Merge remote-tracking branch 'tty/tty-next'

22 files changed, 463 insertions, 104 deletions

diff --git a/Documentation/ABI/stable/sysfs-driver-aspeed-vuart b/Documentation/ABI/stable/sysfs-driver-aspeed-vuart
new file mode 100644
index 000000000000..8062953ce77b
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-driver-aspeed-vuart
@@ -0,0 +1,15 @@
+What:		/sys/bus/platform/drivers/aspeed-vuart/*/lpc_address
+Date:		April 2017
+Contact:	Jeremy Kerr <jk@ozlabs.org>
+Description:	Configures which IO port the host side of the UART
+		will appear on the host <-> BMC LPC bus.
+Users:		OpenBMC.  Proposed changes should be mailed to
+		openbmc@lists.ozlabs.org
+
+What:		/sys/bus/platform/drivers/aspeed-vuart*/sirq
+Date:		April 2017
+Contact:	Jeremy Kerr <jk@ozlabs.org>
+Description:	Configures which interrupt number the host side of
+		the UART will appear on the host <-> BMC LPC bus.
+Users:		OpenBMC.  Proposed changes should be mailed to
+		openbmc@lists.ozlabs.org
diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
index 10276a46ecef..656733949309 100644
--- a/Documentation/devicetree/bindings/serial/8250.txt
+++ b/Documentation/devicetree/bindings/serial/8250.txt
@@ -20,6 +20,8 @@ Required properties:
 	- "fsl,16550-FIFO64"
 	- "fsl,ns16550"
 	- "ti,da830-uart"
+	- "aspeed,ast2400-vuart"
+	- "aspeed,ast2500-vuart"
 	- "serial" if the port type is unknown.
 - reg : offset and length of the register set for the device.
 - interrupts : should contain uart interrupt.
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index 99bb875178d7..423e28ec27fb 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -1242,8 +1242,7 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
 		free_irq(irq, hvcsd);
 		return;
 	} else if (hvcsd->port.count < 0) {
-		printk(KERN_ERR "HVCS: vty-server@%X open_count: %d"
-				" is missmanaged.\n",
+		printk(KERN_ERR "HVCS: vty-server@%X open_count: %d is mismanaged.\n",
 		hvcsd->vdev->unit_address, hvcsd->port.count);
 	}
 
diff --git a/drivers/tty/serdev/serdev-ttyport.c b/drivers/tty/serdev/serdev-ttyport.c
index d0a021c93986..302018d67efa 100644
--- a/drivers/tty/serdev/serdev-ttyport.c
+++ b/drivers/tty/serdev/serdev-ttyport.c
@@ -148,7 +148,7 @@ static unsigned int ttyport_set_baudrate(struct serdev_controller *ctrl, unsigne
 
 	/* tty_set_termios() return not checked as it is always 0 */
 	tty_set_termios(tty, &ktermios);
-	return speed;
+	return ktermios.c_ospeed;
 }
 
 static void ttyport_set_flow_control(struct serdev_controller *ctrl, bool enable)
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index ce8d4ffcc425..b2bdc35f7495 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -81,6 +81,9 @@ struct serial8250_config {
 #define UART_CAP_HFIFO	(1 << 14)	/* UART has a "hidden" FIFO */
 #define UART_CAP_RPM	(1 << 15)	/* Runtime PM is active while idle */
 #define UART_CAP_IRDA	(1 << 16)	/* UART supports IrDA line discipline */
+#define UART_CAP_MINI	(1 << 17)	/* Mini UART on BCM283X family lacks:
+					 * STOP PARITY EPAR SPAR WLEN5 WLEN6
+					 */
 
