/*
 * Freescale CPM1/CPM2 I2C interface.
 * Copyright (c) 1999 Dan Malek (dmalek@jlc.net).
 *
 * moved into proper i2c interface;
 * Brad Parker (brad@heeltoe.com)
 *
 * Parts from dbox2_i2c.c (cvs.tuxbox.org)
 * (C) 2000-2001 Felix Domke (tmbinc@gmx.net), Gillem (htoa@gmx.net)
 *
 * (C) 2007 Montavista Software, Inc.
 * Vitaly Bordug <vitb@kernel.crashing.org>
 *
 * Converted to of_platform_device. Renamed to i2c-cpm.c.
 * (C) 2007,2008 Jochen Friedrich <jochen@scram.de>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/stddef.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/of_i2c.h>
#include <sysdev/fsl_soc.h>
#include <asm/cpm.h>

/* Try to define this if you have an older CPU (earlier than rev D4) */
/* However, better use a GPIO based bitbang driver in this case :/   */
#undef  I2C_CHIP_ERRATA

#define CPM_MAX_READ    513
#define CPM_MAXBD       4

#define I2C_EB                  (0x10) /* Big endian mode */
#define I2C_EB_CPM2             (0x30) /* Big endian mode, memory snoop */

#define DPRAM_BASE              ((u8 __iomem __force *)cpm_muram_addr(0))

/* I2C parameter RAM. */
struct i2c_ram {
        ushort  rbase;          /* Rx Buffer descriptor base address */
        ushort  tbase;          /* Tx Buffer descriptor base address */
        u_char  rfcr;           /* Rx function code */
        u_char  tfcr;           /* Tx function code */
        ushort  mrblr;          /* Max receive buffer length */
        uint    rstate;         /* Internal */
        uint    rdp;            /* Internal */
        ushort  rbptr;          /* Rx Buffer descriptor pointer */
        ushort  rbc;            /* Internal */
        uint    rxtmp;          /* Internal */
        uint    tstate;         /* Internal */
        uint    tdp;            /* Internal */
        ushort  tbptr;          /* Tx Buffer descriptor pointer */
        ushort  tbc;            /* Internal */
        uint    txtmp;          /* Internal */
        char    res1[4];        /* Reserved */
        ushort  rpbase;         /* Relocation pointer */
        char    res2[2];        /* Reserved */
};

#define I2COM_START     0x80
#define I2COM_MASTER    0x01
#define I2CER_TXE       0x10
#define I2CER_BUSY      0x04
#define I2CER_TXB       0x02
#define I2CER_RXB       0x01
#define I2MOD_EN        0x01

/* I2C Registers */
struct i2c_reg {
        u8      i2mod;
        u8      res1[3];
        u8      i2add;
        u8      res2[3];
        u8      i2brg;
        u8      res3[3];
        u8      i2com;
        u8      res4[3];
        u8      i2cer;
        u8      res5[3];
        u8      i2cmr;
};

struct cpm_i2c {
        char *base;
        struct platform_device *ofdev;
        struct i2c_adapter adap;
        uint dp_addr;
        int version; /* CPM1=1, CPM2=2 */
        int irq;
        int cp_command;
        int freq;
        struct i2c_reg __iomem *i2c_reg;
        struct i2c_ram __iomem *i2c_ram;
        u16 i2c_addr;
        wait_queue_head_t i2c_wait;
        cbd_t __iomem *tbase;
        cbd_t __iomem *rbase;
        u_char *txbuf[CPM_MAXBD];
        u_char *rxbuf[CPM_MAXBD];
        u32 txdma[CPM_MAXBD];
        u32 rxdma[CPM_MAXBD];
};

static irqreturn_t cpm_i2c_interrupt(int irq, void *dev_id)
{
        struct cpm_i2c *cpm;
        struct i2c_reg __iomem *i2c_reg;
        struct i2c_adapter *adap = dev_id;
        int i;

        cpm = i2c_get_adapdata(dev_id);
        i2c_reg = cpm->i2c_reg;

        /* Clear interrupt. */
        i = in_8(&i2c_reg->i2cer);
        out_8(&i2c_reg->i2cer, i);

        dev_dbg(&adap->dev, "Interrupt: %x\n", i);

        wake_up(&cpm->i2c_wait);

        return i ? IRQ_HANDLED : IRQ_NONE;
}

static void cpm_reset_i2c_params(struct cpm_i2c *cpm)
{
        struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;

