From: Philippe De Muyter on
Hello all,

On Mon, Jan 25, 2010 at 11:56:30AM -0800, Steven King wrote:
> > >
> > > Add support for the I2C controller used on Freescale/Motorola Coldfire
> > > MCUs.
> > >
> > > Signed-off-by: Steven King <sfking(a)fdwdc.com>

What's the status of this ?

I need to use i2c for a coldfire uclinux project (with a mcf5484) and I
now have 3 different coldfire i2c drivers, none of which is in mainline.

i2c-mcf.c (from uClinux-dist-20090618, but not in http://git.kernel.org/?p=linux/kernel/git/gerg/m68knommu.git;a=summary)
i2c-mcf548x.c (from ltib-m5475evb-20080808, found as "Linux BSP for MCF5484LITE, MCF5475/85EVB" at http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MCF548X&fpsp=1&tab=Design_Tools_Tab)
i2c-coldfire.c (from http://lkml.org/lkml/2010/1/11/165)

I like to work with mainline sources to be be able to contribute to and benefit
from collective work.

Which one has the best chances to be put in mainline ?

Best regards

Philippe
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From: Lennart Sorensen on
On Fri, Mar 12, 2010 at 12:04:53PM +0100, Philippe De Muyter wrote:
> Hello all,
>
> On Mon, Jan 25, 2010 at 11:56:30AM -0800, Steven King wrote:
> > > >
> > > > Add support for the I2C controller used on Freescale/Motorola Coldfire
> > > > MCUs.
> > > >
> > > > Signed-off-by: Steven King <sfking(a)fdwdc.com>
>
> What's the status of this ?
>
> I need to use i2c for a coldfire uclinux project (with a mcf5484) and I
> now have 3 different coldfire i2c drivers, none of which is in mainline.
>
> i2c-mcf.c (from uClinux-dist-20090618, but not in http://git.kernel.org/?p=linux/kernel/git/gerg/m68knommu.git;a=summary)

It seems I use that one based on the filename.

> i2c-mcf548x.c (from ltib-m5475evb-20080808, found as "Linux BSP for MCF5484LITE, MCF5475/85EVB" at http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MCF548X&fpsp=1&tab=Design_Tools_Tab)
> i2c-coldfire.c (from http://lkml.org/lkml/2010/1/11/165)
>
> I like to work with mainline sources to be be able to contribute to and benefit
> from collective work.
>
> Which one has the best chances to be put in mainline ?

No idea.

I am using this one on a 5271:

http://www.bitshrine.org/gpp/0006-I2C-device-driver.patch
http://www.bitshrine.org/gpp/0043-I2C-bug-fix.patch

No problems so far.

This is the patch that I use on top of
git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k.git

diff -urN build-2.6.29-1-m68k-uclinux-target1-nfs/arch/m68k/include/asm/m527xsim.h build-2.6.29-1-m68k-uclinux-target1/arch/m68k/include/asm/m527xsim.h
--- build-2.6.29-1-m68k-uclinux-target1-nfs/arch/m68k/include/asm/m527xsim.h 2010-02-12 11:49:19.000000000 -0500
+++ build-2.6.29-1-m68k-uclinux-target1/arch/m68k/include/asm/m527xsim.h 2010-02-12 12:10:59.000000000 -0500
@@ -248,5 +248,44 @@
#define MCF_RCR_SWRESET 0x80 /* Software reset bit */
#define MCF_RCR_FRCSTOUT 0x40 /* Force external reset */

