From c2d5c4df27e0c7883e4f9d5633ab96bc4b8964d6 Mon Sep 17 00:00:00 2001 From: Daniel Golle Date: Fri, 7 Feb 2020 11:53:35 +0200 Subject: [PATCH] serial: ar933x_uart: set UART_CS_{RX,TX}_READY_ORIDE [ Upstream commit 87c5cbf71ecbb9e289d60a2df22eb686c70bf196 ] On AR934x this UART is usually not initialized by the bootloader as it is only used as a secondary serial port while the primary UART is a newly introduced NS16550-compatible. In order to make use of the ar933x-uart on AR934x without RTS/CTS hardware flow control, one needs to set the UART_CS_{RX,TX}_READY_ORIDE bits as other than on AR933x where this UART is used as primary/console, the bootloader on AR934x typically doesn't set those bits. Setting them explicitely on AR933x should not do any harm, so just set them unconditionally. Tested-by: Chuanhong Guo Signed-off-by: Daniel Golle Link: https://lore.kernel.org/r/20200207095335.GA179836@makrotopia.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/tty/serial/ar933x_uart.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/tty/serial/ar933x_uart.c b/drivers/tty/serial/ar933x_uart.c index 3bdd56a1021b..ea12f10610b6 100644 --- a/drivers/tty/serial/ar933x_uart.c +++ b/drivers/tty/serial/ar933x_uart.c @@ -286,6 +286,10 @@ static void ar933x_uart_set_termios(struct uart_port *port, ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, AR933X_UART_CS_HOST_INT_EN); + /* enable RX and TX ready overide */ + ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, + AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE); + /* reenable the UART */ ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S, @@ -418,6 +422,10 @@ static int ar933x_uart_startup(struct uart_port *port) ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, AR933X_UART_CS_HOST_INT_EN); + /* enable RX and TX ready overide */ + ar933x_uart_rmw_set(up, AR933X_UART_CS_REG, + AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE); + /* Enable RX interrupts */ up->ier = AR933X_UART_INT_RX_VALID; ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);