 #define UART_BUG_QUOT	(1 << 0)	/* UART has buggy quot LSB */
 #define UART_BUG_TXEN	(1 << 1)	/* UART has buggy TX IIR status */
diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
new file mode 100644
index 000000000000..822be4906763
--- /dev/null
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -0,0 +1,323 @@
+/*
+ *  Serial Port driver for Aspeed VUART device
+ *
+ *    Copyright (C) 2016 Jeremy Kerr <jk@ozlabs.org>, IBM Corp.
+ *    Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/clk.h>
+
+#include "8250.h"
+
+#define ASPEED_VUART_GCRA		0x20
+#define ASPEED_VUART_GCRA_VUART_EN		BIT(0)
+#define ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD BIT(5)
+#define ASPEED_VUART_GCRB		0x24
+#define ASPEED_VUART_GCRB_HOST_SIRQ_MASK	GENMASK(7, 4)
+#define ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT	4
+#define ASPEED_VUART_ADDRL		0x28
+#define ASPEED_VUART_ADDRH		0x2c
+
+struct aspeed_vuart {
+	struct device		*dev;
+	void __iomem		*regs;
+	struct clk		*clk;
+	int			line;
+};
+
+/*
+ * The VUART is basically two UART 'front ends' connected by their FIFO
+ * (no actual serial line in between). One is on the BMC side (management
+ * controller) and one is on the host CPU side.
+ *
+ * It allows the BMC to provide to the host a "UART" that pipes into
+ * the BMC itself and can then be turned by the BMC into a network console
+ * of some sort for example.
+ *
+ * This driver is for the BMC side. The sysfs files allow the BMC
+ * userspace which owns the system configuration policy, to specify
+ * at what IO port and interrupt number the host side will appear
+ * to the host on the Host <-> BMC LPC bus. It could be different on a
+ * different system (though most of them use 3f8/4).
+ */
+
+static ssize_t lpc_address_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	u16 addr;
+
+	addr = (readb(vuart->regs + ASPEED_VUART_ADDRH) << 8) |
+		(readb(vuart->regs + ASPEED_VUART_ADDRL));
+
+	return snprintf(buf, PAGE_SIZE - 1, "0x%x\n", addr);
+}
+
+static ssize_t lpc_address_store(struct device *dev,
+				 struct device_attribute *attr,
+				 const char *buf, size_t count)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	unsigned long val;
+	int err;
+
+	err = kstrtoul(buf, 0, &val);
+	if (err)
+		return err;
+
+	writeb(val >> 8, vuart->regs + ASPEED_VUART_ADDRH);
+	writeb(val >> 0, vuart->regs + ASPEED_VUART_ADDRL);
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(lpc_address);
+
+static ssize_t sirq_show(struct device *dev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	u8 reg;
+
+	reg = readb(vuart->regs + ASPEED_VUART_GCRB);
+	reg &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK;
+	reg >>= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT;
+
+	return snprintf(buf, PAGE_SIZE - 1, "%u\n", reg);
+}
+
+static ssize_t sirq_store(struct device *dev, struct device_attribute *attr,
+			  const char *buf, size_t count)
+{
+	struct aspeed_vuart *vuart = dev_get_drvdata(dev);
+	unsigned long val;
+	int err;
+	u8 reg;
+
+	err = kstrtoul(buf, 0, &val);
+	if (err)
+		return err;
+
+	val <<= ASPEED_VUART_GCRB_HOST_SIRQ_SHIFT;
+	val &= ASPEED_VUART_GCRB_HOST_SIRQ_MASK;
+
+	reg = readb(vuart->regs + ASPEED_VUART_GCRB);
+	reg &= ~ASPEED_VUART_GCRB_HOST_SIRQ_MASK;
+	reg |= val;
+	writeb(reg, vuart->regs + ASPEED_VUART_GCRB);
+
+	return count;
+}
+
+static DEVICE_ATTR_RW(sirq);
+
+static struct attribute *aspeed_vuart_attrs[] = {
+	&dev_attr_sirq.attr,
+	&dev_attr_lpc_address.attr,
+	NULL,
+};
+
+static const struct attribute_group aspeed_vuart_attr_group = {
+	.attrs = aspeed_vuart_attrs,
+};
+
+static void aspeed_vuart_set_enabled(struct aspeed_vuart *vuart, bool enabled)
+{
+	u8 reg = readb(vuart->regs + ASPEED_VUART_GCRA);
+
+	if (enabled)
+		reg |= ASPEED_VUART_GCRA_VUART_EN;
+	else
+		reg &= ~ASPEED_VUART_GCRA_VUART_EN;
+
+	writeb(reg, vuart->regs + ASPEED_VUART_GCRA);
+}
+
+static void aspeed_vuart_set_host_tx_discard(struct aspeed_vuart *vuart,
+					     bool discard)
+{
+	u8 reg;
+
+	reg = readb(vuart->regs + ASPEED_VUART_GCRA);
+
+	/* If the DISABLE_HOST_TX_DISCARD bit is set, discard is disabled */
+	if (!discard)
+		reg |= ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD;
+	else
+		reg &= ~ASPEED_VUART_GCRA_DISABLE_HOST_TX_DISCARD;
+
+	writeb(reg, vuart->regs + ASPEED_VUART_GCRA);
+}
+
+static int aspeed_vuart_startup(struct uart_port *uart_port)
+{
+	struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port);
+	struct aspeed_vuart *vuart = uart_8250_port->port.private_data;
+	int rc;
