 80 byte buffer which allows us to transfer up to 16
words at a time.  For transfers longer than 16 words, we split the buffer in
half so we can update in one half while the controller is operating on the
other half.  Interrupt latencies then ultimately limits our sustained thru-put
to something less than half the maximum speed supported by the part.

Signed-off-by: Steven King <sfking@fdwdc.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 640 insertions, 0 deletions

diff --git a/drivers/spi/coldfire_qspi.c b/drivers/spi/coldfire_qspi.c
new file mode 100644
index 000000000000..59be3efe0636
--- /dev/null
+++ b/drivers/spi/coldfire_qspi.c
@@ -0,0 +1,640 @@
+/*
+ * Freescale/Motorola Coldfire Queued SPI driver
+ *
+ * Copyright 2010 Steven King <sfking@fdwdc.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
+ *
+*/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/spi/spi.h>
+
+#include <asm/coldfire.h>
+#include <asm/mcfqspi.h>
+
+#define DRIVER_NAME "mcfqspi"
+
+#define MCFQSPI_BUSCLK                  (MCF_BUSCLK / 2)
+
+#define MCFQSPI_QMR                     0x00
+#define         MCFQSPI_QMR_MSTR        0x8000
+#define         MCFQSPI_QMR_CPOL        0x0200
+#define         MCFQSPI_QMR_CPHA        0x0100
+#define MCFQSPI_QDLYR                   0x04
+#define         MCFQSPI_QDLYR_SPE       0x8000
+#define MCFQSPI_QWR                     0x08
+#define         MCFQSPI_QWR_HALT        0x8000
+#define         MCFQSPI_QWR_WREN        0x4000
+#define         MCFQSPI_QWR_CSIV        0x1000
+#define MCFQSPI_QIR                     0x0C
+#define         MCFQSPI_QIR_WCEFB       0x8000
+#define         MCFQSPI_QIR_ABRTB       0x4000
+#define         MCFQSPI_QIR_ABRTL       0x1000
+#define         MCFQSPI_QIR_WCEFE       0x0800
+#define         MCFQSPI_QIR_ABRTE       0x0400
+#define         MCFQSPI_QIR_SPIFE       0x0100
+#define         MCFQSPI_QIR_WCEF        0x0008
+#define         MCFQSPI_QIR_ABRT        0x0004
+#define         MCFQSPI_QIR_SPIF        0x0001
+#define MCFQSPI_QAR                     0x010
+#define         MCFQSPI_QAR_TXBUF       0x00
+#define         MCFQSPI_QAR_RXBUF       0x10
+#define         MCFQSPI_QAR_CMDBUF      0x20
+#define MCFQSPI_QDR                     0x014
+#define MCFQSPI_QCR                     0x014
+#define         MCFQSPI_QCR_CONT        0x8000
+#define         MCFQSPI_QCR_BITSE       0x4000
+#define         MCFQSPI_QCR_DT          0x2000
+
+struct mcfqspi {
+        void __iomem *iobase;
+        int irq;
+        struct clk *clk;
+        struct mcfqspi_cs_control *cs_control;
+
+        wait_queue_head_t waitq;
+
+        struct work_struct work;
+        struct workqueue_struct *workq;
+        spinlock_t lock;
+        struct list_head msgq;
+};
+
+static void mcfqspi_wr_qmr(struct mcfqspi *mcfqspi, u16 val)
+{
+        writew(val, mcfqspi->iobase + MCFQSPI_QMR);
+}
+
+static void mcfqspi_wr_qdlyr(struct mcfqspi *mcfqspi, u16 val)
+{
+        writew(val, mcfqspi->iobase + MCFQSPI_QDLYR);
+}
+
+static u16 mcfqspi_rd_qdlyr(struct mcfqspi *mcfqspi)
+{
+        return readw(mcfqspi->iobase + MCFQSPI_QDLYR);
+}
+
+static void mcfqspi_wr_qwr(struct mcfqspi *mcfqspi, u16 val)
+{
+        writew(val, mcfqspi->iobase + MCFQSPI_QWR);
+}
+
+static void mcfqspi_wr_qir(struct mcfqspi *mcfqspi, u16 val)
+{
+        writew(val, mcfqspi->iobase + MCFQSPI_QIR);
+}
+
+static void mcfqspi_wr_qar(struct mcfqspi *mcfqspi, u16 val)
+{
+        writew(val, mcfqspi->iobase + MCFQSPI_QAR);
+}
+
+static void mcfqspi_wr_qdr(struct mcfqspi *mcfqspi, u16 val)
+{
+        writew(val, mcfqspi->iobase + MCFQSPI_QDR);
+}
+
+static u16 mcfqspi_rd_qdr(struct mcfqspi *mcfqspi)
+{
+        return readw(mcfqspi->iobase + MCFQSPI_QDR);
+}
+
+static void mcfqspi_cs_select(struct mcfqspi *mcfqspi, u8 chip_select,
+                            bool cs_high)
+{
