TTY/Serial driver fixes for 5.4-rc3

Here are some small tty and serial driver fixes for 5.4-rc3 that resolve
 a number of reported issues and regressions.
 
 None of these are huge, full details are in the shortlog.  THere's also
 a MAINTAINERS update that I think you might have already taken in your
 tree already, but git should handle that merge easily.
 
 All have been in linux-next with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver fixes from Greg KH:
 "Here are some small tty and serial driver fixes for 5.4-rc3 that
  resolve a number of reported issues and regressions.

  None of these are huge, full details are in the shortlog. There's also
  a MAINTAINERS update that I think you might have already taken in your
  tree already, but git should handle that merge easily.

  All have been in linux-next with no reported issues"

* tag 'tty-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  MAINTAINERS: kgdb: Add myself as a reviewer for kgdb/kdb
  tty: serial: imx: Use platform_get_irq_optional() for optional IRQs
  serial: fix kernel-doc warning in comments
  serial: 8250_omap: Fix gpio check for auto RTS/CTS
  serial: mctrl_gpio: Check for NULL pointer
  tty: serial: fsl_lpuart: Fix lpuart_flush_buffer()
  tty: serial: Fix PORT_LINFLEXUART definition
  tty: n_hdlc: fix build on SPARC
  serial: uartps: Fix uartps_major handling
  serial: uartlite: fix exit path null pointer
  tty: serial: linflexuart: Fix magic SysRq handling
  serial: sh-sci: Use platform_get_irq_optional() for optional interrupts
  dt-bindings: serial: sh-sci: Document r8a774b1 bindings
  serial/sifive: select SERIAL_EARLYCON
  tty: serial: rda: Fix the link time qualifier of 'rda_uart_exit()'
  tty: serial: owl: Fix the link time qualifier of 'owl_uart_exit()'

Documentation/devicetree/bindings/serial/renesas,sci-serial.txt

@@ -26,6 +26,8 @@ Required properties:
     - "renesas,hscif-r8a77470" for R8A77470 (RZ/G1C) HSCIF compatible UART.
     - "renesas,scif-r8a774a1" for R8A774A1 (RZ/G2M) SCIF compatible UART.
     - "renesas,hscif-r8a774a1" for R8A774A1 (RZ/G2M) HSCIF compatible UART.
+    - "renesas,scif-r8a774b1" for R8A774B1 (RZ/G2N) SCIF compatible UART.
+    - "renesas,hscif-r8a774b1" for R8A774B1 (RZ/G2N) HSCIF compatible UART.
     - "renesas,scif-r8a774c0" for R8A774C0 (RZ/G2E) SCIF compatible UART.
     - "renesas,hscif-r8a774c0" for R8A774C0 (RZ/G2E) HSCIF compatible UART.
     - "renesas,scif-r8a7778" for R8A7778 (R-Car M1) SCIF compatible UART.

drivers/tty/n_hdlc.c

@@ -968,6 +968,11 @@ static int __init n_hdlc_init(void)
 	
 }	/* end of init_module() */
 
+#ifdef CONFIG_SPARC
+#undef __exitdata
+#define __exitdata
+#endif
+
 static const char hdlc_unregister_ok[] __exitdata =
 	KERN_INFO "N_HDLC: line discipline unregistered\n";
 static const char hdlc_unregister_fail[] __exitdata =

drivers/tty/serial/8250/8250_omap.c

@@ -141,7 +141,7 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
 
 	serial8250_do_set_mctrl(port, mctrl);
 
-	if (!up->gpios) {
+	if (!mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS)) {
 		/*
 		 * Turn off autoRTS if RTS is lowered and restore autoRTS
 		 * setting if RTS is raised
@@ -456,7 +456,8 @@ static void omap_8250_set_termios(struct uart_port *port,
 	up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
 