+/*********************************************************************
+*
+* I2C Module (I2C) (Stolen from m5301xsim.h)
+*
+*********************************************************************/
+/* Register read/write macros */
+#ifdef CONFIG_M5271
+#define MCF_I2C_I2ADR (volatile unsigned char *)(MCF_MBAR + 0x300)
+#define MCF_I2C_I2FDR (volatile unsigned char *)(MCF_MBAR + 0x304)
+#define MCF_I2C_I2CR (volatile unsigned char *)(MCF_MBAR + 0x308)
+#define MCF_I2C_I2SR (volatile unsigned char *)(MCF_MBAR + 0x30C)
+#define MCF_I2C_I2DR (volatile unsigned char *)(MCF_MBAR + 0x310)
+
+/* Bit definitions and macros for I2AR */
+#define MCF_I2C_I2AR_ADR(x) (((x)&0x7F)<<1)
+
+/* Bit definitions and macros for I2FDR */
+#define MCF_I2C_I2FDR_IC(x) (((x)&0x3F))
+
+/* Bit definitions and macros for I2CR */
+#define MCF_I2C_I2CR_RSTA (0x04)
+#define MCF_I2C_I2CR_TXAK (0x08)
+#define MCF_I2C_I2CR_MTX (0x10)
+#define MCF_I2C_I2CR_MSTA (0x20)
+#define MCF_I2C_I2CR_IIEN (0x40)
+#define MCF_I2C_I2CR_IEN (0x80)
+
+/* Bit definitions and macros for I2SR */
+#define MCF_I2C_I2SR_RXAK (0x01)
+#define MCF_I2C_I2SR_IIF (0x02)
+#define MCF_I2C_I2SR_SRW (0x04)
+#define MCF_I2C_I2SR_IAL (0x10)
+#define MCF_I2C_I2SR_IBB (0x20)
+#define MCF_I2C_I2SR_IAAS (0x40)
+#define MCF_I2C_I2SR_ICF (0x80)
+
+/* Bit definitions and macros for I2DR */
+#define MCF_I2C_I2DR_DATA(x) (x)
+#endif /* I2C Module for CONFIG_M5271 */
/****************************************************************************/
#endif /* m527xsim_h */
diff -urN build-2.6.29-1-m68k-uclinux-target1-nfs/drivers/i2c/busses/Kconfig build-2.6.29-1-m68k-uclinux-target1/drivers/i2c/busses/Kconfig
--- build-2.6.29-1-m68k-uclinux-target1-nfs/drivers/i2c/busses/Kconfig 2010-02-12 11:49:21.000000000 -0500
+++ build-2.6.29-1-m68k-uclinux-target1/drivers/i2c/busses/Kconfig 2010-02-12 12:10:59.000000000 -0500
@@ -417,6 +417,16 @@
This driver is deprecated and will be dropped soon. Use i2c-gpio
instead.

+config I2C_MCF
+ tristate "MCF ColdFire"
+ depends on I2C && EXPERIMENTAL
+ help
+ If you say yes to this option, support will be included for the
+ I2C on most ColdFire CPUs
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-mcf.
+
config I2C_MPC
tristate "MPC107/824x/85xx/52xx/86xx"
depends on PPC32
diff -urN build-2.6.29-1-m68k-uclinux-target1-nfs/drivers/i2c/busses/Makefile build-2.6.29-1-m68k-uclinux-target1/drivers/i2c/busses/Makefile
--- build-2.6.29-1-m68k-uclinux-target1-nfs/drivers/i2c/busses/Makefile 2010-02-12 11:49:21.000000000 -0500
+++ build-2.6.29-1-m68k-uclinux-target1/drivers/i2c/busses/Makefile 2010-02-12 12:10:59.000000000 -0500
@@ -71,6 +71,7 @@
obj-$(CONFIG_I2C_STUB) += i2c-stub.o
obj-$(CONFIG_SCx200_ACB) += scx200_acb.o
obj-$(CONFIG_SCx200_I2C) += scx200_i2c.o
+obj-$(CONFIG_I2C_MCF) += i2c-mcf.o

