]> err.no Git - linux-2.6/commitdiff
i2c: Add support for I2C bus on Freescale CPM1/CPM2 controllers
authorJochen Friedrich <jochen@scram.de>
Mon, 14 Jul 2008 20:38:27 +0000 (22:38 +0200)
committerJean Delvare <khali@mahadeva.delvare>
Mon, 14 Jul 2008 20:38:27 +0000 (22:38 +0200)
This driver uses the port of 2.4 code from Vitaly Bordug
<vitb@kernel.crashing.org> and the actual algorithm used by the i2c
driver of the DBox code on cvs.tuxboc.org from Felix Domke
(tmbinc@gmx.net) and Gillem (htoa@gmx.net) converted to an
of_platform_driver. Tested on CPM1 (MPC823 on dbox2 hardware) and
CPM2 (MPC8272).

Signed-off-by: Jochen Friedrich <jochen@scram.de>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
drivers/i2c/busses/Kconfig
drivers/i2c/busses/Makefile
drivers/i2c/busses/i2c-cpm.c [new file with mode: 0644]

index 56b6f29c9a3c4db0c7b704d1e1c4d06c704bfeb9..6ee997b2817c450b3ac2fae2bf32e5ad035ff5d3 100644 (file)
@@ -299,6 +299,16 @@ config I2C_BLACKFIN_TWI_CLK_KHZ
        help
          The unit of the TWI clock is kHz.
 
+config I2C_CPM
+       tristate "Freescale CPM1 or CPM2 (MPC8xx/826x)"
+       depends on (CPM1 || CPM2) && OF_I2C
+       help
+         This supports the use of the I2C interface on Freescale
+         processors with CPM1 or CPM2.
+
+         This driver can also be built as a module.  If so, the module
+         will be called i2c-cpm.
+
 config I2C_DAVINCI
        tristate "DaVinci I2C driver"
        depends on ARCH_DAVINCI
index cbeac7dc9bfc9d1d04e473563f153ea8a900d0ae..97dbfa2107fee2fe7b7170219c9aebf552b8381b 100644 (file)
@@ -28,6 +28,7 @@ obj-$(CONFIG_I2C_POWERMAC)    += i2c-powermac.o
 obj-$(CONFIG_I2C_AT91)         += i2c-at91.o
 obj-$(CONFIG_I2C_AU1550)       += i2c-au1550.o
 obj-$(CONFIG_I2C_BLACKFIN_TWI) += i2c-bfin-twi.o
+obj-$(CONFIG_I2C_CPM)          += i2c-cpm.o
 obj-$(CONFIG_I2C_DAVINCI)      += i2c-davinci.o
 obj-$(CONFIG_I2C_GPIO)         += i2c-gpio.o
 obj-$(CONFIG_I2C_IBM_IIC)      += i2c-ibm_iic.o
diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c
new file mode 100644 (file)
index 0000000..1c955a8
--- /dev/null
@@ -0,0 +1,745 @@
+/*
+ * 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 of_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_interruptible(&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_iic_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_BUSY | 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_interruptible_timeout(cpm->i2c_wait,
+                               !(in_be16(&rbdf[rptr].cbd_sc) & BD_SC_EMPTY),
+                               1 * HZ);
+               else
+                       ret = wait_event_interruptible_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,
+       .class          = I2C_CLASS_HWMON,
+};
+
+static int __devinit cpm_i2c_setup(struct cpm_i2c *cpm)
+{
+       struct of_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->node, 0, NULL);
+       if (cpm->irq == NO_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->node, 1);
+       if (i2c_base == NULL) {
+               ret = -EINVAL;
+               goto out_irq;
+       }
+
+       if (of_device_is_compatible(ofdev->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->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->node, 0);
+       if (cpm->i2c_reg == NULL) {
+               ret = -EINVAL;
+               goto out_ram;
+       }
+
+       data = of_get_property(ofdev->node, "fsl,cpm-command", &len);
+       if (!data || len != 4) {
+               ret = -EINVAL;
+               goto out_reg;
+       }
+       cpm->cp_command = *data;
+
+       data = of_get_property(ofdev->node, "linux,i2c-class", &len);
+       if (data && len == 4)
+               cpm->adap.class = *data;
+
+       data = of_get_property(ofdev->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(
+                       NULL, 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(
+                       NULL, 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 %p, i2c_addr 0x%04x\n",
+               cpm->i2c_ram, cpm->i2c_addr);
+       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(NULL, CPM_MAX_READ + 1,
+                               cpm->rxbuf[i], cpm->rxdma[i]);
+               if (cpm->txbuf[i])
+                       dma_free_coherent(NULL, 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(NULL, CPM_MAX_READ + 1,
+                       cpm->rxbuf[i], cpm->rxdma[i]);
+               dma_free_coherent(NULL, 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 of_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;
+
+       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->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_register_i2c_devices(&cpm->adap, ofdev->node);
+
+       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 of_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 = {
+       .match_table    = cpm_i2c_match,
+       .probe          = cpm_i2c_probe,
+       .remove         = __devexit_p(cpm_i2c_remove),
+       .driver         = {
+               .name   = "fsl-i2c-cpm",
+               .owner  = THIS_MODULE,
+       }
+};
+
+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");