1 /*
2 * rs5c372.c
3 *
4 * Device driver for Ricoh's Real Time Controller RS5C372A.
5 *
6 * Copyright (C) 2004 Gary Jennejohn garyj@denx.de
7 *
8 * Based in part in ds1307.c -
9 * (C) Copyright 2001, 2002, 2003
10 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
11 * Keith Outwater, keith_outwater@mvis.com`
12 * Steven Scholz, steven.scholz@imc-berlin.de
13 *
14 * See file CREDITS for list of people who contributed to this
15 * project.
16 *
17 * This program is free software; you can redistribute it and/or modify
18 * it under the terms of the GNU General Public License version 2 as
19 * published by the Free Software Foundation.
20 */
21
22 #include <common.h>
23 #include <command.h>
24 #include <rtc.h>
25 #include <i2c.h>
26
27 /*
28 * Reads are always done starting with register 15, which requires some
29 * jumping-through-hoops to access the data correctly.
30 *
31 * Writes are always done starting with register 0.
32 */
33
34 #define DEBUG 0
35
36 #if DEBUG
37 static unsigned int rtc_debug = DEBUG;
38 #else
39 #define rtc_debug 0 /* gcc will remove all the debug code for us */
40 #endif
41
42 #ifndef CONFIG_SYS_I2C_RTC_ADDR
43 #define CONFIG_SYS_I2C_RTC_ADDR 0x32
44 #endif
45
46 #define RS5C372_RAM_SIZE 0x10
47 #define RATE_32000HZ 0x80 /* Rate Select 32.000KHz */
48 #define RATE_32768HZ 0x00 /* Rate Select 32.768KHz */
49
50 #define STATUS_XPT 0x10 /* data invalid because voltage was 0 */
51
52 #define USE_24HOUR_MODE 0x20
53 #define TWELVE_HOUR_MODE(n) ((((n) >> 5) & 1) == 0)
54 #define HOURS_AP(n) (((n) >> 5) & 1)
55 #define HOURS_12(n) bcd2bin((n) & 0x1F)
56 #define HOURS_24(n) bcd2bin((n) & 0x3F)
57
58
59 static int setup_done = 0;
60
61 static int
rs5c372_readram(unsigned char * buf,int len)62 rs5c372_readram(unsigned char *buf, int len)
63 {
64 int ret;
65
66 ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, len);
67 if (ret != 0) {
68 printf("%s: failed to read\n", __FUNCTION__);
69 return ret;
70 }
71
72 if (buf[0] & STATUS_XPT)
73 printf("### Warning: RTC lost power\n");
74
75 return ret;
76 }
77
78 static void
rs5c372_enable(void)79 rs5c372_enable(void)
80 {
81 unsigned char buf[RS5C372_RAM_SIZE + 1];
82 int ret;
83
84 /* note that this returns reg. 15 in buf[1] */
85 ret = rs5c372_readram(&buf[1], RS5C372_RAM_SIZE);
86 if (ret != 0) {
87 printf("%s: failed\n", __FUNCTION__);
88 return;
89 }
90
91 buf[0] = 0;
92 /* we want to start writing at register 0 so we have to copy the */
93 /* register contents up one slot */
94 for (ret = 2; ret < 9; ret++)
95 buf[ret - 1] = buf[ret];
96 /* registers 0 to 6 (time values) are not touched */
97 buf[8] = RATE_32768HZ; /* reg. 7 */
98 buf[9] = 0; /* reg. 8 */
99 buf[10] = 0; /* reg. 9 */
100 buf[11] = 0; /* reg. 10 */
101 buf[12] = 0; /* reg. 11 */
102 buf[13] = 0; /* reg. 12 */
103 buf[14] = 0; /* reg. 13 */
104 buf[15] = 0; /* reg. 14 */
105 buf[16] = USE_24HOUR_MODE; /* reg. 15 */
106 ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, RS5C372_RAM_SIZE+1);
107 if (ret != 0) {
108 printf("%s: failed\n", __FUNCTION__);
109 return;
110 }
111 setup_done = 1;
112
113 return;
114 }
115
116 static void
rs5c372_convert_to_time(struct rtc_time * dt,unsigned char * buf)117 rs5c372_convert_to_time(struct rtc_time *dt, unsigned char *buf)
118 {
119 /* buf[0] is register 15 */
120 dt->tm_sec = bcd2bin(buf[1]);
121 dt->tm_min = bcd2bin(buf[2]);
122
123 if (TWELVE_HOUR_MODE(buf[0])) {
