Add i2c driver (to etrax) improved by Geert Vancompernolle

SVN-Revision: 14462

5 files changed, 1461 insertions, 0 deletions

diff --git a/target/linux/etrax/files/arch/cris/arch-v10/drivers/etraxi2c.h b/target/linux/etrax/files/arch/cris/arch-v10/drivers/etraxi2c.h
new file mode 100644
index 0000000..9d5c9bf
--- /dev/null
+++ b/target/linux/etrax/files/arch/cris/arch-v10/drivers/etraxi2c.h
@@ -0,0 +1,49 @@
+#ifndef _LINUX_ETRAXI2C_H
+#define _LINUX_ETRAXI2C_H
+
+/* etraxi2c _IOC_TYPE, bits 8 to 15 in ioctl cmd */
+
+#define ETRAXI2C_IOCTYPE 44
+
+/* supported ioctl _IOC_NR's */
+
+/* in write operations, the argument contains both i2c
+ * slave, register and value.
+ */
+
+#define I2C_WRITEARG(slave, reg, value) (((slave) << 16) | ((reg) << 8) | (value))
+#define I2C_READARG(slave, reg) (((slave) << 16) | ((reg) << 8))
+
+#define I2C_ARGSLAVE(arg) ((arg) >> 16)
+#define I2C_ARGREG(arg) (((arg) >> 8) & 0xff)
+#define I2C_ARGVALUE(arg) ((arg) & 0xff)
+
+#define I2C_WRITEREG    0x1   /* write to an I2C register */
+#define I2C_READREG     0x2   /* read from an I2C register */
+
+/*
+EXAMPLE usage:
+
+    i2c_arg = I2C_WRITEARG(STA013_WRITE_ADDR, reg, val);
+    ioctl(fd, _IO(ETRAXI2C_IOCTYPE, I2C_WRITEREG), i2c_arg);
+
+    i2c_arg = I2C_READARG(STA013_READ_ADDR, reg);
+    val = ioctl(fd, _IO(ETRAXI2C_IOCTYPE, I2C_READREG), i2c_arg);
+
+*/
+
+/* Extended part */
+#define I2C_READ        0x4     /* reads from I2C device */
+#define I2C_WRITE       0x3     /* writes to I2C device */
+#define I2C_WRITEREAD   0x5	    /* writes to I2C device where to start reading */
+
+typedef struct _I2C_DATA 
+{
+    unsigned char slave;        /* I2C address (8-bit representation) of slave device */
+    unsigned char wbuf[256];    /* Write buffer (length = 256 bytes) */
+	unsigned int  wlen;         /* Number of bytes to write from wbuf[] */   
+	unsigned char rbuf[256];    /* Read buffer (length = 256 bytes) */
+    unsigned int  rlen;         /* Number of bytes to read into rbuf[] */
+} I2C_DATA;
+
+#endif
diff --git a/target/linux/etrax/files/arch/cris/arch-v10/drivers/i2c_errno.h b/target/linux/etrax/files/arch/cris/arch-v10/drivers/i2c_errno.h
new file mode 100644
index 0000000..ddd99b0
--- /dev/null
+++ b/target/linux/etrax/files/arch/cris/arch-v10/drivers/i2c_errno.h
@@ -0,0 +1,20 @@
+#ifndef _I2C_ERRNO_H
+#define _I2C_ERRNO_H
+
+#define EI2CNOERRORS  0     /* All fine */
+#define EI2CBUSNFREE  1     /* I2C bus not free */
+#define EI2CWADDRESS  2     /* Address write failed */
+#define EI2CRADDRESS  3     /* Address read failed */
+#define EI2CSENDDATA  4     /* Sending data failed */
+#define EI2CRECVDATA  5     /* Receiving data failed */
+#define EI2CSTRTCOND  6     /* Start condition failed */
+#define EI2CRSTACOND  7     /* Repeated start condition failed */
+#define EI2CSTOPCOND  8     /* Stop condition failed */
+#define EI2CNOSNDBYT  9     /* Number of send bytes is 0, while there's a send buffer defined */ 
+#define EI2CNOSNDBUF  10    /* No send buffer defined, while number of send bytes is not 0 */
+#define EI2CNORCVBYT  11    /* Number of receive bytes is 0, while there's a receive buffer defined */
+#define EI2CNORCVBUF  12    /* No receive buffer defined, while number of receive bytes is not 0 */
+#define EI2CNOACKNLD  13    /* No acknowledge received from slave */
+#define EI2CNOMNUMBR  14    /* No MAJOR number received from kernel while registering the device */
+
+#endif /* _I2C_ERRNO_H */
diff --git a/target/linux/etrax/files/arch/cris/arch-v10/drivers/i2c_gvc.c b/target/linux/etrax/files/arch/cris/arch-v10/drivers/i2c_gvc.c
new file mode 100644
index 0000000..d94bc1a
--- /dev/null
+++ b/target/linux/etrax/files/arch/cris/arch-v10/drivers/i2c_gvc.c
@@ -0,0 +1,1316 @@
+/*!***************************************************************************
+*!
+*! FILE NAME  : i2c.c
+*!
+*!
+*! ---------------------------------------------------------------------------
+*!
+*! ( C ) Copyright 1999-2002 Axis Communications AB, LUND, SWEDEN
+*!
+*!***************************************************************************/
+/* $Id: i2c.c,v 1.16 2005/09/29 13:33:35 bjarne Exp $ */
+
+#define DYNAMIC_MAJOR_I2CDEV_NUMBER_ALLOC
+//#undef  DYNAMIC_MAJOR_I2CDEV_NUMBER_ALLOC
+
+/******************** INCLUDE FILES SECTION ****************************/
+
+#include <linux/module.h>
+#include <linux/fs.h>
+
+/**GVC**/
+#ifdef DYNAMIC_MAJOR_I2CDEV_NUMBER_ALLOC
+#include <linux/types.h> /* for dev_t */
+#include <linux/cdev.h>  /* for struct cdev */
+#endif
+/**END GVC**/
+
+#include "etraxi2c.h"
+
+/**GVC**/
+#include "i2c_errno.h"
+/**END GVC**/
+
+#include <asm/io.h>
+#include <asm/delay.h>
+#include <asm/arch/io_interface_mux.h>
+#include <asm/uaccess.h>
+
+#include "i2c_gvc.h"
+
+MODULE_DESCRIPTION( "I2C Device Driver - 1.1" );
+
+/*!*********************************************************************
+ *!History I2C driver Geert Vancompernolle
+ *!---------------------------------------
+ *!
+ *! - v1.0:
+ *!     First official version.
+ *!
+ *! - v1.1:
+ *!     Changes to remove unwanted spikes at ACK/NACK time.
