The fact that the Qualcomm GENI hardware interface is based around
"packets" is really awkward to fit into Linux's UART design.
Specifically, in order to send bytes you need to start up a new
"command" saying how many bytes you want to send and then you need to
send all those bytes. Once you've committed to sending that number of
bytes it's very awkward to change your mind and send fewer, especially
if you want to do so without dropping bytes on the ground.
+static void qcom_geni_serial_enable_cmd_done(struct uart_port *uport)
+{
+ struct qcom_geni_serial_port *port = to_dev_port(uport);
+
+ /* If we're not in FIFO mode we don't use CMD_DONE. */
+ if (port->dev_data->mode != GENI_SE_FIFO)
+ return;
+
+ writel(M_CMD_DONE_EN, uport->membase + SE_GENI_M_IRQ_EN_SET);
+}