+
+	rc = serial8250_do_startup(uart_port);
+	if (rc)
+		return rc;
+
+	aspeed_vuart_set_host_tx_discard(vuart, false);
+
+	return 0;
+}
+
+static void aspeed_vuart_shutdown(struct uart_port *uart_port)
+{
+	struct uart_8250_port *uart_8250_port = up_to_u8250p(uart_port);
+	struct aspeed_vuart *vuart = uart_8250_port->port.private_data;
+
+	aspeed_vuart_set_host_tx_discard(vuart, true);
+
+	serial8250_do_shutdown(uart_port);
+}
+
+static int aspeed_vuart_probe(struct platform_device *pdev)
+{
+	struct uart_8250_port port;
+	struct aspeed_vuart *vuart;
+	struct device_node *np;
+	struct resource *res;
+	u32 clk, prop;
+	int rc;
+
+	np = pdev->dev.of_node;
+
+	vuart = devm_kzalloc(&pdev->dev, sizeof(*vuart), GFP_KERNEL);
+	if (!vuart)
+		return -ENOMEM;
+
+	vuart->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	vuart->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(vuart->regs))
+		return PTR_ERR(vuart->regs);
+
+	memset(&port, 0, sizeof(port));
+	port.port.private_data = vuart;
+	port.port.membase = vuart->regs;
+	port.port.mapbase = res->start;
+	port.port.mapsize = resource_size(res);
+	port.port.startup = aspeed_vuart_startup;
+	port.port.shutdown = aspeed_vuart_shutdown;
+	port.port.dev = &pdev->dev;
+
+	rc = sysfs_create_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
+	if (rc < 0)
+		return rc;
+
+	if (of_property_read_u32(np, "clock-frequency", &clk)) {
+		vuart->clk = devm_clk_get(&pdev->dev, NULL);
+		if (IS_ERR(vuart->clk)) {
+			dev_warn(&pdev->dev,
+				"clk or clock-frequency not defined\n");
+			return PTR_ERR(vuart->clk);
+		}
+
+		rc = clk_prepare_enable(vuart->clk);
+		if (rc < 0)
+			return rc;
+
+		clk = clk_get_rate(vuart->clk);
+	}
+
+	/* If current-speed was set, then try not to change it. */
+	if (of_property_read_u32(np, "current-speed", &prop) == 0)
+		port.port.custom_divisor = clk / (16 * prop);
+
+	/* Check for shifted address mapping */
+	if (of_property_read_u32(np, "reg-offset", &prop) == 0)
+		port.port.mapbase += prop;
+
+	/* Check for registers offset within the devices address range */
+	if (of_property_read_u32(np, "reg-shift", &prop) == 0)
+		port.port.regshift = prop;
+
+	/* Check for fifo size */
+	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
+		port.port.fifosize = prop;
+
+	/* Check for a fixed line number */
+	rc = of_alias_get_id(np, "serial");
+	if (rc >= 0)
+		port.port.line = rc;
+
+	port.port.irq = irq_of_parse_and_map(np, 0);
+	port.port.irqflags = IRQF_SHARED;
+	port.port.iotype = UPIO_MEM;
+	port.port.type = PORT_16550A;
+	port.port.uartclk = clk;
+	port.port.flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF
+		| UPF_FIXED_PORT | UPF_FIXED_TYPE | UPF_NO_THRE_TEST;
+
+	if (of_property_read_bool(np, "no-loopback-test"))
+		port.port.flags |= UPF_SKIP_TEST;
+
+	if (port.port.fifosize)
+		port.capabilities = UART_CAP_FIFO;
+
+	if (of_property_read_bool(np, "auto-flow-control"))
+		port.capabilities |= UART_CAP_AFE;
+
+	rc = serial8250_register_8250_port(&port);
+	if (rc < 0)
+		goto err_clk_disable;
+
+	vuart->line = rc;
+
+	aspeed_vuart_set_enabled(vuart, true);
+	aspeed_vuart_set_host_tx_discard(vuart, true);
+	platform_set_drvdata(pdev, vuart);
+
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(vuart->clk);
+	irq_dispose_mapping(port.port.irq);
+	return rc;
+}
+
+static int aspeed_vuart_remove(struct platform_device *pdev)
+{
+	struct aspeed_vuart *vuart = platform_get_drvdata(pdev);
+
+	aspeed_vuart_set_enabled(vuart, false);
+	serial8250_unregister_port(vuart->line);
+	sysfs_remove_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
+	clk_disable_unprepare(vuart->clk);
+
+	return 0;
+}
+
+static const struct of_device_id aspeed_vuart_table[] = {
+	{ .compatible = "aspeed,ast2400-vuart" },
+	{ .compatible = "aspeed,ast2500-vuart" },
+	{ },
+};
+
+static struct platform_driver aspeed_vuart_driver = {
+	.driver = {
+		.name = "aspeed-vuart",
+		.of_match_table = aspeed_vuart_table,
+	},
+	.probe = aspeed_vuart_probe,
+	.remove = aspeed_vuart_remove,
+};
+
+module_platform_driver(aspeed_vuart_driver);
+
+MODULE_AUTHOR("Jeremy Kerr <jk@ozlabs.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Driver for Aspeed VUART device");
diff --git a/drivers/tty/serial/8250/8250_bcm2835aux.c b/drivers/tty/serial/8250/8250_bcm2835aux.c
index e10f1244409b..a23c7da42ea8 100644
--- a/drivers/tty/serial/8250/8250_bcm2835aux.c
+++ b/drivers/tty/serial/8250/8250_bcm2835aux.c
@@ -39,7 +39,7 @@ static int bcm2835aux_serial_probe(struct platform_device *pdev)
 
