drivers/pc80/rtc: Separate {get|set}_option() support

Move things depending on option_table.h to a separate file.

Change-Id: Ib23fcd89bf4efef9072fcaea1d8699145c1f2983
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38193
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

1 files changed, 235 insertions, 0 deletions

diff --git a/src/drivers/pc80/rtc/option.c b/src/drivers/pc80/rtc/option.c
new file mode 100644
index 0000000000..c7851e5357
--- /dev/null
+++ b/src/drivers/pc80/rtc/option.c
@@ -0,0 +1,235 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * 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 <console/console.h>
+#include <string.h>
+#include <cbfs.h>
+#include <option.h>
+#include <pc80/mc146818rtc.h>
+#include <types.h>
+
+/* option_table.h is autogenerated */
+#include "option_table.h"
+
+/* Don't warn for checking >= LB_CKS_RANGE_START even though it may be 0. */
+#pragma GCC diagnostic ignored "-Wtype-limits"
+
+/*
+ * 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 than 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;
+}
+
+static enum cb_err locate_cmos_layout(struct region_device *rdev)
+{
+	uint32_t cbfs_type = CBFS_COMPONENT_CMOS_LAYOUT;
+	MAYBE_STATIC_BSS struct cbfsf fh = {};
+
+	/*
+	 * In case VBOOT is enabled and this function is called from SMM,
+	 * we have multiple CMOS layout files and to locate them we'd need to
+	 * include VBOOT into SMM...
+	 *
+	 * Support only one CMOS layout in the 'COREBOOT' region for now.
+	 */
+	if (!region_device_sz(&(fh.data))) {
+		if (cbfs_locate_file_in_region(&fh, "COREBOOT", "cmos_layout.bin",
+					       &cbfs_type)) {
+			printk(BIOS_ERR, "RTC: cmos_layout.bin could not be found. "
+						"Options are disabled\n");
+			return CB_CMOS_LAYOUT_NOT_FOUND;
+		}
+	}
+
+	cbfs_file_data(rdev, &fh);
+
+	return CB_SUCCESS;
+}
+
+enum cb_err cmos_get_option(void *dest, const char *name)
+{
+	struct cmos_option_table *ct;
+	struct region_device rdev;
+	struct cmos_entries *ce;
+	size_t namelen;
+	int found = 0;
+
+	/* Figure out how long name is */
+	namelen = strnlen(name, CMOS_MAX_NAME_LENGTH);
+
+	if (locate_cmos_layout(&rdev) != CB_SUCCESS) {
+		return CB_CMOS_LAYOUT_NOT_FOUND;
+	}
+	ct = rdev_mmap_full(&rdev);
+	if (!ct) {
+		printk(BIOS_ERR, "RTC: cmos_layout.bin could not be mapped. "
+		       "Options are disabled\n");
+
+		return CB_CMOS_LAYOUT_NOT_FOUND;
+	}
+
+	/* find the requested entry record */
+	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, "No CMOS option '%s'.\n", name);
+		rdev_munmap(&rdev, ct);
+		return CB_CMOS_OPTION_NOT_FOUND;
+	}
+
+	if (!cmos_checksum_valid(LB_CKS_RANGE_START, LB_CKS_RANGE_END, LB_CKS_LOC)) {
+		rdev_munmap(&rdev, ct);
+		return CB_CMOS_CHECKSUM_INVALID;
+	}
+	if (get_cmos_value(ce->bit, ce->length, dest) != CB_SUCCESS) {
+		rdev_munmap(&rdev, ct);
+		return CB_CMOS_ACCESS_ERROR;
+	}
+	rdev_munmap(&rdev, ct);
+	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 cmos_set_option(const char *name, void *value)
+{
+	struct cmos_option_table *ct;
+	struct region_device rdev;
+	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);
+
+	if (locate_cmos_layout(&rdev) != CB_SUCCESS) {
+		return CB_CMOS_LAYOUT_NOT_FOUND;
+	}
+	ct = rdev_mmap_full(&rdev);
+	if (!ct) {
+		printk(BIOS_ERR, "RTC: cmos_layout.bin could not be mapped. "
+		       "Options are disabled\n");
+
+		return CB_CMOS_LAYOUT_NOT_FOUND;
+	}
+
+	/* find the requested entry record */
+	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);
+		rdev_munmap(&rdev, ct);
+		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) {
+			rdev_munmap(&rdev, ct);
+			return CB_CMOS_ACCESS_ERROR;
+		}
+	}
+
+	if (set_cmos_value(ce->bit, length, value) != CB_SUCCESS) {
+		rdev_munmap(&rdev, ct);
+		return CB_CMOS_ACCESS_ERROR;
+	}
+
+	rdev_munmap(&rdev, ct);
+	return CB_SUCCESS;
+}