ifeq ($(CONFIG_I2C_DEBUG_BUS),y)
EXTRA_CFLAGS += -DDEBUG
diff -urN build-2.6.29-1-m68k-uclinux-target1-nfs/drivers/i2c/busses/i2c-mcf.c build-2.6.29-1-m68k-uclinux-target1/drivers/i2c/busses/i2c-mcf.c
--- build-2.6.29-1-m68k-uclinux-target1-nfs/drivers/i2c/busses/i2c-mcf.c 1969-12-31 19:00:00.000000000 -0500
+++ build-2.6.29-1-m68k-uclinux-target1/drivers/i2c/busses/i2c-mcf.c 2010-02-12 12:10:59.000000000 -0500
@@ -0,0 +1,601 @@
+/*
+ i2c-mcf.c - Part of lm_sensors, Linux kernel modules for hardware monitoring
+
+ Copyright (c) 2005, Derek CL Cheung <derek.cheung(a)sympatico.ca>
+ <http://www3.sympatico.ca/derek.cheung>
+
+ Copyright (c) 2006, emlix Sebastian Hess <sh(a)emlix.com>
+
+ Yaroslav Vinogradov <yaroslav.vinogradov(a)freescale.com>
+ Copyright Freescale Semiconductor, Inc 2006-2007
+
+ 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.
+
+ Changes:
+ v0.1 26 March 2005
+ Initial Release - developed on uClinux with 2.6.9 kernel
+
+ v0.2 29 May 2006
+ Modified to be more generic and added support for
+ i2c_master_xfer
+
+ v0.3 12 Sep 2007
+ Added support for more Coldfire systems, removed c++ comments
+
+ This I2C adaptor supports the ColdFire 5282 CPU I2C module. Since most Coldfire
+ CPUs' I2C module use the same register set (e.g., MCF5249), the code is very
+ portable and re-usable to other Coldfire CPUs.
+
+ The transmission frequency is set at about 100KHz for the 5282Lite CPU board with
+ 8MHz crystal. If the CPU board uses different system clock frequency, you should
+ change the following line:
+ static int __init i2c_coldfire_init(void)
+ {
+ .........
+ // Set transmission frequency 0x15 = ~100kHz
+ *MCF_I2C_I2FDR = 0x15;
+ ........
+ }
+
+ Remember to perform a dummy read to set the ColdFire CPU's I2C module for read before
+ reading the actual byte from a device
+
+ The I2C_SM_BUS_BLOCK_DATA function are not yet ready but most lm_senors do not care
+
+*/
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <asm/coldfire.h>
+#include <asm/mcfsim.h>
+#include <asm/types.h>
+#include <linux/platform_device.h>
+#include "i2c-mcf.h"
+
+static struct i2c_algorithm coldfire_algorithm = {
+ .smbus_xfer = coldfire_i2c_access,
+ .master_xfer = coldfire_i2c_master,
+ .functionality = coldfire_func,
+};
+
+static struct i2c_adapter coldfire_adapter = {
+ .owner = THIS_MODULE,
+ .class = I2C_CLASS_HWMON,
+ .algo = &coldfire_algorithm,
+ .name = "ColdFire I2C adapter",
+};
+
+__u16 lastaddr;
+__u16 lastop;
+
+static inline int coldfire_do_first_start(__u16 addr, __u16 flags)
+{
+ int err;
+ /*
+ * Generate a stop and put the I2C module into slave mode
+ */
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_MSTA;
+
+ /*
+ * Generate a new Start signal
+ */
+ err =
+ coldfire_i2c_start(flags & I2C_M_RD ? I2C_SMBUS_READ :
+ I2C_SMBUS_WRITE, addr, FIRST_START);
+ if (err)
+ return err;
+
+ lastaddr = addr;
+ lastop = flags & I2C_M_RD; /* Ensure everything for new start */
+ return 0;
+}
+
+/*
+ * read one byte data from the I2C bus
+ */
+static int coldfire_read_data(u8 * const rxData,
