From bc4b786156b3dd51de75f512d05679d5b413399b Mon Sep 17 00:00:00 2001
From: Daisuke Nojiri <dnojiri@chromium.org>
Date: Fri, 12 Jan 2018 12:52:18 -0800
Subject: CBI: Add host command to set board info

This patch adds host command to write board information in EERPOM.

BUG=b:70294260
BRANCH=none
TEST=Run ectool cbi set <type> <value> to write BOARD_VERSION, OEM_ID,
and SKU_ID. Enable WP and verify cbi set command fails.

Change-Id: I39536d146313408ace666f350a107d89b331bf7a
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/865570
---
 common/cbi.c | 87 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 87 insertions(+)

(limited to 'common/cbi.c')

diff --git a/common/cbi.c b/common/cbi.c
index b82d0375c2..41e8606487 100644
--- a/common/cbi.c
+++ b/common/cbi.c
@@ -9,12 +9,14 @@
 #include "console.h"
 #include "crc8.h"
 #include "cros_board_info.h"
+#include "gpio.h"
 #include "host_command.h"
 #include "i2c.h"
 #include "util.h"
 
 #define CPRINTS(format, args...) cprints(CC_SYSTEM, "CBI " format, ## args)
 
+#define EEPROM_PAGE_WRITE_SIZE	16
 static struct board_info bi;
 /* TODO: Init it to -1. On error (I2C or bad contents), retry a read and set it
  * to enum ec_error_list if it still fails. The successive calls can be
@@ -95,6 +97,38 @@ static int read_board_info(void)
 	return EC_SUCCESS;
 }
 
+static int eeprom_is_write_protected(void)
+{
+	return !gpio_get_level(GPIO_WP_L);
+}
+
+static int write_board_info(void)
+{
+	uint8_t buf[sizeof(bi) + 1];
+	/* The code is only tested for ST M24C02, whose page size for a single
+	 * write is 16 byte. To support different EEPROMs, you may need to
+	 * craft the i2c packets accordingly. */
+	_Static_assert(sizeof(bi) <= EEPROM_PAGE_WRITE_SIZE,
+		       "struct board_info exceeds page write size");
+	int rv;
+
+	if (eeprom_is_write_protected()) {
+		CPRINTS("Failed to write for WP");
+		return EC_ERROR_ACCESS_DENIED;
+	}
+
+	buf[0] = 0;	/* Offset 0 */
+	memcpy(&buf[1], &bi, sizeof(bi));
+	rv = i2c_xfer(I2C_PORT_EEPROM, I2C_ADDR_EEPROM, buf,
+		     sizeof(bi) + 1, NULL, 0, I2C_XFER_SINGLE);
+	if (rv) {
+		CPRINTS("Failed to write for %d", rv);
+		return rv;
+	}
+
+	return EC_SUCCESS;
+}
+
 int cbi_get_board_version(uint32_t *version)
 {
 	if (read_board_info())
@@ -154,3 +188,56 @@ static int hc_cbi_get(struct host_cmd_handler_args *args)
 DECLARE_HOST_COMMAND(EC_CMD_GET_CROS_BOARD_INFO,
 		     hc_cbi_get,
 		     EC_VER_MASK(0));
+
+static int hc_cbi_set(struct host_cmd_handler_args *args)
+{
+	const struct __ec_align4 ec_params_set_cbi *p = args->params;
+
+	if (p->flag & CBI_SET_INIT) {
+		memset(&bi, 0, sizeof(bi));
+		memcpy(&bi.head.magic, cbi_magic, sizeof(cbi_magic));
+		initialized = 1;
+	} else {
+		if (read_board_info())
+			return EC_RES_ERROR;
+	}
+
+	switch (p->type) {
+	case CBI_DATA_BOARD_VERSION:
+		if (p->data > UINT16_MAX)
+			return EC_RES_INVALID_PARAM;
+		bi.version = p->data;
+		break;
+	case CBI_DATA_OEM_ID:
+		if (p->data > UINT8_MAX)
+			return EC_RES_INVALID_PARAM;
+		bi.oem_id = p->data;
+		break;
+	case CBI_DATA_SKU_ID:
+		if (p->data > UINT8_MAX)
+			return EC_RES_INVALID_PARAM;
+		bi.sku_id = p->data;
+		break;
+	default:
+		return EC_RES_INVALID_PARAM;
+	}
+
+	/* Whether we're modifying existing data or creating new one,
+	 * we take over the format. */
+	bi.head.major_version = CBI_VERSION_MAJOR;
+	bi.head.minor_version = CBI_VERSION_MINOR;
+	bi.head.total_size = sizeof(bi);
+	bi.head.crc = cbi_crc8(&bi);
+
+	/* Skip write if client asks so. */
+	if (p->flag & CBI_SET_NO_SYNC)
+		return EC_RES_SUCCESS;
+
+	if (write_board_info())
+		return EC_RES_ERROR;
+
+	return EC_RES_SUCCESS;
+}
+DECLARE_HOST_COMMAND(EC_CMD_SET_CROS_BOARD_INFO,
+		     hc_cbi_set,
+		     EC_VER_MASK(0));
-- 
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