        /* Set up the I2C parameters in the parameter ram. */
        out_be16(&i2c_ram->tbase, (u8 __iomem *)cpm->tbase - DPRAM_BASE);
        out_be16(&i2c_ram->rbase, (u8 __iomem *)cpm->rbase - DPRAM_BASE);

        if (cpm->version == 1) {
                out_8(&i2c_ram->tfcr, I2C_EB);
                out_8(&i2c_ram->rfcr, I2C_EB);
        } else {
                out_8(&i2c_ram->tfcr, I2C_EB_CPM2);
                out_8(&i2c_ram->rfcr, I2C_EB_CPM2);
        }

        out_be16(&i2c_ram->mrblr, CPM_MAX_READ);

        out_be32(&i2c_ram->rstate, 0);
        out_be32(&i2c_ram->rdp, 0);
        out_be16(&i2c_ram->rbptr, 0);
        out_be16(&i2c_ram->rbc, 0);
        out_be32(&i2c_ram->rxtmp, 0);
        out_be32(&i2c_ram->tstate, 0);
        out_be32(&i2c_ram->tdp, 0);
        out_be16(&i2c_ram->tbptr, 0);
        out_be16(&i2c_ram->tbc, 0);
        out_be32(&i2c_ram->txtmp, 0);
}

static void cpm_i2c_force_close(struct i2c_adapter *adap)
{
        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
        struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;

        dev_dbg(&adap->dev, "cpm_i2c_force_close()\n");

        cpm_command(cpm->cp_command, CPM_CR_CLOSE_RX_BD);

        out_8(&i2c_reg->i2cmr, 0x00);   /* Disable all interrupts */
        out_8(&i2c_reg->i2cer, 0xff);
}

static void cpm_i2c_parse_message(struct i2c_adapter *adap,
        struct i2c_msg *pmsg, int num, int tx, int rx)
{
        cbd_t __iomem *tbdf;
        cbd_t __iomem *rbdf;
        u_char addr;
        u_char *tb;
        u_char *rb;
        struct cpm_i2c *cpm = i2c_get_adapdata(adap);

        tbdf = cpm->tbase + tx;
        rbdf = cpm->rbase + rx;

        addr = pmsg->addr << 1;
        if (pmsg->flags & I2C_M_RD)
                addr |= 1;

        tb = cpm->txbuf[tx];
        rb = cpm->rxbuf[rx];

        /* Align read buffer */
        rb = (u_char *) (((ulong) rb + 1) & ~1);

        tb[0] = addr;           /* Device address byte w/rw flag */

        out_be16(&tbdf->cbd_datlen, pmsg->len + 1);
        out_be16(&tbdf->cbd_sc, 0);

        if (!(pmsg->flags & I2C_M_NOSTART))
                setbits16(&tbdf->cbd_sc, BD_I2C_START);

        if (tx + 1 == num)
                setbits16(&tbdf->cbd_sc, BD_SC_LAST | BD_SC_WRAP);

        if (pmsg->flags & I2C_M_RD) {
                /*
                 * To read, we need an empty buffer of the proper length.
                 * All that is used is the first byte for address, the remainder
                 * is just used for timing (and doesn't really have to exist).
                 */

                dev_dbg(&adap->dev, "cpm_i2c_read(abyte=0x%x)\n", addr);

                out_be16(&rbdf->cbd_datlen, 0);
                out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_INTRPT);

                if (rx + 1 == CPM_MAXBD)
                        setbits16(&rbdf->cbd_sc, BD_SC_WRAP);

                eieio();
                setbits16(&tbdf->cbd_sc, BD_SC_READY);
        } else {
                dev_dbg(&adap->dev, "cpm_i2c_write(abyte=0x%x)\n", addr);

                memcpy(tb+1, pmsg->buf, pmsg->len);

                eieio();
                setbits16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_INTRPT);
        }
}

static int cpm_i2c_check_message(struct i2c_adapter *adap,
        struct i2c_msg *pmsg, int tx, int rx)
{
        cbd_t __iomem *tbdf;
        cbd_t __iomem *rbdf;
        u_char *tb;
        u_char *rb;
        struct cpm_i2c *cpm = i2c_get_adapdata(adap);

        tbdf = cpm->tbase + tx;
        rbdf = cpm->rbase + rx;

        tb = cpm->txbuf[tx];
        rb = cpm->rxbuf[rx];

