cbi: Introduce CONFIG_CBI_GPIO

For the boards where SKU_ID/BRD_ID comes from the strapping pins on EC,
this new config enables AP to ask EC for those hardware configs using
the CBI host command `EC_CMD_GET_CROS_BOARD_INFO`.

BRANCH=None
BUG=b:186264627
TEST=make buildall -j
TEST=Enabled CONFIG_CBI_GPIO for lazor and manually verified with
`ectool cbi get`.

Change-Id: I7ec9097bab96d2076d9d42db2d003460db000113
Signed-off-by: Philip Chen <philipchen@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3002452
Reviewed-by: Keith Short <keithshort@chromium.org>
Commit-Queue: Philip Chen <philipchen@chromium.org>
Tested-by: Philip Chen <philipchen@chromium.org>

1 files changed, 72 insertions, 0 deletions

diff --git a/common/cbi_gpio.c b/common/cbi_gpio.c
new file mode 100644
index 0000000000..7b9fb25ebb
--- /dev/null
+++ b/common/cbi_gpio.c
@@ -0,0 +1,72 @@
+/* Copyright 2021 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* Support Cros Board Info GPIO */
+
+#include "console.h"
+#include "cros_board_info.h"
+#include "gpio.h"
+#include "system.h"
+#include "util.h"
+
+#define CPRINTS(format, args...) cprints(CC_SYSTEM, "CBI " format, ## args)
+
+static int cbi_gpio_read(uint8_t offset, uint8_t *data, int len)
+{
+	int board_id;
+	int sku_id;
+	int rv;
+	int err = 0;
+
+	if (cbi_get_cache_status() == CBI_CACHE_STATUS_SYNCED)
+		return EC_SUCCESS;
+
+	cbi_create();
+
+	board_id = system_get_board_version();
+	if (board_id < 0) {
+		CPRINTS("Failed (%d) to get a valid board id", -board_id);
+		err++;
+	} else {
+		rv = cbi_set_board_info(CBI_TAG_BOARD_VERSION,
+					(uint8_t *)&board_id, sizeof(int));
+		if (rv) {
+			CPRINTS("Failed (%d) to set BOARD_VERSION tag", rv);
+			err++;
+		}
+	}
+
+	sku_id = system_get_sku_id();
+	rv = cbi_set_board_info(CBI_TAG_SKU_ID,
+				(uint8_t *)&sku_id, sizeof(int));
+	if (rv) {
+		CPRINTS("Failed (%d) to set SKU_ID tag", rv);
+		err++;
+	}
+
+	if (err > 0)
+		return EC_ERROR_UNKNOWN;
+
+	return EC_SUCCESS;
+}
+
+static int cbi_gpio_is_write_protected(void)
+{
+	/*
+	 * When CBI comes from strapping pins, any attempts for updating CBI
+	 * storage should be rejected.
+	 */
+	return 1;
+}
+
+const struct cbi_storage_driver gpio_drv = {
+	.load = cbi_gpio_read,
+	.is_protected = cbi_gpio_is_write_protected,
+};
+
+const struct cbi_storage_config_t cbi_config = {
+	.storage_type = CBI_STORAGE_TYPE_GPIO,
+	.drv = &gpio_drv,
+};