1 files changed, 97 insertions, 0 deletions

diff --git a/firmware/target/coldfire/mpio/adc-mpio.c b/firmware/target/coldfire/mpio/adc-mpio.c
new file mode 100644
index 0000000000..92b9479279
--- /dev/null
+++ b/firmware/target/coldfire/mpio/adc-mpio.c
@@ -0,0 +1,97 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2010 Marcin Bukat
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "config.h"
+#include "cpu.h"
+#include "system.h"
+#include "kernel.h"
+#include "thread.h"
+#include "adc.h"
+
+volatile unsigned short adc_data[NUM_ADC_CHANNELS] IBSS_ATTR;
+
+/* Reading takes 4096 adclk ticks
+ * 1) tick task is created that enables ADC interrupt
+ * 2) On interrupt single channel is readed and
+ *    ADC is prepared for next channel
+ * 3) When all 4 channels are scanned ADC interrupt is disabled
+ */
+
+void ADC(void) __attribute__ ((interrupt_handler,section(".icode")));
+void ADC(void)
+{
+    static unsigned char channel IBSS_ATTR;
+    /* read current value */
+    adc_data[(channel&0x03)] = ADVALUE;
+
+    /* switch channel
+     *
+     * set source remark
+     * ADCONFIG is 16bit wide so we have to shift data by 16bits left
+     * thats why we shift <<24 instead of <<8
+     */
+
+    channel++;
+
+    and_l(~(0x03<<24),&ADCONFIG);
+    or_l( (((channel&0x03) << 8 )|(1<<7))<<16, &ADCONFIG);
+    
+    if ( (channel & 0x03) == 0 )
+        /* disable ADC interrupt */
+        and_l((~(1<<6))<<16,&ADCONFIG);
+}
+
+unsigned short adc_scan(int channel)
+{
+    /* maybe we can drop &0x03 part */
+    return adc_data[(channel&0x03)];
+}
+
+void adc_tick(void)
+{
+    /* enable ADC interrupt */
+    or_l( ((1<<6))<<16, &ADCONFIG);
+}
+
+void adc_init(void)
+{
+    /* GPIO38 GPIO39 */
+    and_l(~((1<<6)|(1<<7)), &GPIO1_FUNCTION);
+
+    /* ADOUT_SEL = 01
+     * SOURCE SELECT = 000
+     * CLEAR INTERRUPT FLAG
+     * ENABLE INTERRUPT = 0
+     * ADOUT_DRIVE = 00
+     * ADCLK_SEL = 011 (busclk/8)
+     */
+
+    ADCONFIG = (1<<10)|(1<<8)|(1<<7)|0x03;
+
+    /* ADC interrupt level 4.0 */
+    or_l((4<<28), &INTPRI8);
+
+    /* create tick task which enables ADC interrupt */
+    tick_add_task(adc_tick);
+
+    /* let the interrupt handler fill readout array */
+    sleep(2);
+}