iRiver I2C driver by Andy Young

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@6203 a1c6a512-1295-4272-9138-f99709370657

firmware/drivers/i2c-h100.c

@@ -0,0 +1,166 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2005 by Andy Young
+ *
+ * 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 "cpu.h"
+#include "kernel.h"
+#include "debug.h"
+#include "system.h"
+#include "i2c-h100.h"
+
+#define I2C_DEVICE_1    ((volatile unsigned char *)&MADR)
+#define I2C_DEVICE_2    ((volatile unsigned char *)&MADR2)
+
+/* Local functions definitions */
+
+static int i2c_write_byte(int device, unsigned char data);
+static int i2c_gen_start(int device);
+static void i2c_gen_stop(int device);
+static volatile unsigned char *i2c_get_addr(int device);
+
+/* Public functions */
+
+void i2c_init(void)
+{
+    /* Audio Codec */
+    MADR = 0x6c; /* iRiver firmware uses this addr */
+    MBDR = 0;    /* iRiver firmware does this */
+    MBCR = IEN;  /* Enable interface */
+
+#if 0
+    /* FM Tuner */
+    MADR2 = 0x6c;
+    MBDR2 = 0;
+    MBCR2 = IEN;
+#endif
+}
+
+void i2c_close(void)
+{
+    MBCR  = 0;
+
+#if 0 
+    MBCR2 = 0;
+#endif
+}
+
+/**
+ * Writes bytes to the selected device.
+ *
+ * Use device=1 for bus 1 at 0x40000280 (Audio Codec)
+ * Use device=2 for bus 2 at 0x80000440 (Tuner ?)
+ * 
+ * Returns number of bytes successfully send or -1 if START failed
+ */
+int i2c_write(int device, unsigned char *buf, int count)
+{
+    int i;
+
+    if (i2c_gen_start(device) == -1)
+    {
+        DEBUGF("i2c: gen_start failed (d=%d)", device);
+        return -1;
+    }
+
+    for (i=0; i<count; i++)
+    {
+        if (i2c_write_byte(device, buf[i]) == -1)
+        {
+            DEBUGF("i2c: write failed at (d=%d,i=%d)", device, i);
+            return i-1;
+        }
+    }
+
+    i2c_gen_stop(device);
+
+    return count;
+}
+
+/* Write a byte to the interface, returns 0 on success, -1 otherwise. */
+int i2c_write_byte(int device, unsigned char data)
+{
+    volatile unsigned char *regs = i2c_get_addr(device);
+
+    long count = 0;
+
+    regs[O_MBDR] = data;                /* Write data byte */   
+
+    /* Wait for bus busy */
+    while (!(regs[O_MBSR] & IBB) && count < MAX_LOOP)
+    {
+        yield();  
+        count++;
+    }
+    
+    if (count >= MAX_LOOP)
+        return -1;
+
+    /* Wait for interrupt flag */
+    while (!(regs[O_MBSR] & IFF) && count < MAX_LOOP)
+    {
+        yield();
+        count++;            
+    }
+
+    if (count >= MAX_LOOP)
+        return -1;
+
+    regs[O_MBSR] &= ~IFF;       /* Clear interrupt flag  */
+    
+    if (!(regs[O_MBSR] & ICF))  /* Check that transfer is complete */
+        return -1;      
+
+    if (regs[O_MBSR] & RXAK)    /* Check that the byte has been ACKed */
+        return -1;
+    
+    return 0;
+}
+
+
+/* Returns 0 on success, -1 on failure */
+int i2c_gen_start(int device)
+{
+    volatile unsigned char *regs = i2c_get_addr(device);
+    long count = 0;
+        
+    /* Wait for bus to become free */
+    while ((regs[O_MBSR] & IBB) && (count < MAX_LOOP))
+        count++;
+                
+    if (count >= MAX_LOOP)
+        return -1;
+
+    regs[O_MBCR] |= MSTA | MTX;         /* Generate START */
+
+    return 0;   
+}  
+
+void i2c_gen_stop(int device)
+{
+    volatile unsigned char *regs = i2c_get_addr(device);
+    regs[O_MBCR] &= ~MSTA;          /* Clear MSTA to generate STOP */
+}
+
+
+volatile unsigned char *i2c_get_addr(int device)
+{
+    if (device == 1)
+        return I2C_DEVICE_1;
+    
+    return I2C_DEVICE_2;        
+}

firmware/export/i2c-h100.h

@@ -0,0 +1,64 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2002 by Linus Nielsen Feltzing
+ *
+ * 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.
+ *
+ ****************************************************************************/
+
+/*
+ *  Driver for MCF5249's I2C interface
+ *  2005-02-17 hubble@mochine.com
+ *
+ */
+ 
+#ifndef _I2C_H100_H
+#define _I2C_H100_H
+
+void i2c_init(void);
+int i2c_write(int device, unsigned char *buf, int count);
+void i2c_close(void);
+
+
+#define MAX_LOOP    0x10000     /* TODO: select a better value */
+
+/* PLLCR control */
+#define QSPISEL (1 << 11)		/* Selects QSPI or I2C interface */
+
+/* Offsets to I2C registers from base address */
+#define O_MADR	0x00            /* Slave Address        */
+#define O_MFDR	0x04            /* Frequency divider    */
+#define O_MBCR	0x08            /* Control register     */
+#define O_MBSR	0x0c            /* Status register      */
+#define O_MBDR	0x10            /* Data register        */
+
+/* MBSR - Status register */
+#define ICF     (1 << 7)        /* Transfer Complete	*/
+#define IAAS    (1 << 6)        /* Addressed As Alave	*/
+#define IBB     (1 << 5)        /* Bus Busy		        */
+#define IAL     (1 << 4)        /* Arbitration Lost	    */
+#define SRW     (1 << 2)        /* Slave R/W		    */
+#define IFF     (1 << 1)        /* I2C Interrupt	    */
+#define RXAK    (1 << 0)        /* No Ack bit		    */
+
+/* MBCR - Control register */
+#define IEN     (1 << 7)		/* I2C Enable		    */
+#define IIEN    (1 << 6)		/* Interrupt Enable	    */
+#define MSTA    (1 << 5)		/* Master/Slave select	*/
+#define MTX     (1 << 4)		/* Transmit/Receive	    */
+#define TXAK    (1 << 3)		/* Transfer ACK		    */
+#define RSTA    (1 << 2)		/* Restart..		    */
+
+
+#endif