summaryrefslogtreecommitdiff
path: root/src/drivers/pc80/mc146818rtc.c
blob: d8d1778b5cc533c7c0d6c0f28083d30acb2365a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
#include <stdint.h>
#include <build.h>
#include <console/console.h>
#include <pc80/mc146818rtc.h>
#include <boot/coreboot_tables.h>
#include <string.h>
#if CONFIG_USE_OPTION_TABLE
#include "option_table.h"
#include <cbfs.h>
#endif
#if CONFIG_HAVE_ACPI_RESUME
#include <arch/acpi.h>
#endif


static void rtc_update_cmos_date(u8 has_century)
{
	/* Now setup a default date equals to the build date */
	cmos_write(0, RTC_CLK_SECOND);
	cmos_write(0, RTC_CLK_MINUTE);
	cmos_write(1, RTC_CLK_HOUR);
	cmos_write(COREBOOT_BUILD_WEEKDAY_BCD + 1, RTC_CLK_DAYOFWEEK);
	cmos_write(COREBOOT_BUILD_DAY_BCD, RTC_CLK_DAYOFMONTH);
	cmos_write(COREBOOT_BUILD_MONTH_BCD, RTC_CLK_MINUTE);
	cmos_write(COREBOOT_BUILD_YEAR_BCD, RTC_CLK_YEAR);
	if (has_century) cmos_write(0x20, RTC_CLK_ALTCENTURY);
}

#if CONFIG_USE_OPTION_TABLE
static int rtc_checksum_valid(int range_start, int range_end, int cks_loc)
{
	int i;
	u16 sum, old_sum;
	sum = 0;
	for(i = range_start; i <= range_end; i++) {
		sum += cmos_read(i);
	}
	old_sum = ((cmos_read(cks_loc)<<8) | cmos_read(cks_loc+1))&0x0ffff;
	return sum == old_sum;
}

static void rtc_set_checksum(int range_start, int range_end, int cks_loc)
{
	int i;
	u16 sum;
	sum = 0;
	for(i = range_start; i <= range_end; i++) {
		sum += cmos_read(i);
	}
	cmos_write(((sum >> 8) & 0x0ff), cks_loc);
	cmos_write(((sum >> 0) & 0x0ff), cks_loc+1);
}
#endif

#if CONFIG_ARCH_X86
#define RTC_CONTROL_DEFAULT (RTC_24H)
#define RTC_FREQ_SELECT_DEFAULT (RTC_REF_CLCK_32KHZ | RTC_RATE_1024HZ)
#else
#if CONFIG_ARCH_ALPHA
#define RTC_CONTROL_DEFAULT (RTC_SQWE | RTC_24H)
#define RTC_FREQ_SELECT_DEFAULT (RTC_REF_CLCK_32KHZ | RTC_RATE_1024HZ)
#endif
#endif

#ifndef __SMM__
void rtc_init(int invalid)
{
	int cmos_invalid = 0;
	int checksum_invalid = 0;
#if CONFIG_USE_OPTION_TABLE
	unsigned char x;
#endif

	printk(BIOS_DEBUG, "RTC Init\n");

#if CONFIG_USE_OPTION_TABLE
	/* See if there has been a CMOS power problem. */
	x = cmos_read(RTC_VALID);
	cmos_invalid = !(x & RTC_VRT);

	/* See if there is a CMOS checksum error */
	checksum_invalid = !rtc_checksum_valid(PC_CKS_RANGE_START,
			PC_CKS_RANGE_END,PC_CKS_LOC);

#define CLEAR_CMOS 0
#else
#define CLEAR_CMOS 1
#endif

	if (invalid || cmos_invalid || checksum_invalid) {
#if CLEAR_CMOS
		int i;

		cmos_write(0, 0x01);
		cmos_write(0, 0x03);
		cmos_write(0, 0x05);
		for(i = 10; i < 128; i++) {
			cmos_write(0, i);
		}
#endif
		if (cmos_invalid) {
			rtc_update_cmos_date(RTC_HAS_NO_ALTCENTURY);
		}

		printk(BIOS_WARNING, "RTC:%s%s%s%s\n",
			invalid?" Clear requested":"",
			cmos_invalid?" Power Problem":"",
			checksum_invalid?" Checksum invalid":"",
			CLEAR_CMOS?" zeroing cmos":"");
	}