 	/* initialize data */
 	spin_lock_init(&data->uart.port.lock);
-	data->uart.capabilities = UART_CAP_FIFO;
+	data->uart.capabilities = UART_CAP_FIFO | UART_CAP_MINI;
 	data->uart.port.dev = &pdev->dev;
 	data->uart.port.regshift = 2;
 	data->uart.port.type = PORT_16550;
diff --git a/drivers/tty/serial/8250/8250_exar.c b/drivers/tty/serial/8250/8250_exar.c
index 1270ff163f63..0a20f7185094 100644
--- a/drivers/tty/serial/8250/8250_exar.c
+++ b/drivers/tty/serial/8250/8250_exar.c
@@ -109,7 +109,6 @@ pci_fastcom335_setup(struct exar8250 *priv, struct pci_dev *pcidev,
 	u8 __iomem *p;
 	int err;
 
-	port->port.flags |= UPF_EXAR_EFR;
 	port->port.uartclk = baud * 16;
 
 	err = default_setup(priv, pcidev, idx, offset, port);
@@ -177,13 +176,13 @@ static void setup_gpio(u8 __iomem *p)
 	writeb(0x00, p + UART_EXAR_MPIOLVL_7_0);
 	writeb(0x00, p + UART_EXAR_MPIO3T_7_0);
 	writeb(0x00, p + UART_EXAR_MPIOINV_7_0);
-	writeb(0x00, p + UART_EXAR_MPIOSEL_7_0);
+	writeb(0xff, p + UART_EXAR_MPIOSEL_7_0);
 	writeb(0x00, p + UART_EXAR_MPIOOD_7_0);
 	writeb(0x00, p + UART_EXAR_MPIOINT_15_8);
 	writeb(0x00, p + UART_EXAR_MPIOLVL_15_8);
 	writeb(0x00, p + UART_EXAR_MPIO3T_15_8);
 	writeb(0x00, p + UART_EXAR_MPIOINV_15_8);
-	writeb(0x00, p + UART_EXAR_MPIOSEL_15_8);
+	writeb(0xff, p + UART_EXAR_MPIOSEL_15_8);
 	writeb(0x00, p + UART_EXAR_MPIOOD_15_8);
 }
 
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index e7e64913a748..d81bac98d190 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -613,6 +613,10 @@ static int omap_8250_startup(struct uart_port *port)
 	up->lsr_saved_flags = 0;
 	up->msr_saved_flags = 0;
 
+	/* Disable DMA for console UART */
+	if (uart_console(port))
+		up->dma = NULL;
+
 	if (up->dma) {
 		ret = serial8250_request_dma(up);
 		if (ret) {
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 68fd045a7025..4c620bedfbf4 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -2228,7 +2228,7 @@ int serial8250_do_startup(struct uart_port *port)
 		}
 	}
 
-	if (port->irq) {
+	if (port->irq && !(up->port.flags & UPF_NO_THRE_TEST)) {
 		unsigned char iir1;
 		/*
 		 * Test for UARTs that do not reassert THRE when the
@@ -2585,6 +2585,12 @@ serial8250_do_set_termios(struct uart_port *port, struct ktermios *termios,
 	unsigned long flags;
 	unsigned int baud, quot, frac = 0;
 
+	if (up->capabilities & UART_CAP_MINI) {
+		termios->c_cflag &= ~(CSTOPB | PARENB | PARODD | CMSPAR);
+		if ((termios->c_cflag & CSIZE) == CS5 ||
+		    (termios->c_cflag & CSIZE) == CS6)
+			termios->c_cflag = (termios->c_cflag & ~CSIZE) | CS7;
+	}
 	cval = serial8250_compute_lcr(up, termios->c_cflag);
 
 	baud = serial8250_get_baud_rate(port, termios, old);
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 0e3f529d50e9..a1161ec0256f 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -224,6 +224,16 @@ config SERIAL_8250_ACCENT
 	  To compile this driver as a module, choose M here: the module
 	  will be called 8250_accent.
 