        /* Align read buffer */
        rb = (u_char *) (((uint) rb + 1) & ~1);

        eieio();
        if (pmsg->flags & I2C_M_RD) {
                dev_dbg(&adap->dev, "tx sc 0x%04x, rx sc 0x%04x\n",
                        in_be16(&tbdf->cbd_sc), in_be16(&rbdf->cbd_sc));

                if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
                        dev_dbg(&adap->dev, "I2C read; No ack\n");
                        return -ENXIO;
                }
                if (in_be16(&rbdf->cbd_sc) & BD_SC_EMPTY) {
                        dev_err(&adap->dev,
                                "I2C read; complete but rbuf empty\n");
                        return -EREMOTEIO;
                }
                if (in_be16(&rbdf->cbd_sc) & BD_SC_OV) {
                        dev_err(&adap->dev, "I2C read; Overrun\n");
                        return -EREMOTEIO;
                }
                memcpy(pmsg->buf, rb, pmsg->len);
        } else {
                dev_dbg(&adap->dev, "tx sc %d 0x%04x\n", tx,
                        in_be16(&tbdf->cbd_sc));

                if (in_be16(&tbdf->cbd_sc) & BD_SC_NAK) {
                        dev_dbg(&adap->dev, "I2C write; No ack\n");
                        return -ENXIO;
                }
                if (in_be16(&tbdf->cbd_sc) & BD_SC_UN) {
                        dev_err(&adap->dev, "I2C write; Underrun\n");
                        return -EIO;
                }
                if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) {
                        dev_err(&adap->dev, "I2C write; Collision\n");
                        return -EIO;
                }
        }
        return 0;
}

static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
{
        struct cpm_i2c *cpm = i2c_get_adapdata(adap);
        struct i2c_reg __iomem *i2c_reg = cpm->i2c_reg;
        struct i2c_ram __iomem *i2c_ram = cpm->i2c_ram;
        struct i2c_msg *pmsg;
        int ret, i;
        int tptr;
        int rptr;
        cbd_t __iomem *tbdf;
        cbd_t __iomem *rbdf;

        if (num > CPM_MAXBD)
                return -EINVAL;

        /* Check if we have any oversized READ requests */
        for (i = 0; i < num; i++) {
                pmsg = &msgs[i];
                if (pmsg->len >= CPM_MAX_READ)
                        return -EINVAL;
        }

        /* Reset to use first buffer */
        out_be16(&i2c_ram->rbptr, in_be16(&i2c_ram->rbase));
        out_be16(&i2c_ram->tbptr, in_be16(&i2c_ram->tbase));

        tbdf = cpm->tbase;
        rbdf = cpm->rbase;

        tptr = 0;
        rptr = 0;

        while (tptr < num) {
                pmsg = &msgs[tptr];
                dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr);

                cpm_i2c_parse_message(adap, pmsg, num, tptr, rptr);
                if (pmsg->flags & I2C_M_RD)
                        rptr++;
                tptr++;
        }
        /* Start transfer now */
        /* Enable RX/TX/Error interupts */
        out_8(&i2c_reg->i2cmr, I2CER_TXE | I2CER_TXB | I2CER_RXB);
        out_8(&i2c_reg->i2cer, 0xff);   /* Clear interrupt status */
        /* Chip bug, set enable here */
        setbits8(&i2c_reg->i2mod, I2MOD_EN);    /* Enable */
        /* Begin transmission */
        setbits8(&i2c_reg->i2com, I2COM_START);

        tptr = 0;
        rptr = 0;

