[PATCH 2/3 v6] serial: 8250: Add MSR/MCR TIOCM conversion wrapper functions

From: Stefan Roese
Date: Thu Jun 13 2019 - 11:50:52 EST


This patch adds wrapper functions to convert MSR <-> TIOCM and also
MCR <-> TIOCM. These functions are used now in serial8250_do_set_mctrl()
and serial8250_do_get_mctrl().

Signed-off-by: Stefan Roese <sr@xxxxxxx>
Suggested-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Giulio Benetti <giulio.benetti@xxxxxxxxxxxxxxxx>
---
v6:
- New patch

drivers/tty/serial/8250/8250.h | 54 +++++++++++++++++++++++++++++
drivers/tty/serial/8250/8250_port.c | 25 ++-----------
2 files changed, 57 insertions(+), 22 deletions(-)

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index ebfb0bd5bef5..793da2e510e0 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -139,6 +139,60 @@ void serial8250_rpm_put_tx(struct uart_8250_port *p);
int serial8250_em485_init(struct uart_8250_port *p);
void serial8250_em485_destroy(struct uart_8250_port *p);

+/* MCR <-> TIOCM conversion */
+static inline int serial8250_TIOCM_to_MCR(int tiocm)
+{
+ int mcr = 0;
+
+ if (tiocm & TIOCM_RTS)
+ mcr |= UART_MCR_RTS;
+ if (tiocm & TIOCM_DTR)
+ mcr |= UART_MCR_DTR;
+ if (tiocm & TIOCM_OUT1)
+ mcr |= UART_MCR_OUT1;
+ if (tiocm & TIOCM_OUT2)
+ mcr |= UART_MCR_OUT2;
+ if (tiocm & TIOCM_LOOP)
+ mcr |= UART_MCR_LOOP;
+
+ return mcr;
+}
+
+static inline int serial8250_MCR_to_TIOCM(int mcr)
+{
+ int tiocm = 0;
+
+ if (mcr & UART_MCR_RTS)
+ tiocm |= TIOCM_RTS;
+ if (mcr & UART_MCR_DTR)
+ tiocm |= TIOCM_DTR;
+ if (mcr & UART_MCR_OUT1)
+ tiocm |= TIOCM_OUT1;
+ if (mcr & UART_MCR_OUT2)
+ tiocm |= TIOCM_OUT2;
+ if (mcr & UART_MCR_LOOP)
+ tiocm |= TIOCM_LOOP;
+
+ return tiocm;
+}
+
+/* MSR <-> TIOCM conversion */
+static inline int serial8250_MSR_to_TIOCM(int msr)
+{
+ int tiocm = 0;
+
+ if (msr & UART_MSR_DCD)
+ tiocm |= TIOCM_CAR;
+ if (msr & UART_MSR_RI)
+ tiocm |= TIOCM_RNG;
+ if (msr & UART_MSR_DSR)
+ tiocm |= TIOCM_DSR;
+ if (msr & UART_MSR_CTS)
+ tiocm |= TIOCM_CTS;
+
+ return tiocm;
+}
+
static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
{
serial_out(up, UART_MCR, value);
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 2304a84eee3b..47f0a8d01a57 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1944,22 +1944,12 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
unsigned int status;
- unsigned int ret;

serial8250_rpm_get(up);
status = serial8250_modem_status(up);
serial8250_rpm_put(up);

- ret = 0;
- if (status & UART_MSR_DCD)
- ret |= TIOCM_CAR;
- if (status & UART_MSR_RI)
- ret |= TIOCM_RNG;
- if (status & UART_MSR_DSR)
- ret |= TIOCM_DSR;
- if (status & UART_MSR_CTS)
- ret |= TIOCM_CTS;
- return ret;
+ return serial8250_MSR_to_TIOCM(status);
}
EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);

@@ -1973,18 +1963,9 @@ static unsigned int serial8250_get_mctrl(struct uart_port *port)
void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct uart_8250_port *up = up_to_u8250p(port);
- unsigned char mcr = 0;
+ unsigned char mcr;

- if (mctrl & TIOCM_RTS)
- mcr |= UART_MCR_RTS;
- if (mctrl & TIOCM_DTR)
- mcr |= UART_MCR_DTR;
- if (mctrl & TIOCM_OUT1)
- mcr |= UART_MCR_OUT1;
- if (mctrl & TIOCM_OUT2)
- mcr |= UART_MCR_OUT2;
- if (mctrl & TIOCM_LOOP)
- mcr |= UART_MCR_LOOP;
+ mcr = serial8250_TIOCM_to_MCR(mctrl);

mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;

--
2.22.0