+config SERIAL_8250_ASPEED_VUART
+	tristate "Aspeed Virtual UART"
+	depends on SERIAL_8250
+	depends on OF
+	help
+	  If you want to use the virtual UART (VUART) device on Aspeed
+	  BMC platforms, enable this option. This enables the 16550A-
+	  compatible device on the local LPC bus, giving a UART device
+	  with no physical RS232 connections.
+
 config SERIAL_8250_BOCA
 	tristate "Support Boca cards"
 	depends on SERIAL_8250 != n && ISA && SERIAL_8250_MANY_PORTS
diff --git a/drivers/tty/serial/8250/Makefile b/drivers/tty/serial/8250/Makefile
index 2f30f9ecdb1b..a44a99a3e623 100644
--- a/drivers/tty/serial/8250/Makefile
+++ b/drivers/tty/serial/8250/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_SERIAL_8250_EXAR)		+= 8250_exar.o
 obj-$(CONFIG_SERIAL_8250_HP300)		+= 8250_hp300.o
 obj-$(CONFIG_SERIAL_8250_CS)		+= serial_cs.o
 obj-$(CONFIG_SERIAL_8250_ACORN)		+= 8250_acorn.o
+obj-$(CONFIG_SERIAL_8250_ASPEED_VUART)	+= 8250_aspeed_vuart.o
 obj-$(CONFIG_SERIAL_8250_BCM2835AUX)	+= 8250_bcm2835aux.o
 obj-$(CONFIG_SERIAL_8250_CONSOLE)	+= 8250_early.o
 obj-$(CONFIG_SERIAL_8250_FOURPORT)	+= 8250_fourport.o
diff --git a/drivers/tty/serial/amba-pl010.c b/drivers/tty/serial/amba-pl010.c
index f2f251075109..24180adb1cbb 100644
--- a/drivers/tty/serial/amba-pl010.c
+++ b/drivers/tty/serial/amba-pl010.c
@@ -697,6 +697,7 @@ static struct console amba_console = {
 #define AMBA_CONSOLE	NULL
 #endif
 
+static DEFINE_MUTEX(amba_reg_lock);
 static struct uart_driver amba_reg = {
 	.owner			= THIS_MODULE,
 	.driver_name		= "ttyAM",
@@ -749,6 +750,19 @@ static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
 	amba_ports[i] = uap;
 
 	amba_set_drvdata(dev, uap);
+
+	mutex_lock(&amba_reg_lock);
+	if (!amba_reg.state) {
+		ret = uart_register_driver(&amba_reg);
+		if (ret < 0) {
+			mutex_unlock(&amba_reg_lock);
+			dev_err(uap->port.dev,
+				"Failed to register AMBA-PL010 driver\n");
+			return ret;
+		}
+	}
+	mutex_unlock(&amba_reg_lock);
+
 	ret = uart_add_one_port(&amba_reg, &uap->port);
 	if (ret)
 		amba_ports[i] = NULL;
@@ -760,12 +774,18 @@ static int pl010_remove(struct amba_device *dev)
 {
 	struct uart_amba_port *uap = amba_get_drvdata(dev);
 	int i;
+	bool busy = false;
 
 	uart_remove_one_port(&amba_reg, &uap->port);
 
 	for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
 		if (amba_ports[i] == uap)
 			amba_ports[i] = NULL;
+		else if (amba_ports[i])
+			busy = true;
+
+	if (!busy)
+		uart_unregister_driver(&amba_reg);
 
 	return 0;
 }
@@ -816,23 +836,14 @@ static struct amba_driver pl010_driver = {
 
 static int __init pl010_init(void)
 {
-	int ret;
-
 	printk(KERN_INFO "Serial: AMBA driver\n");
 
-	ret = uart_register_driver(&amba_reg);
-	if (ret == 0) {
-		ret = amba_driver_register(&pl010_driver);
-		if (ret)
-			uart_unregister_driver(&amba_reg);
-	}
-	return ret;
+	return  amba_driver_register(&pl010_driver);
 }
 
 static void __exit pl010_exit(void)
 {
 	amba_driver_unregister(&pl010_driver);
-	uart_unregister_driver(&amba_reg);
 }
 
 module_init(pl010_init);
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index c355ac9abafc..d25f044158ff 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -46,6 +46,7 @@
 #include <linux/err.h>
 #include <linux/irq.h>
 #include <linux/suspend.h>
+#include <linux/mm.h>
 
 #include <asm/io.h>
 #include <asm/ioctls.h>
@@ -959,7 +960,7 @@ static int atmel_prepare_tx_dma(struct uart_port *port)
 	sg_set_page(&atmel_port->sg_tx,
 			virt_to_page(port->state->xmit.buf),
 			UART_XMIT_SIZE,
-			(unsigned long)port->state->xmit.buf & ~PAGE_MASK);
+			offset_in_page(port->state->xmit.buf));
 	nent = dma_map_sg(port->dev,
 				&atmel_port->sg_tx,
 				1,
@@ -1141,7 +1142,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port)
 	sg_set_page(&atmel_port->sg_rx,
 		    virt_to_page(ring->buf),
 		    sizeof(struct atmel_uart_char) * ATMEL_SERIAL_RINGSIZE,
-		    (unsigned long)ring->buf & ~PAGE_MASK);
+		    offset_in_page(ring->buf));
 	nent = dma_map_sg(port->dev,
 			  &atmel_port->sg_rx,
 			  1,
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index bbefddd92bfe..92606b1e55bd 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1340,29 +1340,13 @@ static int imx_startup(struct uart_port *port)
 	imx_enable_ms(&sport->port);
 