        while (tptr < num) {
                /* Check for outstanding messages */
                dev_dbg(&adap->dev, "test ready.\n");
                pmsg = &msgs[tptr];
                if (pmsg->flags & I2C_M_RD)
                        ret = wait_event_timeout(cpm->i2c_wait,
                                (in_be16(&tbdf[tptr].cbd_sc) & BD_SC_NAK) ||
                                !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
                                1 * HZ);
                else
                        ret = wait_event_timeout(cpm->i2c_wait,
                                !(in_be16(&tbdf[tptr].cbd_sc) & BD_SC_READY),
                                1 * HZ);
                if (ret == 0) {
                        ret = -EREMOTEIO;
                        dev_err(&adap->dev, "I2C transfer: timeout\n");
                        goto out_err;
                }
                if (ret > 0) {
                        dev_dbg(&adap->dev, "ready.\n");
                        ret = cpm_i2c_check_message(adap, pmsg, tptr, rptr);
                        tptr++;
                        if (pmsg->flags & I2C_M_RD)
                                rptr++;
                        if (ret)
                                goto out_err;
                }
        }
#ifdef I2C_CHIP_ERRATA
        /*
         * Chip errata, clear enable. This is not needed on rev D4 CPUs.
         * Disabling I2C too early may cause too short stop condition
         */
        udelay(4);
        clrbits8(&i2c_reg->i2mod, I2MOD_EN);
#endif
        return (num);

out_err:
        cpm_i2c_force_close(adap);
#ifdef I2C_CHIP_ERRATA
        /*
         * Chip errata, clear enable. This is not needed on rev D4 CPUs.
         */
        clrbits8(&i2c_reg->i2mod, I2MOD_EN);
#endif
        return ret;
}

static u32 cpm_i2c_func(struct i2c_adapter *adap)
{
        return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
}

/* -----exported algorithm data: -------------------------------------  */

static const struct i2c_algorithm cpm_i2c_algo = {
        .master_xfer = cpm_i2c_xfer,
        .functionality = cpm_i2c_func,
};

static const struct i2c_adapter cpm_ops = {
        .owner          = THIS_MODULE,
        .name           = "i2c-cpm",
        .algo           = &cpm_i2c_algo,
};

static int __devinit cpm_i2c_setup(struct cpm_i2c *cpm)
{
        struct platform_device *ofdev = cpm->ofdev;
        const u32 *data;
        int len, ret, i;
        void __iomem *i2c_base;
        cbd_t __iomem *tbdf;
        cbd_t __iomem *rbdf;
        unsigned char brg;

        dev_dbg(&cpm->ofdev->dev, "cpm_i2c_setup()\n");

        init_waitqueue_head(&cpm->i2c_wait);

        cpm->irq = of_irq_to_resource(ofdev->dev.of_node, 0, NULL);
        if (!cpm->irq)
                return -EINVAL;

        /* Install interrupt handler. */
        ret = request_irq(cpm->irq, cpm_i2c_interrupt, 0, "cpm_i2c",
                          &cpm->adap);
        if (ret)
                return ret;

        /* I2C parameter RAM */
        i2c_base = of_iomap(ofdev->dev.of_node, 1);
        if (i2c_base == NULL) {
                ret = -EINVAL;
                goto out_irq;
        }

        if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm1-i2c")) {

                /* Check for and use a microcode relocation patch. */
                cpm->i2c_ram = i2c_base;
                cpm->i2c_addr = in_be16(&cpm->i2c_ram->rpbase);

                /*
                 * Maybe should use cpm_muram_alloc instead of hardcoding
                 * this in micropatch.c
                 */
                if (cpm->i2c_addr) {
                        cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
                        iounmap(i2c_base);
                }

                cpm->version = 1;

        } else if (of_device_is_compatible(ofdev->dev.of_node, "fsl,cpm2-i2c")) {
                cpm->i2c_addr = cpm_muram_alloc(sizeof(struct i2c_ram), 64);
                cpm->i2c_ram = cpm_muram_addr(cpm->i2c_addr);
                out_be16(i2c_base, cpm->i2c_addr);
                iounmap(i2c_base);

                cpm->version = 2;

        } else {
                iounmap(i2c_base);
                ret = -EINVAL;
                goto out_irq;
        }

        /* I2C control/status registers */
        cpm->i2c_reg = of_iomap(ofdev->dev.of_node, 0);
        if (cpm->i2c_reg == NULL) {
                ret = -EINVAL;
                goto out_ram;
        }

        data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
        if (!data || len != 4) {
                ret = -EINVAL;
                goto out_reg;
        }
        cpm->cp_command = *data;

        data = of_get_property(ofdev->dev.of_node, "linux,i2c-class", &len);
        if (data && len == 4)
                cpm->adap.class = *data;

        data = of_get_property(ofdev->dev.of_node, "clock-frequency", &len);
        if (data && len == 4)
                cpm->freq = *data;
        else
                cpm->freq = 60000; /* use 60kHz i2c clock by default */