 	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW &&
-	    !up->gpios) {
+	    !mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS) &&
+	    !mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_CTS)) {
 		/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
 		up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
 		priv->efr |= UART_EFR_CTS;

drivers/tty/serial/Kconfig

@@ -1032,6 +1032,7 @@ config SERIAL_SIFIVE_CONSOLE
 	bool "Console on SiFive UART"
 	depends on SERIAL_SIFIVE=y
 	select SERIAL_CORE_CONSOLE
+	select SERIAL_EARLYCON
 	help
 	  Select this option if you would like to use a SiFive UART as the
 	  system console.

drivers/tty/serial/fsl_linflexuart.c

@@ -3,7 +3,7 @@
  * Freescale linflexuart serial port driver
  *
  * Copyright 2012-2016 Freescale Semiconductor, Inc.
- * Copyright 2017-2018 NXP
+ * Copyright 2017-2019 NXP
  */
 
 #if defined(CONFIG_SERIAL_FSL_LINFLEXUART_CONSOLE) && \
@@ -246,12 +246,14 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id)
 	struct tty_port *port = &sport->state->port;
 	unsigned long flags, status;
 	unsigned char rx;
+	bool brk;
 
 	spin_lock_irqsave(&sport->lock, flags);
 
 	status = readl(sport->membase + UARTSR);
 	while (status & LINFLEXD_UARTSR_RMB) {
 		rx = readb(sport->membase + BDRM);
+		brk = false;
 		flg = TTY_NORMAL;
 		sport->icount.rx++;
 
@@ -261,8 +263,11 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id)
 				status |= LINFLEXD_UARTSR_SZF;
 			if (status & LINFLEXD_UARTSR_BOF)
 				status |= LINFLEXD_UARTSR_BOF;
-			if (status & LINFLEXD_UARTSR_FEF)
+			if (status & LINFLEXD_UARTSR_FEF) {
+				if (!rx)
+					brk = true;
 				status |= LINFLEXD_UARTSR_FEF;
+			}
 			if (status & LINFLEXD_UARTSR_PE)
 				status |=  LINFLEXD_UARTSR_PE;
 		}
@@ -271,13 +276,15 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id)
 		       sport->membase + UARTSR);
 		status = readl(sport->membase + UARTSR);
 
-		if (uart_handle_sysrq_char(sport, (unsigned char)rx))
-			continue;
-
+		if (brk) {
+			uart_handle_break(sport);
+		} else {
 #ifdef SUPPORT_SYSRQ
-			sport->sysrq = 0;
+			if (uart_handle_sysrq_char(sport, (unsigned char)rx))
+				continue;
 #endif
-		tty_insert_flip_char(port, rx, flg);
+			tty_insert_flip_char(port, rx, flg);
+		}
 	}
 
 	spin_unlock_irqrestore(&sport->lock, flags);

drivers/tty/serial/fsl_lpuart.c

@@ -548,7 +548,7 @@ static void lpuart_flush_buffer(struct uart_port *port)
 		val |= UARTFIFO_TXFLUSH | UARTFIFO_RXFLUSH;
 		lpuart32_write(&sport->port, val, UARTFIFO);
 	} else {
-		val = readb(sport->port.membase + UARTPFIFO);
+		val = readb(sport->port.membase + UARTCFIFO);
 		val |= UARTCFIFO_TXFLUSH | UARTCFIFO_RXFLUSH;
 		writeb(val, sport->port.membase + UARTCFIFO);
 	}

drivers/tty/serial/imx.c

@@ -2222,8 +2222,8 @@ static int imx_uart_probe(struct platform_device *pdev)
 		return PTR_ERR(base);
 
 	rxirq = platform_get_irq(pdev, 0);
-	txirq = platform_get_irq(pdev, 1);
-	rtsirq = platform_get_irq(pdev, 2);
+	txirq = platform_get_irq_optional(pdev, 1);
+	rtsirq = platform_get_irq_optional(pdev, 2);
 
 	sport->port.dev = &pdev->dev;
 	sport->port.mapbase = res->start;

drivers/tty/serial/owl-uart.c

@@ -740,7 +740,7 @@ static int __init owl_uart_init(void)
 	return ret;
 }
 
-static void __init owl_uart_exit(void)
+static void __exit owl_uart_exit(void)
 {
 	platform_driver_unregister(&owl_uart_platform_driver);
 	uart_unregister_driver(&owl_uart_driver);

