firmware/drivers/rtc/rtc_mr100.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2008 by Robert Kukla
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21 #include "rtc.h"
  22 #include "logf.h"
  23 #include "sw_i2c.h"
  24 #include "i2c-pp.h"
  25
  26 /* The RTC chip is unknown, the information about it was gathered by
  27  * reverse engineering the bootloader.
  28  */
  29
  30 #define RTC_ADDR   0x60
  31
  32 #define RTC_CMD_CTRL 0 /* OF uses it with single byte 1 or 2 */
  33 #define RTC_CMD_UNKN 1 /* OF uses it with single byte 8 */
  34 #define RTC_CMD_DATA 2
  35 #define RTC_CMD_TEST 7 /* OF uses it with single byte 0xAA */
  36
  37 /* private */
  38
  39 static void reverse_bits(unsigned char* v, int size) {
  40
  41     int i,j,in,out=0;
  42
  43     for(j=0; j<size; j++) {
  44         in = v[j];
  45         out = in;
  46         for(i=0; i<7; i++) {
  47            in  = in >>1;
  48            out = out<<1;
  49            out |= (in & 1);
  50         }
  51         v[j] = out;
  52     }
  53 }
  54
  55 static int sw_i2c(int access, int cmd, unsigned char* buf, int count) {
  56     int i, addr;
  57
  58     i2c_lock();
  59     GPIOC_ENABLE |=  0x00000030;
  60
  61     addr = RTC_ADDR | (cmd<<1);
  62
  63     if(access == SW_I2C_READ) {
  64         i = sw_i2c_read(addr, 0, buf, count);
  65         reverse_bits(buf, count);
  66     } else {
  67         reverse_bits(buf, count);
  68         i = sw_i2c_write(addr, 0, buf, count);
  69     }
  70
  71     GPIOC_ENABLE &= ~0x00000030;
  72     i2c_unlock();
  73
  74     return i;
  75 }
  76
  77 /* public */
  78
  79 void rtc_init(void)
  80 {
  81     sw_i2c_init();
  82
  83 #if 0
  84     /* init sequence from OF for reference */
  85     /* currently we rely on the bootloader doing it for us */
  86
  87     bool flag = true;
  88     unsigned char data;
  89     unsigned char v[7] = {0x00,0x47,0x17,0x06,0x03,0x02,0x08}; /* random time */
  90
  91     if(flag) {
  92
  93         GPIOB_ENABLE |= 0x80;
  94         GPIOB_OUTPUT_EN |= 0x80;
  95         GPIOB_OUTPUT_VAL &= ~0x80;
  96
  97         DEV_EN |= 0x1000;
  98         /* some more stuff that is not clear */
  99
 100         sw_i2c(SW_I2C_READ, RTC_CMD_CTRL, &data, 1);
 101         if((data<<0x18)>>0x1e) {        /* bit 7 & 6 */
 102
 103             data = 1;
 104             sw_i2c(SW_I2C_WRITE, RTC_CMD_CTRL, &data, 1);
 105
 106             data = 1;
 107             sw_i2c(SW_I2C_WRITE, RTC_CMD_CTRL, &data, 1);
 108
 109             data = 8;
 110             sw_i2c(SW_I2C_WRITE, RTC_CMD_UNKN, &data, 1);
 111
 112             /* more stuff, perhaps set up time array? */
 113
 114             rtc_write_datetime(v);
 115
 116         }
 117         data = 2;
 118         sw_i2c(SW_I2C_WRITE, RTC_CMD_CTRL, &data, 1);
 119
 120     }
 121     data = 2;
 122     sw_i2c(SW_I2C_WRITE, RTC_CMD_CTRL, &data, 1);
 123 #endif
 124
 125 }
 126
 127 int rtc_read_datetime(unsigned char* buf)
 128 {
 129     int i;
 130     unsigned char v[7];
 131
 132     i = sw_i2c(SW_I2C_READ, RTC_CMD_DATA, v, 7);
 133
 134     v[4] &= 0x3f; /* mask out p.m. flag */
 135
 136     for(i=0; i<7; i++)
 137         buf[i] = v[6-i];
 138
 139     return i;
 140 }
 141
 142 int rtc_write_datetime(unsigned char* buf)
 143 {
 144     int i;
 145     unsigned char v[7];
 146
 147     for(i=0; i<7; i++)
 148         v[i]=buf[6-i];
 149
 150     i = sw_i2c(SW_I2C_WRITE, RTC_CMD_DATA, v, 7);
 151
 152     return i;
 153 }
 154