+ const enum I2C_ACK_TYPE ackType)
+{
+
+ int timeout;
+
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_MTX; /* master receive mode */
+
+ if (ackType == NACK)
+ *MCF_I2C_I2CR |= MCF_I2C_I2CR_TXAK; /* generate NA */
+ else
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_TXAK; /* generate ACK */
+
+ /* read data from the I2C bus */
+ *rxData = *MCF_I2C_I2DR;
+
+ /* printk(">>> %s I2DR data is %.2x \n", __FUNCTION__, *rxData); */
+
+ /* wait for data transfer to complete */
+ timeout = 500;
+ while (timeout-- && !(*MCF_I2C_I2SR & MCF_I2C_I2SR_IIF))
+ udelay(1);
+ if (timeout <= 0)
+ printk("%s - I2C IIF never set. Timeout is %d \n", __FUNCTION__,
+ timeout);
+
+ /* reset the interrupt bit */
+ *MCF_I2C_I2SR &= ~MCF_I2C_I2SR_IIF;
+
+ if (timeout <= 0)
+ return -1;
+ else
+ return 0;
+
+};
+
+/*
+ * write one byte data onto the I2C bus
+ */
+static int coldfire_write_data(const u8 txData)
+{
+
+ int timeout;
+
+ timeout = 500;
+
+ *MCF_I2C_I2CR |= MCF_I2C_I2CR_MTX; /* I2C module into TX mode */
+ *MCF_I2C_I2DR = txData; /* send the data */
+
+ /* wait for data transfer to complete */
+ /* rely on the interrupt handling bit */
+ timeout = 500;
+ while (timeout-- && !(*MCF_I2C_I2SR & MCF_I2C_I2SR_IIF))
+ udelay(1);
+ if (timeout <= 0)
+ printk("%s - I2C IIF never set. Timeout is %d \n", __FUNCTION__,
+ timeout);
+
+ /* reset the interrupt bit */
+ *MCF_I2C_I2SR &= ~MCF_I2C_I2SR_IIF;
+#if defined(CONFIG_M532x) || defined(CONFIG_M537x)
+ if (timeout <= 0 || (*MCF_I2C_I2SR & MCF_I2C_I2SR_RXAK))
+#else
+ if (timeout <= 0)
+#endif
+ return -1;
+ else
+ return 0;
+
+};
+
+/*
+ * Generate I2C start or repeat start signal
+ * Combine the 7 bit target_address and the R/W bit and put it onto the I2C bus
+ */
+static int coldfire_i2c_start(const char read_write, const u16 target_address,
+ const enum I2C_START_TYPE start_type)
+{
+
+ int timeout;
+
+ /* printk(">>> %s START TYPE %s \n", __FUNCTION__, start_type == FIRST_START ? "FIRST_START" : "REPEAT_START"); */
+
+ *MCF_I2C_I2CR |= MCF_I2C_I2CR_IEN;
+
+ if (start_type == FIRST_START) {
+ /* Make sure the I2C bus is idle */
+ timeout = 500; /* 500us timeout */
+ while (timeout-- && (*MCF_I2C_I2SR & MCF_I2C_I2SR_IBB))
+ udelay(1);
+ if (timeout <= 0) {
+ printk
+ ("%s - I2C bus always busy in the past 500us timeout is %d \n",
+ __FUNCTION__, timeout);
+ goto check_rc;
+ }
+ /* generate a START and put the I2C module into MASTER TX mode */
+ *MCF_I2C_I2CR |= (MCF_I2C_I2CR_MSTA | MCF_I2C_I2CR_MTX);
+
+ /* wait for bus busy to be set */
+ timeout = 500;
+ while (timeout-- && !(*MCF_I2C_I2SR & MCF_I2C_I2SR_IBB))
+ udelay(1);
+ if (timeout <= 0) {
+ printk
+ ("%s - I2C bus is never busy after START. Timeout is %d \n",
+ __FUNCTION__, timeout);
+ goto check_rc;
+ }
+
+ } else {
+ /* this is repeat START */
+ udelay(500); /* need some delay before repeat start */
+ *MCF_I2C_I2CR |= (MCF_I2C_I2CR_MSTA | MCF_I2C_I2CR_RSTA);
+ }
+
+ /* combine the R/W bit and the 7 bit target address and put it onto the I2C bus */
