1 #include <console/console.h>
2 #include <pc80/mc146818rtc.h>
3 #include <boot/coreboot_tables.h>
5 #if CONFIG_USE_OPTION_TABLE
6 #include "option_table.h"
9 /* control registers - Moto names
17 /**********************************************************************
19 **********************************************************************/
20 #define RTC_FREQ_SELECT RTC_REG_A
22 /* update-in-progress - set to "1" 244 microsecs before RTC goes off the bus,
23 * reset after update (may take 1.984ms @ 32768Hz RefClock) is complete,
24 * totalling to a max high interval of 2.228 ms.
27 # define RTC_DIV_CTL 0x70
28 /* divider control: refclock values 4.194 / 1.049 MHz / 32.768 kHz */
29 # define RTC_REF_CLCK_4MHZ 0x00
30 # define RTC_REF_CLCK_1MHZ 0x10
31 # define RTC_REF_CLCK_32KHZ 0x20
32 /* 2 values for divider stage reset, others for "testing purposes only" */
33 # define RTC_DIV_RESET1 0x60
34 # define RTC_DIV_RESET2 0x70
35 /* Periodic intr. / Square wave rate select. 0=none, 1=32.8kHz,... 15=2Hz */
36 # define RTC_RATE_SELECT 0x0F
37 # define RTC_RATE_NONE 0x00
38 # define RTC_RATE_32786HZ 0x01
39 # define RTC_RATE_16384HZ 0x02
40 # define RTC_RATE_8192HZ 0x03
41 # define RTC_RATE_4096HZ 0x04
42 # define RTC_RATE_2048HZ 0x05
43 # define RTC_RATE_1024HZ 0x06
44 # define RTC_RATE_512HZ 0x07
45 # define RTC_RATE_256HZ 0x08
46 # define RTC_RATE_128HZ 0x09
47 # define RTC_RATE_64HZ 0x0a
48 # define RTC_RATE_32HZ 0x0b
49 # define RTC_RATE_16HZ 0x0c
50 # define RTC_RATE_8HZ 0x0d
51 # define RTC_RATE_4HZ 0x0e
52 # define RTC_RATE_2HZ 0x0f
54 /**********************************************************************/
55 #define RTC_CONTROL RTC_REG_B
56 # define RTC_SET 0x80 /* disable updates for clock setting */
57 # define RTC_PIE 0x40 /* periodic interrupt enable */
58 # define RTC_AIE 0x20 /* alarm interrupt enable */
59 # define RTC_UIE 0x10 /* update-finished interrupt enable */
60 # define RTC_SQWE 0x08 /* enable square-wave output */
61 # define RTC_DM_BINARY 0x04 /* all time/date values are BCD if clear */
62 # define RTC_24H 0x02 /* 24 hour mode - else hours bit 7 means pm */
63 # define RTC_DST_EN 0x01 /* auto switch DST - works f. USA only */
65 /**********************************************************************/
66 #define RTC_INTR_FLAGS RTC_REG_C
67 /* caution - cleared by read */
68 # define RTC_IRQF 0x80 /* any of the following 3 is active */
73 /**********************************************************************/
74 #define RTC_VALID RTC_REG_D
75 # define RTC_VRT 0x80 /* valid RAM and time */
76 /**********************************************************************/
78 #if CONFIG_USE_OPTION_TABLE
79 static int rtc_checksum_valid(int range_start, int range_end, int cks_loc)
82 unsigned sum, old_sum;
84 for(i = range_start; i <= range_end; i++) {
88 old_sum = ((cmos_read(cks_loc)<<8) | cmos_read(cks_loc+1))&0x0ffff;
89 return sum == old_sum;
92 static void rtc_set_checksum(int range_start, int range_end, int cks_loc)
97 for(i = range_start; i <= range_end; i++) {
100 sum = ~(sum & 0x0ffff);
101 cmos_write(((sum >> 8) & 0x0ff), cks_loc);
102 cmos_write(((sum >> 0) & 0x0ff), cks_loc+1);
107 #define RTC_CONTROL_DEFAULT (RTC_24H)
108 #define RTC_FREQ_SELECT_DEFAULT (RTC_REF_CLCK_32KHZ | RTC_RATE_1024HZ)
110 #if CONFIG_ARCH_ALPHA
111 #define RTC_CONTROL_DEFAULT (RTC_SQWE | RTC_24H)
112 #define RTC_FREQ_SELECT_DEFAULT (RTC_REF_CLCK_32KHZ | RTC_RATE_1024HZ)