+ *!
+ *!*********************************************************************/
+ 
+MODULE_LICENSE( "GPL" );
+
+/******************            MACRO's            **********************/
+
+#define D( x )
+
+/**GVC**/
+#ifndef DYNAMIC_MAJOR_I2CDEV_NUMBER_ALLOC
+/**END GVC**/
+#define I2C_MAJOR 123  				/* LOCAL/EXPERIMENTAL */
+/**GVC**/
+#endif
+/**END GVC**/
+
+/**GVC**/
+#define WAITONEUS                 1
+/* Following are abbreviations taken from Philips I2C standard */
+/* Values are representing time in us and are rounded to next whole number, if relevant */ 
+#define THDSTA                    4     /* Hold delay time for (repeated) START condition */
+#define TLOW                      5     /* LOW period of the SCL clock */
+#define THDDAT	                  1     /* Hold delay time for DATA: value of 0 is allowed but 1 taken to be sure */
+#define TSUDAT                    1     /* Set-up time for DATA */
+#define THIGH                     4     /* HIGH period of the SCL clock */
+#define TSUSTA                    5     /* Set-up time for a repeated START condition */
+#define TSUSTO                    4     /* Set-up time for STOP condition */
+#define TBUF                      5     /* Bus-free time between STOP and START condition */
+
+#define MAXBUSFREERETRIES         5
+#define MAXRETRIES                3
+#define WRITEADDRESS_MASK         ( 0xFE )
+#define READADDRESS_MASK          ( 0x01 )
+/**END GVC**/
+
+#define SCL_HIGH                  1
+#define SCL_LOW                   0
+#define SDA_HIGH                  1
+#define SDA_LOW                   0
+
+#ifdef CONFIG_ETRAX_I2C_USES_PB_NOT_PB_I2C
+/* Use PB and not PB_I2C */
+#ifndef CONFIG_ETRAX_I2C_DATA_PORT
+#define CONFIG_ETRAX_I2C_DATA_PORT 0
+#endif
+#ifndef CONFIG_ETRAX_I2C_CLK_PORT
+#define CONFIG_ETRAX_I2C_CLK_PORT 1
+#endif
+
+#define SDABIT CONFIG_ETRAX_I2C_DATA_PORT
+#define SCLBIT CONFIG_ETRAX_I2C_CLK_PORT
+#define i2c_enable() 
+#define i2c_disable() 
+
+/* enable or disable output-enable, to select output or input on the i2c bus */
+#define i2c_sda_dir_out() \
+  REG_SHADOW_SET( R_PORT_PB_DIR, port_pb_dir_shadow, SDABIT, 1 )
+#define i2c_sda_dir_in()  \
+  REG_SHADOW_SET( R_PORT_PB_DIR, port_pb_dir_shadow, SDABIT, 0 )
+
+/* control the i2c clock and data signals */
+#define i2c_set_scl( x ) \
+  REG_SHADOW_SET( R_PORT_PB_DATA, port_pb_data_shadow, SCLBIT, x )
+#define i2c_set_sda( x ) \
+  REG_SHADOW_SET( R_PORT_PB_DATA, port_pb_data_shadow, SDABIT, x )
+
+/* read status of SDA bit from the i2c interface */
+#define i2c_sda_is_high() ( ( ( *R_PORT_PB_READ & ( 1 << SDABIT ) ) ) >> SDABIT )
+
+/**GVC**/
+/* read status of SCL bit from the i2c interface */
+#define i2c_scl_is_high() ( ( ( *R_PORT_PB_READ & ( 1 << SCLBIT ) ) ) >> SCLBIT )
+/**END GVC**/
+
+#else
+/* enable or disable the i2c interface */
+#define i2c_enable() *R_PORT_PB_I2C = ( port_pb_i2c_shadow |= IO_MASK( R_PORT_PB_I2C, i2c_en ) )
+#define i2c_disable() *R_PORT_PB_I2C = ( port_pb_i2c_shadow &= ~IO_MASK( R_PORT_PB_I2C, i2c_en ) )
+
+/* enable or disable output-enable, to select output or input on the i2c bus */
+#define i2c_sda_dir_out() \
+	*R_PORT_PB_I2C = ( port_pb_i2c_shadow &= ~IO_MASK( R_PORT_PB_I2C, i2c_oe_ ) ); \
+	REG_SHADOW_SET( R_PORT_PB_DIR, port_pb_dir_shadow, 0, 1 ); 
+#define i2c_sda_dir_in() \
+	*R_PORT_PB_I2C = ( port_pb_i2c_shadow |= IO_MASK( R_PORT_PB_I2C, i2c_oe_ ) ); \
+	REG_SHADOW_SET( R_PORT_PB_DIR, port_pb_dir_shadow, 0, 0 );
+
+/* control the i2c clock and data signals */
+#define i2c_set_scl( x ) \
+	*R_PORT_PB_I2C = ( port_pb_i2c_shadow = ( port_pb_i2c_shadow & \
+       ~IO_MASK( R_PORT_PB_I2C, i2c_set_scl ) ) | IO_FIELD( R_PORT_PB_I2C, i2c_set_scl, ( x ) ) ); \
+       REG_SHADOW_SET( R_PORT_PB_DATA, port_pb_data_shadow, 1, x );
+
+#define i2c_set_sda( x ) \
+	*R_PORT_PB_I2C = ( port_pb_i2c_shadow = ( port_pb_i2c_shadow & \
+	   ~IO_MASK( R_PORT_PB_I2C, i2c_d ) ) | IO_FIELD( R_PORT_PB_I2C, i2c_d, ( x ) ) ); \
+	REG_SHADOW_SET( R_PORT_PB_DATA, port_pb_data_shadow, 0, x );
+
+/* read a bit from the i2c interface */
+#define i2c_sda_is_high() ( *R_PORT_PB_READ & 0x1 )
+#endif
+
+/* use the kernels delay routine */
+#define i2c_delay( usecs ) udelay( usecs )
+
+
+/******************           TYPEDEF's           **********************/
+
+
+/****************** STATIC (file scope) VARIABLES **********************/
+static DEFINE_SPINLOCK( i2c_lock ); /* Protect directions etc */
+/**GVC**/
+#ifdef DYNAMIC_MAJOR_I2CDEV_NUMBER_ALLOC
+static const char i2c_name[] = "i2cgvc";
+#else
+static const char i2c_name[] = "i2c";
+#endif
+/**END GVC**/
+
+
+/******************     PROTOTYPING SECTION     *************************/
+static int  i2c_open( struct inode *inode, struct file *filp );
+static int  i2c_release( struct inode *inode, struct file *filp );
+/**GVC**/
+static int  i2c_command( unsigned char  slave
+                       , unsigned char* wbuf
+                       , unsigned char  wlen
+                       , unsigned char* rbuf
+                       , unsigned char  rlen
+                       );
+static int  i2c_bus_free_check( unsigned char maxretries );
+static void i2c_finalise( const char* text, unsigned long irqflags );
+/**END GVC**/
+                           
+
+/************************************************************************/
+/******************         AUXILIARIES         *************************/
+/************************************************************************/
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_open
+ *#
+ *# DESCRIPTION  : opens an I2C device
+ *#
+ *# PARAMETERS   : *inode: reference to inode
+ *#                *filp : reference to file pointer 
+ *#
+ *#---------------------------------------------------------------------------
+ */
+static int i2c_open( struct inode *inode, struct file *filp )
+{
+    return 0;
+}   /* i2c_open */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_release
+ *#
+ *# DESCRIPTION  : Releases the I2C device
+ *#
+ *# PARAMETERS   : *inode: reference to inode
+ *#                *filp : reference to file pointer 
+ *#
+ *#---------------------------------------------------------------------------
+ */
+static int i2c_release( struct inode *inode, struct file *filp )
+{
+    return 0;
+}   /* i2c_release */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_ioctl
+ *#
+ *# DESCRIPTION  : Main device API: ioctl's to write/read 
+ *#                to/from i2c registers
+ *#
+ *# PARAMETERS   : *inode: reference to inode
+ *#                *filp : reference to file pointer 
+ *#                cmd   : command to be executed during the ioctl call 
+ *#                arg   : pointer to a structure with the data??? 