 	/*
-	 * If the serial port is opened for reading start RX DMA immediately
-	 * instead of waiting for RX FIFO interrupts. In our iMX53 the average
-	 * delay for the first reception dropped from approximately 35000
-	 * microseconds to 1000 microseconds.
+	 * Start RX DMA immediately instead of waiting for RX FIFO interrupts.
+	 * In our iMX53 the average delay for the first reception dropped from
+	 * approximately 35000 microseconds to 1000 microseconds.
 	 */
 	if (sport->dma_is_enabled) {
-		struct tty_struct *tty = sport->port.state->port.tty;
-		struct tty_file_private *file_priv;
-		int readcnt = 0;
-
-		spin_lock(&tty->files_lock);
-
-		if (!list_empty(&tty->tty_files))
-			list_for_each_entry(file_priv, &tty->tty_files, list)
-				if (!(file_priv->file->f_flags & O_WRONLY))
-					readcnt++;
-
-		spin_unlock(&tty->files_lock);
-
-		if (readcnt > 0) {
-			imx_disable_rx_int(sport);
-			start_rx_dma(sport);
-		}
+		imx_disable_rx_int(sport);
+		start_rx_dma(sport);
 	}
 
 	spin_unlock_irqrestore(&sport->port.lock, flags);
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
index 60f16795d16b..c0e34dabadd8 100644
--- a/drivers/tty/serial/meson_uart.c
+++ b/drivers/tty/serial/meson_uart.c
@@ -286,7 +286,7 @@ static int meson_uart_startup(struct uart_port *port)
 	writel(val, port->membase + AML_UART_MISC);
 
 	ret = request_irq(port->irq, meson_uart_interrupt, 0,
-			  meson_uart_type(port), port);
+			  port->name, port);
 
 	return ret;
 }
@@ -298,8 +298,6 @@ static void meson_uart_change_speed(struct uart_port *port, unsigned long baud)
 	while (!meson_uart_tx_empty(port))
 		cpu_relax();
 
-	val = readl(port->membase + AML_UART_REG5);
-	val &= ~AML_UART_BAUD_MASK;
 	if (port->uartclk == 24000000) {
 		val = ((port->uartclk / 3) / baud) - 1;
 		val |= AML_UART_BAUD_XTAL;
@@ -355,7 +353,7 @@ static void meson_uart_set_termios(struct uart_port *port,
 	if (cflags & CSTOPB)
 		val |= AML_UART_STOP_BIN_2SB;
 	else
-		val &= ~AML_UART_STOP_BIN_1SB;
+		val |= AML_UART_STOP_BIN_1SB;
 
 	if (cflags & CRTSCTS)
 		val &= ~AML_UART_TWO_WIRE_EN;
@@ -395,51 +393,25 @@ static int meson_uart_verify_port(struct uart_port *port,
 	return ret;
 }
 
-static int meson_uart_res_size(struct uart_port *port)
-{
-	struct platform_device *pdev = to_platform_device(port->dev);
-	struct resource *res;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (!res) {
-		dev_err(port->dev, "cannot obtain I/O memory region");
-		return -ENODEV;
-	}
-
-	return resource_size(res);
-}
-
 static void meson_uart_release_port(struct uart_port *port)
 {
-	int size = meson_uart_res_size(port);
-
-	if (port->flags & UPF_IOREMAP) {
-		devm_release_mem_region(port->dev, port->mapbase, size);
-		devm_iounmap(port->dev, port->membase);
-		port->membase = NULL;
-	}
+	devm_iounmap(port->dev, port->membase);
+	port->membase = NULL;
+	devm_release_mem_region(port->dev, port->mapbase, port->mapsize);
 }
 
 static int meson_uart_request_port(struct uart_port *port)
 {
-	int size = meson_uart_res_size(port);
-
-	if (size < 0)
-		return size;
-
-	if (!devm_request_mem_region(port->dev, port->mapbase, size,
+	if (!devm_request_mem_region(port->dev, port->mapbase, port->mapsize,
 				     dev_name(port->dev))) {
 		dev_err(port->dev, "Memory region busy\n");
 		return -EBUSY;
 	}
 
-	if (port->flags & UPF_IOREMAP) {
-		port->membase = devm_ioremap_nocache(port->dev,
-						     port->mapbase,
-						     size);
-		if (port->membase == NULL)
-			return -ENOMEM;
-	}
+	port->membase = devm_ioremap_nocache(port->dev, port->mapbase,
+					     port->mapsize);
+	if (!port->membase)
+		return -ENOMEM;
 
 	return 0;
 }
@@ -470,6 +442,14 @@ static struct uart_ops meson_uart_ops = {
 };
 