	/* Setup the real time clock */
	cmos_write(RTC_CONTROL_DEFAULT, RTC_CONTROL);
	/* Setup the frequency it operates at */
	cmos_write(RTC_FREQ_SELECT_DEFAULT, RTC_FREQ_SELECT);
	/* Ensure all reserved bits are 0 in register D */
	cmos_write(RTC_VRT, RTC_VALID);

#if CONFIG_USE_OPTION_TABLE
	/* See if there is a LB CMOS checksum error */
	checksum_invalid = !rtc_checksum_valid(LB_CKS_RANGE_START,
			LB_CKS_RANGE_END,LB_CKS_LOC);
	if(checksum_invalid)
		printk(BIOS_DEBUG, "RTC: coreboot checksum invalid\n");

	/* Make certain we have a valid checksum */
	rtc_set_checksum(PC_CKS_RANGE_START,
                        PC_CKS_RANGE_END,PC_CKS_LOC);
#endif

#if CONFIG_HAVE_ACPI_RESUME
	/*
	 * Avoid clearing pending interrupts in the resume path because
	 * the Linux kernel relies on this to know if it should restart
	 * the RTC timerqueue if the wake was due to the RTC alarm.
	 */
	if (acpi_slp_type == 3)
		return;
#endif

	/* Clear any pending interrupts */
	(void) cmos_read(RTC_INTR_FLAGS);
}
#endif


#if CONFIG_USE_OPTION_TABLE
/* This routine returns the value of the requested bits
	input bit = bit count from the beginning of the cmos image
	      length = number of bits to include in the value
	      ret = a character pointer to where the value is to be returned
	output the value placed in ret
	      returns 0 = successful, -1 = an error occurred
*/
static int get_cmos_value(unsigned long bit, unsigned long length, void *vret)
{
	unsigned char *ret;
	unsigned long byte,byte_bit;
	unsigned long i;
	unsigned char uchar;

	/* The table is checked when it is built to ensure all
		values are valid. */
	ret = vret;
	byte=bit/8;	/* find the byte where the data starts */
	byte_bit=bit%8; /* find the bit in the byte where the data starts */
	if(length<9) {	/* one byte or less */
		uchar = cmos_read(byte); /* load the byte */
		uchar >>= byte_bit;	/* shift the bits to byte align */
		/* clear unspecified bits */
		ret[0] = uchar & ((1 << length) -1);
	}
	else {	/* more that one byte so transfer the whole bytes */
		for(i=0;length;i++,length-=8,byte++) {
			/* load the byte */
			ret[i]=cmos_read(byte);
		}
	}
	return 0;
}

int get_option(void *dest, const char *name)
{
	struct cmos_option_table *ct;
	struct cmos_entries *ce;
	size_t namelen;
	int found=0;

	/* Figure out how long name is */
	namelen = strnlen(name, CMOS_MAX_NAME_LENGTH);

	/* find the requested entry record */
	ct=cbfs_find_file("cmos_layout.bin", CBFS_COMPONENT_CMOS_LAYOUT);
	if (!ct) {
		printk(BIOS_ERR, "RTC: cmos_layout.bin could not be found. "
						"Options are disabled\n");
		return(-2);
	}
	ce=(struct cmos_entries*)((unsigned char *)ct + ct->header_length);
	for(;ce->tag==LB_TAG_OPTION;
		ce=(struct cmos_entries*)((unsigned char *)ce + ce->size)) {
		if (memcmp(ce->name, name, namelen) == 0) {
			found=1;
			break;
		}
	}
	if(!found) {
		printk(BIOS_DEBUG, "WARNING: No CMOS option '%s'.\n", name);
		return(-2);
	}

	if(get_cmos_value(ce->bit, ce->length, dest))
		return(-3);
	if(!rtc_checksum_valid(LB_CKS_RANGE_START,
			LB_CKS_RANGE_END,LB_CKS_LOC))
		return(-4);
	return(0);
}

static int set_cmos_value(unsigned long bit, unsigned long length, void *vret)
{
	unsigned char *ret;
	unsigned long byte,byte_bit;
	unsigned long i;
	unsigned char uchar, mask;
	unsigned int chksum_update_needed = 0;

	ret = vret;
	byte = bit / 8;			/* find the byte where the data starts */
	byte_bit = bit % 8;		/* find the bit in the byte where the data starts */
	if(length <= 8) {		/* one byte or less */
		mask = (1 << length) - 1;
		mask <<= byte_bit;

		uchar = cmos_read(byte);
		uchar &= ~mask;
		uchar |= (ret[0] << byte_bit);
		cmos_write(uchar, byte);
		if (byte >= LB_CKS_RANGE_START && byte <= LB_CKS_RANGE_END)
			chksum_update_needed = 1;
	} else {			/* more that one byte so transfer the whole bytes */
		if (byte_bit || length % 8)
			return -1;

		for(i=0; length; i++, length-=8, byte++)
			cmos_write(ret[i], byte);
			if (byte >= LB_CKS_RANGE_START && byte <= LB_CKS_RANGE_END)
				chksum_update_needed = 1;
	}

	if (chksum_update_needed) {
		rtc_set_checksum(LB_CKS_RANGE_START,
			LB_CKS_RANGE_END,LB_CKS_LOC);
	}
	return 0;
}


int set_option(const char *name, void *value)
{
	struct cmos_option_table *ct;
	struct cmos_entries *ce;
	unsigned long length;
	size_t namelen;
	int found=0;

	/* Figure out how long name is */
	namelen = strnlen(name, CMOS_MAX_NAME_LENGTH);

	/* find the requested entry record */
	ct=cbfs_find_file("cmos_layout.bin", CBFS_COMPONENT_CMOS_LAYOUT);
	if (!ct) {
		printk(BIOS_ERR, "cmos_layout.bin could not be found. Options are disabled\n");
		return(-2);
	}
	ce=(struct cmos_entries*)((unsigned char *)ct + ct->header_length);
	for(;ce->tag==LB_TAG_OPTION;
		ce=(struct cmos_entries*)((unsigned char *)ce + ce->size)) {
		if (memcmp(ce->name, name, namelen) == 0) {
			found=1;
			break;
		}
	}
	if(!found) {
		printk(BIOS_DEBUG, "WARNING: No CMOS option '%s'.\n", name);
		return(-2);
	}

	length = ce->length;
	if (ce->config == 's') {
		length = MAX(strlen((const char *)value) * 8, ce->length - 8);
		/* make sure the string is null terminated */
		if ((set_cmos_value(ce->bit + ce->length - 8, 8, &(u8[]){0})))
			return (-3);
	}

	if ((set_cmos_value(ce->bit, length, value)))
		return (-3);

	return 0;
}
#endif /* CONFIG_USE_OPTION_TABLE */

/*
 * If the CMOS is cleared, the rtc_reg has the invalid date. That
 * hurts some OSes. Even if we don't set USE_OPTION_TABLE, we need
 * to make sure the date is valid.
 */
void rtc_check_update_cmos_date(u8 has_century)
{
	u8 year, century;

	/* Note: We need to check if the hardware supports RTC_CLK_ALTCENTURY. */
	century	= has_century ? cmos_read(RTC_CLK_ALTCENTURY) : 0;
	year	= cmos_read(RTC_CLK_YEAR);

	/* TODO: If century is 0xFF, 100% that the cmos is cleared.
	 * Other than that, so far rtc_year is the only entry to check if the date is valid. */
	if (century > 0x99 || year > 0x99) {	/* Invalid date */
		rtc_update_cmos_date(has_century);
	}
}