+        mcfqspi->cs_control->select(mcfqspi->cs_control, chip_select, cs_high);
+}
+
+static void mcfqspi_cs_deselect(struct mcfqspi *mcfqspi, u8 chip_select,
+                                bool cs_high)
+{
+        mcfqspi->cs_control->deselect(mcfqspi->cs_control, chip_select, cs_high);
+}
+
+static int mcfqspi_cs_setup(struct mcfqspi *mcfqspi)
+{
+        return (mcfqspi->cs_control && mcfqspi->cs_control->setup) ?
+                mcfqspi->cs_control->setup(mcfqspi->cs_control) : 0;
+}
+
+static void mcfqspi_cs_teardown(struct mcfqspi *mcfqspi)
+{
+        if (mcfqspi->cs_control && mcfqspi->cs_control->teardown)
+                mcfqspi->cs_control->teardown(mcfqspi->cs_control);
+}
+
+static u8 mcfqspi_qmr_baud(u32 speed_hz)
+{
+        return clamp((MCFQSPI_BUSCLK + speed_hz - 1) / speed_hz, 2u, 255u);
+}
+
+static bool mcfqspi_qdlyr_spe(struct mcfqspi *mcfqspi)
+{
+        return mcfqspi_rd_qdlyr(mcfqspi) & MCFQSPI_QDLYR_SPE;
+}
+
+static irqreturn_t mcfqspi_irq_handler(int this_irq, void *dev_id)
+{
+        struct mcfqspi *mcfqspi = dev_id;
+
+        /* clear interrupt */
+        mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE | MCFQSPI_QIR_SPIF);
+        wake_up(&mcfqspi->waitq);
+
+        return IRQ_HANDLED;
+}
+
+static void mcfqspi_transfer_msg8(struct mcfqspi *mcfqspi, unsigned count,
+                                  const u8 *txbuf, u8 *rxbuf)
+{
+        unsigned i, n, offset = 0;
+
+        n = min(count, 16u);
+
+        mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
+        for (i = 0; i < n; ++i)
+                mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
+
+        mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
+        if (txbuf)
+                for (i = 0; i < n; ++i)
+                        mcfqspi_wr_qdr(mcfqspi, *txbuf++);
+        else
+                for (i = 0; i < count; ++i)
+                        mcfqspi_wr_qdr(mcfqspi, 0);
+
+        count -= n;
+        if (count) {
+                u16 qwr = 0xf08;
+                mcfqspi_wr_qwr(mcfqspi, 0x700);
+                mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
+
+                do {
+                        wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
+                        mcfqspi_wr_qwr(mcfqspi, qwr);
+                        mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
+                        if (rxbuf) {
+                                mcfqspi_wr_qar(mcfqspi,
+                                               MCFQSPI_QAR_RXBUF + offset);
+                                for (i = 0; i < 8; ++i)
+                                        *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
+                        }
+                        n = min(count, 8u);
+                        if (txbuf) {
+                                mcfqspi_wr_qar(mcfqspi,
+                                               MCFQSPI_QAR_TXBUF + offset);
+                                for (i = 0; i < n; ++i)
+                                        mcfqspi_wr_qdr(mcfqspi, *txbuf++);
+                        }
+                        qwr = (offset ? 0x808 : 0) + ((n - 1) << 8);
+                        offset ^= 8;
+                        count -= n;
+                } while (count);
+                wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
+                mcfqspi_wr_qwr(mcfqspi, qwr);
+                mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
+                if (rxbuf) {
+                        mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
+                        for (i = 0; i < 8; ++i)
+                                *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
+                        offset ^= 8;
+                }
+        } else {
+                mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
+                mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
+        }
+        wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
+        if (rxbuf) {
+                mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
+                for (i = 0; i < n; ++i)
+                        *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
+        }
+}
+
+static void mcfqspi_transfer_msg16(struct mcfqspi *mcfqspi, unsigned count,
+                                   const u16 *txbuf, u16 *rxbuf)
+{
+        unsigned i, n, offset = 0;
+
+        n = min(count, 16u);
+
+        mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_CMDBUF);
+        for (i = 0; i < n; ++i)
+                mcfqspi_wr_qdr(mcfqspi, MCFQSPI_QCR_BITSE);
+
+        mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_TXBUF);
+        if (txbuf)
+                for (i = 0; i < n; ++i)
+                        mcfqspi_wr_qdr(mcfqspi, *txbuf++);
+        else
+                for (i = 0; i < count; ++i)
+                        mcfqspi_wr_qdr(mcfqspi, 0);
+
+        count -= n;
+        if (count) {
+                u16 qwr = 0xf08;
+                mcfqspi_wr_qwr(mcfqspi, 0x700);
+                mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
+
+                do {
+                        wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
+                        mcfqspi_wr_qwr(mcfqspi, qwr);
+                        mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
+                        if (rxbuf) {
+                                mcfqspi_wr_qar(mcfqspi,
+                                               MCFQSPI_QAR_RXBUF + offset);
+                                for (i = 0; i < 8; ++i)
+                                        *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
+                        }
+                        n = min(count, 8u);
+                        if (txbuf) {
+                                mcfqspi_wr_qar(mcfqspi,
+                                               MCFQSPI_QAR_TXBUF + offset);
+                                for (i = 0; i < n; ++i)
+                                        mcfqspi_wr_qdr(mcfqspi, *txbuf++);
+                        }
+                        qwr = (offset ? 0x808 : 0x000) + ((n - 1) << 8);
+                        offset ^= 8;
+                        count -= n;
+                } while (count);
+                wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
+                mcfqspi_wr_qwr(mcfqspi, qwr);
+                mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
+                if (rxbuf) {
+                        mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
+                        for (i = 0; i < 8; ++i)
+                                *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
+                        offset ^= 8;
+                }
+        } else {
+                mcfqspi_wr_qwr(mcfqspi, (n - 1) << 8);
+                mcfqspi_wr_qdlyr(mcfqspi, MCFQSPI_QDLYR_SPE);
+        }
+        wait_event(mcfqspi->waitq, !mcfqspi_qdlyr_spe(mcfqspi));
+        if (rxbuf) {
+                mcfqspi_wr_qar(mcfqspi, MCFQSPI_QAR_RXBUF + offset);
+                for (i = 0; i < n; ++i)
+                        *rxbuf++ = mcfqspi_rd_qdr(mcfqspi);
+        }
+}
+
+static void mcfqspi_work(struct work_struct *work)
+{
+        struct mcfqspi *mcfqspi = container_of(work, struct mcfqspi, work);
+        unsigned long flags;
+
+        spin_lock_irqsave(&mcfqspi->lock, flags);
+        while (!list_empty(&mcfqspi->msgq)) {
+                struct spi_message *msg;
+                struct spi_device *spi;
+                struct spi_transfer *xfer;
+                int status = 0;
+
+                msg = container_of(mcfqspi->msgq.next, struct spi_message,
+                                   queue);
+
+                list_del_init(&mcfqspi->msgq);
+                spin_unlock_irqrestore(&mcfqspi->lock, flags);
+
+                spi = msg->spi;
+
+                list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+                        bool cs_high = spi->mode & SPI_CS_HIGH;
+                        u16 qmr = MCFQSPI_QMR_MSTR;
+
+                        if (xfer->bits_per_word)
+                                qmr |= xfer->bits_per_word << 10;
+                        else
+                                qmr |= spi->bits_per_word << 10;
+                        if (spi->mode & SPI_CPHA)
+                                qmr |= MCFQSPI_QMR_CPHA;
+                        if (spi->mode & SPI_CPOL)
+                                qmr |= MCFQSPI_QMR_CPOL;
+                        if (xfer->speed_hz)
+                                qmr |= mcfqspi_qmr_baud(xfer->speed_hz);
+                        else
+                                qmr |= mcfqspi_qmr_baud(spi->max_speed_hz);
+                        mcfqspi_wr_qmr(mcfqspi, qmr);
+
+                        mcfqspi_cs_select(mcfqspi, spi->chip_select, cs_high);
+
+                        mcfqspi_wr_qir(mcfqspi, MCFQSPI_QIR_SPIFE);
+                        if ((xfer->bits_per_word ? xfer->bits_per_word :
+                                                spi->bits_per_word) == 8)
+                                mcfqspi_transfer_msg8(mcfqspi, xfer->len,
+                                                      xfer->tx_buf,
+                                                      xfer->rx_buf);
+                        else
+                                mcfqspi_transfer_msg16(mcfqspi, xfer->len / 2,
+                                                       xfer->tx_buf,
+                                                       xfer->rx_buf);
+                        mcfqspi_wr_qir(mcfqspi, 0);
+
+                        if (xfer->delay_usecs)
+                                udelay(xfer->delay_usecs);
+                        if (xfer->cs_change) {
+                                if (!list_is_last(&xfer->transfer_list,
+                                                  &msg->transfers))
+                                        mcfqspi_cs_deselect(mcfqspi,
+                                                            spi->chip_select,
+                                                            cs_high);
+                        } else {
+                                if (list_is_last(&xfer->transfer_list,
+                                                 &msg->transfers))
+                                        mcfqspi_cs_deselect(mcfqspi,
+                                                            spi->chip_select,
+                                                            cs_high);
+                        }
+                        msg->actual_length += xfer->len;
+                }
+                msg->status = status;
+                msg->complete(msg->context);
+
+                spin_lock_irqsave(&mcfqspi->lock, flags);
+        }
+        spin_unlock_irqrestore(&mcfqspi->lock, flags);
+}
+
+static int mcfqspi_transfer(struct spi_device *spi, struct spi_message *msg)
+{
+        struct mcfqspi *mcfqspi;
+        struct spi_transfer *xfer;
+        unsigned long flags;
+
+        mcfqspi = spi_master_get_devdata(spi->master);
+
+        list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+                if (xfer->bits_per_word && ((xfer->bits_per_word < 8)
+                                        || (xfer->bits_per_word > 16))) {
+                        dev_dbg(&spi->dev,
+                                "%d bits per word is not supported\n",
+                                xfer->bits_per_word);
+                        goto fail;
+                }
+                if (xfer->speed_hz) {