+ *#
+ *# RETURN       : result of the ioctl call
+ *#
+ *#---------------------------------------------------------------------------
+ */
+static int i2c_ioctl( struct inode *inode
+                    , struct file *file
+                    , unsigned int cmd
+                    , unsigned long arg
+                    )
+{
+    /* the acme ioctls */
+    I2C_DATA i2cdata;
+    int RetVal = EI2CNOERRORS;
+    
+    if ( _IOC_TYPE( cmd ) != ETRAXI2C_IOCTYPE ) 
+    {
+        return ( -EINVAL );
+    }
+    
+    switch ( _IOC_NR( cmd ) ) 
+    {
+    case I2C_WRITEREG:
+        /* write to an i2c slave */
+        RetVal = i2c_writereg( I2C_ARGSLAVE( arg )
+                             , I2C_ARGREG( arg )
+                             , I2C_ARGVALUE( arg )
+                             );
+        break;                       
+
+    case I2C_READREG:
+        RetVal = i2c_readreg( I2C_ARGSLAVE( arg ), I2C_ARGREG( arg ) );
+        break;
+    
+/**GVC**/
+    /* New functions added by GVC */    
+    case I2C_READ:
+        copy_from_user( (char*)&i2cdata, (char*)arg, sizeof( I2C_DATA ) );
+        {
+            int RetryCntr = MAXRETRIES;
+            
+            do
+            {
+                RetVal = i2c_command( i2cdata.slave
+                                    , NULL
+                                    , 0 
+                                    , i2cdata.rbuf
+                                    , i2cdata.rlen
+                                    );
+             } while ( ( EI2CNOERRORS != RetVal )
+                     &&( --RetryCntr )
+                     );
+        }
+        copy_to_user( (char*)arg, (char*)&i2cdata, sizeof( I2C_DATA ) );
+        break;
+
+    case I2C_WRITE:
+        copy_from_user( (char*)&i2cdata, (char*)arg, sizeof( I2C_DATA ) );
+        {
+            int RetryCntr = MAXRETRIES;
+            
+            do
+            {
+                RetVal = i2c_command( i2cdata.slave
+                                    , i2cdata.wbuf
+                                    , i2cdata.wlen
+                                    , NULL
+                                    , 0 
+                                    );
+             } while ( ( EI2CNOERRORS != RetVal )
+                     &&( --RetryCntr )
+                     );
+        }
+        break;
+          
+    case I2C_WRITEREAD:
+        copy_from_user( (char*)&i2cdata, (char*)arg, sizeof( I2C_DATA ) );
+        {
+            int RetryCntr = MAXRETRIES;
+            
+            do
+            {
+                RetVal = i2c_command( i2cdata.slave
+                                    , i2cdata.wbuf
+                                    , i2cdata.wlen
+                                    , i2cdata.rbuf
+                                    , i2cdata.rlen 
+                                    );
+             } while ( ( EI2CNOERRORS != RetVal )
+                     &&( --RetryCntr )
+                     );
+        }
+        copy_to_user( (char*)arg, (char*)&i2cdata, sizeof( I2C_DATA ) );
+        break;
+/**END GVC**/    
+    
+    default:
+        RetVal = -EINVAL;
+    }
+    
+    return ( -RetVal );
+}   /* i2c_ioctl */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_command
+ *#
+ *# DESCRIPTION  : general routine to read/write bytes from an I2C device
+ *#                
+ *#                'i2c_command()' sends wlen bytes to the I2c bus and receives
+ *#                rlen bytes from the I2c bus.  
+ *#                The data to be send must be placed in wbuf[ 0 ] upto wbuf[ wlen - 1 ).
+ *#                The data to be received is assembled in rbuf[ 0 ] upto rbuf[ rlen - 1 ].
+ *#                 
+ *#                If no data is to be sent or received, put appropriate buffer parameter
+ *#                to "NULL" and appropriate length parameter to "0".
+ *# 
+ *# PARAMETERS   : slave = slave address of the I2C device
+ *#                wbuf  = address of first element of write buffer (wbuf)
+ *#                wlen  = number of bytes to be written to slave
+ *#                rbuf  = address of first element of read buffer (rbuf)
+ *#                rlen  = number of bytes to be read from slave
+ *#
+ *# RETURN       : 
+ *#    EI2CNOERRORS: I2C communication went fine
+ *#    EI2CBUSNFREE: I2C bus is not free
+ *#    EI2CWADDRESS: I2C write address failed
+ *#    EI2CRADDRESS: I2C read address failed
+ *#    EI2CSENDDATA: I2C send data failed
+ *#    EI2CRECVDATA: I2C receive data failed
+ *#    EI2CSTRTCOND: I2C start condition failed
+ *#    EI2CRSTACOND: I2C repeated start condition failed
+ *#    EI2CSTOPCOND: I2C stop condition failed
+ *#    EI2CNOSNDBYT: I2C no bytes to be sent
+ *#    EI2CNOSNDBUF: I2C no send buffer defined
+ *#    EI2CNORCVBYT: I2C no bytes to be received
+ *#    EI2CNORCVBUF: I2C no receive buffer defined
+ *#    EI2CNOACKNLD: I2C no acknowledge received
+ *#
+ *# REMARK       :
+ *#   First, the send part is completed.  
