From: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx>
This patch permits the usage for GPIOs to control
the CTS/RTS/DTR/DSR/DCD/RI signals.
Signed-off-by: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250.h | 35 ++++++++++++++++++++++++++++++++++-
drivers/tty/serial/8250/8250_core.c | 12 ++++++++++++
drivers/tty/serial/8250/8250_omap.c | 31 ++++++++++++++++++-------------
drivers/tty/serial/8250/8250_port.c | 7 ++++++-
drivers/tty/serial/8250/Kconfig | 1 +
include/linux/serial_8250.h | 1 +
6 files changed, 72 insertions(+), 15 deletions(-)
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index b2bdc35..c47ef69 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -15,6 +15,8 @@
#include <linux/serial_reg.h>
#include <linux/dmaengine.h>
+#include "../serial_mctrl_gpio.h"
+
struct uart_8250_dma {
int (*tx_dma)(struct uart_8250_port *p);
int (*rx_dma)(struct uart_8250_port *p);
@@ -145,12 +147,43 @@ void serial8250_em485_destroy(struct uart_8250_port *p);
static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
{
+ int mctrl_gpio = 0;
+
serial_out(up, UART_MCR, value);
+
+ if (value & UART_MCR_RTS)
+ mctrl_gpio |= TIOCM_RTS;
+ if (value & UART_MCR_DTR)
+ mctrl_gpio |= TIOCM_DTR;
+
+ mctrl_gpio_set(up->gpios, mctrl_gpio);
}
static inline int serial8250_in_MCR(struct uart_8250_port *up)
{
- return serial_in(up, UART_MCR);
+ int mctrl, mctrl_gpio = 0;
+
+ mctrl = serial_in(up, UART_MCR);
+
+ /* save current MCR values */
+ if (mctrl & UART_MCR_RTS)
+ mctrl_gpio |= TIOCM_RTS;
+ if (mctrl & UART_MCR_DTR)
+ mctrl_gpio |= TIOCM_DTR;
+
+ mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
+
+ if (mctrl_gpio & TIOCM_RTS)
+ mctrl |= UART_MCR_RTS;
+ else
+ mctrl &= ~UART_MCR_RTS;
+
+ if (mctrl_gpio & TIOCM_DTR)
+ mctrl |= UART_MCR_DTR;
+ else
+ mctrl &= ~UART_MCR_DTR;
+
+ return mctrl;
}
#if defined(__alpha__) && !defined(CONFIG_PCI)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index b5def35..3371c5c 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -975,6 +975,8 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
uart = serial8250_find_match_or_unused(&up->port);
if (uart && uart->port.type != PORT_8250_CIR) {
+ struct mctrl_gpios *gpios;
+
if (uart->port.dev)
uart_remove_one_port(&serial8250_reg, &uart->port);
@@ -1012,6 +1014,15 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
if (up->port.flags & UPF_FIXED_TYPE)
uart->port.type = up->port.type;
+ gpios = mctrl_gpio_init(&uart->port, 0);
+ if (IS_ERR(gpios)) {
+ if (PTR_ERR(gpios) != -ENOSYS) {
+ ret = PTR_ERR(gpios);
+ goto out;
+ }
+ } else
+ uart->gpios = gpios;
+
serial8250_set_defaults(uart);
/* Possibly override default I/O functions. */
@@ -1051,6 +1062,7 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
if (ret == 0)
ret = uart->port.line;
}
+out:
mutex_unlock(&serial_mutex);
return ret;
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 833771b..93fe5b9 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -134,18 +134,21 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
serial8250_do_set_mctrl(port, mctrl);
- /*
- * Turn off autoRTS if RTS is lowered and restore autoRTS setting
- * if RTS is raised
- */
- lcr = serial_in(up, UART_LCR);
- serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
- if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
- priv->efr |= UART_EFR_RTS;
- else
- priv->efr &= ~UART_EFR_RTS;
- serial_out(up, UART_EFR, priv->efr);
- serial_out(up, UART_LCR, lcr);
+ if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios,
+ UART_GPIO_RTS))) {
+ /*
+ * Turn off autoRTS if RTS is lowered and restore autoRTS
+ * setting if RTS is raised
+ */
+ lcr = serial_in(up, UART_LCR);
+ serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+ if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
+ priv->efr |= UART_EFR_RTS;
+ else
+ priv->efr &= ~UART_EFR_RTS;
+ serial_out(up, UART_EFR, priv->efr);
+ serial_out(up, UART_LCR, lcr);
+ }
}
/*
@@ -446,7 +449,9 @@ static void omap_8250_set_termios(struct uart_port *port,
priv->efr = 0;
up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
- if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
+ if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW
+ && IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios,
+ UART_GPIO_RTS))) {
/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
priv->efr |= UART_EFR_CTS;
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index a5fe0e6..f173cda 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1631,6 +1631,8 @@ static void serial8250_disable_ms(struct uart_port *port)
if (up->bugs & UART_BUG_NOMSR)
return;
+ mctrl_gpio_disable_ms(up->gpios);
+
up->ier &= ~UART_IER_MSI;
serial_port_out(port, UART_IER, up->ier);
}
@@ -1643,6 +1645,8 @@ static void serial8250_enable_ms(struct uart_port *port)
if (up->bugs & UART_BUG_NOMSR)
return;
+ mctrl_gpio_enable_ms(up->gpios);
+
up->ier |= UART_IER_MSI;
serial8250_rpm_get(up);
@@ -1946,7 +1950,8 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port)
ret |= TIOCM_DSR;
if (status & UART_MSR_CTS)
ret |= TIOCM_CTS;
- return ret;
+
+ return mctrl_gpio_get(up->gpios, &ret);
}
EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index a1161ec..c0e51b0 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -6,6 +6,7 @@
config SERIAL_8250
tristate "8250/16550 and compatible serial support"
select SERIAL_CORE
+ select SERIAL_MCTRL_GPIO if GPIOLIB
---help---
This selects whether you want to include the driver for the standard
serial ports. The standard answer is Y. People who might say N
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 61fbb44..23b6ab1 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -113,6 +113,7 @@ struct uart_8250_port {
* if no_console_suspend
*/
unsigned char probe;
+ struct mctrl_gpios *gpios;
#define UART_PROBE_RSA (1 << 0)
/*
--
2.1.4
--
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