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From patchwork Fri Feb 7 09:53:35 2020
Content-Type: text/plain; charset="utf-8"
MIME-Version: 1.0
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X-Patchwork-Submitter: Daniel Golle <daniel@makrotopia.org>
X-Patchwork-Id: 1190470
Date: Fri, 7 Feb 2020 11:53:35 +0200
From: Daniel Golle <daniel@makrotopia.org>
To: linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.com>,
Chuanhong Guo <gch981213@gmail.com>,
Eitan Cohen <eitan@neot-semadar.com>,
Ori Gofen <origofen@gmail.com>
Subject: [PATCH] serial: ar933x_uart: set UART_CS_{RX,TX}_READY_ORIDE
Message-ID: <20200207095335.GA179836@makrotopia.org>
MIME-Version: 1.0
Content-Disposition: inline
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
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 <gch981213@gmail.com>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
drivers/tty/serial/ar933x_uart.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/tty/serial/ar933x_uart.c
+++ b/drivers/tty/serial/ar933x_uart.c
@@ -286,6 +286,10 @@ static void ar933x_uart_set_termios(stru
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 ua
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);
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