+ *#   In the send routine, there is no stop generated.  This is because maybe
+ *#   a repeated start condition must be generated.
+ *#   This happens when we want to receive some data from the I2c bus.  If not,
+ *#   at the end of the general I2c loop the stopcondition is generated.
+ *#   If, on the contrary, there are a number of bytes to be received, a new
+ *#   startcondition is generated in the 'if' part of the main I2c routine, 
+ *#   which controls the receiving part.  
+ *#   Only when the receiving of data is finished, a final stopcondition is 
+ *#   generated.
+ *#
+ *#---------------------------------------------------------------------------
+ */
+static int i2c_command( unsigned char  slave
+                      , unsigned char* wbuf
+                      , unsigned char  wlen
+                      , unsigned char* rbuf
+                      , unsigned char  rlen
+                      )
+{
+    /* Check arguments and report error if relevant... */
+    if ( ( wlen > 0 ) && ( wbuf == NULL ) )
+    {
+        printk( KERN_DEBUG "I2C: EI2CNOSNDBUF\n" );
+        return ( EI2CNOSNDBUF );
+    }
+    else if ( ( wlen == 0 ) && ( wbuf != NULL ) )
+    {
+        printk( KERN_DEBUG "I2C: EI2CNOSNDBYT\n" );
+        return ( EI2CNOSNDBYT );
+    }
+    else if ( ( rlen > 0 ) && ( rbuf == NULL ) )
+    {
+        printk( KERN_DEBUG "I2C: EI2CNORCVBUF\n" );
+        return ( EI2CNORCVBUF );
+    }
+    else if ( ( rlen == 0 ) && ( rbuf != NULL ) )
+    {
+        printk( KERN_DEBUG "I2C: EI2CNORCVBYT\n" );
+        return ( EI2CNORCVBYT );
+    }
+    else if ( EI2CBUSNFREE == i2c_bus_free_check( MAXBUSFREERETRIES ) )
+    {
+        /* There's no need to try more, since we weren't even
+         * able to start the I2C communication.
+         * So, no IRQ flags are stored yet, no changes to any other
+         * stuff like START, STOP, SENDBYTES...
+         * Result, simply write down the error and return the correct error code.
+         */
+        printk( KERN_DEBUG "I2C: EI2CBUSNFREE\n" );
+        return ( EI2CBUSNFREE );
+    }
+    else
+    {
+        /* Finally... We made it... */
+        unsigned long irqflags = 0;
+
+        /* we don't like to be interrupted */
+        local_irq_save( irqflags );
+
+        /* Check if there are bytes to be send, 
+         * or if you immediately want to receive data.
+         */
+        if ( 0 < wlen )
+        {
+            /* start I2C communication */        
+            if ( EI2CNOERRORS != i2c_start() )
+            {
+                return ( i2c_finalise( "I2C: EI2CSTRTCOND\n", irqflags  )
+                       , EI2CSTRTCOND 
+                       );
+            }
+
+            /* send slave address: xxxxxxx0B (last bit must be zero) */
+            if ( EI2CNOERRORS != i2c_outbyte( slave & WRITEADDRESS_MASK ) )
+            {
+                return ( i2c_finalise( "I2C: EI2CWADDRESS\n", irqflags  )
+                       , EI2CWADDRESS 
+                       );
+            }
+
+            while ( wlen-- )
+            {   
+                /* send register data */
+                if ( EI2CNOERRORS != i2c_outbyte( *wbuf ) )
+                {
+                    return ( i2c_finalise( "I2C: EI2CSENDDATA\n", irqflags  )
+                           , EI2CSENDDATA 
+                           );
+                }
+                
+                wbuf++;
+            };
+                
+            i2c_delay( TLOW );
+        }
+
+        /*
+         * Receiving data from I2c_bus
+         * If there are bytes to be received, a new start condition is
+         * generated => Repeated Startcondition.
+         * A final stopcondition is generated at the end of the main I2c
+         * routine.
+         */
+        if ( 0 < rlen )
+        {
+            /*
+             * Generate start condition if wlen == 0 
+             * or repeated start condition if wlen != 0...
+             */
+            if ( EI2CNOERRORS != i2c_start() )
+            {
+                return ( i2c_finalise( ( ( 0 < wlen ) 
+                                       ? "I2C: EI2CRSTACOND\n"
+                                       : "I2C: EI2CSTRTCOND\n"
+                                       )
+                                     , irqflags
+                                     )
+                       , ( ( 0 < wlen ) ? EI2CRSTACOND : EI2CSTRTCOND )
+                       );
+            }
+
+            /* Send ReadAddress: xxxxxxx1B (last bit must be one) */
+            if ( EI2CNOERRORS != i2c_outbyte( slave | READADDRESS_MASK ) )
+            {
+                return ( i2c_finalise( "I2C: EI2CRADDRESS\n", irqflags )
+                       , EI2CRADDRESS
+                       );
+            }
+            
+            while ( rlen-- )
+            {
+                /* fetch register */
+                *rbuf = i2c_inbyte();
+                rbuf++;
+                
+                /* last received byte needs to be NACK-ed instead of ACK-ed */
+                if ( rlen )
+                {
+                    i2c_sendack();
+                }
+                else 
+                {
+                    i2c_sendnack(); 
+                }
+            };
+        }
+
+        /* Generate final stop condition */
+        if ( EI2CNOERRORS != i2c_stop() )
+        {
+            return ( i2c_finalise( "I2C: EI2CSTOPCOND\n", irqflags )
+                   , EI2CSTOPCOND
+                   );
+        } 
+    
+        /* enable interrupt again */
+        local_irq_restore( irqflags );
+    }
+    
+    return ( EI2CNOERRORS );
+} /*  i2c_command */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_bus_free_check
+ *#
+ *# DESCRIPTION  : checks if the I2C bus is free before starting
+ *#                an I2C communication
+ *# 
+ *# PARAMETERS   : maxretries, the number of times we will try to release
+ *#                the I2C bus  
+ *#
+ *# RETURN       : I2cStatus_I2cBusNotFreeError in case the bus is not free,
+ *#                I2cStatus_I2cNoError otherwise 
+ *#
+ *#---------------------------------------------------------------------------
+ */
+static int i2c_bus_free_check( unsigned char maxretries )
+{
+    i2c_sda_dir_in();        /* Release SDA line */
+    i2c_set_scl( SCL_HIGH ); /* put SCL line high */
+    
+    i2c_delay( WAITONEUS );
+        
+    while ( ( !i2c_sda_is_high() || !i2c_scl_is_high() )
+          &&( maxretries-- )
+          )
+    {
+        /* Try to release I2C bus by generating STOP conditions */
+        i2c_stop();
+    }
+    
+    if ( 0 == maxretries )
+    {
+        printk( KERN_DEBUG "I2C: EI2CBUSNFREE\n" );
+        return ( EI2CBUSNFREE );
+    }
+    else 
+    {
+        return ( EI2CNOERRORS );
+    }
+} /* i2c_bus_free_check */
+
+
+static void i2c_finalise( const char* errortxt
+                        , unsigned long irqflags
+                        )
+{
+    printk( KERN_DEBUG "%s", errortxt );
+    local_irq_restore( irqflags );
+    /* The least we can do when things go terribly wrong,
+     * is to try to release the bus.