+ *MCF_I2C_I2DR =
+ ((target_address & 0x7F) << 1) | (read_write ==
+ I2C_SMBUS_WRITE ? 0x00 : 0x01);
+
+ /* wait for bus transfer to complete */
+ /* when one byte transfer is completed, IIF set at the faling edge of the 9th clock */
+ timeout = 500;
+ while (timeout-- && !(*MCF_I2C_I2SR & MCF_I2C_I2SR_IIF))
+ udelay(1);
+ if (timeout <= 0)
+ printk("%s - I2C IIF never set. Timeout is %d \n", __FUNCTION__,
+ timeout);
+
+ check_rc:
+ /* reset the interrupt bit */
+ *MCF_I2C_I2SR &= ~MCF_I2C_I2SR_IIF;
+
+#if defined(CONFIG_M532x) || defined(CONFIG_M537x)
+ if (timeout <= 0 || (*MCF_I2C_I2SR & MCF_I2C_I2SR_RXAK))
+#else
+ if (timeout <= 0)
+#endif
+ return -1;
+ else
+ return 0;
+};
+
+/*
+ * 5282 SMBUS supporting functions
+ */
+
+static s32 coldfire_i2c_access(struct i2c_adapter *adap, u16 addr,
+ unsigned short flags, char read_write,
+ u8 command, int size, union i2c_smbus_data *data)
+{
+ int i, len, rc = 0;
+ u8 rxData, tempRxData[2];
+
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ rc = coldfire_i2c_start(read_write, addr, FIRST_START); /* generate START */
+ break;
+ case I2C_SMBUS_BYTE:
+ rc = coldfire_i2c_start(read_write, addr, FIRST_START);
+ *MCF_I2C_I2CR |= MCF_I2C_I2CR_TXAK; /* generate NA */
+ if (read_write == I2C_SMBUS_WRITE)
+ rc += coldfire_write_data(command);
+ else {
+ coldfire_read_data(&rxData, NACK); /* dummy read */
+ rc += coldfire_read_data(&rxData, NACK);
+ data->byte = rxData;
+ }
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_TXAK; /* reset ACK bit */
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ rc = coldfire_i2c_start(I2C_SMBUS_WRITE, addr, FIRST_START);
+ rc += coldfire_write_data(command);
+ if (read_write == I2C_SMBUS_WRITE)
+ rc += coldfire_write_data(data->byte);
+ else {
+ /* This is SMBus READ Byte Data Request. Perform REPEAT START */
+ rc +=
+ coldfire_i2c_start(I2C_SMBUS_READ, addr,
+ REPEAT_START);
+ coldfire_read_data(&rxData, ACK); /* dummy read */
+ /* Disable Acknowledge, generate STOP after next byte transfer */
+ rc += coldfire_read_data(&rxData, NACK);
+ data->byte = rxData;
+ }
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_TXAK; /* reset to normal ACk */
+ break;
+ case I2C_SMBUS_PROC_CALL:
+ case I2C_SMBUS_WORD_DATA:
+ dev_info(&adap->dev, "size = I2C_SMBUS_WORD_DATA \n");
+ rc = coldfire_i2c_start(I2C_SMBUS_WRITE, addr, FIRST_START);
+ rc += coldfire_write_data(command);
+ if (read_write == I2C_SMBUS_WRITE) {
+ rc += coldfire_write_data(data->word & 0x00FF);
+ rc += coldfire_write_data((data->word & 0x00FF) >> 8);
+ } else {
+ /* This is SMBUS READ WORD request. Peform REPEAT START */
+ rc +=
+ coldfire_i2c_start(I2C_SMBUS_READ, addr,
+ REPEAT_START);
+ coldfire_read_data(&rxData, ACK); /* dummy read */
+ /* Disable Acknowledge, generate STOP after next byte transfer */
+ /* read the MS byte from the device */
+ rc += coldfire_read_data(&rxData, NACK);
+ tempRxData[1] = rxData;
+ /* read the LS byte from the device */
+ rc += coldfire_read_data(&rxData, NACK);
+ tempRxData[0] = rxData;
