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>

10 files changed, 124 insertions, 6 deletions

diff --git a/common/build.mk b/common/build.mk
index 36724d619e..5d76188f7b 100644
--- a/common/build.mk
+++ b/common/build.mk
@@ -51,6 +51,7 @@ common-$(CONFIG_BODY_DETECTION)+=body_detection.o
 common-$(CONFIG_CAPSENSE)+=capsense.o
 common-$(CONFIG_CEC)+=cec.o
 common-$(CONFIG_CBI_EEPROM)+=cbi.o cbi_eeprom.o
+common-$(CONFIG_CBI_GPIO)+=cbi.o cbi_gpio.o
 ifeq ($(HAS_MOCK_CHARGE_MANAGER),)
 common-$(CONFIG_CHARGE_MANAGER)+=charge_manager.o
 endif
diff --git a/common/cbi.c b/common/cbi.c
index 9e6aa2cda1..345e313c54 100644
--- a/common/cbi.c
+++ b/common/cbi.c
@@ -145,7 +145,8 @@ static int do_cbi_read(void)
 	}
 
 	/* Check CRC. This supports new fields unknown to this parser. */
-	if (cbi_crc8(head) != head->crc) {
+	if (cbi_config.storage_type != CBI_STORAGE_TYPE_GPIO &&
+			cbi_crc8(head) != head->crc) {
 		CPRINTS("Bad CRC");
 		return EC_ERROR_INVAL;
 	}
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,
+};
diff --git a/include/config.h b/include/config.h
index 32ba1b71aa..3136dd18fe 100644
--- a/include/config.h
+++ b/include/config.h
@@ -5167,6 +5167,9 @@
  */
 #undef CONFIG_CBI_EEPROM
 
+/* Define this to support Cros Board Info from GPIO. */
+#undef CONFIG_CBI_GPIO
+
 /*****************************************************************************/
 /*
  * ISH config defaults
@@ -6365,6 +6368,10 @@
 	"are mutually exclusive. "
 #endif /* CONFIG_BOARD_VERSION_CBI && CONFIG_BOARD_VERSION_GPIO */
 
+#if defined(CONFIG_CBI_EEPROM) && defined(CONFIG_CBI_GPIO)
+#error "CONFIG_CBI_EEPROM and CONFIG_CBI_GPIO are mutually exclusive."
+#endif
+
 #if !defined(CONFIG_ZEPHYR) && !defined(CONFIG_ACCELGYRO_ICM_COMM_SPI) && \
 	!defined(CONFIG_ACCELGYRO_ICM_COMM_I2C)
 #ifdef I2C_PORT_ACCEL
diff --git a/include/cros_board_info.h b/include/cros_board_info.h
index 6f2871916e..ee5a717ee5 100644
--- a/include/cros_board_info.h
+++ b/include/cros_board_info.h
@@ -12,7 +12,18 @@
 
 #define CBI_VERSION_MAJOR	0
 #define CBI_VERSION_MINOR	0
+
+#ifdef CONFIG_CBI_GPIO
+/*
+ * if CBI is sourced from GPIO, the CBI cache only needs to accomondate
+ * BOARD_VERSION and SKU_ID
+ */
+#define CBI_IMAGE_SIZE		(sizeof(struct cbi_header) +  (2 * \
+				(sizeof(struct cbi_data) + sizeof(uint32_t))))
+#else
 #define CBI_IMAGE_SIZE		256
+#endif
+
 static const uint8_t cbi_magic[] = { 0x43, 0x42, 0x49 };  /* 'C' 'B' 'I' */
 
 struct cbi_header {
@@ -48,6 +59,7 @@ enum cbi_cache_status {
 
 enum cbi_storage_type {
 	CBI_STORAGE_TYPE_EEPROM = 0,
+	CBI_STORAGE_TYPE_GPIO = 1
 };
 