+     * If this fails, well, then I don't know
+     * what I can do more for the moment...
+     */
+    (void)i2c_bus_free_check( MAXBUSFREERETRIES );
+}   /* i2c_finalise */                         
+
+
+static struct file_operations i2c_fops = 
+{
+    .owner    = THIS_MODULE
+,   .ioctl    = i2c_ioctl
+,   .open     = i2c_open
+,   .release  = i2c_release
+};
+
+
+/***********************************************************************/
+/************* EXTERNAL FUNCTION DEFINITION SECTION ********************/
+/***********************************************************************/
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_init
+ *#
+ *# DESCRIPTION  : initialises the I2C device driver
+ *#
+ *# PARAMETERS   :
+ *#
+ *#---------------------------------------------------------------------------
+ */
+int __init i2c_init( void )
+{
+    static int res = 0;
+    static int first = 1;
+
+    if ( !first ) 
+    {
+        return res;
+    }
+    
+    first = 0;
+
+    /* Setup and enable the Port B I2C interface */
+
+#ifndef CONFIG_ETRAX_I2C_USES_PB_NOT_PB_I2C
+    /* here, we're using the dedicated I2C pins of FoxBoard */
+    if ( ( res = cris_request_io_interface( if_i2c, "I2C" ) ) ) 
+    {
+        printk( KERN_CRIT "i2c_init: Failed to get IO interface\n" );
+        return res;
+    }
+
+    *R_PORT_PB_I2C = port_pb_i2c_shadow |= 
+        IO_STATE( R_PORT_PB_I2C, i2c_en,  on ) |
+        IO_FIELD( R_PORT_PB_I2C, i2c_d,   1 )  |
+        IO_FIELD( R_PORT_PB_I2C, i2c_set_scl, 1 )  |
+        IO_STATE( R_PORT_PB_I2C, i2c_oe_, enable );
+
+    port_pb_dir_shadow &= ~IO_MASK( R_PORT_PB_DIR, dir0 );
+    port_pb_dir_shadow &= ~IO_MASK( R_PORT_PB_DIR, dir1 );
+
+    *R_PORT_PB_DIR = ( port_pb_dir_shadow |=
+              IO_STATE( R_PORT_PB_DIR, dir0, input )  |
+              IO_STATE( R_PORT_PB_DIR, dir1, output ) );
+#else
+        /* If everything goes fine, res = 0, meaning "if" fails => 
+         * will do the "else" too and as such initialise the clock port...
+         * Clever trick! 
+         */
+        if ( ( res = cris_io_interface_allocate_pins( if_i2c
+                                                    , 'b'
+                                                    , CONFIG_ETRAX_I2C_DATA_PORT
+                                                    , CONFIG_ETRAX_I2C_DATA_PORT 
+                                                    ) 
+             ) 
+           ) 
+        {
+            printk( KERN_WARNING "i2c_init: Failed to get IO pin for I2C data port\n" );
+            return ( res );
+        }
+        /* Same here...*/ 
+        else if ( ( res = cris_io_interface_allocate_pins( if_i2c
+                                                         , 'b'
+                                                         , CONFIG_ETRAX_I2C_CLK_PORT
+                                                         , CONFIG_ETRAX_I2C_CLK_PORT 
+                                                         ) 
+                  ) 
+                ) 
+        {
+            cris_io_interface_free_pins( if_i2c
+                                       , 'b'
+                                       , CONFIG_ETRAX_I2C_DATA_PORT
+                                       , CONFIG_ETRAX_I2C_DATA_PORT 
+                                       );
+            printk( KERN_WARNING "i2c_init: Failed to get IO pin for I2C clk port\n" );
+        }
+#endif
+
+    return ( res );
+}   /* i2c_init */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_register
+ *#
+ *# DESCRIPTION  : this registers the i2c driver as a character device
+ *#
+ *# PARAMETERS   :
+ *#
+ *#---------------------------------------------------------------------------
+ */
+static int __init i2c_register( void )
+{
+    int res;
+/**GVC**/
+#ifdef DYNAMIC_MAJOR_I2CDEV_NUMBER_ALLOC
+    dev_t devt;
+    struct cdev *my_i2cdev = NULL;
+#endif
+/**END GVC**/
+
+    res = i2c_init();
+    
+    if ( res < 0 )
+    {
+        return res;
+    }
+    
+/**GVC**/
+#ifdef DYNAMIC_MAJOR_I2CDEV_NUMBER_ALLOC
+    res = alloc_chrdev_region( &devt, 0, 1, i2c_name );
+    
+    if ( res < 0 )
+    {
+        printk( KERN_DEBUG "I2C: EI2CNOMNUMBR\n" );
+        return ( res );
+    }
+    
+    my_i2cdev = cdev_alloc();
+    my_i2cdev->ops = &i2c_fops;
+    my_i2cdev->owner = THIS_MODULE;
+   
+    /* make device "alive" */ 
+    res = cdev_add( my_i2cdev, devt, 1 );
+    
+    if ( res < 0 )
+    { 
+        printk( KERN_DEBUG "I2C: EI2CDADDFAIL\n" );
+        return ( res );
+    }
+#else
+/**END GVC**/
+    res = register_chrdev( I2C_MAJOR, i2c_name, &i2c_fops );
+    
+    if ( res < 0 ) 
+    {
+        printk( KERN_ERR "i2c: couldn't get a major number.\n" );
+        return res;
+    }
+/**GVC**/
+#endif
+/**END GVC**/
+
+    printk( KERN_INFO "I2C driver v2.2, (c) 1999-2004 Axis Communications AB\n" );
+
+/**GVC**/
+    printk( KERN_INFO "  ==> Improvements done by Geert Vancompernolle - December 2006\n" );
+
+#ifdef DYNAMIC_MAJOR_I2CDEV_NUMBER_ALLOC
+    printk( KERN_INFO "I2C Major: %d / I2C Name: %s\n", MAJOR( devt ), i2c_name );
+#else
+/**END GVC**/
+    printk( KERN_INFO "I2C Major: %d / I2C Name: %s\n", I2C_MAJOR, i2c_name );
+/**GVC**/
+#endif    
+/**END GVC**/
+    
+    return ( 0 );
+}   /* i2c_register */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_start
+ *#
+ *# DESCRIPTION  : generate i2c start condition
+ *#
+ *# PARAMETERS   : none
+ *#
+ *# RETURN       : EI2CNOERRORS if OK, EI2CSTRTCOND otherwise
+ *#
+ *#---------------------------------------------------------------------------
+ */
+int i2c_start( void )
+{
+    /* Set SCL=1, SDA=1 */
+    i2c_sda_dir_out();
+    i2c_set_sda( SDA_HIGH );
+    i2c_delay( WAITONEUS );
+    i2c_set_scl( SCL_HIGH );
+    i2c_delay( WAITONEUS );
+    
+    /* Set SCL=1, SDA=0 */
+    i2c_set_sda( SDA_LOW );
+    i2c_delay( THDSTA );
+    
+    /* Set SCL=0, SDA=0 */
+    i2c_set_scl( SCL_LOW );
+    /* We can take 1 us less than defined in spec (5 us), since the next action
+     * will be to set the dataline high or low and this action is 1 us
+     * before the clock is put high, so that makes our 5 us.
