From: Lukas Wunner <lukas@wunner.de>
Date: Tue, 12 May 2020 14:40:02 +0200
Subject: serial: Allow uart_get_rs485_mode() to return errno
Git-commit: c150c0f362c1e51c0e3216c9912b85b71d00e70d
Patch-mainline: v5.8-rc1
References: jsc#SLE-16106
We're about to amend uart_get_rs485_mode() to support a GPIO pin for
rs485 bus termination. Retrieving the GPIO descriptor may fail, so
allow uart_get_rs485_mode() to return an errno and change all callers
to check for failure.
The GPIO descriptor is going to be stored in struct uart_port. Pass
that struct to uart_get_rs485_mode() in lieu of a struct device and
struct serial_rs485, both of which are directly accessible from struct
uart_port.
A few drivers call uart_get_rs485_mode() before setting the struct
device pointer in struct uart_port. Shuffle those calls around where
necessary.
[Heiko Stuebner did the ar933x_uart.c portion, hence his Signed-off-by.]
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/271e814af4b0db3bffbbb74abf2b46b75add4516.1589285873.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
---
drivers/tty/serial/8250/8250_core.c | 4 +++-
drivers/tty/serial/atmel_serial.c | 6 ++++--
drivers/tty/serial/fsl_lpuart.c | 5 ++++-
drivers/tty/serial/imx.c | 6 +++++-
drivers/tty/serial/omap-serial.c | 4 +++-
drivers/tty/serial/serial_core.c | 6 +++++-
drivers/tty/serial/stm32-usart.c | 8 ++++----
include/linux/serial_core.h | 2 +-
8 files changed, 29 insertions(+), 12 deletions(-)
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1016,7 +1016,9 @@ int serial8250_register_8250_port(struct
if (up->port.dev) {
uart->port.dev = up->port.dev;
- uart_get_rs485_mode(uart->port.dev, &uart->port.rs485);
+ ret = uart_get_rs485_mode(&uart->port);
+ if (ret)
+ goto err;
}
if (up->port.flags & UPF_FIXED_TYPE)
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -2533,8 +2533,6 @@ static int atmel_init_port(struct atmel_
atmel_init_property(atmel_port, pdev);
atmel_set_ops(port);
- uart_get_rs485_mode(&mpdev->dev, &port->rs485);
-
port->iotype = UPIO_MEM;
port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP;
port->ops = &atmel_pops;
@@ -2548,6 +2546,10 @@ static int atmel_init_port(struct atmel_
memset(&atmel_port->rx_ring, 0, sizeof(atmel_port->rx_ring));
+ ret = uart_get_rs485_mode(port);
+ if (ret)
+ return ret;
+
/* for console, the clock could already be configured */
if (!atmel_port->clk) {
atmel_port->clk = clk_get(&mpdev->dev, "usart");
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -2407,7 +2407,9 @@ static int lpuart_probe(struct platform_
if (ret)
goto failed_attach_port;
- uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
+ ret = uart_get_rs485_mode(&sport->port);
+ if (ret)
+ goto failed_get_rs485;
if (sport->port.rs485.flags & SER_RS485_RX_DURING_TX)
dev_err(&pdev->dev, "driver doesn't support RX during TX\n");
@@ -2430,6 +2432,7 @@ static int lpuart_probe(struct platform_
return 0;
+failed_get_rs485:
failed_attach_port:
failed_irq_request:
lpuart_disable_clks(sport);
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -2304,7 +2304,11 @@ static int imx_uart_probe(struct platfor
sport->ucr4 = readl(sport->port.membase + UCR4);
sport->ufcr = readl(sport->port.membase + UFCR);
- uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
+ ret = uart_get_rs485_mode(&sport->port);
+ if (ret) {
+ clk_disable_unprepare(sport->clk_ipg);
+ return ret;
+ }
if (sport->port.rs485.flags & SER_RS485_ENABLED &&
(!sport->have_rtscts && !sport->have_rtsgpio))
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -1610,7 +1610,9 @@ static int serial_omap_probe_rs485(struc
if (!np)
return 0;
- uart_get_rs485_mode(up->dev, rs485conf);
+ ret = uart_get_rs485_mode(&up->port);
+ if (ret)
+ return ret;
if (of_property_read_bool(np, "rs485-rts-active-high")) {
rs485conf->flags |= SER_RS485_RTS_ON_SEND;
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -3097,8 +3097,10 @@ EXPORT_SYMBOL(uart_remove_one_port);
* This function implements the device tree binding described in
* Documentation/devicetree/bindings/serial/rs485.txt.
*/
-void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf)
+int uart_get_rs485_mode(struct uart_port *port)
{
+ struct serial_rs485 *rs485conf = &port->rs485;
+ struct device *dev = port->dev;
u32 rs485_delay[2];
int ret;
@@ -3130,6 +3132,8 @@ void uart_get_rs485_mode(struct device *
rs485conf->flags &= ~SER_RS485_RTS_ON_SEND;
rs485conf->flags |= SER_RS485_RTS_AFTER_SEND;
}
+
+ return 0;
}
EXPORT_SYMBOL_GPL(uart_get_rs485_mode);
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -161,9 +161,7 @@ static int stm32_init_rs485(struct uart_
if (!pdev->dev.of_node)
return -ENODEV;
- uart_get_rs485_mode(&pdev->dev, rs485conf);
-
- return 0;
+ return uart_get_rs485_mode(port);
}
static int stm32_pending_rx(struct uart_port *port, u32 *sr, int *last_res,
@@ -936,7 +934,9 @@ static int stm32_init_port(struct stm32_
port->rs485_config = stm32_config_rs485;
- stm32_init_rs485(port, pdev);
+ ret = stm32_init_rs485(port, pdev);
+ if (ret)
+ return ret;
if (stm32port->info->cfg.has_wakeup) {
stm32port->wakeirq = platform_get_irq(pdev, 1);
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -543,5 +543,5 @@ static inline int uart_handle_break(stru
(cflag) & CRTSCTS || \
!((cflag) & CLOCAL))
-void uart_get_rs485_mode(struct device *dev, struct serial_rs485 *rs485conf);
+int uart_get_rs485_mode(struct uart_port *port);
#endif /* LINUX_SERIAL_CORE_H */