1 files changed, 400 insertions, 0 deletions
diff --git a/src/drivers/pc80/rtc/mc146818rtc.c b/src/drivers/pc80/rtc/mc146818rtc.c
new file mode 100644
index 0000000000..35dad3256a
--- /dev/null
+++ b/src/drivers/pc80/rtc/mc146818rtc.c
@@ -0,0 +1,400 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2014 The Chromium OS Authors. All rights reserved.
+ * Copyright (C) 2015 Timothy Pearson <tpearson@raptorengineeringinc.com>, Raptor Engineering
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/acpi.h>
+#include <bcd.h>
+#include <stdint.h>
+#include <version.h>
+#include <console/console.h>
+#include <pc80/mc146818rtc.h>
+#include <boot/coreboot_tables.h>
+#include <rtc.h>
+#include <string.h>
+#include <cbfs.h>
+
+/* There's no way around this include guard. option_table.h is autogenerated */
+#if CONFIG_USE_OPTION_TABLE
+#include "option_table.h"
+#else
+#define LB_CKS_RANGE_START	0
+#define LB_CKS_RANGE_END	0
+#define LB_CKS_LOC		0
+#endif
+
+#include <smp/spinlock.h>
+
+#if (defined(__PRE_RAM__) &&	\
+IS_ENABLED(CONFIG_HAVE_ROMSTAGE_NVRAM_CBFS_SPINLOCK))
+	#define LOCK_NVRAM_CBFS_SPINLOCK() spin_lock(romstage_nvram_cbfs_lock())
+	#define UNLOCK_NVRAM_CBFS_SPINLOCK() spin_unlock(romstage_nvram_cbfs_lock())
+#else
+	#define LOCK_NVRAM_CBFS_SPINLOCK() { }
+	#define UNLOCK_NVRAM_CBFS_SPINLOCK() { }
+#endif
+
+static void cmos_reset_date(void)
+{
+	/* Now setup a default date equals to the build date */
+	struct rtc_time time = {
+		.sec = 0,
+		.min = 0,
+		.hour = 1,
+		.mday = bcd2bin(coreboot_build_date.day),
+		.mon = bcd2bin(coreboot_build_date.month),
+		.year = (bcd2bin(coreboot_build_date.century) * 100) +
+			bcd2bin(coreboot_build_date.year),
+		.wday = bcd2bin(coreboot_build_date.weekday)
+	};
+	rtc_set(&time);
+}
+
+static int cmos_checksum_valid(int range_start, int range_end, int cks_loc)
+{
+	int i;
+	u16 sum, old_sum;
+
+	if (IS_ENABLED(CONFIG_STATIC_OPTION_TABLE))
+		return 1;
+
+	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 cmos_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);
+}
+
+#define RTC_CONTROL_DEFAULT (RTC_24H)
+#define RTC_FREQ_SELECT_DEFAULT (RTC_REF_CLCK_32KHZ | RTC_RATE_1024HZ)
+
+#ifndef __SMM__
+void cmos_init(bool invalid)
+{
+	bool cmos_invalid = invalid;
+	bool checksum_invalid = false;
+	bool clear_cmos;
+	size_t i;
+	uint8_t x;
+
+#ifndef __PRE_RAM__
+	/*
+	 * Avoid clearing pending interrupts and resetting the RTC control
+	 * register in the resume path because the Linux kernel relies on
+	 * this to know if it should restart the RTC timer queue if the wake
+	 * was due to the RTC alarm.
+	 */
+	if (acpi_is_wakeup_s3())
+		return;
+#endif /* __PRE_RAM__ */
+
+	printk(BIOS_DEBUG, "RTC Init\n");
+
+	if (IS_ENABLED(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 = !cmos_checksum_valid(PC_CKS_RANGE_START,
+						PC_CKS_RANGE_END, PC_CKS_LOC);
+
+		clear_cmos = false;
+	} else {
+		clear_cmos = true;
+	}
+
+	if (invalid || cmos_invalid || checksum_invalid) {
+		if (clear_cmos) {
+			cmos_write(0, 0x01);
+			cmos_write(0, 0x03);
+			cmos_write(0, 0x05);
+			for (i = 10; i < 128; i++)
+				cmos_write(0, i);
+		}
+
+		if (cmos_invalid)
+			cmos_reset_date();
+
+		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 (IS_ENABLED(CONFIG_USE_OPTION_TABLE)) {
+		/* See if there is a LB CMOS checksum error */
+		checksum_invalid = !cmos_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 */
+		cmos_set_checksum(PC_CKS_RANGE_START, PC_CKS_RANGE_END, PC_CKS_LOC);
+	}
+
+	/* Clear any pending interrupts */
+	cmos_read(RTC_INTR_FLAGS);
+}
+#endif	/* __SMM__ */
+
+
+/*
+ * 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
+ * returns CB_SUCCESS = successful, cb_err code if an error occurred
+ */