        /*
         * Allocate space for CPM_MAXBD transmit and receive buffer
         * descriptors in the DP ram.
         */
        cpm->dp_addr = cpm_muram_alloc(sizeof(cbd_t) * 2 * CPM_MAXBD, 8);
        if (!cpm->dp_addr) {
                ret = -ENOMEM;
                goto out_reg;
        }

        cpm->tbase = cpm_muram_addr(cpm->dp_addr);
        cpm->rbase = cpm_muram_addr(cpm->dp_addr + sizeof(cbd_t) * CPM_MAXBD);

        /* Allocate TX and RX buffers */

        tbdf = cpm->tbase;
        rbdf = cpm->rbase;

        for (i = 0; i < CPM_MAXBD; i++) {
                cpm->rxbuf[i] = dma_alloc_coherent(&cpm->ofdev->dev,
                                                   CPM_MAX_READ + 1,
                                                   &cpm->rxdma[i], GFP_KERNEL);
                if (!cpm->rxbuf[i]) {
                        ret = -ENOMEM;
                        goto out_muram;
                }
                out_be32(&rbdf[i].cbd_bufaddr, ((cpm->rxdma[i] + 1) & ~1));

                cpm->txbuf[i] = (unsigned char *)dma_alloc_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1, &cpm->txdma[i], GFP_KERNEL);
                if (!cpm->txbuf[i]) {
                        ret = -ENOMEM;
                        goto out_muram;
                }
                out_be32(&tbdf[i].cbd_bufaddr, cpm->txdma[i]);
        }

        /* Initialize Tx/Rx parameters. */

        cpm_reset_i2c_params(cpm);

        dev_dbg(&cpm->ofdev->dev, "i2c_ram 0x%p, i2c_addr 0x%04x, freq %d\n",
                cpm->i2c_ram, cpm->i2c_addr, cpm->freq);
        dev_dbg(&cpm->ofdev->dev, "tbase 0x%04x, rbase 0x%04x\n",
                (u8 __iomem *)cpm->tbase - DPRAM_BASE,
                (u8 __iomem *)cpm->rbase - DPRAM_BASE);

        cpm_command(cpm->cp_command, CPM_CR_INIT_TRX);

        /*
         * Select an invalid address. Just make sure we don't use loopback mode
         */
        out_8(&cpm->i2c_reg->i2add, 0x7f << 1);

        /*
         * PDIV is set to 00 in i2mod, so brgclk/32 is used as input to the
         * i2c baud rate generator. This is divided by 2 x (DIV + 3) to get
         * the actual i2c bus frequency.
         */
        brg = get_brgfreq() / (32 * 2 * cpm->freq) - 3;
        out_8(&cpm->i2c_reg->i2brg, brg);

        out_8(&cpm->i2c_reg->i2mod, 0x00);
        out_8(&cpm->i2c_reg->i2com, I2COM_MASTER);      /* Master mode */

        /* Disable interrupts. */
        out_8(&cpm->i2c_reg->i2cmr, 0);
        out_8(&cpm->i2c_reg->i2cer, 0xff);

        return 0;

out_muram:
        for (i = 0; i < CPM_MAXBD; i++) {
                if (cpm->rxbuf[i])
                        dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
                                cpm->rxbuf[i], cpm->rxdma[i]);
                if (cpm->txbuf[i])
                        dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
                                cpm->txbuf[i], cpm->txdma[i]);
        }
        cpm_muram_free(cpm->dp_addr);
out_reg:
        iounmap(cpm->i2c_reg);
out_ram:
        if ((cpm->version == 1) && (!cpm->i2c_addr))
                iounmap(cpm->i2c_ram);
        if (cpm->version == 2)
                cpm_muram_free(cpm->i2c_addr);
out_irq:
        free_irq(cpm->irq, &cpm->adap);
        return ret;
}

static void cpm_i2c_shutdown(struct cpm_i2c *cpm)
{
        int i;

