From: Lukas Wunner <lukas@wunner.de>
Date: Fri, 28 Feb 2020 14:31:03 +0100
Subject: serial: 8250: Deduplicate ->rs485_config() callback
Git-commit: 283e096ffb7077c2b677eee043ff36965e43d37b
Patch-mainline: v5.7-rc1
References: jsc#SLE-16106
Commit e490c9144cfa ("tty: Add software emulated RS485 support for 8250")
introduced support to use RTS as an rs485 Transmit Enable signal.
Drivers opt in to the feature by calling serial8250_em485_init() from
their ->rs485_config() callback.
So far there are two drivers doing that, 8250_omap.c and 8250_of.c.
Both use an identical callback. We're about to add a third user of that
callback, therefore deduplicate it and move it to 8250_port.c.
Drivers now opt in to rs485 software emulation by assigning the generic
serial8250_rs485_config() callback introduced herein to their
.rs485_config struct member. This change allows unexporting
serial8250_em485_init() and declaring it static.
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: Matwey V. Kornilov <matwey@sai.msu.ru>
Cc: Heiko Schocher <hs@denx.de>
Link: https://lore.kernel.org/r/fcef63642dc4eae41ae7842d23747b2bf5d40285.1582895077.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.h | 2 -
drivers/tty/serial/8250/8250_of.c | 32 ----------------------------
drivers/tty/serial/8250/8250_omap.c | 32 ----------------------------
drivers/tty/serial/8250/8250_port.c | 41 ++++++++++++++++++++++++++++++++++--
4 files changed, 42 insertions(+), 65 deletions(-)
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -156,7 +156,7 @@ void serial8250_rpm_put(struct uart_8250
void serial8250_rpm_get_tx(struct uart_8250_port *p);
void serial8250_rpm_put_tx(struct uart_8250_port *p);
-int serial8250_em485_init(struct uart_8250_port *p);
+int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485);
void serial8250_em485_destroy(struct uart_8250_port *p);
/* MCR <-> TIOCM conversion */
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -25,36 +25,6 @@ struct of_serial_info {
int line;
};
-static int of_8250_rs485_config(struct uart_port *port,
- struct serial_rs485 *rs485)
-{
- struct uart_8250_port *up = up_to_u8250p(port);
-
- /* Clamp the delays to [0, 100ms] */
- rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
- rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
-
- port->rs485 = *rs485;
-
- /*
- * Both serial8250_em485_init and serial8250_em485_destroy
- * are idempotent
- */
- if (rs485->flags & SER_RS485_ENABLED) {
- int ret = serial8250_em485_init(up);
-
- if (ret) {
- rs485->flags &= ~SER_RS485_ENABLED;
- port->rs485.flags &= ~SER_RS485_ENABLED;
- }
- return ret;
- }
-
- serial8250_em485_destroy(up);
-
- return 0;
-}
-
/*
* Fill a struct uart_port for a given device node
*/
@@ -184,7 +154,7 @@ static int of_platform_serial_setup(stru
port->flags |= UPF_SKIP_TEST;
port->dev = &ofdev->dev;
- port->rs485_config = of_8250_rs485_config;
+ port->rs485_config = serial8250_em485_config;
switch (type) {
case PORT_RT2880:
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -718,36 +718,6 @@ static void omap_8250_throttle(struct ua
pm_runtime_put_autosuspend(port->dev);
}
-static int omap_8250_rs485_config(struct uart_port *port,
- struct serial_rs485 *rs485)
-{
- struct uart_8250_port *up = up_to_u8250p(port);
-
- /* Clamp the delays to [0, 100ms] */
- rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
- rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
-
- port->rs485 = *rs485;
-
- /*
- * Both serial8250_em485_init and serial8250_em485_destroy
- * are idempotent
- */
- if (rs485->flags & SER_RS485_ENABLED) {
- int ret = serial8250_em485_init(up);
-
- if (ret) {
- rs485->flags &= ~SER_RS485_ENABLED;
- port->rs485.flags &= ~SER_RS485_ENABLED;
- }
- return ret;
- }
-
- serial8250_em485_destroy(up);
-
- return 0;
-}
-
static void omap_8250_unthrottle(struct uart_port *port)
{
struct omap8250_priv *priv = port->private_data;
@@ -1191,7 +1161,7 @@ static int omap8250_probe(struct platfor
up.port.shutdown = omap_8250_shutdown;
up.port.throttle = omap_8250_throttle;
up.port.unthrottle = omap_8250_unthrottle;
- up.port.rs485_config = omap_8250_rs485_config;
+ up.port.rs485_config = serial8250_em485_config;
ret = of_alias_get_id(np, "serial");
if (ret < 0) {
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -618,7 +618,7 @@ EXPORT_SYMBOL_GPL(serial8250_rpm_put);
*
* Return 0 - success, -errno - otherwise
*/
-int serial8250_em485_init(struct uart_8250_port *p)
+static int serial8250_em485_init(struct uart_8250_port *p)
{
if (p->em485)
return 0;
@@ -639,7 +639,6 @@ int serial8250_em485_init(struct uart_82
return 0;
}
-EXPORT_SYMBOL_GPL(serial8250_em485_init);
/**
* serial8250_em485_destroy() - put uart_8250_port into normal state
@@ -667,6 +666,44 @@ void serial8250_em485_destroy(struct uar
}
EXPORT_SYMBOL_GPL(serial8250_em485_destroy);
+/**
+ * serial8250_em485_config() - generic ->rs485_config() callback
+ * @port: uart port
+ * @rs485: rs485 settings
+ *
+ * Generic callback usable by 8250 uart drivers to activate rs485 settings
+ * if the uart is incapable of driving RTS as a Transmit Enable signal in
+ * hardware, relying on software emulation instead.
+ */
+int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485)
+{
+ struct uart_8250_port *up = up_to_u8250p(port);
+
+ /* clamp the delays to [0, 100ms] */
+ rs485->delay_rts_before_send = min(rs485->delay_rts_before_send, 100U);
+ rs485->delay_rts_after_send = min(rs485->delay_rts_after_send, 100U);
+
+ port->rs485 = *rs485;
+
+ /*
+ * Both serial8250_em485_init() and serial8250_em485_destroy()
+ * are idempotent.
+ */
+ if (rs485->flags & SER_RS485_ENABLED) {
+ int ret = serial8250_em485_init(up);
+
+ if (ret) {
+ rs485->flags &= ~SER_RS485_ENABLED;
+ port->rs485.flags &= ~SER_RS485_ENABLED;
+ }
+ return ret;
+ }
+
+ serial8250_em485_destroy(up);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(serial8250_em485_config);
+
/*
* These two wrappers ensure that enable_runtime_pm_tx() can be called more than
* once and disable_runtime_pm_tx() will still disable RPM because the fifo is