[PATCH v1 1/1] Revert "tty/serial/8250: use mctrl_gpio helpers"

From: Andy Shevchenko
Date: Tue Aug 16 2016 - 08:07:26 EST


Serial console is broken in v4.8-rcX. Mika and I independently bisected down to
commit 4ef03d328769 ("tty/serial/8250: use mctrl_gpio helpers").

Since neither author nor anyone else didn't propose a solution we better revert
it for now.

This reverts commit 4ef03d328769eddbfeca1f1c958fdb181a69c341.

Cc: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Link: https://lkml.kernel.org/r/20160809130229.GN1729@xxxxxxxxxxxxxxxxxx
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
Documentation/devicetree/bindings/serial/8250.txt | 19 ------------
drivers/tty/serial/8250/8250.h | 35 +----------------------
drivers/tty/serial/8250/8250_core.c | 9 ------
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 -
7 files changed, 15 insertions(+), 88 deletions(-)

diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
index f5561ac..936ab5b 100644
--- a/Documentation/devicetree/bindings/serial/8250.txt
+++ b/Documentation/devicetree/bindings/serial/8250.txt
@@ -42,9 +42,6 @@ Optional properties:
- auto-flow-control: one way to enable automatic flow control support. The
driver is allowed to detect support for the capability even without this
property.
-- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD
- line respectively. It will use specified GPIO instead of the peripheral
- function pin for the UART feature. If unsure, don't specify this property.

Note:
* fsl,ns16550:
@@ -66,19 +63,3 @@ Example:
interrupts = <10>;
reg-shift = <2>;
};
-
-Example for OMAP UART using GPIO-based modem control signals:
-
- uart4: serial@49042000 {
- compatible = "ti,omap3-uart";
- reg = <0x49042000 0x400>;
- interrupts = <80>;
- ti,hwmods = "uart4";
- clock-frequency = <48000000>;
- cts-gpios = <&gpio3 5 GPIO_ACTIVE_LOW>;
- rts-gpios = <&gpio3 6 GPIO_ACTIVE_LOW>;
- dtr-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
- dsr-gpios = <&gpio1 13 GPIO_ACTIVE_LOW>;
- dcd-gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;
- rng-gpios = <&gpio1 15 GPIO_ACTIVE_LOW>;
- };
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 122e0e4..1a16fea 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -15,8 +15,6 @@
#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);
@@ -133,43 +131,12 @@ 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)
{
- 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;
+ return serial_in(up, UART_MCR);
}

#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 13ad5c3..dcf43f6 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -974,8 +974,6 @@ 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);

@@ -1013,13 +1011,6 @@ 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)
- return PTR_ERR(gpios);
- } else
- uart->gpios = gpios;
-
serial8250_set_defaults(uart);

/* Possibly override default I/O functions. */
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index e14982f..61ad6c3 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -134,21 +134,18 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl)

serial8250_do_set_mctrl(port, mctrl);

- 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);
- }
+ /*
+ * 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);
}

/*
@@ -449,9 +446,7 @@ 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
- && IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios,
- UART_GPIO_RTS))) {
+ if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
/* 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 7481b95..bdfa659 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1618,8 +1618,6 @@ 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);
}
@@ -1632,8 +1630,6 @@ 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);
@@ -1917,8 +1913,7 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port)
ret |= TIOCM_DSR;
if (status & UART_MSR_CTS)
ret |= TIOCM_CTS;
-
- return mctrl_gpio_get(up->gpios, &ret);
+ return ret;
}
EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);

diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index c9ec839..7c6f7af 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -6,7 +6,6 @@
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 923266c..48ec765 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -111,7 +111,6 @@ struct uart_8250_port {
* if no_console_suspend
*/
unsigned char probe;
- struct mctrl_gpios *gpios;
#define UART_PROBE_RSA (1 << 0)

/*
--
2.8.1