116 void rtc_init(int invalid)
118 #if CONFIG_USE_OPTION_TABLE
120 int cmos_invalid, checksum_invalid;
123 printk(BIOS_DEBUG, "RTC Init\n");
125 #if CONFIG_USE_OPTION_TABLE
126 /* See if there has been a CMOS power problem. */
127 x = cmos_read(RTC_VALID);
128 cmos_invalid = !(x & RTC_VRT);
130 /* See if there is a CMOS checksum error */
131 checksum_invalid = !rtc_checksum_valid(PC_CKS_RANGE_START,
132 PC_CKS_RANGE_END,PC_CKS_LOC);
134 if (invalid || cmos_invalid || checksum_invalid) {
135 printk(BIOS_WARNING, "RTC:%s%s%s zeroing cmos\n",
136 invalid?" Clear requested":"",
137 cmos_invalid?" Power Problem":"",
138 checksum_invalid?" Checksum invalid":"");
143 for(i = 10; i < 48; i++) {
148 /* Now setup a default date of Sat 1 January 2000 */
149 cmos_write(0, 0x00); /* seconds */
150 cmos_write(0, 0x02); /* minutes */
151 cmos_write(1, 0x04); /* hours */
152 cmos_write(7, 0x06); /* day of week */
153 cmos_write(1, 0x07); /* day of month */
154 cmos_write(1, 0x08); /* month */
155 cmos_write(0, 0x09); /* year */
161 /* Setup the real time clock */
162 cmos_write(RTC_CONTROL_DEFAULT, RTC_CONTROL);
163 /* Setup the frequency it operates at */
164 cmos_write(RTC_FREQ_SELECT_DEFAULT, RTC_FREQ_SELECT);
166 #if CONFIG_USE_OPTION_TABLE
167 /* See if there is a LB CMOS checksum error */
168 checksum_invalid = !rtc_checksum_valid(LB_CKS_RANGE_START,
169 LB_CKS_RANGE_END,LB_CKS_LOC);
171 printk(BIOS_DEBUG, "Invalid CMOS LB checksum\n");
173 /* Make certain we have a valid checksum */
174 rtc_set_checksum(PC_CKS_RANGE_START,
175 PC_CKS_RANGE_END,PC_CKS_LOC);
178 /* Clear any pending interrupts */
179 (void) cmos_read(RTC_INTR_FLAGS);
183 #if CONFIG_USE_OPTION_TABLE
184 /* This routine returns the value of the requested bits
185 input bit = bit count from the beginning of the cmos image
186 length = number of bits to include in the value
187 ret = a character pointer to where the value is to be returned
188 output the value placed in ret
189 returns 0 = successful, -1 = an error occurred
191 static int get_cmos_value(unsigned long bit, unsigned long length, void *vret)
194 unsigned long byte,byte_bit;
198 /* The table is checked when it is built to ensure all
201 byte=bit/8; /* find the byte where the data starts */
202 byte_bit=bit%8; /* find the bit in the byte where the data starts */
203 if(length<9) { /* one byte or less */
204 uchar = cmos_read(byte); /* load the byte */
205 uchar >>= byte_bit; /* shift the bits to byte align */
206 /* clear unspecified bits */
207 ret[0] = uchar & ((1 << length) -1);
209 else { /* more that one byte so transfer the whole bytes */
210 for(i=0;length;i++,length-=8,byte++) {
212 ret[i]=cmos_read(byte);
218 int get_option(void *dest, const char *name)
220 extern struct cmos_option_table option_table;
221 struct cmos_option_table *ct;
222 struct cmos_entries *ce;
226 /* Figure out how long name is */
227 namelen = strnlen(name, CMOS_MAX_NAME_LENGTH);
229 /* find the requested entry record */
231 ce=(struct cmos_entries*)((unsigned char *)ct + ct->header_length);
232 for(;ce->tag==LB_TAG_OPTION;
233 ce=(struct cmos_entries*)((unsigned char *)ce + ce->size)) {
234 if (memcmp(ce->name, name, namelen) == 0) {
240 printk(BIOS_DEBUG, "WARNING: No CMOS option '%s'.\n", name);
244 if(get_cmos_value(ce->bit, ce->length, dest))
246 if(!rtc_checksum_valid(LB_CKS_RANGE_START,
247 LB_CKS_RANGE_END,LB_CKS_LOC))
251 #endif /* CONFIG_USE_OPTION_TABLE */