1 files changed, 301 insertions, 0 deletions

diff --git a/firmware/drivers/sw_i2c.c b/firmware/drivers/sw_i2c.c
new file mode 100644
index 0000000000..c1f6868226
--- /dev/null
+++ b/firmware/drivers/sw_i2c.c
@@ -0,0 +1,301 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2006 by Miika Pekkarinen
+ *
+ * All files in this archive are subject to the GNU General Public License.
+ * See the file COPYING in the source tree root for full license agreement.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "system.h"
+#include "logf.h"
+#include "inttypes.h"
+
+#include "sw_i2c.h"
+
+/**
+ * I2C-functions are copied and ported from fmradio.c.
+ * later fixed, adapted and moved to a seperate file so they can be re-used 
+ * by the rtc-ds1339c and later by the m:robe-100 code by Robert Kukla
+ */
+
+/* cute little functions, atomic read-modify-write */
+
+#ifdef MROBE_100
+
+/* SCL is GPIOC, 4 */
+#define SCL       (GPIOC_INPUT_VAL &  0x00000010)
+#define SCL_OUT_LO GPIOC_OUTPUT_VAL&=~0x00000010
+#define SCL_LO     GPIOC_OUTPUT_EN |= 0x00000010
+#define SCL_HI     GPIOC_OUTPUT_EN &=~0x00000010
+
+/* SDA is GPIOC, 5 */
+#define SDA       (GPIOC_INPUT_VAL &  0x00000020)
+#define SDA_OUT_LO GPIOC_OUTPUT_VAL&=~0x00000020
+#define SDA_LO     GPIOC_OUTPUT_EN |= 0x00000020
+#define SDA_HI     GPIOC_OUTPUT_EN &=~0x00000020
+
+#define DELAY  do { volatile int _x; for(_x=0;_x<22;_x++);} while(0)
+
+#else
+
+/* SCL is GPIO, 12 */
+#define SCL             ( 0x00001000 & GPIO_READ)
+#define SCL_OUT_LO and_l(~0x00001000, &GPIO_OUT)
+#define SCL_LO      or_l( 0x00001000, &GPIO_ENABLE)
+#define SCL_HI     and_l(~0x00001000, &GPIO_ENABLE)
+
+/* SDA is GPIO1, 13 */
+#define SDA             ( 0x00002000 & GPIO1_READ)
+#define SDA_OUT_LO and_l(~0x00002000, &GPIO1_OUT)
+#define SDA_LO      or_l( 0x00002000, &GPIO1_ENABLE)
+#define SDA_HI     and_l(~0x00002000, &GPIO1_ENABLE)
+
+/* delay loop to achieve 400kHz at 120MHz CPU frequency */
+#define DELAY   \
+    ({                                \
+        int _x_;                      \
+        asm volatile (                \
+            "move.l #21, %[_x_] \r\n" \
+        "1:                     \r\n" \
+            "subq.l #1, %[_x_]  \r\n" \
+            "bhi.b  1b          \r\n" \
+            : [_x_]"=&d"(_x_)         \
+        );                            \
+    })
+
+#endif
+
+void sw_i2c_init(void)
+{
+#ifndef MROBE_100
+    or_l(0x00001000, &GPIO_FUNCTION);
+    or_l(0x00002000, &GPIO1_FUNCTION);
+#endif
+  
+    SDA_HI;
+    SCL_HI;
+    SDA_OUT_LO;
+    SCL_OUT_LO;
+}
+
+/*   in: C=? D=?
+ *  out: C=L D=L
+ */
+static void sw_i2c_start(void)
+{
+    SCL_LO;
+    DELAY;
+    SDA_HI;
+    DELAY;
+    SCL_HI;
+    DELAY;
+    SDA_LO;
+    DELAY;
+    SCL_LO;
+}
+
+/*   in: C=L D=?