+     */
+    i2c_delay( TLOW - WAITONEUS );
+    
+    if ( i2c_sda_is_high() || i2c_scl_is_high() )
+    {
+        printk( KERN_DEBUG "I2C: EI2CSTRTCOND\n" );
+        return ( EI2CSTRTCOND );
+    }
+    
+    return ( EI2CNOERRORS );
+}   /* i2c_start */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_stop
+ *#
+ *# DESCRIPTION  : generate i2c stop condition
+ *#
+ *# PARAMETERS   : none
+ *#
+ *# RETURN       : none
+ *#
+ *#---------------------------------------------------------------------------
+ */
+int i2c_stop( void )
+{
+    i2c_sda_dir_out();
+
+    /* Set SCL=0, SDA=0 */
+    /* Don't change order, otherwise you might generate a start condition! */
+    i2c_set_scl( SCL_LOW );
+    i2c_delay( WAITONEUS );
+    i2c_set_sda( SDA_LOW );
+    i2c_delay( WAITONEUS );
+    
+    /* Set SCL=1, SDA=0 */
+    i2c_set_scl( SCL_HIGH );
+    i2c_delay( TSUSTO );
+    
+    /* Set SCL=1, SDA=1 */
+    i2c_set_sda( SDA_HIGH );
+    i2c_delay( TBUF );
+
+    i2c_sda_dir_in();
+    
+    if ( !i2c_sda_is_high() || !i2c_scl_is_high() )
+    {
+        printk( KERN_DEBUG "I2C: EI2CSTOPCOND\n" );
+        return ( EI2CSTOPCOND );
+    }
+    
+    return ( EI2CNOERRORS );
+}   /* i2c_stop */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_outbyte
+ *#
+ *# DESCRIPTION  : write a byte to the i2c interface
+ *#
+ *# PARAMETERS   : x: byte to be sent on the I2C bus
+ *#
+ *# RETURN       : none
+ *#
+ *#---------------------------------------------------------------------------
+ */
+int i2c_outbyte( unsigned char x )
+{
+    int i;
+
+    i2c_sda_dir_out();
+
+    for ( i = 0; i < 8; i++ ) 
+    {
+        if ( x & 0x80 ) 
+        {
+            i2c_set_sda( SDA_HIGH );
+        } 
+        else 
+        {
+            i2c_set_sda( SDA_LOW );
+        }
+        
+        i2c_delay( TSUDAT );
+        i2c_set_scl( SCL_HIGH );
+        i2c_delay( THIGH );
+        i2c_set_scl( SCL_LOW );
+        i2c_delay( TSUDAT );
+        i2c_set_sda( SDA_LOW );
+        /* There should be only 5 us between falling edge and new rising
+         * edge of clock pulse.
+         * Since we spend already 1 us since clock edge was low, there are
+         * only ( TLOW - TSUDAT ) us left.
+         * Next to this, since the data line will be set up 1 us before the
+         * clock line is set up, we can reduce the delay with another us.
+         */
+        i2c_delay( TLOW - TSUDAT - WAITONEUS );
+        x <<= 1;
+    }
+    
+    /* enable input */
+    i2c_sda_dir_in();
+    
+    if ( !i2c_getack() )
+    {
+        printk( KERN_DEBUG "I2C: EI2CNOACKNLD\n" );
+        return( EI2CNOACKNLD );
+    }
+    
+    return ( EI2CNOERRORS );
+}   /* i2c_outbyte */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_inbyte
+ *#
+ *# DESCRIPTION  : read a byte from the i2c interface
+ *#
+ *# PARAMETERS   : none
+ *#
+ *# RETURN       : returns the byte read from the I2C device
+ *#
+ *#---------------------------------------------------------------------------
+ */
+unsigned char i2c_inbyte( void )
+{
+    unsigned char aBitByte = 0;
+    unsigned char Mask     = 0x80;    /* !!! ATTENTION: do NOT use 'char', otherwise shifting is wrong!!! */
+                                      /* Must be UNSIGNED, not SIGNED! */
+
+
+    /* Switch off I2C to get bit */
+    i2c_disable();
+    i2c_sda_dir_in();
+
+    while ( Mask != 0 )
+    {
+        i2c_set_scl( SCL_HIGH );
+        i2c_delay( THIGH );
+
+        if ( i2c_sda_is_high() )
+        {
+            aBitByte |= Mask;
+        }
+
+        i2c_set_scl( SCL_LOW );
+
+        Mask >>= 1;
+
+        i2c_delay( TLOW );
+    }
+
+    /*
+     * we leave the clock low, getbyte is usually followed
+     * by sendack/nack, they assume the clock to be low
+     */
+    return ( aBitByte );
+}   /* i2c_inbyte */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_getack
+ *#
+ *# DESCRIPTION  : checks if ack was received from ic2
+ *#
+ *# PARAMETERS   : none
+ *#
+ *# RETURN       : returns the ack state of the I2C device
+ *#
+ *#---------------------------------------------------------------------------
+ */
+int i2c_getack( void )
+{
+    int ack = 1;
+
+    /* generate ACK clock pulse */
+    i2c_set_scl( SCL_HIGH );
+    
+    /* switch off I2C */
+    i2c_disable();
+
+    /* now wait for ack */
+    i2c_delay( THIGH );
+    /* check for ack: if SDA is high, then NACK, else ACK */
+    if ( i2c_sda_is_high() )
+    {
+        ack = 0;
+    }
+    else
+    {
+        ack = 1;
+    }
+    
+    /* end clock pulse */
+    i2c_enable();
+    i2c_set_scl( SCL_LOW );
+    i2c_sda_dir_out();
+    i2c_set_sda( SDA_LOW );
+
+    /* Since we "lost" already THDDAT time, we can subtract it here... */
+    i2c_delay( TLOW  - THDDAT );
+    
+    return ( ack );
+}   /* i2c_getack */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_sendack
+ *#
+ *# DESCRIPTION  : sends ACK on received data
+ *#
+ *# PARAMETERS   : none
+ *#
+ *# RETURN       : none
+ *#
+ *#---------------------------------------------------------------------------
+ */
+void i2c_sendack( void )
+{
+    /* enable output */
+    /* Clock has been set to TLOW already at end of i2c_inbyte()
+     * and i2c_outbyte(), so no need to do it again.
+     */
+    i2c_sda_dir_out();
+    /* set ack pulse low */
+    i2c_set_sda( SDA_LOW );
+    /* generate clock pulse */
+    i2c_delay( TSUDAT );
+    i2c_set_scl( SCL_HIGH );
+    i2c_delay( THIGH );
+    i2c_set_scl( SCL_LOW );
+    i2c_delay( THDDAT );
+    /* reset data out */
+    i2c_set_sda( SDA_HIGH );
+    /* Subtract time spend already when waited to put SDA high */
+    i2c_delay( TLOW - THDDAT );
+
+    /* release the SDA line */
+    i2c_sda_dir_in();
+}   /* i2c_sendack */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_sendnack
+ *#
+ *# DESCRIPTION  : sends NACK on received data
+ *#
+ *# PARAMETERS   : none
+ *#
+ *# RETURN       : none
+ *#
+ *#---------------------------------------------------------------------------
+ */
+void i2c_sendnack( void )
+{
+    /* make sure the SDA line is set high prior to activation of the output.
+     * this way, you avoid an unnecessary peak to ground when a NACK has to
+     * be created.
+     */
+    /* set data high */
+    i2c_set_sda( SDA_HIGH );
+    /* enable output */
+    i2c_sda_dir_out();
+
+    /* generate clock pulse */
+    i2c_delay( TSUDAT );
+    i2c_set_scl( SCL_HIGH );
+    i2c_delay( THIGH );
+    i2c_set_scl( SCL_LOW );
+    i2c_delay( TSUDAT );
+    i2c_set_sda( SDA_LOW );
+    i2c_delay( TLOW - TSUDAT );
+    
+    /* There's no need to change the direction of SDA to "in" again,
+     * since a NACK is always followed by a stop condition.
+     * A STOP condition will put the direction of SDA back to "out"
+     * resulting in a useless SDA "dip" on the line...
+     */
+    /* i2c_sda_dir_in(); */
+}   /* i2c_sendnack */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_writereg
+ *#
+ *# DESCRIPTION  : writes a value to a register of an I2C device
+ *#
+ *# PARAMETERS   : theSlave = slave address of the I2C device
+ *#                theReg   = register of the I2C device that needs to be written
+ *#                theValue = value to be written to the register
+ *#
+ *# RETURN       : returns OR-ed result of the write action:
+ *#                  0 = Ok
+ *#                  1 = Slave_NoAck
+ *#                  2 = Reg_NoAck
+ *#                  4 = Val_NoAck
+ *#
+ *#---------------------------------------------------------------------------
+ */
+int i2c_writereg( unsigned char theSlave
+                , unsigned char theReg
+                , unsigned char theValue 
+                )
+{
+    int error, cntr = 3;
+    unsigned long flags;
+
+    spin_lock( &i2c_lock );
+
+    do 
+    {
+        error = 0;
+        /* we don't like to be interrupted */
+        local_irq_save( flags );
+
+        i2c_start();
+        /* send slave address */
+        if ( EI2CNOACKNLD == i2c_outbyte( theSlave & 0xfe ) )
+        {
+            error = 1;
+        }
+            
+        /* now select register */
+        if ( EI2CNOACKNLD == i2c_outbyte( theReg ) )
+        {
+            error |= 2;
+        }
+        
+        /* send register register data */
+        if ( EI2CNOACKNLD == i2c_outbyte( theValue ) )
+        {
+            error |= 4;
+        }
+             
+        /* end byte stream */
+        i2c_stop();
+        /* enable interrupt again */
+        local_irq_restore( flags );
+        
+    } while ( error && cntr-- );
+
+    i2c_delay( TLOW );
+
+    spin_unlock( &i2c_lock );
+
+    return ( -error );
+}   /* i2c_writereg */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_readreg
+ *#
+ *# DESCRIPTION  : reads the value from a certain register of an I2C device.
+ *#                Function first writes the register that it wants to read
+ *#                later on.
+ *#  
+ *# PARAMETERS   : theSlave = slave address of the I2C device
+ *#                theReg   = register of the I2C device that needs to be written
+ *#
+ *# RETURN       : returns OR-ed result of the write action:
+ *#                  0 = Ok
+ *#                  1 = Slave_NoAck
+ *#                  2 = Reg_NoAck
+ *#                  4 = Val_NoAck
+ *#
+ *#---------------------------------------------------------------------------
+ */
+unsigned char i2c_readreg( unsigned char theSlave
+                         , unsigned char theReg 
+                         )
+{
+    unsigned char b = 0;
+    int error, cntr = 3;
+    unsigned long flags;
+
+    spin_lock( &i2c_lock );
+
+    do 
+    {
+        error = 0;
+        
+        /* we don't like to be interrupted */
+        local_irq_save( flags );
+        
+        /* generate start condition */
+        i2c_start();
+    
+        /* send slave address */
+        if ( EI2CNOACKNLD == i2c_outbyte( theSlave & 0xfe ) )
+        {
+            error = 1;
+        }
+
+        /* now select register */
+        i2c_sda_dir_out();
+
+        if ( EI2CNOACKNLD == i2c_outbyte( theReg ) )
+        {
+            error |= 2;
+        }            
+
+        /* repeat start condition */
+        i2c_delay( TLOW );
+        i2c_start();
+        
+        /* send slave address */
+        if ( EI2CNOACKNLD == i2c_outbyte( theSlave | 0x01 ) )
+        {
+            error |= 1;
+        }
+            
+        /* fetch register */
+        b = i2c_inbyte();
+        /*
+         * last received byte needs to be nacked
+         * instead of acked
+         */
+        i2c_sendnack();
+        
+        /* end sequence */
+        i2c_stop();
+        
