1 files changed, 49 insertions, 14 deletions

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index c4caf2e2de82..ff767dccdf0f 100644
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -60,8 +60,8 @@ static int prepare_packet(struct cros_ec_device *ec_dev,
 	int i;
 	u8 csum = 0;
 
-	BUG_ON(ec_dev->proto_version != EC_HOST_REQUEST_VERSION);
-	BUG_ON(msg->outsize + sizeof(*request) > ec_dev->dout_size);
+	if (msg->outsize + sizeof(*request) > ec_dev->dout_size)
+		return -EINVAL;
 
 	out = ec_dev->dout;
 	request = (struct ec_host_request *)out;
@@ -165,7 +165,7 @@ static int send_command(struct cros_ec_device *ec_dev,
  * only SPI uses it. Once LPC uses the same protocol it can start using it.
  * I2C could use it now, with a refactor of the existing code.
  *
- * Return: 0 on success or negative error code.
+ * Return: number of prepared bytes on success or negative error code.
  */
 int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
 		       struct cros_ec_command *msg)
@@ -177,7 +177,9 @@ int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
 	if (ec_dev->proto_version > 2)
 		return prepare_packet(ec_dev, msg);
 
-	BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
+	if (msg->outsize > EC_PROTO2_MAX_PARAM_SIZE)
+		return -EINVAL;
+
 	out = ec_dev->dout;
 	out[0] = EC_CMD_VERSION0 + msg->version;
 	out[1] = msg->command;
@@ -560,22 +562,28 @@ exit:
 EXPORT_SYMBOL(cros_ec_query_all);
 
 /**
- * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
+ * cros_ec_cmd_xfer() - Send a command to the ChromeOS EC.
  * @ec_dev: EC device.
  * @msg: Message to write.
  *
- * Call this to send a command to the ChromeOS EC. This should be used instead of calling the EC's
- * cmd_xfer() callback directly. It returns success status only if both the command was transmitted
- * successfully and the EC replied with success status.
+ * Call this to send a command to the ChromeOS EC. This should be used instead
+ * of calling the EC's cmd_xfer() callback directly. This function does not
+ * convert EC command execution error codes to Linux error codes. Most
+ * in-kernel users will want to use cros_ec_cmd_xfer_status() instead since
+ * that function implements the conversion.
  *
  * Return:
- * >=0 - The number of bytes transferred
- * <0 - Linux error code
+ * >0 - EC command was executed successfully. The return value is the number
+ *      of bytes returned by the EC (excluding the header).
+ * =0 - EC communication was successful. EC command execution results are
+ *      reported in msg->result. The result will be EC_RES_SUCCESS if the
+ *      command was executed successfully or report an EC command execution
+ *      error.
+ * <0 - EC communication error. Return value is the Linux error code.
  */
-int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
-			    struct cros_ec_command *msg)
+int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
 {
-	int ret, mapped;
+	int ret;
 
 	mutex_lock(&ec_dev->lock);
 	if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) {
@@ -616,6 +624,32 @@ int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
 	ret = send_command(ec_dev, msg);
 	mutex_unlock(&ec_dev->lock);
 
+	return ret;
+}
+EXPORT_SYMBOL(cros_ec_cmd_xfer);
+
+/**
+ * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
+ * @ec_dev: EC device.
+ * @msg: Message to write.
+ *
+ * Call this to send a command to the ChromeOS EC. This should be used instead of calling the EC's
+ * cmd_xfer() callback directly. It returns success status only if both the command was transmitted
+ * successfully and the EC replied with success status.
+ *
+ * Return:
+ * >=0 - The number of bytes transferred.
+ * <0 - Linux error code
+ */
+int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
+			    struct cros_ec_command *msg)
+{
+	int ret, mapped;
+
+	ret = cros_ec_cmd_xfer(ec_dev, msg);
+	if (ret < 0)
+		return ret;
+
 	mapped = cros_ec_map_error(msg->result);
 	if (mapped) {
 		dev_dbg(ec_dev->dev, "Command result (err: %d [%d])\n",
@@ -783,7 +817,8 @@ u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
 {
 	u32 host_event;
 
-	BUG_ON(!ec_dev->mkbp_event_supported);
+	if (!ec_dev->mkbp_event_supported)
+		return 0;
 
 	if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
 		return 0;