124 dt->tm_hour = HOURS_12(buf[3]);
125 if (HOURS_AP(buf[3])) /* PM */
126 dt->tm_hour += 12;
127 } else /* 24-hour-mode */
128 dt->tm_hour = HOURS_24(buf[3]);
129
130 dt->tm_mday = bcd2bin(buf[5]);
131 dt->tm_mon = bcd2bin(buf[6]);
132 dt->tm_year = bcd2bin(buf[7]);
133 if (dt->tm_year >= 70)
134 dt->tm_year += 1900;
135 else
136 dt->tm_year += 2000;
137 /* 0 is Sunday */
138 dt->tm_wday = bcd2bin(buf[4] & 0x07);
139 dt->tm_yday = 0;
140 dt->tm_isdst= 0;
141
142 if(rtc_debug > 2) {
143 printf("rs5c372_convert_to_time: year = %d\n", dt->tm_year);
144 printf("rs5c372_convert_to_time: mon = %d\n", dt->tm_mon);
145 printf("rs5c372_convert_to_time: mday = %d\n", dt->tm_mday);
146 printf("rs5c372_convert_to_time: hour = %d\n", dt->tm_hour);
147 printf("rs5c372_convert_to_time: min = %d\n", dt->tm_min);
148 printf("rs5c372_convert_to_time: sec = %d\n", dt->tm_sec);
149 }
150 }
151
152 /*
153 * Get the current time from the RTC
154 */
155 int
rtc_get(struct rtc_time * tmp)156 rtc_get (struct rtc_time *tmp)
157 {
158 unsigned char buf[RS5C372_RAM_SIZE];
159 int ret;
160
161 if (!setup_done)
162 rs5c372_enable();
163
164 if (!setup_done)
165 return -1;
166
167 memset(buf, 0, sizeof(buf));
168
169 /* note that this returns reg. 15 in buf[0] */
170 ret = rs5c372_readram(buf, RS5C372_RAM_SIZE);
171 if (ret != 0) {
172 printf("%s: failed\n", __FUNCTION__);
173 return -1;
174 }
175
176 rs5c372_convert_to_time(tmp, buf);
177
178 return 0;
179 }
180
181 /*
182 * Set the RTC
183 */
rtc_set(struct rtc_time * tmp)184 int rtc_set (struct rtc_time *tmp)
185 {
186 unsigned char buf[8], reg15;
187 int ret;
188
189 if (!setup_done)
190 rs5c372_enable();
191
192 if (!setup_done)
193 return -1;
194
195 if(rtc_debug > 2) {
196 printf("rtc_set: tm_year = %d\n", tmp->tm_year);
197 printf("rtc_set: tm_mon = %d\n", tmp->tm_mon);
198 printf("rtc_set: tm_mday = %d\n", tmp->tm_mday);
199 printf("rtc_set: tm_hour = %d\n", tmp->tm_hour);
200 printf("rtc_set: tm_min = %d\n", tmp->tm_min);
201 printf("rtc_set: tm_sec = %d\n", tmp->tm_sec);
202 }
203
204 memset(buf, 0, sizeof(buf));
205
206 /* only read register 15 */
207 ret = i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 1);
208
209 if (ret == 0) {
210 /* need to save register 15 */
211 reg15 = buf[0];
212 buf[0] = 0; /* register address on RS5C372 */
213 buf[1] = bin2bcd(tmp->tm_sec);
214 buf[2] = bin2bcd(tmp->tm_min);
215 /* need to handle 12 hour mode */
216 if (TWELVE_HOUR_MODE(reg15)) {
217 if (tmp->tm_hour >= 12) { /* PM */
218 /* 12 PM is a special case */
219 if (tmp->tm_hour == 12)
220 buf[3] = bin2bcd(tmp->tm_hour);
221 else
222 buf[3] = bin2bcd(tmp->tm_hour - 12);
223 buf[3] |= 0x20;
224 }
225 } else {
226 buf[3] = bin2bcd(tmp->tm_hour);
227 }
228
229 buf[4] = bin2bcd(tmp->tm_wday);
230 buf[5] = bin2bcd(tmp->tm_mday);
231 buf[6] = bin2bcd(tmp->tm_mon);
232 if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
233 printf("WARNING: year should be between 1970 and 2069!\n");
234 buf[7] = bin2bcd(tmp->tm_year % 100);
235
236 ret = i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 0, buf, 8);
237 if (ret != 0) {
238 printf("rs5c372_set_datetime(), i2c_master_send() returned %d\n",ret);
239 return -1;
240 }
241 } else {
242 return -1;
243 }
244
245 return 0;
246 }
247
248 /*
249 * Reset the RTC.
250 */
251 void
rtc_reset(void)252 rtc_reset (void)
253 {
254 if (!setup_done)
255 rs5c372_enable();
256 }
257