 /*
diff --git a/zephyr/CMakeLists.txt b/zephyr/CMakeLists.txt
index 496c1574ef..51c1b8b7da 100644
--- a/zephyr/CMakeLists.txt
+++ b/zephyr/CMakeLists.txt
@@ -191,6 +191,9 @@ zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_CHARGE_RAMP_SW
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_CBI_EEPROM
                                                 "${PLATFORM_EC}/common/cbi.c"
                                                 "${PLATFORM_EC}/common/cbi_eeprom.c")
+zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_CBI_GPIO
+                                                "${PLATFORM_EC}/common/cbi.c"
+                                                "${PLATFORM_EC}/common/cbi_gpio.c")
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_CONSOLE_CMD_MEM
                                                 "${PLATFORM_EC}/common/memory_commands.c")
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_DPTF
diff --git a/zephyr/Kconfig b/zephyr/Kconfig
index ef41309d28..ea437bda40 100644
--- a/zephyr/Kconfig
+++ b/zephyr/Kconfig
@@ -141,20 +141,35 @@ config PLATFORM_EC_BYPASS_CBI_EEPROM_WP_CHECK
 	  When defined, ectool can be used to reprogram all CBI fields,
 	  regardless of the state of the hardware write protect.
 
+choice PLATFORM_EC_CBI_STORAGE_TYPE
+	prompt "Select CBI storage Type"
+	optional
+	help
+	  CBI is a means for accessing board information, typically set
+	  during the factory process. This allows selection of the physical
+	  storage of CBI source.
+
+	  See here for detailed information on CBI:
+
+	  https://chromium.googlesource.com/chromiumos/docs/+/master/design_docs/cros_board_info.md
+
 config PLATFORM_EC_CBI_EEPROM
 	bool "CBI EEPROM support"
 	depends on PLATFORM_EC_I2C
 	help
-	  Enables various Chromium OS Board Info (CBI) accessors as well as
-	  host and console commands. CBI is a means for accessing information
-	  about a board, typically written during the factory process.
+	  Enables Chromium OS Board Info (CBI) from EEPROM.
 
 	  One must specify both I2C_PORT_EEPROM and I2C_ADDR_EEPROM_FLAGS to the
 	  CBI EEPROM's i2c port and 7-bit i2c address.
 
-	  See here for information on CBI:
+config PLATFORM_EC_CBI_GPIO
+	bool "CBI GPIO support"
+	help
+	  Enables Chromium OS Board Info (CBI) from strapping pins. EC reads
+	  the BOARD ID and SKU ID from GPIOs and then substantiate in-memory
+	  CBI for AP to query.
 
-	  https://chromium.googlesource.com/chromiumos/docs/+/master/design_docs/cros_board_info.md
+endchoice
 
 config PLATFORM_EC_CHIPSET_RESET_HOOK
 	bool "Provide a hook for when the AP resets"
diff --git a/zephyr/drivers/cros_cbi/CMakeLists.txt b/zephyr/drivers/cros_cbi/CMakeLists.txt
index 6ba5b25a97..644865ae77 100644
--- a/zephyr/drivers/cros_cbi/CMakeLists.txt
+++ b/zephyr/drivers/cros_cbi/CMakeLists.txt
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: Apache-2.0
 
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_CBI_EEPROM	cros_cbi.c)
+zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_CBI_GPIO	cros_cbi.c)
diff --git a/zephyr/shim/include/config_chip.h b/zephyr/shim/include/config_chip.h
index f04e5f9945..0cfd9de4d7 100644
--- a/zephyr/shim/include/config_chip.h
+++ b/zephyr/shim/include/config_chip.h
@@ -1425,6 +1425,11 @@
 #define I2C_ADDR_EEPROM_FLAGS DT_REG_ADDR(DT_NODELABEL(cbi_eeprom))
 #endif
 
+#undef CONFIG_CBI_GPIO
+#ifdef CONFIG_PLATFORM_EC_CBI_GPIO
+#define CONFIG_CBI_GPIO
+#endif
+
 #undef CONFIG_VBOOT_HASH
 #ifdef CONFIG_PLATFORM_EC_VBOOT_HASH
 #define CONFIG_VBOOT_HASH
diff --git a/zephyr/shim/src/CMakeLists.txt b/zephyr/shim/src/CMakeLists.txt
index b10b3789ef..9b198ec3f2 100644
--- a/zephyr/shim/src/CMakeLists.txt
+++ b/zephyr/shim/src/CMakeLists.txt
@@ -17,6 +17,7 @@ zephyr_library_sources_ifdef(no_libgcc                  libgcc_${ARCH}.S)
 
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_ADC         adc.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_CBI_EEPROM  cbi.c)
+zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_CBI_GPIO    cbi.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_ESPI        espi.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_FAN         fan.c)
 zephyr_library_sources_ifdef(CONFIG_PLATFORM_EC_FLASH_CROS  flash.c)