+ /* the host driver expect little endian convention. Swap the byte */
+ data->word = (tempRxData[0] << 8) | tempRxData[1];
+ }
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_TXAK;
+ break;
+ case I2C_SMBUS_BLOCK_DATA:
+ /* this is not ready yet!!! */
+ break;
+ case I2C_SMBUS_BLOCK_PROC_CALL:
+ {
+ rc = coldfire_i2c_start(I2C_SMBUS_WRITE, addr,
+ FIRST_START);
+ rc += coldfire_write_data(command);
+ if (read_write == I2C_SMBUS_READ) {
+ /* This is SMBUS READ BLOCK request. Peform REPEAT START */
+ rc +=
+ coldfire_i2c_start(I2C_SMBUS_READ, addr,
+ REPEAT_START);
+ coldfire_read_data(&rxData, ACK); /* dummy read */
+ len = data->block[0];
+ if (len < 0)
+ len = 0;
+ if (len > 32)
+ len = 32;
+ for (i = 1; i < len; i++) {
+ /* read byte from the device */
+ rc +=
+ coldfire_read_data(&data->block[i],
+ ACK);
+ }
+ /* read last byte from the device */
+ rc += coldfire_read_data(&data->block[i], NACK);
+ }
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_TXAK;
+ break;
+ }
+ default:
+ printk("Unsupported I2C size \n");
+ rc = -1;
+ break;
+ };
+
+ /* Generate a STOP and put I2C module into slave mode */
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_MSTA;
+
+ /* restore interrupt */
+ *MCF_I2C_I2CR |= MCF_I2C_I2CR_IIEN;
+
+ if (rc < 0)
+ return -1;
+ else
+ return 0;
+};
+
+/*
+ * List the SMBUS functions supported by this I2C adaptor
+ * Also tell the I2C Subsystem that we are able of master_xfer()
+ */
+static u32 coldfire_func(struct i2c_adapter *adapter)
+{
+ return (I2C_FUNC_SMBUS_QUICK |
+ I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SMBUS_PROC_CALL |
+ I2C_FUNC_SMBUS_BYTE_DATA |
+ I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_I2C | I2C_FUNC_SMBUS_BLOCK_DATA);
+};
+
+static int coldfire_i2c_master(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ u8 dummyRead;
+ struct i2c_msg *p;
+ int i, err = 0;
+ int ic = 0;
+
+ lastaddr = 0;
+ lastop = 8;
+
+ /* disable the IRQ, we are doing polling */
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_IIEN;
+
+ dev_dbg(&adap->dev, "Num of actions: %d\n", num);
+
+ for (i = 0; !err && i < num; i++) {
+ p = &msgs[i];
+
+ if (!p->len) {
+ dev_dbg(&adap->dev, "p->len == 0!\n");
+ continue;
+ }
+ /*
+ * Generate a new Start, if the target address differs from the last target,
+ * generate a stop in this case first
+ */
+ if (p->addr != lastaddr) {
+ err = coldfire_do_first_start(p->addr, p->flags);
+ if (err) {
+ dev_dbg(&adap->dev, "First Init failed!\n");
+ break;
+ }
+ }
+
+ else if ((p->flags & I2C_M_RD) != lastop) {
+ /*
+ * If the Operational Mode changed, we need to do this here ...
+ */
+ dev_dbg(&adap->dev,
+ "%s(): Direction changed, was: %d; is now: %d\n",
+ __FUNCTION__, lastop, p->flags & I2C_M_RD);
+
+ /* Last op was an read, now it's write: complete stop and reinit */
+ if (lastop & I2C_M_RD) {
+ dev_dbg(&adap->dev,
+ "%s(): The device is in read state, we must reset!\n",
+ __FUNCTION__);
+ if ((err =
+ coldfire_do_first_start(p->addr,
+ p->flags)))
+ break;
+ } else {