+static enum cb_err 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 CB_SUCCESS;
+}
+
+enum cb_err get_option(void *dest, const char *name)
+{
+	struct cmos_option_table *ct;
+	struct cmos_entries *ce;
+	size_t namelen;
+	int found = 0;
+
+	if (!IS_ENABLED(CONFIG_USE_OPTION_TABLE))
+		return CB_CMOS_OTABLE_DISABLED;
+
+	LOCK_NVRAM_CBFS_SPINLOCK();
+
+	/* Figure out how long name is */
+	namelen = strnlen(name, CMOS_MAX_NAME_LENGTH);
+
+	/* find the requested entry record */
+	ct = cbfs_boot_map_with_leak("cmos_layout.bin",
+					CBFS_COMPONENT_CMOS_LAYOUT, NULL);
+	if (!ct) {
+		printk(BIOS_ERR, "RTC: cmos_layout.bin could not be found. "
+						"Options are disabled\n");
+
+		UNLOCK_NVRAM_CBFS_SPINLOCK();
+		return CB_CMOS_LAYOUT_NOT_FOUND;
+	}
+	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);
+		UNLOCK_NVRAM_CBFS_SPINLOCK();
+		return CB_CMOS_OPTION_NOT_FOUND;
+	}
+
+	if (get_cmos_value(ce->bit, ce->length, dest) != CB_SUCCESS) {
+		UNLOCK_NVRAM_CBFS_SPINLOCK();
+		return CB_CMOS_ACCESS_ERROR;
+	}
+	if (!cmos_checksum_valid(LB_CKS_RANGE_START, LB_CKS_RANGE_END, LB_CKS_LOC)) {
+		UNLOCK_NVRAM_CBFS_SPINLOCK();
+		return CB_CMOS_CHECKSUM_INVALID;
+	}
+	UNLOCK_NVRAM_CBFS_SPINLOCK();
+	return CB_SUCCESS;
+}
+
+static enum cb_err 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 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 CB_ERR_ARG;
+
+		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) {
+		cmos_set_checksum(LB_CKS_RANGE_START, LB_CKS_RANGE_END,
+				  LB_CKS_LOC);
+	}
+	return CB_SUCCESS;
+}
+
+
+enum cb_err 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;
+
+	if (!IS_ENABLED(CONFIG_USE_OPTION_TABLE))
+		return CB_CMOS_OTABLE_DISABLED;
+
+	/* Figure out how long name is */
+	namelen = strnlen(name, CMOS_MAX_NAME_LENGTH);
+
+	/* find the requested entry record */
+	ct = cbfs_boot_map_with_leak("cmos_layout.bin",
+					CBFS_COMPONENT_CMOS_LAYOUT, NULL);
+	if (!ct) {
+		printk(BIOS_ERR, "cmos_layout.bin could not be found. "
+				 "Options are disabled\n");
+		return CB_CMOS_LAYOUT_NOT_FOUND;
+	}
+	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 CB_CMOS_OPTION_NOT_FOUND;
+	}
+
+	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})
+		    != CB_SUCCESS)
+			return CB_CMOS_ACCESS_ERROR;
+	}
+
+	if (set_cmos_value(ce->bit, length, value) != CB_SUCCESS)
+		return CB_CMOS_ACCESS_ERROR;
+
+	return CB_SUCCESS;
+}
+
+/*
+ * 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 cmos_check_update_date(void)
+{
+	u8 year, century;
+
+	/* Assume hardware always supports RTC_CLK_ALTCENTURY. */
+	century = cmos_read(RTC_CLK_ALTCENTURY);
+	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 */
+		cmos_reset_date();
+}
+
+int rtc_set(const struct rtc_time *time)
+{
+	cmos_write(bin2bcd(time->sec), RTC_CLK_SECOND);
+	cmos_write(bin2bcd(time->min), RTC_CLK_MINUTE);
+	cmos_write(bin2bcd(time->hour), RTC_CLK_HOUR);
+	cmos_write(bin2bcd(time->mday), RTC_CLK_DAYOFMONTH);
+	cmos_write(bin2bcd(time->mon), RTC_CLK_MONTH);
+	cmos_write(bin2bcd(time->year % 100), RTC_CLK_YEAR);
+	/* Same assumption as above: We always have RTC_CLK_ALTCENTURY */
+	cmos_write(bin2bcd(time->year / 100), RTC_CLK_ALTCENTURY);
+	cmos_write(bin2bcd(time->wday + 1), RTC_CLK_DAYOFWEEK);
+	return 0;
+}
+
+int rtc_get(struct rtc_time *time)
+{
+	time->sec = bcd2bin(cmos_read(RTC_CLK_SECOND));
+	time->min = bcd2bin(cmos_read(RTC_CLK_MINUTE));
+	time->hour = bcd2bin(cmos_read(RTC_CLK_HOUR));
+	time->mday = bcd2bin(cmos_read(RTC_CLK_DAYOFMONTH));
+	time->mon = bcd2bin(cmos_read(RTC_CLK_MONTH));
+	time->year = bcd2bin(cmos_read(RTC_CLK_YEAR));
+	/* Same assumption as above: We always have RTC_CLK_ALTCENTURY */
+	time->year += bcd2bin(cmos_read(RTC_CLK_ALTCENTURY)) * 100;
+	time->wday = bcd2bin(cmos_read(RTC_CLK_DAYOFWEEK)) - 1;
+	return 0;
+}