Change in flashrom[master]: [RFC] writeprotect.h: add structure to represent chip wp state

[Nikolai Artemiev (Code Review)]

Nikolai Artemiev has uploaded this change for review. ( https://review.coreboot.org/c/flashrom/+/58478 )

Change subject: [RFC] writeprotect.h: add structure to represent chip wp state
......................................................................

[RFC] writeprotect.h: add structure to represent chip wp state

Adds a wp_chip_state structure to capture the complete state of a chip's
wp-related status bits and serve as an intermediate representation
throughout writeprotect code.

Also adds a function that fills out the wp_chip_state strucutre by
reading the chip's registers and intrepreting them using the status
register bit map.

BUG=b:195381327,b:153800563
TEST=writeprotect commands
BRANCH=none

Change-Id: I17dee630248ce7b51e624a6e46d7097d5d0de809
Signed-off-by: Nikolai Artemiev 
---
M writeprotect.c
M writeprotect.h
2 files changed, 67 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/78/58478/1

diff --git a/writeprotect.c b/writeprotect.c
index 1d907f6..24239db 100644
--- a/writeprotect.c
+++ b/writeprotect.c
@@ -23,6 +23,54 @@
 #include "chipdrivers.h"
 #include "writeprotect.h"

+
+static int read_reg_bit(
+		const struct flashctx *flash,
+		const struct reg_bit_info bit,
+		uint8_t *value,
+		bool *present)
+{
+	*value = 0;
+	*present = bit.reg != INVALID_REG;
+
+	if (*present) {
+		if (spi_read_register(flash, bit.reg, value))
+			return 1;
+		*value = (*value >> bit.bit_index) & 1;
+	}
+
+	return 0;
+}
+
+static int read_wp_chip_state(struct flashctx *flash, struct wp_chip_state *wpst)
+{
+	const struct reg_bit_map *bits = &flash->chip->reg_bits;
+	bool tmp;
+
+	*wpst = (struct wp_chip_state) {0};
+
+	int ret = 0;
+	ret |= read_reg_bit(flash, bits->tb,  &wpst->tb,  &wpst->tb_bit_present);
+	ret |= read_reg_bit(flash, bits->sec, &wpst->sec, &wpst->sec_bit_present);
+	ret |= read_reg_bit(flash, bits->cmp, &wpst->cmp, &wpst->cmp_bit_present);
+
+	for(size_t i = 0; bits->bp[i].reg != INVALID_REG; i++) {
+		ret |= read_reg_bit(flash, bits->bp[i], &wpst->bp[i], &tmp);
+		wpst->bp_bit_count = i + 1;
+	}
+
+	for(size_t i = 0; bits->srp[i].reg != INVALID_REG; i++) {
+		ret |= read_reg_bit(flash, bits->srp[i], &wpst->srp[i], &tmp);
+		wpst->srp_bit_count = i + 1;
+	}
+
+	if (ret)
+		msg_gerr("Reading write protection configuration failed!\n");
+
+	return ret;
+}
+void *suppress_unused_warning_for_read_wp_chip_state = read_wp_chip_state;
+
 bool wp_supported(struct flashctx *flash)
 {
    /* TODO */
diff --git a/writeprotect.h b/writeprotect.h
index db7f3aa..21d1484 100644
--- a/writeprotect.h
+++ b/writeprotect.h
@@ -42,4 +42,23 @@
 int wp_list_ranges(struct flashctx *flash);
 int wp_print_status(struct flashctx *flash);

+/* Complete description of a chip's wp-related state */
+struct wp_chip_state {
+	size_t srp_bit_count;
+	uint8_t srp[MAX_SRP_BITS];
+
+	size_t bp_bit_count;
+	uint8_t bp[MAX_BP_BITS];
+
+	bool tb_bit_present;
+	uint8_t tb;
+
+	bool sec_bit_present;
+	uint8_t sec;
+
+	bool cmp_bit_present;
+	uint8_t cmp;
+
+	/* TODO: WPS, sector registers */
+};
 #endif