+ dev_dbg(&adap->dev,
+ "%s(): We switchted to read mode\n",
+ __FUNCTION__);
+ if ((err =
+ coldfire_i2c_start((p->
+ flags & I2C_M_RD) ?
+ I2C_SMBUS_READ :
+ I2C_SMBUS_WRITE,
+ p->addr, REPEAT_START)))
+ break;
+ }
+
+ lastop = p->flags & I2C_M_RD; /* Save the last op */
+ }
+
+ if (p->flags & I2C_M_RD) {
+ /*
+ * When ever we get here, a new session was activated, so
+ * read a dummy byte
+ */
+ coldfire_read_data(&dummyRead, ACK);
+ /*
+ * read p->len -1 bytes with ACK to the slave,
+ * read the last byte without the ACK, to inform him about the
+ * stop afterwards
+ */
+ ic = 0;
+ while (!err && (ic < p->len - 1)) {
+ err = coldfire_read_data(p->buf + ic, ACK);
+ ic++;
+ }
+ if (!err)
+ err = coldfire_read_data(p->buf + ic, NACK);
+ dev_dbg(&coldfire_adapter.dev, "read: %2x\n",
+ p->buf[ic]);
+ } else {
+ if (p->len == 2)
+ dev_dbg(&coldfire_adapter.dev,
+ "writing: 0x %2x %2x\n", p->buf[0],
+ p->buf[1]);
+
+ /*
+ * Write data to the slave
+ */
+ for (ic = 0; !err && ic < p->len; ic++) {
+ err = coldfire_write_data(p->buf[ic]);
+ if (err) {
+ dev_dbg(&coldfire_adapter.dev,
+ "Failed to write data\n");
+ }
+ }
+ }
+ }
+
+ /*
+ * Put the device into slave mode to enable the STOP Generation (the RTC needs this)
+ */
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_MSTA;
+
+ *MCF_I2C_I2CR &= ~MCF_I2C_I2CR_TXAK; /* reset the ACK bit */
+
+ /* restore interrupt */
+ *MCF_I2C_I2CR |= MCF_I2C_I2CR_IIEN;
+
+ /* Return the number of messages processed, or the error code. */
+ if (err == 0)
+ err = num;
+ return err;
+}
+
+/*
+ * Initalize the 5282 I2C module
+ * Disable the 5282 I2C interrupt capability. Just use callback
+ */
+
+static int __init i2c_coldfire_init(void)
+{
+ int retval;
+ u8 dummyRead;
+
+#if defined(CONFIG_M532x) || defined(CONFIG_M523x) || defined(CONFIG_M537x)
+ /*
+ * Initialize the GPIOs for I2C
+ */
+ MCF_GPIO_PAR_FECI2C |= (0 | MCF_GPIO_PAR_FECI2C_PAR_SDA(3)
+ | MCF_GPIO_PAR_FECI2C_PAR_SCL(3));
+#elif defined(CONFIG_M5253)
+ {
+ volatile u32 *reg;
+ /* GPIO Bit 41 = SCL0, Bit 42 = SDA0 */
+ reg = (volatile u32 *)(MCF_MBAR2 + MCFSIM2_GPIO1FUNC);
+ *reg &= 0xFFFFF9FF;
+ }
+#elif defined(CONFIG_M5227x)
+ /* Initialize the GPIOs for I2C */
+ MCF_GPIO_PAR_I2C |= (0
+ | MCF_GPIO_PAR_I2C_PAR_SDA_SDA
+ | MCF_GPIO_PAR_I2C_PAR_SCL_SCL);
+#elif defined(CONFIG_M5301x)
+ MCF_GPIO_PAR_FECI2C |= (0
+ | MCF_GPIO_PAR_FECI2C_PAR_SDA_SDA
+ | MCF_GPIO_PAR_FECI2C_PAR_SCL_SCL);
+#else
+ /* Initialize PASP0 and PASP1 to I2C functions, 5282 user guide 26-19 */
+ /* Port AS Pin Assignment Register (PASPAR) */
+ /* PASPA1 = 11 = AS1 pin is I2C SDA */
+ /* PASPA0 = 11 = AS0 pin is I2C SCL */
+ *MCF5282_GPIO_PASPAR |= 0x000F; /* u16 declaration */
+#endif
+
+ /* Set transmission frequency 0x15 = ~100kHz */
+ *MCF_I2C_I2FDR = 0x15;
+
+ /* set the 5282 I2C slave address though we never use it */
+ *MCF_I2C_I2ADR = 0x6A;
+
+ /* Enable I2C module and if IBB is set, do the special initialzation */
+ /* procedures as are documented at the 5282 User Guide page 24-11 */
