[PATCH v2 6/7] serial: liteuart: separate RX loop from poll timer

From: Gabriel Somlo
Date: Wed Nov 09 2022 - 19:45:26 EST


Move the character-receive (RX) loop to its own dedicated function,
and (for now) call that from the poll timer, liteuart_timer().

This is in preparation for adding IRQ support to the receive path.

Signed-off-by: Gabriel Somlo <gsomlo@xxxxxxxxx>
---
drivers/tty/serial/liteuart.c | 25 +++++++++++++++----------
1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/tty/serial/liteuart.c b/drivers/tty/serial/liteuart.c
index 047d5ad32e13..aa7052280197 100644
--- a/drivers/tty/serial/liteuart.c
+++ b/drivers/tty/serial/liteuart.c
@@ -67,29 +67,34 @@ static struct uart_driver liteuart_driver = {
#endif
};

-static void liteuart_timer(struct timer_list *t)
+static void liteuart_rx_chars(struct uart_port *port)
{
- struct liteuart_port *uart = from_timer(uart, t, timer);
- struct uart_port *port = &uart->port;
unsigned char __iomem *membase = port->membase;
- unsigned int flg = TTY_NORMAL;
- int ch;
- unsigned long status;
+ unsigned int status;
+ unsigned char ch;

while ((status = !litex_read8(membase + OFF_RXEMPTY)) == 1) {
ch = litex_read8(membase + OFF_RXTX);
port->icount.rx++;

/* necessary for RXEMPTY to refresh its value */
- litex_write8(membase + OFF_EV_PENDING, EV_TX | EV_RX);
+ litex_write8(membase + OFF_EV_PENDING, EV_RX);

/* no overflow bits in status */
if (!(uart_handle_sysrq_char(port, ch)))
- uart_insert_char(port, status, 0, ch, flg);
-
- tty_flip_buffer_push(&port->state->port);
+ uart_insert_char(port, status, 0, ch, TTY_NORMAL);
}

+ tty_flip_buffer_push(&port->state->port);
+}
+
+static void liteuart_timer(struct timer_list *t)
+{
+ struct liteuart_port *uart = from_timer(uart, t, timer);
+ struct uart_port *port = &uart->port;
+
+ liteuart_rx_chars(port);
+
mod_timer(&uart->timer, jiffies + uart_poll_timeout(port));
}

--
2.37.3