drivers/tty/serial/rda-uart.c

@@ -815,7 +815,7 @@ static int __init rda_uart_init(void)
 	return ret;
 }
 
-static void __init rda_uart_exit(void)
+static void __exit rda_uart_exit(void)
 {
 	platform_driver_unregister(&rda_uart_platform_driver);
 	uart_unregister_driver(&rda_uart_driver);

drivers/tty/serial/serial_core.c

@@ -1964,8 +1964,10 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co)
  *	   console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options>
  *
  *	The optional form
+ *
  *	   earlycon=<name>,0x<addr>,<options>
  *	   console=<name>,0x<addr>,<options>
+ *
  *	is also accepted; the returned @iotype will be UPIO_MEM.
  *
  *	Returns 0 on success or -EINVAL on failure

drivers/tty/serial/serial_mctrl_gpio.c

@@ -66,6 +66,9 @@ EXPORT_SYMBOL_GPL(mctrl_gpio_set);
 struct gpio_desc *mctrl_gpio_to_gpiod(struct mctrl_gpios *gpios,
 				      enum mctrl_gpio_idx gidx)
 {
+	if (gpios == NULL)
+		return NULL;
+
 	return gpios->gpio[gidx];
 }
 EXPORT_SYMBOL_GPL(mctrl_gpio_to_gpiod);

drivers/tty/serial/sh-sci.c

@@ -2894,8 +2894,12 @@ static int sci_init_single(struct platform_device *dev,
 	port->mapbase = res->start;
 	sci_port->reg_size = resource_size(res);
 
-	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i)
-		sci_port->irqs[i] = platform_get_irq(dev, i);
+	for (i = 0; i < ARRAY_SIZE(sci_port->irqs); ++i) {
+		if (i)
+			sci_port->irqs[i] = platform_get_irq_optional(dev, i);
+		else
+			sci_port->irqs[i] = platform_get_irq(dev, i);
+	}
 
 	/* The SCI generates several interrupts. They can be muxed together or
 	 * connected to different interrupt lines. In the muxed case only one

drivers/tty/serial/uartlite.c

@@ -897,7 +897,8 @@ static int __init ulite_init(void)
 static void __exit ulite_exit(void)
 {
 	platform_driver_unregister(&ulite_platform_driver);
-	uart_unregister_driver(&ulite_uart_driver);
+	if (ulite_uart_driver.state)
+		uart_unregister_driver(&ulite_uart_driver);
 }
 
 module_init(ulite_init);

drivers/tty/serial/xilinx_uartps.c

@@ -1550,7 +1550,6 @@ static int cdns_uart_probe(struct platform_device *pdev)
 		goto err_out_id;
 	}
 
-	uartps_major = cdns_uart_uart_driver->tty_driver->major;
 	cdns_uart_data->cdns_uart_driver = cdns_uart_uart_driver;
 
 	/*
@@ -1680,6 +1679,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
 		console_port = NULL;
 #endif
 
+	uartps_major = cdns_uart_uart_driver->tty_driver->major;
 	cdns_uart_data->cts_override = of_property_read_bool(pdev->dev.of_node,
 							     "cts-override");
 	return 0;
@@ -1741,6 +1741,12 @@ static int cdns_uart_remove(struct platform_device *pdev)
 		console_port = NULL;
 #endif
 
+	/* If this is last instance major number should be initialized */
+	mutex_lock(&bitmap_lock);
+	if (bitmap_empty(bitmap, MAX_UART_INSTANCES))
+		uartps_major = 0;
+	mutex_unlock(&bitmap_lock);
+
 	uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
 	return rc;
 }

include/uapi/linux/serial_core.h

@@ -291,6 +291,6 @@
 #define PORT_SUNIX	121
 
 /* Freescale Linflex UART */
-#define PORT_LINFLEXUART	121
+#define PORT_LINFLEXUART	122
 
 #endif /* _UAPILINUX_SERIAL_CORE_H */