+ *MCF_I2C_I2CR |= MCF_I2C_I2CR_IEN;
+ if ((*MCF_I2C_I2SR & MCF_I2C_I2SR_IBB) == 1) {
+ printk("%s - do special 5282 I2C init procedures \n",
+ __FUNCTION__);
+ *MCF_I2C_I2CR = 0x00;
+ *MCF_I2C_I2CR = 0xA0;
+ dummyRead = *MCF_I2C_I2DR;
+ *MCF_I2C_I2SR = 0x00;
+ *MCF_I2C_I2CR = 0x00;
+ }
+
+ /* default I2C mode is - slave and receive */
+ *MCF_I2C_I2CR &= ~(MCF_I2C_I2CR_MSTA | MCF_I2C_I2CR_MTX);
+
+ coldfire_adapter.dev.parent = &platform_bus;
+ retval = i2c_add_adapter(&coldfire_adapter);
+
+ if (retval < 0)
+ printk("%s - return code is: %d \n", __FUNCTION__, retval);
+
+ return retval;
+};
+
+/*
+ * I2C module exit function
+ */
+
+static void __exit i2c_coldfire_exit(void)
+{
+ /* disable I2C and Interrupt */
+ *MCF_I2C_I2CR &= ~(MCF_I2C_I2CR_IEN | MCF_I2C_I2CR_IIEN);
+ i2c_del_adapter(&coldfire_adapter);
+
+};
+
+MODULE_AUTHOR("Derek CL Cheung <derek.cheung(a)sympatico.ca>");
+MODULE_DESCRIPTION("MCF5282 I2C adaptor");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_coldfire_init);
+module_exit(i2c_coldfire_exit);
diff -urN build-2.6.29-1-m68k-uclinux-target1-nfs/drivers/i2c/busses/i2c-mcf.h build-2.6.29-1-m68k-uclinux-target1/drivers/i2c/busses/i2c-mcf.h
--- build-2.6.29-1-m68k-uclinux-target1-nfs/drivers/i2c/busses/i2c-mcf.h 1969-12-31 19:00:00.000000000 -0500
+++ build-2.6.29-1-m68k-uclinux-target1/drivers/i2c/busses/i2c-mcf.h 2010-02-12 12:10:59.000000000 -0500
@@ -0,0 +1,52 @@
+/*
+ i2c-mcf5282.h - header file for i2c-mcf5282.c
+
+ Copyright (c) 2005, Derek CL Cheung <derek.cheung(a)sympatico.ca>
+ <http://www3.sympatico.ca/derek.cheung>
+
+ Copyright (c) 2006, emlix and Freescale
+ Sebastian Hess <sh(a)emlix.com>
+ Yaroslav Vinogradov <yaroslav.vinogradov(a)freescale.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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+ Changes:
+ v0.1 26 March 2005
+ Initial Release - developed on uClinux with 2.6.9 kernel
+ v0.2 29 May 2006
+ Modified to be more generic and added support for
+ i2c_master_xfer
+*/
+
+
+#ifndef __I2C_MCF5282_H__
+#define __I2C_MCF5282_H__
+
+enum I2C_START_TYPE { FIRST_START, REPEAT_START };
+enum I2C_ACK_TYPE { ACK, NACK};
+
+/* Function prototypes */
+static u32 coldfire_func(struct i2c_adapter *adapter);
+static s32 coldfire_i2c_access(struct i2c_adapter *adap, u16 address,
+ unsigned short flags, char read_write,
+ u8 command, int size, union i2c_smbus_data *data);
+static int coldfire_write_data(const u8 data);
+static int coldfire_i2c_start(const char read_write, const u16 target_address, const enum I2C_START_TYPE i2c_start);
+static int coldfire_read_data(u8 * const rxData, const enum I2C_ACK_TYPE ackType);
+static int coldfire_i2c_master(struct i2c_adapter *adap,struct i2c_msg *msgs, int num);
+void dumpReg(char *, u16 addr, u8 data);
+
+/********************************************************************/
+#endif /* __I2C_MCF5282_H__ */

I think that __I2C_MCF5282_H__ should be __I2C_MCF_H__ instead, but well
what can you do.

--
Len Sorensen
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