+                        u32 real_speed = MCFQSPI_BUSCLK /
+                                mcfqspi_qmr_baud(xfer->speed_hz);
+                        if (real_speed != xfer->speed_hz)
+                                dev_dbg(&spi->dev,
+                                        "using speed %d instead of %d\n",
+                                        real_speed, xfer->speed_hz);
+                }
+        }
+        msg->status = -EINPROGRESS;
+        msg->actual_length = 0;
+
+        spin_lock_irqsave(&mcfqspi->lock, flags);
+        list_add_tail(&msg->queue, &mcfqspi->msgq);
+        queue_work(mcfqspi->workq, &mcfqspi->work);
+        spin_unlock_irqrestore(&mcfqspi->lock, flags);
+
+        return 0;
+fail:
+        msg->status = -EINVAL;
+        return -EINVAL;
+}
+
+static int mcfqspi_setup(struct spi_device *spi)
+{
+        if ((spi->bits_per_word < 8) || (spi->bits_per_word > 16)) {
+                dev_dbg(&spi->dev, "%d bits per word is not supported\n",
+                        spi->bits_per_word);
+                return -EINVAL;
+        }
+        if (spi->chip_select >= spi->master->num_chipselect) {
+                dev_dbg(&spi->dev, "%d chip select is out of range\n",
+                        spi->chip_select);
+                return -EINVAL;
+        }
+
+        mcfqspi_cs_deselect(spi_master_get_devdata(spi->master),
+                            spi->chip_select, spi->mode & SPI_CS_HIGH);
+
+        dev_dbg(&spi->dev,
+                        "bits per word %d, chip select %d, speed %d KHz\n",
+                        spi->bits_per_word, spi->chip_select,
+                        (MCFQSPI_BUSCLK / mcfqspi_qmr_baud(spi->max_speed_hz))
+                        / 1000);
+
+        return 0;
+}
+
+static int __devinit mcfqspi_probe(struct platform_device *pdev)
+{
+        struct spi_master *master;
+        struct mcfqspi *mcfqspi;
+        struct resource *res;
+        struct mcfqspi_platform_data *pdata;
+        int status;
+
+        master = spi_alloc_master(&pdev->dev, sizeof(*mcfqspi));
+        if (master == NULL) {
+                dev_dbg(&pdev->dev, "spi_alloc_master failed\n");
+                return -ENOMEM;
+        }
+
+        mcfqspi = spi_master_get_devdata(master);
+
+        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        if (!res) {
+                dev_dbg(&pdev->dev, "platform_get_resource failed\n");
+                status = -ENXIO;
+                goto fail0;
+        }
+
+        if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
+                dev_dbg(&pdev->dev, "request_mem_region failed\n");
+                status = -EBUSY;
+                goto fail0;
+        }
+
+        mcfqspi->iobase = ioremap(res->start, resource_size(res));
+        if (!mcfqspi->iobase) {
+                dev_dbg(&pdev->dev, "ioremap failed\n");
+                status = -ENOMEM;
+                goto fail1;
+        }
+
+        mcfqspi->irq = platform_get_irq(pdev, 0);
+        if (mcfqspi->irq < 0) {
+                dev_dbg(&pdev->dev, "platform_get_irq failed\n");
+                status = -ENXIO;
+                goto fail2;
+        }
+
+        status = request_irq(mcfqspi->irq, mcfqspi_irq_handler, IRQF_DISABLED,
+                             pdev->name, mcfqspi);
+        if (status) {
+                dev_dbg(&pdev->dev, "request_irq failed\n");
+                goto fail2;
+        }
+
+        mcfqspi->clk = clk_get(&pdev->dev, "qspi_clk");
+        if (IS_ERR(mcfqspi->clk)) {
+                dev_dbg(&pdev->dev, "clk_get failed\n");
+                status = PTR_ERR(mcfqspi->clk);
+                goto fail3;
+        }
+        clk_enable(mcfqspi->clk);
+
+        mcfqspi->workq = create_singlethread_workqueue(dev_name(master->dev.parent));
+        if (!mcfqspi->workq) {
+                dev_dbg(&pdev->dev, "create_workqueue failed\n");