        /* Shut down I2C. */
        clrbits8(&cpm->i2c_reg->i2mod, I2MOD_EN);

        /* Disable interrupts */
        out_8(&cpm->i2c_reg->i2cmr, 0);
        out_8(&cpm->i2c_reg->i2cer, 0xff);

        free_irq(cpm->irq, &cpm->adap);

        /* Free all memory */
        for (i = 0; i < CPM_MAXBD; i++) {
                dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
                        cpm->rxbuf[i], cpm->rxdma[i]);
                dma_free_coherent(&cpm->ofdev->dev, CPM_MAX_READ + 1,
                        cpm->txbuf[i], cpm->txdma[i]);
        }

        cpm_muram_free(cpm->dp_addr);
        iounmap(cpm->i2c_reg);

        if ((cpm->version == 1) && (!cpm->i2c_addr))
                iounmap(cpm->i2c_ram);
        if (cpm->version == 2)
                cpm_muram_free(cpm->i2c_addr);
}

static int __devinit cpm_i2c_probe(struct platform_device *ofdev,
                         const struct of_device_id *match)
{
        int result, len;
        struct cpm_i2c *cpm;
        const u32 *data;

        cpm = kzalloc(sizeof(struct cpm_i2c), GFP_KERNEL);
        if (!cpm)
                return -ENOMEM;

        cpm->ofdev = ofdev;

        dev_set_drvdata(&ofdev->dev, cpm);

        cpm->adap = cpm_ops;
        i2c_set_adapdata(&cpm->adap, cpm);
        cpm->adap.dev.parent = &ofdev->dev;
        cpm->adap.dev.of_node = of_node_get(ofdev->dev.of_node);

        result = cpm_i2c_setup(cpm);
        if (result) {
                dev_err(&ofdev->dev, "Unable to init hardware\n");
                goto out_free;
        }

        /* register new adapter to i2c module... */

        data = of_get_property(ofdev->dev.of_node, "linux,i2c-index", &len);
        if (data && len == 4) {
                cpm->adap.nr = *data;
                result = i2c_add_numbered_adapter(&cpm->adap);
        } else
                result = i2c_add_adapter(&cpm->adap);

        if (result < 0) {
                dev_err(&ofdev->dev, "Unable to register with I2C\n");
                goto out_shut;
        }

        dev_dbg(&ofdev->dev, "hw routines for %s registered.\n",
                cpm->adap.name);

        /*
         * register OF I2C devices
         */
        of_i2c_register_devices(&cpm->adap);

        return 0;
out_shut:
        cpm_i2c_shutdown(cpm);
out_free:
        dev_set_drvdata(&ofdev->dev, NULL);
        kfree(cpm);

        return result;
}

static int __devexit cpm_i2c_remove(struct platform_device *ofdev)
{
        struct cpm_i2c *cpm = dev_get_drvdata(&ofdev->dev);

        i2c_del_adapter(&cpm->adap);

        cpm_i2c_shutdown(cpm);

        dev_set_drvdata(&ofdev->dev, NULL);
        kfree(cpm);

        return 0;
}

static const struct of_device_id cpm_i2c_match[] = {
        {
                .compatible = "fsl,cpm1-i2c",
        },
        {
                .compatible = "fsl,cpm2-i2c",
        },
        {},
};

MODULE_DEVICE_TABLE(of, cpm_i2c_match);

static struct of_platform_driver cpm_i2c_driver = {
        .probe          = cpm_i2c_probe,
        .remove         = __devexit_p(cpm_i2c_remove),
        .driver = {
                .name = "fsl-i2c-cpm",
                .owner = THIS_MODULE,
                .of_match_table = cpm_i2c_match,
        },
};

static int __init cpm_i2c_init(void)
{
        return of_register_platform_driver(&cpm_i2c_driver);
}

static void __exit cpm_i2c_exit(void)
{
        of_unregister_platform_driver(&cpm_i2c_driver);
}

module_init(cpm_i2c_init);
module_exit(cpm_i2c_exit);

MODULE_AUTHOR("Jochen Friedrich <jochen@scram.de>");
MODULE_DESCRIPTION("I2C-Bus adapter routines for CPM boards");
MODULE_LICENSE("GPL");