platform/chrome: cros_ec_proto: separate cros_ec_wait_until_complete()

EC returns EC_RES_IN_PROGRESS if the host command needs more time to
complete.  Whenever receives the return code, cros_ec_send_command()
sends EC_CMD_GET_COMMS_STATUS to query the command status.

Separate cros_ec_wait_until_complete() from cros_ec_send_command().
It sends EC_CMD_GET_COMMS_STATUS and waits until the previous command
was completed, or encountered error, or timed out.

Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/20220718050914.2267370-7-tzungbi@kernel.org

diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c
index 0cec013..a6ad7f7 100644 (file)
--- a/drivers/platform/chrome/cros_ec_proto.c
+++ b/drivers/platform/chrome/cros_ec_proto.c
@@ -134,56 +134,52 @@ static int cros_ec_xfer_command(struct cros_ec_device *ec_dev, struct cros_ec_co
        return ret;
 }
 
-static int cros_ec_send_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
+static int cros_ec_wait_until_complete(struct cros_ec_device *ec_dev, uint32_t *result)
 {
-       int ret = cros_ec_xfer_command(ec_dev, msg);
+       struct {
+               struct cros_ec_command msg;
+               struct ec_response_get_comms_status status;
+       } __packed buf;
+       struct cros_ec_command *msg = &buf.msg;
+       struct ec_response_get_comms_status *status = &buf.status;
+       int ret = 0, i;
 
-       if (msg->result == EC_RES_IN_PROGRESS) {
-               int i;
-               struct cros_ec_command *status_msg;
-               struct ec_response_get_comms_status *status;
+       msg->version = 0;
+       msg->command = EC_CMD_GET_COMMS_STATUS;
+       msg->insize = sizeof(*status);
+       msg->outsize = 0;
 
-               status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
-                                    GFP_KERNEL);
-               if (!status_msg)
-                       return -ENOMEM;
+       /* Query the EC's status until it's no longer busy or we encounter an error. */
+       for (i = 0; i < EC_COMMAND_RETRIES; ++i) {
+               usleep_range(10000, 11000);
 
-               status_msg->version = 0;
-               status_msg->command = EC_CMD_GET_COMMS_STATUS;
-               status_msg->insize = sizeof(*status);
-               status_msg->outsize = 0;
+               ret = cros_ec_xfer_command(ec_dev, msg);
+               if (ret == -EAGAIN)
+                       continue;
+               if (ret < 0)
+                       return ret;
 
-               /*
-                * Query the EC's status until it's no longer busy or
-                * we encounter an error.
-                */
-               for (i = 0; i < EC_COMMAND_RETRIES; i++) {
-                       usleep_range(10000, 11000);
-
-                       trace_cros_ec_request_start(status_msg);
-                       ret = (*xfer_fxn)(ec_dev, status_msg);
-                       trace_cros_ec_request_done(status_msg, ret);
-                       if (ret == -EAGAIN)
-                               continue;
-                       if (ret < 0)
-                               break;
-
-                       msg->result = status_msg->result;
-                       if (status_msg->result != EC_RES_SUCCESS)
-                               break;
-
-                       status = (struct ec_response_get_comms_status *)
-                                status_msg->data;
-                       if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
-                               break;
-               }
+               *result = msg->result;
+               if (msg->result != EC_RES_SUCCESS)
+                       return ret;
 
-               kfree(status_msg);
+               if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
+                       return ret;
        }
 
        return ret;
 }
 
+static int cros_ec_send_command(struct cros_ec_device *ec_dev, struct cros_ec_command *msg)
+{
+       int ret = cros_ec_xfer_command(ec_dev, msg);
+
+       if (msg->result == EC_RES_IN_PROGRESS)
+               ret = cros_ec_wait_until_complete(ec_dev, &msg->result);
+
+       return ret;
+}
+
 /**
  * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
  * @ec_dev: Device to register.