+                status = -ENOMEM;
+                goto fail4;
+        }
+        INIT_WORK(&mcfqspi->work, mcfqspi_work);
+        spin_lock_init(&mcfqspi->lock);
+        INIT_LIST_HEAD(&mcfqspi->msgq);
+        init_waitqueue_head(&mcfqspi->waitq);
+
+        pdata = pdev->dev.platform_data;
+        if (!pdata) {
+                dev_dbg(&pdev->dev, "platform data is missing\n");
+                goto fail5;
+        }
+        master->bus_num = pdata->bus_num;
+        master->num_chipselect = pdata->num_chipselect;
+
+        mcfqspi->cs_control = pdata->cs_control;
+        status = mcfqspi_cs_setup(mcfqspi);
+        if (status) {
+                dev_dbg(&pdev->dev, "error initializing cs_control\n");
+                goto fail5;
+        }
+
+        master->mode_bits = SPI_CS_HIGH | SPI_CPOL | SPI_CPHA;
+        master->setup = mcfqspi_setup;
+        master->transfer = mcfqspi_transfer;
+
+        platform_set_drvdata(pdev, master);
+
+        status = spi_register_master(master);
+        if (status) {
+                dev_dbg(&pdev->dev, "spi_register_master failed\n");
+                goto fail6;
+        }
+        dev_info(&pdev->dev, "Coldfire QSPI bus driver\n");
+
+        return 0;
+
+fail6:
+        mcfqspi_cs_teardown(mcfqspi);
+fail5:
+        destroy_workqueue(mcfqspi->workq);
+fail4:
+        clk_disable(mcfqspi->clk);
+        clk_put(mcfqspi->clk);
+fail3:
+        free_irq(mcfqspi->irq, mcfqspi);
+fail2:
+        iounmap(mcfqspi->iobase);
+fail1:
+        release_mem_region(res->start, resource_size(res));
+fail0:
+        spi_master_put(master);
+
+        dev_dbg(&pdev->dev, "Coldfire QSPI probe failed\n");
+
+        return status;
+}
+
+static int __devexit mcfqspi_remove(struct platform_device *pdev)
+{
+        struct spi_master *master = platform_get_drvdata(pdev);
+        struct mcfqspi *mcfqspi = spi_master_get_devdata(master);
+        struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+        /* disable the hardware (set the baud rate to 0) */
+        mcfqspi_wr_qmr(mcfqspi, MCFQSPI_QMR_MSTR);
+
+        platform_set_drvdata(pdev, NULL);
+        mcfqspi_cs_teardown(mcfqspi);
+        destroy_workqueue(mcfqspi->workq);
+        clk_disable(mcfqspi->clk);
+        clk_put(mcfqspi->clk);
+        free_irq(mcfqspi->irq, mcfqspi);
+        iounmap(mcfqspi->iobase);
+        release_mem_region(res->start, resource_size(res));
+        spi_unregister_master(master);
+        spi_master_put(master);
+
+        return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int mcfqspi_suspend(struct device *dev)
+{
+        struct mcfqspi *mcfqspi = platform_get_drvdata(to_platform_device(dev));
+
+        clk_disable(mcfqspi->clk);
+
+        return 0;
+}
+
+static int mcfqspi_resume(struct device *dev)
+{
+        struct mcfqspi *mcfqspi = platform_get_drvdata(to_platform_device(dev));
+
+        clk_enable(mcfqspi->clk);
+
+        return 0;
+}
+
+static struct dev_pm_ops mcfqspi_dev_pm_ops = {
+        .suspend        = mcfqspi_suspend,
+        .resume         = mcfqspi_resume,
+};
+
+#define MCFQSPI_DEV_PM_OPS      (&mcfqspi_dev_pm_ops)
+#else
+#define MCFQSPI_DEV_PM_OPS      NULL
+#endif
+
+static struct platform_driver mcfqspi_driver = {
+        .driver.name    = DRIVER_NAME,
+        .driver.owner   = THIS_MODULE,
+        .driver.pm      = MCFQSPI_DEV_PM_OPS,
+        .remove         = __devexit_p(mcfqspi_remove),
+};
+
+static int __init mcfqspi_init(void)
+{
+        return platform_driver_probe(&mcfqspi_driver, mcfqspi_probe);
+}
+module_init(mcfqspi_init);
+
+static void __exit mcfqspi_exit(void)
+{
+        platform_driver_unregister(&mcfqspi_driver);
+}
+module_exit(mcfqspi_exit);
+
+MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
+MODULE_DESCRIPTION("Coldfire QSPI Controller Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRIVER_NAME);