 #ifdef CONFIG_SERIAL_MESON_CONSOLE
+static void meson_uart_enable_tx_engine(struct uart_port *port)
+{
+	u32 val;
+
+	val = readl(port->membase + AML_UART_CONTROL);
+	val |= AML_UART_TX_EN;
+	writel(val, port->membase + AML_UART_CONTROL);
+}
 
 static void meson_console_putchar(struct uart_port *port, int ch)
 {
@@ -499,7 +479,6 @@ static void meson_serial_port_write(struct uart_port *port, const char *s,
 	}
 
 	val = readl(port->membase + AML_UART_CONTROL);
-	val |= AML_UART_TX_EN;
 	tmp = val & ~(AML_UART_TX_INT_EN | AML_UART_RX_INT_EN);
 	writel(tmp, port->membase + AML_UART_CONTROL);
 
@@ -538,6 +517,8 @@ static int meson_serial_console_setup(struct console *co, char *options)
 	if (!port || !port->membase)
 		return -ENODEV;
 
+	meson_uart_enable_tx_engine(port);
+
 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
 
@@ -576,6 +557,7 @@ meson_serial_early_console_setup(struct earlycon_device *device, const char *opt
 	if (!device->port.membase)
 		return -ENODEV;
 
+	meson_uart_enable_tx_engine(&device->port);
 	device->con->write = meson_serial_early_console_write;
 	return 0;
 }
@@ -632,8 +614,9 @@ static int meson_uart_probe(struct platform_device *pdev)
 	port->uartclk = clk_get_rate(clk);
 	port->iotype = UPIO_MEM;
 	port->mapbase = res_mem->start;
+	port->mapsize = resource_size(res_mem);
 	port->irq = res_irq->start;
-	port->flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP | UPF_LOW_LATENCY;
+	port->flags = UPF_BOOT_AUTOCONF | UPF_LOW_LATENCY;
 	port->dev = &pdev->dev;
 	port->line = pdev->id;
 	port->type = PORT_MESON;
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 42caccb5e87e..d3796dc26fa9 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -878,8 +878,7 @@ static int dma_handle_rx(struct eg20t_port *priv)
 	sg_dma_len(sg) = priv->trigger_level;
 
 	sg_set_page(&priv->sg_rx, virt_to_page(priv->rx_buf_virt),
-		     sg_dma_len(sg), (unsigned long)priv->rx_buf_virt &
-		     ~PAGE_MASK);
+		     sg_dma_len(sg), offset_in_page(priv->rx_buf_virt));
 
 	sg_dma_address(sg) = priv->rx_buf_dma;
 
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index 71707e8e6e3f..da5ddfc14778 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1450,8 +1450,7 @@ static struct dma_chan *sci_request_dma_chan(struct uart_port *port,
 	chan = dma_request_slave_channel(port->dev,
 					 dir == DMA_MEM_TO_DEV ? "tx" : "rx");
 	if (!chan) {
-		dev_warn(port->dev,
-			 "dma_request_slave_channel_compat failed\n");
+		dev_warn(port->dev, "dma_request_slave_channel failed\n");
 		return NULL;
 	}
 
@@ -1558,7 +1557,16 @@ static void sci_free_dma(struct uart_port *port)
 	if (s->chan_rx)
 		sci_rx_dma_release(s, false);
 }
-#else
+
+static void sci_flush_buffer(struct uart_port *port)
+{
+	/*
+	 * In uart_flush_buffer(), the xmit circular buffer has just been
+	 * cleared, so we have to reset tx_dma_len accordingly.
+	 */
+	to_sci_port(port)->tx_dma_len = 0;
+}
+#else /* !CONFIG_SERIAL_SH_SCI_DMA */
 static inline void sci_request_dma(struct uart_port *port)
 {
 }
@@ -1566,7 +1574,9 @@ static inline void sci_request_dma(struct uart_port *port)
 static inline void sci_free_dma(struct uart_port *port)
 {
 }
-#endif
+
+#define sci_flush_buffer	NULL
+#endif /* !CONFIG_SERIAL_SH_SCI_DMA */
 
 static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
 {
@@ -2581,6 +2591,7 @@ static const struct uart_ops sci_uart_ops = {
 	.break_ctl	= sci_break_ctl,
 	.startup	= sci_startup,
 	.shutdown	= sci_shutdown,
+	.flush_buffer	= sci_flush_buffer,
 	.set_termios	= sci_set_termios,
 	.pm		= sci_pm,
 	.type		= sci_type,
@@ -2950,6 +2961,7 @@ static inline int sci_probe_earlyprintk(struct platform_device *pdev)
 
 static const char banner[] __initconst = "SuperH (H)SCI(F) driver initialized";
 
+static DEFINE_MUTEX(sci_uart_registration_lock);
 static struct uart_driver sci_uart_driver = {
 	.owner		= THIS_MODULE,
 	.driver_name	= "sci",
@@ -3078,6 +3090,16 @@ static int sci_probe_single(struct platform_device *dev,
 		return -EINVAL;
 	}
 