+ *  out: C=H D=H
+ */
+static void sw_i2c_stop(void)
+{
+    SDA_LO;
+    DELAY;
+    SCL_HI;
+    DELAY;
+    SDA_HI;
+}
+
+/*   in: C=L D=H
+ *  out: C=L D=L
+ */
+static void sw_i2c_ack(void)
+{
+    SDA_LO;
+    DELAY;
+    
+    SCL_HI;
+    DELAY;
+    SCL_LO;
+}
+
+/*   in: C=L D=H
+ *  out: C=L D=H
+ */
+static void sw_i2c_nack(void)
+{
+    SDA_HI;          /* redundant */
+    DELAY;
+    
+    SCL_HI;
+    DELAY;
+    SCL_LO;
+}
+
+/*   in: C=L D=?
+ *  out: C=L D=H
+ */
+static bool sw_i2c_getack(void)
+{
+    bool ret = true;
+/*    int count = 10; */
+
+    SDA_HI;   /* sets to input */
+    DELAY;
+    SCL_HI;
+    DELAY;
+
+/*    while (SDA && count--) */
+/*        DELAY; */
+    
+    if (SDA)
+        /* ack failed */
+        ret = false;
+    
+    SCL_LO;
+
+    return ret;
+}
+
+/*   in: C=L D=?
+ *  out: C=L D=?
+ */
+static void sw_i2c_outb(unsigned char byte)
+{
+    int i;
+
+    /* clock out each bit, MSB first */
+    for ( i=0x80; i; i>>=1 )
+    {
+        if ( i & byte )
+            SDA_HI;
+        else
+            SDA_LO;
+        DELAY;
+
+        SCL_HI;
+        DELAY;
+        SCL_LO;
+    }
+}
+
+/*   in: C=L D=?
+ *  out: C=L D=H
+ */
+static unsigned char sw_i2c_inb(void)
+{
+    int i;
+    unsigned char byte = 0;
+
+    SDA_HI;   /* sets to input */
+    
+    /* clock in each bit, MSB first */
+    for ( i=0x80; i; i>>=1 ) 
+    {
+        DELAY;
+        do {
+          SCL_HI;
+          DELAY;
+        }
+        while(SCL==0);    /* wait for any SCL clock stretching */
+        if ( SDA )
+            byte |= i;
+        SCL_LO;
+    }
+
+    return byte;
+}
+
+int sw_i2c_write(unsigned char chip, unsigned char location, unsigned char* buf, int count)
+{
+    int i;
+
+    sw_i2c_start();
+    sw_i2c_outb((chip & 0xfe) | SW_I2C_WRITE);
+    if (!sw_i2c_getack())
+    {
+        sw_i2c_stop();
+        return -1;
+    }
+
+#ifdef MROBE_100 /* does not use register addressing */
+    (void) location;
+#else    
+    sw_i2c_outb(location);
+    if (!sw_i2c_getack())
+    {
+        sw_i2c_stop();
+        return -2;
+    }
+#endif  
+
+    for (i=0; i<count; i++)
+    {
+        sw_i2c_outb(buf[i]);
+        if (!sw_i2c_getack())
+        {
+            sw_i2c_stop();
+            return -3;
+        }
+    }
+
+    sw_i2c_stop();
+    
+    return 0;
+}
+
+int sw_i2c_read(unsigned char chip, unsigned char location, unsigned char* buf, int count)
+{
+    int i;
+
+#ifdef MROBE_100 /* does not use register addressing */
+    (void) location;
+#else    
+    sw_i2c_start();
+    sw_i2c_outb((chip & 0xfe) | SW_I2C_WRITE);
+    if (!sw_i2c_getack())
+    {
+        sw_i2c_stop();
+        return -1;
+    }
+
+    sw_i2c_outb(location);
+    if (!sw_i2c_getack())
+    {
+        sw_i2c_stop();
+        return -2;
+    }
+#endif  
+
+    sw_i2c_start();
+    sw_i2c_outb((chip & 0xfe) | SW_I2C_READ);
+    if (!sw_i2c_getack())
+    {
+        sw_i2c_stop();
+        return -3;
+    }
+    
+    for (i=0; i<count-1; i++)
+    {
+      buf[i] = sw_i2c_inb();
+      sw_i2c_ack();
+    }
+
+    /* 1byte min */
+    buf[i] = sw_i2c_inb();
+    sw_i2c_nack();
+        
+    sw_i2c_stop();
+    
+    return 0;
+}