mrobe 100: real time clock (if anybody recognises the RTC chip let me know)

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@16208 a1c6a512-1295-4272-9138-f99709370657

firmware/drivers/rtc/rtc_mr100.c

@@ -0,0 +1,114 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2008 by Robert Kukla 
+ * 
+ * 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 "rtc.h" 
+#include "logf.h"
+#include "sw_i2c.h"
+#include "i2c-pp.h"
+
+/* The RTC chip is unknown, the information about it was gathered by 
+ * reverse engineering the bootloader.
+ */
+
+#define RTC_ADDR   0x60
+
+#define RTC_CMD_CTRL 0 /* OF uses it with single byte 1 or 2 */
+#define RTC_CMD_UNKN 1 /* OF uses it with single byte 8 */
+#define RTC_CMD_DATA 2
+#define RTC_CMD_TEST 7 /* OF uses it with single byte 0xAA */
+
+/* private */
+
+static void reverse_bits(unsigned char* v, int size) {
+
+    int i,j,in,out=0;
+
+    for(j=0; j<size; j++) {   
+        in = v[j];
+        for(i=0; i<8; i++) {
+           out |= (in & 1);
+           in  = in >>1;
+           out = out<<1;
+        }   
+        v[j] = out>>1;
+    }   
+}    
+
+static int sw_i2c(int access, unsigned char chip, unsigned char cmd, 
+                              unsigned char* buf, int count) {
+    int i;
+
+    i2c_lock();
+    GPIOC_ENABLE |=  0x00000030;
+
+    chip|=cmd<<1;
+
+    if(access == SW_I2C_READ) {
+        i = sw_i2c_read(chip, 0, buf, count);
+        reverse_bits(buf, count);
+    } else {
+        reverse_bits(buf, count);
+        i = sw_i2c_write(chip, 0, buf, count);
+    }    
+
+    GPIOC_ENABLE &= ~0x00000030;
+    i2c_unlock();
+    
+    return i;
+}
+
+/* public */
+
+void rtc_init(void)
+{
+    sw_i2c_init();
+
+    /* to set a time while buttons are stil not working
+    unsigned char v[7] = {0x00,0x47,0x17,0x06,0x03,0x02,0x08};
+    rtc_write_datetime(v);
+    */
+}
+
+int rtc_read_datetime(unsigned char* buf)
+{
+    int i;
+    unsigned char v[7];
+
+    i = sw_i2c(SW_I2C_READ, RTC_ADDR, RTC_CMD_DATA, v, 7);
+
+    v[4] &= 0x3f; /* mask out p.m. flag */
+    
+    for(i=0; i<7; i++) 
+        buf[i] = v[6-i];
+    
+    return i;
+}
+
+int rtc_write_datetime(unsigned char* buf)
+{
+    int i;
+    unsigned char v[7];
+
+    for(i=0; i<7; i++) 
+        v[i]=buf[6-i];
+        
+    i = sw_i2c(SW_I2C_WRITE, RTC_ADDR, RTC_CMD_DATA, v, 7);
+    
+    return i;
+}
+