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From 9d9398944488cd3a3e1e0912b26fbc4d5921e547 Mon Sep 17 00:00:00 2001
From: Daniel Golle <daniel@makrotopia.org>
Date: Mon, 4 Jun 2018 23:33:07 +0200
Subject: [PATCH] tty: serial: exar: generalize RS485 setup
Move the non-board-specific part of the RS485 initialization from
iot2040_rs485_config function to a new generic function used also for
other boards.
This allows using TIOCGRS485 and TIOCSRS485 on boards (such as mPCIe
serial IO modules) which are hard-wired to RS485 or have jumpers for
their configurations.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/tty/serial/8250/8250_exar.c | 38 +++++++++++++++++++----------
1 file changed, 25 insertions(+), 13 deletions(-)
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -275,8 +275,32 @@ static int xr17v35x_register_gpio(struct
return 0;
}
+static int generic_rs485_config(struct uart_port *port,
+ struct serial_rs485 *rs485)
+{
+ bool is_rs485 = !!(rs485->flags & SER_RS485_ENABLED);
+ u8 __iomem *p = port->membase;
+ u8 value;
+
+ value = readb(p + UART_EXAR_FCTR);
+ if (is_rs485)
+ value |= UART_FCTR_EXAR_485;
+ else
+ value &= ~UART_FCTR_EXAR_485;
+
+ writeb(value, p + UART_EXAR_FCTR);
+
+ if (is_rs485)
+ writeb(UART_EXAR_RS485_DLY(4), p + UART_MSR);
+
+ port->rs485 = *rs485;
+
+ return 0;
+}
+
static const struct exar8250_platform exar8250_default_platform = {
.register_gpio = xr17v35x_register_gpio,
+ .rs485_config = generic_rs485_config,
};
static int iot2040_rs485_config(struct uart_port *port,
@@ -309,19 +333,7 @@ static int iot2040_rs485_config(struct u
value |= mode;
writeb(value, p + UART_EXAR_MPIOLVL_7_0);
- value = readb(p + UART_EXAR_FCTR);
- if (is_rs485)
- value |= UART_FCTR_EXAR_485;
- else
- value &= ~UART_FCTR_EXAR_485;
- writeb(value, p + UART_EXAR_FCTR);
-
- if (is_rs485)
- writeb(UART_EXAR_RS485_DLY(4), p + UART_MSR);
-
- port->rs485 = *rs485;
-
- return 0;
+ return generic_rs485_config(port, rs485);
}
static const struct property_entry iot2040_gpio_properties[] = {
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