+        /* enable interrupt again */
+        local_irq_restore( flags );
+        
+    } while ( error && cntr-- );
+
+    spin_unlock( &i2c_lock );
+
+    return ( b );
+}   /* i2c_readreg */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_read
+ *#
+ *# DESCRIPTION  :
+ *#  
+ *# PARAMETERS   :
+ *#
+ *# RETURN       :
+ *#
+ *#---------------------------------------------------------------------------
+ */
+int i2c_read( unsigned char slave, unsigned char* rbuf, unsigned char rlen )
+{
+    return ( i2c_command( slave, NULL, 0, rbuf, rlen ) );
+}   /* i2c_read */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_write
+ *#
+ *# DESCRIPTION  :
+ *#  
+ *# PARAMETERS   :
+ *#
+ *# RETURN       :
+ *#
+ *#---------------------------------------------------------------------------
+ */
+int i2c_write( unsigned char slave, unsigned char* wbuf, unsigned char wlen )
+{
+    return ( i2c_command( slave, wbuf, wlen, NULL, 0 ) );
+}   /* i2c_write */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: i2c_writeread
+ *#
+ *# DESCRIPTION  :
+ *#  
+ *# PARAMETERS   :
+ *#
+ *# RETURN       :
+ *#
+ *#---------------------------------------------------------------------------
+ */
+int i2c_writeread( unsigned char  slave
+                 , unsigned char* wbuf
+                 , unsigned char  wlen
+                 , unsigned char* rbuf
+                 , unsigned char  rlen
+                 )
+{
+    return ( i2c_command( slave, wbuf, wlen, rbuf, rlen ) );
+}   /* i2c_writeread */
+
+
+/*#---------------------------------------------------------------------------
+ *#
+ *# FUNCTION NAME: module_init
+ *#
+ *# DESCRIPTION  : this makes sure that i2c_register is called during boot
+ *#
+ *# PARAMETERS   :
+ *#
+ *#---------------------------------------------------------------------------
+ */
+module_init( i2c_register );
+
+/****************** END OF FILE i2c.c ********************************/
diff --git a/target/linux/etrax/files/arch/cris/arch-v10/drivers/i2c_gvc.h b/target/linux/etrax/files/arch/cris/arch-v10/drivers/i2c_gvc.h
new file mode 100644
index 0000000..3d65d1a
--- /dev/null
+++ b/target/linux/etrax/files/arch/cris/arch-v10/drivers/i2c_gvc.h
@@ -0,0 +1,31 @@
+/* $Id: i2c.h,v 1.3 2004/05/28 09:26:59 starvik Exp $ */
+#ifndef _I2C_H
+#define _I2C_H
+
+int i2c_init(void);
+
+/* High level I2C actions */
+int i2c_writereg(unsigned char theSlave, unsigned char theReg, unsigned char theValue);
+unsigned char i2c_readreg(unsigned char theSlave, unsigned char theReg);
+
+/* Low level I2C */
+int i2c_start(void);
+int i2c_stop(void);
+int i2c_outbyte(unsigned char x);
+unsigned char i2c_inbyte(void);
+int i2c_getack(void);
+void i2c_sendack(void);
+void i2c_sendnack(void);
+
+/**GVC**/
+/* New low level I2C functions */
+int i2c_read( unsigned char slave, unsigned char* rbuf, unsigned char rlen );
+int i2c_write( unsigned char slave, unsigned char* wbuf, unsigned char wlen );
+int i2c_writeread( unsigned char  slave
+                 , unsigned char* wbuf
+                 , unsigned char  wlen
+                 , unsigned char* rbuf
+                 , unsigned char  rlen
+                 );
+/**END GVC**/
+#endif /* _I2C_H */
diff --git a/target/linux/etrax/patches-2.6.25/500-i2c_gvc.patch b/target/linux/etrax/patches-2.6.25/500-i2c_gvc.patch
new file mode 100644
index 0000000..7eed8b2
--- /dev/null
+++ b/target/linux/etrax/patches-2.6.25/500-i2c_gvc.patch
@@ -0,0 +1,45 @@
+Index: linux-2.6.25.20/arch/cris/arch-v10/drivers/Kconfig
+===================================================================
+--- linux-2.6.25.20.orig/arch/cris/arch-v10/drivers/Kconfig	2009-02-09 09:30:40.000000000 +0100
++++ linux-2.6.25.20/arch/cris/arch-v10/drivers/Kconfig	2009-02-09 21:23:12.000000000 +0100
+@@ -450,11 +450,18 @@
+ 	  i2c_arg = I2C_READARG(STA013_READ_ADDR, reg);
+ 	  val = ioctl(fd, _IO(ETRAXI2C_IOCTYPE, I2C_READREG), i2c_arg);
+ 
++config ETRAX_I2C_GVC
++	bool "I2C GVC support"
++	depends on ETRAX_ARCH_V10 && !ETRAX_I2C
++	select ETRAX_I2C_USES_PB_NOT_PB_I2C
++	help
++	  Enables an I2C driver with Geert Vancompernolle improvement.
++
+ # this is true for most products since PB-I2C seems to be somewhat
+ # flawed..
+ config ETRAX_I2C_USES_PB_NOT_PB_I2C
+ 	bool "I2C uses PB not PB-I2C"
+-	depends on ETRAX_I2C
++	depends on ETRAX_I2C || ETRAX_I2C_GVC
+ 	help
+ 	  Select whether to use the special I2C mode in the PB I/O register or
+ 	  not.  This option needs to be selected in order to use some drivers
+@@ -478,7 +485,7 @@
+ 
+ config ETRAX_I2C_EEPROM
+ 	bool "I2C EEPROM (non-volatile RAM) support"
+-	depends on ETRAX_I2C
++	depends on ETRAX_I2C || ETRAX_I2C_GVC
+ 	help
+ 	  Enables I2C EEPROM (non-volatile RAM) on PB0 and PB1 using the I2C
+ 	  driver.  Select size option: Probed, 2k, 8k, 16k.
+Index: linux-2.6.25.20/arch/cris/arch-v10/drivers/Makefile
+===================================================================
+--- linux-2.6.25.20.orig/arch/cris/arch-v10/drivers/Makefile	2009-02-09 09:30:41.000000000 +0100
++++ linux-2.6.25.20/arch/cris/arch-v10/drivers/Makefile	2009-02-09 09:35:39.000000000 +0100
+@@ -4,6 +4,7 @@
+ 
+ obj-$(CONFIG_ETRAX_AXISFLASHMAP)	+= axisflashmap.o
+ obj-$(CONFIG_ETRAX_I2C)			+= i2c.o
++obj-$(CONFIG_ETRAX_I2C_GVC)		+= i2c_gvc.o
+ obj-$(CONFIG_ETRAX_I2C_EEPROM)		+= eeprom.o
+ obj-$(CONFIG_ETRAX_GPIO)		+= gpio.o
+ obj-$(CONFIG_ETRAX_DS1302)		+= ds1302.o