cros_ec: Update cros_ec_read_hash() to specify the image

Allow selection of which EC image to hash.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/cros_ec.c b/cmd/cros_ec.c
index 3ac4f3b..9e2f1b0 100644
--- a/cmd/cros_ec.c
+++ b/cmd/cros_ec.c
@@ -149,7 +149,7 @@
 		struct ec_response_vboot_hash hash;
 		int i;
 
-		if (cros_ec_read_hash(dev, &hash)) {
+		if (cros_ec_read_hash(dev, EC_VBOOT_HASH_OFFSET_ACTIVE, &hash)) {
 			debug("%s: Could not read KBC hash\n", __func__);
 			return 1;
 		}
diff --git a/drivers/misc/cros_ec.c b/drivers/misc/cros_ec.c
index 07e662a..190505c 100644
--- a/drivers/misc/cros_ec.c
+++ b/drivers/misc/cros_ec.c
@@ -444,13 +444,14 @@
 	return 0;
 }
 
-
-int cros_ec_read_hash(struct udevice *dev, struct ec_response_vboot_hash *hash)
+int cros_ec_read_hash(struct udevice *dev, uint hash_offset,
+		      struct ec_response_vboot_hash *hash)
 {
 	struct ec_params_vboot_hash p;
 	int rv;
 
 	p.cmd = EC_VBOOT_HASH_GET;
+	p.offset = hash_offset;
 	if (ec_command(dev, EC_CMD_VBOOT_HASH, 0, &p, sizeof(p),
 		       hash, sizeof(*hash)) < 0)
 		return -1;
@@ -473,7 +474,7 @@
 	p.cmd = EC_VBOOT_HASH_START;
 	p.hash_type = EC_VBOOT_HASH_TYPE_SHA256;
 	p.nonce_size = 0;
-	p.offset = EC_VBOOT_HASH_OFFSET_ACTIVE;
+	p.offset = hash_offset;
 
 	if (ec_command(dev, EC_CMD_VBOOT_HASH, 0, &p, sizeof(p),
 		       hash, sizeof(*hash)) < 0)
diff --git a/include/cros_ec.h b/include/cros_ec.h
index 5576bcf..4771e6b 100644
--- a/include/cros_ec.h
+++ b/include/cros_ec.h
@@ -96,10 +96,12 @@
  * Read the hash of the CROS-EC device firmware.
  *
  * @param dev		CROS-EC device
+ * @param hash_offset	Offset in flash to read from
  * @param hash		Destination for hash information
  * @return 0 if ok, <0 on error
  */
-int cros_ec_read_hash(struct udevice *dev, struct ec_response_vboot_hash *hash);
+int cros_ec_read_hash(struct udevice *dev, uint hash_offset,
+		      struct ec_response_vboot_hash *hash);
 
 /**
  * Send a reboot command to the CROS-EC device.