+	mutex_lock(&sci_uart_registration_lock);
+	if (!sci_uart_driver.state) {
+		ret = uart_register_driver(&sci_uart_driver);
+		if (ret) {
+			mutex_unlock(&sci_uart_registration_lock);
+			return ret;
+		}
+	}
+	mutex_unlock(&sci_uart_registration_lock);
+
 	ret = sci_init_single(dev, sciport, index, p, false);
 	if (ret)
 		return ret;
@@ -3201,24 +3223,17 @@ static struct platform_driver sci_driver = {
 
 static int __init sci_init(void)
 {
-	int ret;
-
 	pr_info("%s\n", banner);
 
-	ret = uart_register_driver(&sci_uart_driver);
-	if (likely(ret == 0)) {
-		ret = platform_driver_register(&sci_driver);
-		if (unlikely(ret))
-			uart_unregister_driver(&sci_uart_driver);
-	}
-
-	return ret;
+	return platform_driver_register(&sci_driver);
 }
 
 static void __exit sci_exit(void)
 {
 	platform_driver_unregister(&sci_driver);
-	uart_unregister_driver(&sci_uart_driver);
+
+	if (sci_uart_driver.state)
+		uart_unregister_driver(&sci_uart_driver);
 }
 
 #ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index c0539950f8d7..b5b77ba3ac65 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -1587,20 +1587,21 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	if (rc) {
 		dev_err(&pdev->dev,
 			"uart_add_one_port() failed; err=%i\n", rc);
-		goto err_out_notif_unreg;
+		goto err_out_pm_disable;
 	}
 
 	return 0;
 
+err_out_pm_disable:
+	pm_runtime_disable(&pdev->dev);
+	pm_runtime_set_suspended(&pdev->dev);
+	pm_runtime_dont_use_autosuspend(&pdev->dev);
 err_out_notif_unreg:
 #ifdef CONFIG_COMMON_CLK
 	clk_notifier_unregister(cdns_uart_data->uartclk,
 			&cdns_uart_data->clk_rate_change_nb);
 #endif
 err_out_clk_disable:
-	pm_runtime_disable(&pdev->dev);
-	pm_runtime_set_suspended(&pdev->dev);
-	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	clk_disable_unprepare(cdns_uart_data->uartclk);
 err_out_clk_dis_pclk:
 	clk_disable_unprepare(cdns_uart_data->pclk);
diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
index 8af8d9542663..f4166263bb3a 100644
--- a/drivers/tty/vt/keyboard.c
+++ b/drivers/tty/vt/keyboard.c
@@ -1203,8 +1203,7 @@ DECLARE_TASKLET_DISABLED(keyboard_tasklet, kbd_bh, 0);
 #if defined(CONFIG_X86) || defined(CONFIG_IA64) || defined(CONFIG_ALPHA) ||\
     defined(CONFIG_MIPS) || defined(CONFIG_PPC) || defined(CONFIG_SPARC) ||\
     defined(CONFIG_PARISC) || defined(CONFIG_SUPERH) ||\
-    (defined(CONFIG_ARM) && defined(CONFIG_KEYBOARD_ATKBD) && !defined(CONFIG_ARCH_RPC)) ||\
-    defined(CONFIG_AVR32)
+    (defined(CONFIG_ARM) && defined(CONFIG_KEYBOARD_ATKBD) && !defined(CONFIG_ARCH_RPC))
 
 #define HW_RAW(dev) (test_bit(EV_MSC, dev->evbit) && test_bit(MSC_RAW, dev->mscbit) &&\
 			((dev)->id.bustype == BUS_I8042) && ((dev)->id.vendor == 0x0001) && ((dev)->id.product == 0x0001))
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 64d892f1e5cd..1775500294bb 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -195,6 +195,7 @@ struct uart_port {
 #define UPF_NO_TXEN_TEST	((__force upf_t) (1 << 15))
 #define UPF_MAGIC_MULTIPLIER	((__force upf_t) ASYNC_MAGIC_MULTIPLIER /* 16 */ )
 
+#define UPF_NO_THRE_TEST	((__force upf_t) (1 << 19))
 /* Port has hardware-assisted h/w flow control */
 #define UPF_AUTO_CTS		((__force upf_t) (1 << 20))
 #define UPF_AUTO_RTS		((__force upf_t) (1 << 21))
diff --git a/include/uapi/linux/serial.h b/include/uapi/linux/serial.h
index 5d59c3ebf459..d2667ecd54ac 100644
--- a/include/uapi/linux/serial.h
+++ b/include/uapi/linux/serial.h
@@ -122,6 +122,9 @@ struct serial_rs485 {
 #define SER_RS485_RTS_AFTER_SEND	(1 << 2)	/* Logical level for
 							   RTS pin after sent*/
 #define SER_RS485_RX_DURING_TX		(1 << 4)
+#define SER_RS485_TERMINATE_BUS		(1 << 5)	/* Enable bus
+							   termination
+							   (if supported) */
 	__u32	delay_rts_before_send;	/* Delay before send (milliseconds) */
 	__u32	delay_rts_after_send;	/* Delay after send (milliseconds) */
 	__u32	padding[5];		/* Memory is cheap, new structs