Merge tag 'tty-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/…

…git/gregkh/tty

Pull tty / serial driver updates from Greg KH:
 "Here is the "large" TTY and Serial driver update for 5.3-rc1.

  It's in the negative number of lines overall as we removed an obsolete
  serial driver that was causing problems for some people who were
  trying to clean up some apis (the mpsc.c driver, which only worked for
  some pre-production hardware that no one has anymore.)

  Other than that, lots of tiny changes, cleaning up small things along
  with some platform-specific serial driver updates.

  All of these have been in linux-next for a while now with no reported
  issues"

* tag 'tty-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (68 commits)
  tty: serial: fsl_lpuart: add imx8qxp support
  serial: imx: set_termios(): preserve RTS state
  serial: imx: set_termios(): clarify RTS/CTS bits calculation
  serial: imx: set_termios(): factor-out 'ucr2' initial value
  serial: sh-sci: Terminate TX DMA during buffer flushing
  serial: sh-sci: Fix TX DMA buffer flushing and workqueue races
  serial: mpsc: Remove obsolete MPSC driver
  serial: 8250: 8250_core: Fix missing unlock on error in serial8250_register_8250_port()
  serial: stm32: add RX and TX FIFO flush
  serial: stm32: add support of RX FIFO threshold
  serial: stm32: add support of TX FIFO threshold
  serial: stm32: update PIO transmission
  serial: stm32: add support of timeout interrupt for RX
  Revert "serial: 8250: Don't service RX FIFO if interrupts are disabled"
  tty/serial/8250: use mctrl_gpio helpers
  serial: mctrl_gpio: Check if GPIO property exisits before requesting it
  serial: 8250: pericom_do_set_divisor can be static
  tty: serial_core: Set port active bit in uart_port_activate
  serial: 8250: Add MSR/MCR TIOCM conversion wrapper functions
  serial: 8250: factor out serial8250_{set,clear}_THRI() helpers
  ...

Documentation/admin-guide/devices.txt

@@ -2693,8 +2693,8 @@
 		 41 = /dev/ttySMX0		Motorola i.MX - port 0
 		 42 = /dev/ttySMX1		Motorola i.MX - port 1
 		 43 = /dev/ttySMX2		Motorola i.MX - port 2
-		 44 = /dev/ttyMM0		Marvell MPSC - port 0
-		 45 = /dev/ttyMM1		Marvell MPSC - port 1
+		 44 = /dev/ttyMM0		Marvell MPSC - port 0 (obsolete unused)
+		 45 = /dev/ttyMM1		Marvell MPSC - port 1 (obsolete unused)
 		 46 = /dev/ttyCPM0		PPC CPM (SCC or SMC) - port 0
 		    ...
 		 47 = /dev/ttyCPM5		PPC CPM (SCC or SMC) - port 5

Documentation/devicetree/bindings/serial/8250.txt

@@ -53,6 +53,9 @@ Optional properties:
   programmable TX FIFO thresholds.
 - resets : phandle + reset specifier pairs
 - overrun-throttle-ms : how long to pause uart rx when input overrun is encountered.
+- {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:
@@ -74,3 +77,19 @@ 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>;
+	};

arch/ia64/hp/sim/simserial.c

@@ -324,8 +324,6 @@ static int rs_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
 	return -ENOIOCTLCMD;
 }
 
-#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
-
 /*
  * This routine will shutdown a serial port; interrupts are disabled, and
  * DTR is dropped if the hangup on close termio flag is on.

drivers/ipack/devices/ipoctal.h

@@ -15,7 +15,6 @@
 #define NR_CHANNELS		8
 #define IPOCTAL_MAX_BOARDS	16
 #define MAX_DEVICES		(NR_CHANNELS * IPOCTAL_MAX_BOARDS)
-#define RELEVANT_IFLAG(iflag) ((iflag) & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
 
 /**
  * struct ipoctal_stats -- Stats since last reset

drivers/tty/serial/8250/8250.h

@@ -11,6 +11,8 @@
 #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);
@@ -128,6 +130,24 @@ static inline void serial_dl_write(struct uart_8250_port *up, int value)
 	up->dl_write(up, value);
 }
 
+static inline bool serial8250_set_THRI(struct uart_8250_port *up)
+{
+	if (up->ier & UART_IER_THRI)
+		return false;
+	up->ier |= UART_IER_THRI;
+	serial_out(up, UART_IER, up->ier);
+	return true;
+}
+
+static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
+{
+	if (!(up->ier & UART_IER_THRI))
+		return false;
+	up->ier &= ~UART_IER_THRI;
+	serial_out(up, UART_IER, up->ier);
+	return true;
+}
+
 struct uart_8250_port *serial8250_get_port(int line);
 
 void serial8250_rpm_get(struct uart_8250_port *p);
@@ -139,14 +159,82 @@ 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);
+
+	if (up->gpios)
+		mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
 }
 
 static inline int serial8250_in_MCR(struct uart_8250_port *up)
 {
-	return serial_in(up, UART_MCR);
+	int mctrl;
+
+	mctrl = serial_in(up, UART_MCR);
+
+	if (up->gpios) {
+		unsigned int mctrl_gpio = 0;
+
+		mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
+		mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
+	}
+
+	return mctrl;
 }
 
 #if defined(__alpha__) && !defined(CONFIG_PCI)

drivers/tty/serial/8250/8250_core.c

@@ -14,6 +14,7 @@
  *	      serial8250_register_8250_port() ports
  */
 
+#include <linux/acpi.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/ioport.h>
@@ -982,6 +983,8 @@ 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);
 
@@ -1016,6 +1019,22 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		if (up->port.flags & UPF_FIXED_TYPE)
 			uart->port.type = up->port.type;
 
+		/*
+		 * Only call mctrl_gpio_init(), if the device has no ACPI
+		 * companion device
+		 */
+		if (!has_acpi_companion(uart->port.dev)) {
+			gpios = mctrl_gpio_init(&uart->port, 0);
+			if (IS_ERR(gpios)) {
+				if (PTR_ERR(gpios) != -ENOSYS) {
+					ret = PTR_ERR(gpios);
+					goto out_unlock;
+				}
+			} else {
+				uart->gpios = gpios;
+			}
+		}
+
 		serial8250_set_defaults(uart);
 
 		/* Possibly override default I/O functions.  */
@@ -1082,6 +1101,7 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		}
 	}
 
+out_unlock:
 	mutex_unlock(&serial_mutex);
 
 	return ret;

drivers/tty/serial/8250/8250_dma.c

@@ -34,10 +34,8 @@ static void __dma_tx_complete(void *param)
 		uart_write_wakeup(&p->port);
 
 	ret = serial8250_tx_dma(p);
-	if (ret) {
-		p->ier |= UART_IER_THRI;
-		serial_port_out(&p->port, UART_IER, p->ier);
-	}
+	if (ret)
+		serial8250_set_THRI(p);
 
 	spin_unlock_irqrestore(&p->port.lock, flags);
 }
@@ -100,10 +98,7 @@ int serial8250_tx_dma(struct uart_8250_port *p)
 	dma_async_issue_pending(dma->txchan);
 	if (dma->tx_err) {
 		dma->tx_err = 0;
-		if (p->ier & UART_IER_THRI) {
-			p->ier &= ~UART_IER_THRI;
-			serial_out(p, UART_IER, p->ier);
-		}
+		serial8250_clear_THRI(p);
 	}
 	return 0;
 err: