Merge tag 'tty-3.3-rc3' tty-next

This is needed to handle the 8250 file merge mess properly for future
patches.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

34 files changed, 1152 insertions, 230 deletions

diff --git a/Documentation/devicetree/bindings/tty/serial/efm32-uart.txt b/Documentation/devicetree/bindings/tty/serial/efm32-uart.txt
new file mode 100644
index 0000000..6588b69
--- /dev/null
+++ b/Documentation/devicetree/bindings/tty/serial/efm32-uart.txt
@@ -0,0 +1,14 @@
+* Energymicro efm32 UART
+
+Required properties:
+- compatible : Should be "efm32,uart"
+- reg : Address and length of the register set
+- interrupts : Should contain uart interrupt
+
+Example:
+
+uart@0x4000c400 {
+	compatible = "efm32,uart";
+	reg = <0x4000c400 0x400>;
+	interrupts = <15>;
+};
diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index e44933d..94948be 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -1015,14 +1015,11 @@ capinc_tty_install(struct tty_driver *driver, struct tty_struct *tty)
 {
 	int idx = tty->index;
 	struct capiminor *mp = capiminor_get(idx);
-	int ret = tty_init_termios(tty);
+	int ret = tty_standard_install(driver, tty);
 
-	if (ret == 0) {
-		tty_driver_kref_get(driver);
-		tty->count++;
+	if (ret == 0)
 		tty->driver_data = mp;
-		driver->ttys[idx] = tty;
-	} else
+	else
 		capiminor_put(mp);
 	return ret;
 }
diff --git a/drivers/misc/pti.c b/drivers/misc/pti.c
index 0b56e3f..471ff4c 100644
--- a/drivers/misc/pti.c
+++ b/drivers/misc/pti.c
@@ -481,13 +481,9 @@ static int pti_tty_install(struct tty_driver *driver, struct tty_struct *tty)
 {
 	int idx = tty->index;
 	struct pti_tty *pti_tty_data;
-	int ret = tty_init_termios(tty);
+	int ret = tty_standard_install(driver, tty);
 
 	if (ret == 0) {
-		tty_driver_kref_get(driver);
-		tty->count++;
-		driver->ttys[idx] = tty;
-
 		pti_tty_data = kmalloc(sizeof(struct pti_tty), GFP_KERNEL);
 		if (pti_tty_data == NULL)
 			return -ENOMEM;
diff --git a/drivers/mmc/card/sdio_uart.c b/drivers/mmc/card/sdio_uart.c
index 2c151e1..bd4a67c 100644
--- a/drivers/mmc/card/sdio_uart.c
+++ b/drivers/mmc/card/sdio_uart.c
@@ -750,15 +750,12 @@ static int sdio_uart_install(struct tty_driver *driver, struct tty_struct *tty)
 {
 	int idx = tty->index;
 	struct sdio_uart_port *port = sdio_uart_port_get(idx);
-	int ret = tty_init_termios(tty);
+	int ret = tty_standard_install(driver, tty);
 
-	if (ret == 0) {
-		tty_driver_kref_get(driver);
-		tty->count++;
+	if (ret == 0)
 		/* This is the ref sdio_uart_port get provided */
 		tty->driver_data = port;
-		driver->ttys[idx] = tty;
-	} else
+	else
 		sdio_uart_port_put(port);
 	return ret;
 }
diff --git a/drivers/tty/hvc/hvc_beat.c b/drivers/tty/hvc/hvc_beat.c
index 5fe4631..1560d23 100644
--- a/drivers/tty/hvc/hvc_beat.c
+++ b/drivers/tty/hvc/hvc_beat.c
@@ -113,7 +113,7 @@ static int __init hvc_beat_init(void)
 	if (!firmware_has_feature(FW_FEATURE_BEAT))
 		return -ENODEV;
 
-	hp = hvc_alloc(0, NO_IRQ, &hvc_beat_get_put_ops, 16);
+	hp = hvc_alloc(0, 0, &hvc_beat_get_put_ops, 16);
 	if (IS_ERR(hp))
 		return PTR_ERR(hp);
 	hvc_beat_dev = hp;
diff --git a/drivers/tty/hvc/hvc_rtas.c b/drivers/tty/hvc/hvc_rtas.c
index 61c4a61..0069bb8 100644
--- a/drivers/tty/hvc/hvc_rtas.c
+++ b/drivers/tty/hvc/hvc_rtas.c
@@ -94,7 +94,7 @@ static int __init hvc_rtas_init(void)
 
 	/* Allocate an hvc_struct for the console device we instantiated
 	 * earlier.  Save off hp so that we can return it on exit */
-	hp = hvc_alloc(hvc_rtas_cookie, NO_IRQ, &hvc_rtas_get_put_ops, 16);
+	hp = hvc_alloc(hvc_rtas_cookie, 0, &hvc_rtas_get_put_ops, 16);
 	if (IS_ERR(hp))
 		return PTR_ERR(hp);
 
diff --git a/drivers/tty/hvc/hvc_udbg.c b/drivers/tty/hvc/hvc_udbg.c
index b0957e6..4c9b13e 100644
--- a/drivers/tty/hvc/hvc_udbg.c
+++ b/drivers/tty/hvc/hvc_udbg.c
@@ -69,7 +69,7 @@ static int __init hvc_udbg_init(void)
 
 	BUG_ON(hvc_udbg_dev);
 
-	hp = hvc_alloc(0, NO_IRQ, &hvc_udbg_ops, 16);
+	hp = hvc_alloc(0, 0, &hvc_udbg_ops, 16);
 	if (IS_ERR(hp))
 		return PTR_ERR(hp);
 
diff --git a/drivers/tty/hvc/hvc_xen.c b/drivers/tty/hvc/hvc_xen.c
index 52fdf60..a1b0a75 100644
--- a/drivers/tty/hvc/hvc_xen.c
+++ b/drivers/tty/hvc/hvc_xen.c
@@ -176,7 +176,7 @@ static int __init xen_hvc_init(void)
 		xencons_irq = bind_evtchn_to_irq(xen_start_info->console.domU.evtchn);
 	}
 	if (xencons_irq < 0)
-		xencons_irq = 0; /* NO_IRQ */
+		xencons_irq = 0;
 	else
 		irq_set_noprobe(xencons_irq);
 
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index b9040be..df7e7a0 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -1203,7 +1203,7 @@ static void hvcs_close(struct tty_struct *tty, struct file *filp)
 {
 	struct hvcs_struct *hvcsd;
 	unsigned long flags;
-	int irq = NO_IRQ;
+	int irq;
 
 	/*
 	 * Is someone trying to close the file associated with this device after
@@ -1264,7 +1264,7 @@ static void hvcs_hangup(struct tty_struct * tty)
 	struct hvcs_struct *hvcsd = tty->driver_data;
 	unsigned long flags;
 	int temp_open_count;
-	int irq = NO_IRQ;
+	int irq;
 
 	spin_lock_irqsave(&hvcsd->lock, flags);
 	/* Preserve this so that we know how many kref refs to put */
diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
index cdfa3e0..1b5f28b 100644
--- a/drivers/tty/hvc/hvsi.c
+++ b/drivers/tty/hvc/hvsi.c
@@ -1237,7 +1237,7 @@ static int __init hvsi_console_init(void)
 		hp->state = HVSI_CLOSED;
 		hp->vtermno = *vtermno;
 		hp->virq = irq_create_mapping(NULL, irq[0]);
-		if (hp->virq == NO_IRQ) {
+		if (hp->virq == 0) {
 			printk(KERN_ERR "%s: couldn't create irq mapping for 0x%x\n",
 				__func__, irq[0]);
 			continue;
diff --git a/drivers/tty/nozomi.c b/drivers/tty/nozomi.c
index fd347ff..580da78 100644
--- a/drivers/tty/nozomi.c
+++ b/drivers/tty/nozomi.c
@@ -1602,13 +1602,9 @@ static int ntty_install(struct tty_driver *driver, struct tty_struct *tty)
 	int ret;
 	if (!port || !dc || dc->state != NOZOMI_STATE_READY)
 		return -ENODEV;
-	ret = tty_init_termios(tty);
-	if (ret == 0) {
-		tty_driver_kref_get(driver);
-		tty->count++;
+	ret = tty_standard_install(driver, tty);
+	if (ret == 0)
 		tty->driver_data = port;
-		driver->ttys[tty->index] = tty;
-	}
 	return ret;
 }
 
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index d8653ab..39afd04 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -21,7 +21,6 @@
 #include <linux/major.h>
 #include <linux/mm.h>
 #include <linux/init.h>
-#include <linux/sysctl.h>
 #include <linux/device.h>
 #include <linux/uaccess.h>
 #include <linux/bitops.h>
@@ -55,11 +54,8 @@ static void pty_close(struct tty_struct *tty, struct file *filp)
 	wake_up_interruptible(&tty->link->write_wait);
 	if (tty->driver->subtype == PTY_TYPE_MASTER) {
 		set_bit(TTY_OTHER_CLOSED, &tty->flags);
-#ifdef CONFIG_UNIX98_PTYS
-		if (tty->driver == ptm_driver)
-			devpts_pty_kill(tty->link);
-#endif
 		tty_unlock();
+		devpts_pty_kill(tty->link);
 		tty_vhangup(tty->link);
 		tty_lock();
 	}
@@ -439,55 +435,9 @@ static inline void legacy_pty_init(void) { }
 
 /* Unix98 devices */
 #ifdef CONFIG_UNIX98_PTYS
-/*
- * sysctl support for setting limits on the number of Unix98 ptys allocated.
- * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
- */
-int pty_limit = NR_UNIX98_PTY_DEFAULT;
-static int pty_limit_min;
-static int pty_limit_max = NR_UNIX98_PTY_MAX;
-static int pty_count;
 
 static struct cdev ptmx_cdev;
 
-static struct ctl_table pty_table[] = {
-	{
-		.procname	= "max",
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.data		= &pty_limit,
-		.proc_handler	= proc_dointvec_minmax,
-		.extra1		= &pty_limit_min,
-		.extra2		= &pty_limit_max,
-	}, {
-		.procname	= "nr",
-		.maxlen		= sizeof(int),
-		.mode		= 0444,
-		.data		= &pty_count,
-		.proc_handler	= proc_dointvec,
-	}, 
-	{}
-};
-
-static struct ctl_table pty_kern_table[] = {
-	{
-		.procname	= "pty",
-		.mode		= 0555,
-		.child		= pty_table,
-	},
-	{}
-};
-
-static struct ctl_table pty_root_table[] = {
-	{
-		.procname	= "kernel",
-		.mode		= 0555,
-		.child		= pty_kern_table,
-	},
-	{}
-};
-
-
 static int pty_unix98_ioctl(struct tty_struct *tty,
 			    unsigned int cmd, unsigned long arg)
 {
@@ -515,10 +465,8 @@ static int pty_unix98_ioctl(struct tty_struct *tty,
 static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
 		struct inode *ptm_inode, int idx)
 {
-	struct tty_struct *tty = devpts_get_tty(ptm_inode, idx);
-	if (tty)
-		tty = tty->link;
-	return tty;
+	/* Master must be open via /dev/ptmx */
+	return ERR_PTR(-EIO);
 }
 
 /**
@@ -589,7 +537,6 @@ static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
 	 */
 	tty_driver_kref_get(driver);
 	tty->count++;
-	pty_count++;
 	return 0;
 err_free_mem:
 	deinitialize_tty_struct(o_tty);
@@ -603,7 +550,6 @@ err_free_tty:
 
 static void ptm_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
 {
-	pty_count--;
 }
 
 static void pts_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
@@ -667,9 +613,7 @@ static int ptmx_open(struct inode *inode, struct file *filp)
 		return retval;
 
 	/* find a device that is not in use. */
-	tty_lock();
 	index = devpts_new_index(inode);
-	tty_unlock();
 	if (index < 0) {
 		retval = index;
 		goto err_file;
@@ -677,7 +621,7 @@ static int ptmx_open(struct inode *inode, struct file *filp)
 
 	mutex_lock(&tty_mutex);
 	tty_lock();
-	tty = tty_init_dev(ptm_driver, index, 1);
+	tty = tty_init_dev(ptm_driver, index);
 	mutex_unlock(&tty_mutex);
 
 	if (IS_ERR(tty)) {
@@ -704,8 +648,8 @@ err_release:
 	tty_release(inode, filp);
 	return retval;
 out:
-	devpts_kill_index(inode, index);
 	tty_unlock();
+	devpts_kill_index(inode, index);
 err_file:
 	tty_free_file(filp);
 	return retval;
@@ -762,8 +706,6 @@ static void __init unix98_pty_init(void)
 	if (tty_register_driver(pts_driver))
 		panic("Couldn't register Unix98 pts driver");
 
-	register_sysctl_table(pty_root_table);
-
 	/* Now create the /dev/ptmx special device */
 	tty_default_fops(&ptmx_fops);
 	ptmx_fops.open = ptmx_open;
diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c
index 1b37626..f899996 100644
--- a/drivers/tty/serial/21285.c
+++ b/drivers/tty/serial/21285.c
@@ -331,7 +331,7 @@ static int serial21285_verify_port(struct uart_port *port, struct serial_struct
 	int ret = 0;
 	if (ser->type != PORT_UNKNOWN && ser->type != PORT_21285)
 		ret = -EINVAL;
-	if (ser->irq != NO_IRQ)
+	if (ser->irq <= 0)
 		ret = -EINVAL;
 	if (ser->baud_base != port->uartclk / 16)
 		ret = -EINVAL;
@@ -360,7 +360,7 @@ static struct uart_ops serial21285_ops = {
 static struct uart_port serial21285_port = {
 	.mapbase	= 0x42000160,
 	.iotype		= UPIO_MEM,
-	.irq		= NO_IRQ,
+	.irq		= 0,
 	.fifosize	= 16,
 	.ops		= &serial21285_ops,
 	.flags		= UPF_BOOT_AUTOCONF,
diff --git a/drivers/tty/serial/8250/8250.c b/drivers/tty/serial/8250/8250.c
index 9b7336fc..b423d0f 100644
--- a/drivers/tty/serial/8250/8250.c
+++ b/drivers/tty/serial/8250/8250.c
@@ -86,13 +86,6 @@ static unsigned int skip_txen_test; /* force skip of txen test at init time */
 #define BOTH_EMPTY 	(UART_LSR_TEMT | UART_LSR_THRE)
 
 
-/*
- * We default to IRQ0 for the "no irq" hack.   Some
- * machine types want others as well - they're free
- * to redefine this in their header file.
- */
-#define is_real_interrupt(irq)	((irq) != 0)
-
 #ifdef CONFIG_SERIAL_8250_DETECT_IRQ
 #define CONFIG_SERIAL_DETECT_IRQ 1
 #endif
@@ -1750,7 +1743,7 @@ static void serial8250_backup_timeout(unsigned long data)
 	 * Must disable interrupts or else we risk racing with the interrupt
 	 * based handler.
 	 */
-	if (is_real_interrupt(up->port.irq)) {
+	if (up->port.irq) {
 		ier = serial_in(up, UART_IER);
 		serial_out(up, UART_IER, 0);
 	}
@@ -1775,7 +1768,7 @@ static void serial8250_backup_timeout(unsigned long data)
 	if (!(iir & UART_IIR_NO_INT))
 		serial8250_tx_chars(up);
 
-	if (is_real_interrupt(up->port.irq))
+	if (up->port.irq)
 		serial_out(up, UART_IER, ier);
 
 	spin_unlock_irqrestore(&up->port.lock, flags);
@@ -2028,7 +2021,7 @@ static int serial8250_startup(struct uart_port *port)
 		serial_outp(up, UART_LCR, 0);
 	}
 
-	if (is_real_interrupt(up->port.irq)) {
+	if (up->port.irq) {
 		unsigned char iir1;
 		/*
 		 * Test for UARTs that do not reassert THRE when the
@@ -2083,7 +2076,7 @@ static int serial8250_startup(struct uart_port *port)
 	 * hardware interrupt, we use a timer-based system.  The original
 	 * driver used to do this with IRQ0.
 	 */
-	if (!is_real_interrupt(up->port.irq)) {
+	if (!up->port.irq) {
 		up->timer.data = (unsigned long)up;
 		mod_timer(&up->timer, jiffies + uart_poll_timeout(port));
 	} else {
@@ -2099,13 +2092,13 @@ static int serial8250_startup(struct uart_port *port)
 
 	spin_lock_irqsave(&up->port.lock, flags);
 	if (up->port.flags & UPF_FOURPORT) {
-		if (!is_real_interrupt(up->port.irq))
+		if (!up->port.irq)
 			up->port.mctrl |= TIOCM_OUT1;
 	} else
 		/*
 		 * Most PC uarts need OUT2 raised to enable interrupts.
 		 */
-		if (is_real_interrupt(up->port.irq))
+		if (up->port.irq)
 			up->port.mctrl |= TIOCM_OUT2;
 
 	serial8250_set_mctrl(&up->port, up->port.mctrl);
@@ -2223,7 +2216,7 @@ static void serial8250_shutdown(struct uart_port *port)
 
 	del_timer_sync(&up->timer);
 	up->timer.function = serial8250_timeout;
-	if (is_real_interrupt(up->port.irq))
+	if (up->port.irq)
 		serial_unlink_irq_chain(up);
 }
 
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 2de9924..76e7764 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1347,4 +1347,17 @@ config SERIAL_AR933X_NR_UARTS
 	  Set this to the number of serial ports you want the driver
 	  to support.
 
+config SERIAL_EFM32_UART
+	tristate "EFM32 UART/USART port."
+	depends on ARCH_EFM32
+	select SERIAL_CORE
+	help
+	  This driver support the USART and UART ports on
+	  Energy Micro's efm32 SoCs.
+
+config SERIAL_EFM32_UART_CONSOLE
+	bool "EFM32 UART/USART console support"
+	depends on SERIAL_EFM32_UART=y
+	select SERIAL_CORE_CONSOLE
+
 endmenu
diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile
index fef32e1..7257c5d 100644
--- a/drivers/tty/serial/Makefile
+++ b/drivers/tty/serial/Makefile
@@ -61,12 +61,12 @@ obj-$(CONFIG_SERIAL_OF_PLATFORM) += of_serial.o
 obj-$(CONFIG_SERIAL_OF_PLATFORM_NWPSERIAL) += nwpserial.o
 obj-$(CONFIG_SERIAL_KS8695) += serial_ks8695.o
 obj-$(CONFIG_SERIAL_OMAP) += omap-serial.o
+obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
 obj-$(CONFIG_KGDB_SERIAL_CONSOLE) += kgdboc.o
 obj-$(CONFIG_SERIAL_QE) += ucc_uart.o
 obj-$(CONFIG_SERIAL_TIMBERDALE)	+= timbuart.o
 obj-$(CONFIG_SERIAL_GRLIB_GAISLER_APBUART) += apbuart.o
 obj-$(CONFIG_SERIAL_ALTERA_JTAGUART) += altera_jtaguart.o
-obj-$(CONFIG_SERIAL_ALTERA_UART) += altera_uart.o
 obj-$(CONFIG_SERIAL_VT8500) += vt8500_serial.o
 obj-$(CONFIG_SERIAL_MRST_MAX3110)	+= mrst_max3110.o
 obj-$(CONFIG_SERIAL_MFD_HSU)	+= mfd.o
@@ -78,3 +78,4 @@ obj-$(CONFIG_SERIAL_LANTIQ)	+= lantiq.o
 obj-$(CONFIG_SERIAL_XILINX_PS_UART) += xilinx_uartps.o
 obj-$(CONFIG_SERIAL_SIRFSOC) += sirfsoc_uart.o
 obj-$(CONFIG_SERIAL_AR933X)   += ar933x_uart.o
+obj-$(CONFIG_SERIAL_EFM32_UART) += efm32-uart.o
diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
index 1d04c50..e790375 100644
--- a/drivers/tty/serial/altera_uart.c
+++ b/drivers/tty/serial/altera_uart.c
@@ -377,6 +377,26 @@ static int altera_uart_verify_port(struct uart_port *port,
 	return 0;
 }
 
+#ifdef CONFIG_CONSOLE_POLL
+static int altera_uart_poll_get_char(struct uart_port *port)
+{
+	while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+		 ALTERA_UART_STATUS_RRDY_MSK))
+		cpu_relax();
+
+	return altera_uart_readl(port, ALTERA_UART_RXDATA_REG);
+}
+
+static void altera_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+	while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
+		 ALTERA_UART_STATUS_TRDY_MSK))
+		cpu_relax();
+
+	altera_uart_writel(port, c, ALTERA_UART_TXDATA_REG);
+}
+#endif
+
 /*
  *	Define the basic serial functions we support.
  */
@@ -397,35 +417,16 @@ static struct uart_ops altera_uart_ops = {
 	.release_port	= altera_uart_release_port,
 	.config_port	= altera_uart_config_port,
 	.verify_port	= altera_uart_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+	.poll_get_char	= altera_uart_poll_get_char,
+	.poll_put_char	= altera_uart_poll_put_char,
+#endif
 };
 
 static struct altera_uart altera_uart_ports[CONFIG_SERIAL_ALTERA_UART_MAXPORTS];
 
 #if defined(CONFIG_SERIAL_ALTERA_UART_CONSOLE)
 
-int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp)
-{
-	struct uart_port *port;
-	int i;
-
-	for (i = 0; i < CONFIG_SERIAL_ALTERA_UART_MAXPORTS && platp[i].mapbase; i++) {
-		port = &altera_uart_ports[i].port;
-
-		port->line = i;
-		port->type = PORT_ALTERA_UART;
-		port->mapbase = platp[i].mapbase;
-		port->membase = ioremap(port->mapbase, ALTERA_UART_SIZE);
-		port->iotype = SERIAL_IO_MEM;
-		port->irq = platp[i].irq;
-		port->uartclk = platp[i].uartclk;
-		port->flags = UPF_BOOT_AUTOCONF;
-		port->ops = &altera_uart_ops;
-		port->private_data = platp;
-	}
-
-	return 0;
-}
-
 static void altera_uart_console_putc(struct uart_port *port, const char c)
 {
 	while (!(altera_uart_readl(port, ALTERA_UART_STATUS_REG) &
diff --git a/drivers/tty/serial/efm32-uart.c b/drivers/tty/serial/efm32-uart.c
new file mode 100644
index 0000000..615e464
--- /dev/null
+++ b/drivers/tty/serial/efm32-uart.c
@@ -0,0 +1,830 @@
+#if defined(CONFIG_SERIAL_EFM32_UART_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/serial_core.h>
+#include <linux/tty_flip.h>
+#include <linux/slab.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <linux/platform_data/efm32-uart.h>
+
+#define DRIVER_NAME "efm32-uart"
+#define DEV_NAME "ttyefm"
+
+#define UARTn_CTRL		0x00
+#define UARTn_CTRL_SYNC		0x0001
+#define UARTn_CTRL_TXBIL		0x1000
+
+#define UARTn_FRAME		0x04
+#define UARTn_FRAME_DATABITS__MASK	0x000f
+#define UARTn_FRAME_DATABITS(n)		((n) - 3)
+#define UARTn_FRAME_PARITY_NONE		0x0000
+#define UARTn_FRAME_PARITY_EVEN		0x0200
+#define UARTn_FRAME_PARITY_ODD		0x0300
+#define UARTn_FRAME_STOPBITS_HALF	0x0000
+#define UARTn_FRAME_STOPBITS_ONE	0x1000
+#define UARTn_FRAME_STOPBITS_TWO	0x3000
+
+#define UARTn_CMD		0x0c
+#define UARTn_CMD_RXEN			0x0001
+#define UARTn_CMD_RXDIS		0x0002
+#define UARTn_CMD_TXEN			0x0004
+#define UARTn_CMD_TXDIS		0x0008
+
+#define UARTn_STATUS		0x10
+#define UARTn_STATUS_TXENS		0x0002
+#define UARTn_STATUS_TXC		0x0020
+#define UARTn_STATUS_TXBL		0x0040
+#define UARTn_STATUS_RXDATAV		0x0080
+
+#define UARTn_CLKDIV		0x14
+
+#define UARTn_RXDATAX		0x18
+#define UARTn_RXDATAX_RXDATA__MASK	0x01ff
+#define UARTn_RXDATAX_PERR		0x4000
+#define UARTn_RXDATAX_FERR		0x8000
+/*
+ * This is a software only flag used for ignore_status_mask and
+ * read_status_mask! It's used for breaks that the hardware doesn't report
+ * explicitly.
+ */
+#define SW_UARTn_RXDATAX_BERR		0x2000
+
+#define UARTn_TXDATA		0x34
+
+#define UARTn_IF		0x40
+#define UARTn_IF_TXC			0x0001
+#define UARTn_IF_TXBL			0x0002
+#define UARTn_IF_RXDATAV		0x0004
+#define UARTn_IF_RXOF			0x0010
+
+#define UARTn_IFS		0x44
+#define UARTn_IFC		0x48
+#define UARTn_IEN		0x4c
+
+#define UARTn_ROUTE		0x54
+#define UARTn_ROUTE_LOCATION__MASK	0x0700
+#define UARTn_ROUTE_LOCATION(n)		(((n) << 8) & UARTn_ROUTE_LOCATION__MASK)
+#define UARTn_ROUTE_RXPEN		0x0001
+#define UARTn_ROUTE_TXPEN		0x0002
+
+struct efm32_uart_port {
+	struct uart_port port;
+	unsigned int txirq;
+	struct clk *clk;
+};
+#define to_efm_port(_port) container_of(_port, struct efm32_uart_port, port)
+#define efm_debug(efm_port, format, arg...)			\
+	dev_dbg(efm_port->port.dev, format, ##arg)
+
+static void efm32_uart_write32(struct efm32_uart_port *efm_port,
+		u32 value, unsigned offset)
+{
+	writel_relaxed(value, efm_port->port.membase + offset);
+}
+
+static u32 efm32_uart_read32(struct efm32_uart_port *efm_port,
+		unsigned offset)
+{
+	return readl_relaxed(efm_port->port.membase + offset);
+}
+
+static unsigned int efm32_uart_tx_empty(struct uart_port *port)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+	u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
+
+	if (status & UARTn_STATUS_TXC)
+		return TIOCSER_TEMT;
+	else
+		return 0;
+}
+
+static void efm32_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+	/* sorry, neither handshaking lines nor loop functionallity */
+}
+
+static unsigned int efm32_uart_get_mctrl(struct uart_port *port)
+{
+	/* sorry, no handshaking lines available */
+	return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR;
+}
+
+static void efm32_uart_stop_tx(struct uart_port *port)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+	u32 ien = efm32_uart_read32(efm_port,  UARTn_IEN);
+
+	efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD);
+	ien &= ~(UARTn_IF_TXC | UARTn_IF_TXBL);
+	efm32_uart_write32(efm_port, ien, UARTn_IEN);
+}
+
+static void efm32_uart_tx_chars(struct efm32_uart_port *efm_port)
+{
+	struct uart_port *port = &efm_port->port;
+	struct circ_buf *xmit = &port->state->xmit;
+
+	while (efm32_uart_read32(efm_port, UARTn_STATUS) &
+			UARTn_STATUS_TXBL) {
+		if (port->x_char) {
+			port->icount.tx++;
+			efm32_uart_write32(efm_port, port->x_char,
+					UARTn_TXDATA);
+			port->x_char = 0;
+			continue;
+		}
+		if (!uart_circ_empty(xmit) && !uart_tx_stopped(port)) {
+			port->icount.tx++;
+			efm32_uart_write32(efm_port, xmit->buf[xmit->tail],
+					UARTn_TXDATA);
+			xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		} else
+			break;
+	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
+
+	if (!port->x_char && uart_circ_empty(xmit) &&
+			efm32_uart_read32(efm_port, UARTn_STATUS) &
+				UARTn_STATUS_TXC)
+		efm32_uart_stop_tx(port);
+}
+
+static void efm32_uart_start_tx(struct uart_port *port)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+	u32 ien;
+
+	efm32_uart_write32(efm_port,
+			UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IFC);
+	ien = efm32_uart_read32(efm_port, UARTn_IEN);
+	efm32_uart_write32(efm_port,
+			ien | UARTn_IF_TXBL | UARTn_IF_TXC, UARTn_IEN);
+	efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD);
+
+	efm32_uart_tx_chars(efm_port);
+}
+
+static void efm32_uart_stop_rx(struct uart_port *port)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+
+	efm32_uart_write32(efm_port, UARTn_CMD_RXDIS, UARTn_CMD);
+}
+
+static void efm32_uart_enable_ms(struct uart_port *port)
+{
+	/* no handshake lines, no modem status interrupts */
+}
+
+static void efm32_uart_break_ctl(struct uart_port *port, int ctl)
+{
+	/* not possible without fiddling with gpios */
+}
+
+static void efm32_uart_rx_chars(struct efm32_uart_port *efm_port,
+		struct tty_struct *tty)
+{
+	struct uart_port *port = &efm_port->port;
+
+	while (efm32_uart_read32(efm_port, UARTn_STATUS) &
+			UARTn_STATUS_RXDATAV) {
+		u32 rxdata = efm32_uart_read32(efm_port, UARTn_RXDATAX);
+		int flag = 0;
+
+		/*
+		 * This is a reserved bit and I only saw it read as 0. But to be
+		 * sure not to be confused too much by new devices adhere to the
+		 * warning in the reference manual that reserverd bits might
+		 * read as 1 in the future.
+		 */
+		rxdata &= ~SW_UARTn_RXDATAX_BERR;
+
+		port->icount.rx++;
+
+		if ((rxdata & UARTn_RXDATAX_FERR) &&
+				!(rxdata & UARTn_RXDATAX_RXDATA__MASK)) {
+			rxdata |= SW_UARTn_RXDATAX_BERR;
+			port->icount.brk++;
+			if (uart_handle_break(port))
+				continue;
+		} else if (rxdata & UARTn_RXDATAX_PERR)
+			port->icount.parity++;
+		else if (rxdata & UARTn_RXDATAX_FERR)
+			port->icount.frame++;
+
+		rxdata &= port->read_status_mask;
+
+		if (rxdata & SW_UARTn_RXDATAX_BERR)
+			flag = TTY_BREAK;
+		else if (rxdata & UARTn_RXDATAX_PERR)
+			flag = TTY_PARITY;
+		else if (rxdata & UARTn_RXDATAX_FERR)
+			flag = TTY_FRAME;
+		else if (uart_handle_sysrq_char(port,
+					rxdata & UARTn_RXDATAX_RXDATA__MASK))
+			continue;
+
+		if (tty && (rxdata & port->ignore_status_mask) == 0)
+			tty_insert_flip_char(tty,
+					rxdata & UARTn_RXDATAX_RXDATA__MASK, flag);
+	}
+}
+
+static irqreturn_t efm32_uart_rxirq(int irq, void *data)
+{
+	struct efm32_uart_port *efm_port = data;
+	u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
+	int handled = IRQ_NONE;
+	struct uart_port *port = &efm_port->port;
+	struct tty_struct *tty;
+
+	spin_lock(&port->lock);
+
+	tty = tty_kref_get(port->state->port.tty);
+
+	if (irqflag & UARTn_IF_RXDATAV) {
+		efm32_uart_write32(efm_port, UARTn_IF_RXDATAV, UARTn_IFC);
+		efm32_uart_rx_chars(efm_port, tty);
+
+		handled = IRQ_HANDLED;
+	}
+
+	if (irqflag & UARTn_IF_RXOF) {
+		efm32_uart_write32(efm_port, UARTn_IF_RXOF, UARTn_IFC);
+		port->icount.overrun++;
+		if (tty)
+			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+
+		handled = IRQ_HANDLED;
+	}
+
+	if (tty) {
+		tty_flip_buffer_push(tty);
+		tty_kref_put(tty);
+	}
+
+	spin_unlock(&port->lock);
+
+	return handled;
+}
+
+static irqreturn_t efm32_uart_txirq(int irq, void *data)
+{
+	struct efm32_uart_port *efm_port = data;
+	u32 irqflag = efm32_uart_read32(efm_port, UARTn_IF);
+
+	/* TXBL doesn't need to be cleared */
+	if (irqflag & UARTn_IF_TXC)
+		efm32_uart_write32(efm_port, UARTn_IF_TXC, UARTn_IFC);
+
+	if (irqflag & (UARTn_IF_TXC | UARTn_IF_TXBL)) {
+		efm32_uart_tx_chars(efm_port);
+		return IRQ_HANDLED;
+	} else
+		return IRQ_NONE;
+}
+
+static int efm32_uart_startup(struct uart_port *port)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+	u32 location = 0;
+	struct efm32_uart_pdata *pdata = dev_get_platdata(port->dev);
+	int ret;
+
+	if (pdata)
+		location = UARTn_ROUTE_LOCATION(pdata->location);
+
+	ret = clk_enable(efm_port->clk);
+	if (ret) {
+		efm_debug(efm_port, "failed to enable clk\n");
+		goto err_clk_enable;
+	}
+	port->uartclk = clk_get_rate(efm_port->clk);
+
+	/* Enable pins at configured location */
+	efm32_uart_write32(efm_port, location | UARTn_ROUTE_RXPEN | UARTn_ROUTE_TXPEN,
+			UARTn_ROUTE);
+
+	ret = request_irq(port->irq, efm32_uart_rxirq, 0,
+			DRIVER_NAME, efm_port);
+	if (ret) {
+		efm_debug(efm_port, "failed to register rxirq\n");
+		goto err_request_irq_rx;
+	}
+
+	/* disable all irqs */
+	efm32_uart_write32(efm_port, 0, UARTn_IEN);
+
+	ret = request_irq(efm_port->txirq, efm32_uart_txirq, 0,
+			DRIVER_NAME, efm_port);
+	if (ret) {
+		efm_debug(efm_port, "failed to register txirq\n");
+		free_irq(port->irq, efm_port);
+err_request_irq_rx:
+
+		clk_disable(efm_port->clk);
+	} else {
+		efm32_uart_write32(efm_port,
+				UARTn_IF_RXDATAV | UARTn_IF_RXOF, UARTn_IEN);
+		efm32_uart_write32(efm_port, UARTn_CMD_RXEN, UARTn_CMD);
+	}
+
+err_clk_enable:
+	return ret;
+}
+
+static void efm32_uart_shutdown(struct uart_port *port)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+
+	efm32_uart_write32(efm_port, 0, UARTn_IEN);
+	free_irq(port->irq, efm_port);
+
+	clk_disable(efm_port->clk);
+}
+
+static void efm32_uart_set_termios(struct uart_port *port,
+		struct ktermios *new, struct ktermios *old)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+	unsigned long flags;
+	unsigned baud;
+	u32 clkdiv;
+	u32 frame = 0;
+
+	/* no modem control lines */
+	new->c_cflag &= ~(CRTSCTS | CMSPAR);
+
+	baud = uart_get_baud_rate(port, new, old,
+			DIV_ROUND_CLOSEST(port->uartclk, 16 * 8192),
+			DIV_ROUND_CLOSEST(port->uartclk, 16));
+
+	switch (new->c_cflag & CSIZE) {
+	case CS5:
+		frame |= UARTn_FRAME_DATABITS(5);
+		break;
+	case CS6:
+		frame |= UARTn_FRAME_DATABITS(6);
+		break;
+	case CS7:
+		frame |= UARTn_FRAME_DATABITS(7);
+		break;
+	case CS8:
+		frame |= UARTn_FRAME_DATABITS(8);
+		break;
+	}
+
+	if (new->c_cflag & CSTOPB)
+		/* the receiver only verifies the first stop bit */
+		frame |= UARTn_FRAME_STOPBITS_TWO;
+	else
+		frame |= UARTn_FRAME_STOPBITS_ONE;
+
+	if (new->c_cflag & PARENB) {
+		if (new->c_cflag & PARODD)
+			frame |= UARTn_FRAME_PARITY_ODD;
+		else
+			frame |= UARTn_FRAME_PARITY_EVEN;
+	} else
+		frame |= UARTn_FRAME_PARITY_NONE;
+
+	/*
+	 * the 6 lowest bits of CLKDIV are dc, bit 6 has value 0.25.
+	 * port->uartclk <= 14e6, so 4 * port->uartclk doesn't overflow.
+	 */
+	clkdiv = (DIV_ROUND_CLOSEST(4 * port->uartclk, 16 * baud) - 4) << 6;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	efm32_uart_write32(efm_port,
+			UARTn_CMD_TXDIS | UARTn_CMD_RXDIS, UARTn_CMD);
+
+	port->read_status_mask = UARTn_RXDATAX_RXDATA__MASK;
+	if (new->c_iflag & INPCK)
+		port->read_status_mask |=
+			UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR;
+	if (new->c_iflag & (BRKINT | PARMRK))
+		port->read_status_mask |= SW_UARTn_RXDATAX_BERR;
+
+	port->ignore_status_mask = 0;
+	if (new->c_iflag & IGNPAR)
+		port->ignore_status_mask |=
+			UARTn_RXDATAX_FERR | UARTn_RXDATAX_PERR;
+	if (new->c_iflag & IGNBRK)
+		port->ignore_status_mask |= SW_UARTn_RXDATAX_BERR;
+
+	uart_update_timeout(port, new->c_cflag, baud);
+
+	efm32_uart_write32(efm_port, UARTn_CTRL_TXBIL, UARTn_CTRL);
+	efm32_uart_write32(efm_port, frame, UARTn_FRAME);
+	efm32_uart_write32(efm_port, clkdiv, UARTn_CLKDIV);
+
+	efm32_uart_write32(efm_port, UARTn_CMD_TXEN | UARTn_CMD_RXEN,
+			UARTn_CMD);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *efm32_uart_type(struct uart_port *port)
+{
+	return port->type == PORT_EFMUART ? "efm32-uart" : NULL;
+}
+
+static void efm32_uart_release_port(struct uart_port *port)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+
+	clk_unprepare(efm_port->clk);
+	clk_put(efm_port->clk);
+	iounmap(port->membase);
+}
+
+static int efm32_uart_request_port(struct uart_port *port)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+	int ret;
+
+	port->membase = ioremap(port->mapbase, 60);
+	if (!efm_port->port.membase) {
+		ret = -ENOMEM;
+		efm_debug(efm_port, "failed to remap\n");
+		goto err_ioremap;
+	}
+
+	efm_port->clk = clk_get(port->dev, NULL);
+	if (IS_ERR(efm_port->clk)) {
+		ret = PTR_ERR(efm_port->clk);
+		efm_debug(efm_port, "failed to get clock\n");
+		goto err_clk_get;
+	}
+
+	ret = clk_prepare(efm_port->clk);
+	if (ret) {
+		clk_put(efm_port->clk);
+err_clk_get:
+
+		iounmap(port->membase);
+err_ioremap:
+		return ret;
+	}
+	return 0;
+}
+
+static void efm32_uart_config_port(struct uart_port *port, int type)
+{
+	if (type & UART_CONFIG_TYPE &&
+			!efm32_uart_request_port(port))
+		port->type = PORT_EFMUART;
+}
+
+static int efm32_uart_verify_port(struct uart_port *port,
+		struct serial_struct *serinfo)
+{
+	int ret = 0;
+
+	if (serinfo->type != PORT_UNKNOWN && serinfo->type != PORT_EFMUART)
+		ret = -EINVAL;
+
+	return ret;
+}
+
+static struct uart_ops efm32_uart_pops = {
+	.tx_empty = efm32_uart_tx_empty,
+	.set_mctrl = efm32_uart_set_mctrl,
+	.get_mctrl = efm32_uart_get_mctrl,
+	.stop_tx = efm32_uart_stop_tx,
+	.start_tx = efm32_uart_start_tx,
+	.stop_rx = efm32_uart_stop_rx,
+	.enable_ms = efm32_uart_enable_ms,
+	.break_ctl = efm32_uart_break_ctl,
+	.startup = efm32_uart_startup,
+	.shutdown = efm32_uart_shutdown,
+	.set_termios = efm32_uart_set_termios,
+	.type = efm32_uart_type,
+	.release_port = efm32_uart_release_port,
+	.request_port = efm32_uart_request_port,
+	.config_port = efm32_uart_config_port,
+	.verify_port = efm32_uart_verify_port,
+};
+
+static struct efm32_uart_port *efm32_uart_ports[5];
+
+#ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE
+static void efm32_uart_console_putchar(struct uart_port *port, int ch)
+{
+	struct efm32_uart_port *efm_port = to_efm_port(port);
+	unsigned int timeout = 0x400;
+	u32 status;
+
+	while (1) {
+		status = efm32_uart_read32(efm_port, UARTn_STATUS);
+
+		if (status & UARTn_STATUS_TXBL)
+			break;
+		if (!timeout--)
+			return;
+	}
+	efm32_uart_write32(efm_port, ch, UARTn_TXDATA);
+}
+
+static void efm32_uart_console_write(struct console *co, const char *s,
+		unsigned int count)
+{
+	struct efm32_uart_port *efm_port = efm32_uart_ports[co->index];
+	u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
+	unsigned int timeout = 0x400;
+
+	if (!(status & UARTn_STATUS_TXENS))
+		efm32_uart_write32(efm_port, UARTn_CMD_TXEN, UARTn_CMD);
+
+	uart_console_write(&efm_port->port, s, count,
+			efm32_uart_console_putchar);
+
+	/* Wait for the transmitter to become empty */
+	while (1) {
+		u32 status = efm32_uart_read32(efm_port, UARTn_STATUS);
+		if (status & UARTn_STATUS_TXC)
+			break;
+		if (!timeout--)
+			break;
+	}
+
+	if (!(status & UARTn_STATUS_TXENS))
+		efm32_uart_write32(efm_port, UARTn_CMD_TXDIS, UARTn_CMD);
+}
+
+static void efm32_uart_console_get_options(struct efm32_uart_port *efm_port,
+		int *baud, int *parity, int *bits)
+{
+	u32 ctrl = efm32_uart_read32(efm_port, UARTn_CTRL);
+	u32 route, clkdiv, frame;
+
+	if (ctrl & UARTn_CTRL_SYNC)
+		/* not operating in async mode */
+		return;
+
+	route = efm32_uart_read32(efm_port, UARTn_ROUTE);
+	if (!(route & UARTn_ROUTE_TXPEN))
+		/* tx pin not routed */
+		return;
+
+	clkdiv = efm32_uart_read32(efm_port, UARTn_CLKDIV);
+
+	*baud = DIV_ROUND_CLOSEST(4 * efm_port->port.uartclk,
+			16 * (4 + (clkdiv >> 6)));
+
+	frame = efm32_uart_read32(efm_port, UARTn_FRAME);
+	if (frame & UARTn_FRAME_PARITY_ODD)
+		*parity = 'o';
+	else if (frame & UARTn_FRAME_PARITY_EVEN)
+		*parity = 'e';
+	else
+		*parity = 'n';
+
+	*bits = (frame & UARTn_FRAME_DATABITS__MASK) -
+			UARTn_FRAME_DATABITS(4) + 4;
+
+	efm_debug(efm_port, "get_opts: options=%d%c%d\n",
+			*baud, *parity, *bits);
+}
+
+static int efm32_uart_console_setup(struct console *co, char *options)
+{
+	struct efm32_uart_port *efm_port;
+	int baud = 115200;
+	int bits = 8;
+	int parity = 'n';
+	int flow = 'n';
+	int ret;
+
+	if (co->index < 0 || co->index >= ARRAY_SIZE(efm32_uart_ports)) {
+		unsigned i;
+		for (i = 0; i < ARRAY_SIZE(efm32_uart_ports); ++i) {
+			if (efm32_uart_ports[i]) {
+				pr_warn("efm32-console: fall back to console index %u (from %hhi)\n",
+						i, co->index);
+				co->index = i;
+				break;
+			}
+		}
+	}
+
+	efm_port = efm32_uart_ports[co->index];
+	if (!efm_port) {
+		pr_warn("efm32-console: No port at %d\n", co->index);
+		return -ENODEV;
+	}
+
+	ret = clk_prepare(efm_port->clk);
+	if (ret) {
+		dev_warn(efm_port->port.dev,
+				"console: clk_prepare failed: %d\n", ret);
+		return ret;
+	}
+
+	efm_port->port.uartclk = clk_get_rate(efm_port->clk);
+
+	if (options)
+		uart_parse_options(options, &baud, &parity, &bits, &flow);
+	else
+		efm32_uart_console_get_options(efm_port,
+				&baud, &parity, &bits);
+
+	return uart_set_options(&efm_port->port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver efm32_uart_reg;
+
+static struct console efm32_uart_console = {
+	.name = DEV_NAME,
+	.write = efm32_uart_console_write,
+	.device = uart_console_device,
+	.setup = efm32_uart_console_setup,
+	.flags = CON_PRINTBUFFER,
+	.index = -1,
+	.data = &efm32_uart_reg,
+};
+
+#else
+#define efm32_uart_console (*(struct console *)NULL)
+#endif /* ifdef CONFIG_SERIAL_EFM32_UART_CONSOLE / else */
+
+static struct uart_driver efm32_uart_reg = {
+	.owner = THIS_MODULE,
+	.driver_name = DRIVER_NAME,
+	.dev_name = DEV_NAME,
+	.nr = ARRAY_SIZE(efm32_uart_ports),
+	.cons = &efm32_uart_console,
+};
+
+static int efm32_uart_probe_dt(struct platform_device *pdev,
+		struct efm32_uart_port *efm_port)
+{
+	struct device_node *np = pdev->dev.of_node;
+	int ret;
+
+	if (!np)
+		return 1;
+
+	ret = of_alias_get_id(np, "serial");
+	if (ret < 0) {
+		dev_err(&pdev->dev, "failed to get alias id: %d\n", ret);
+		return ret;
+	} else {
+		efm_port->port.line = ret;
+		return 0;
+	}
+
+}
+
+static int __devinit efm32_uart_probe(struct platform_device *pdev)
+{
+	struct efm32_uart_port *efm_port;
+	struct resource *res;
+	int ret;
+
+	efm_port = kzalloc(sizeof(*efm_port), GFP_KERNEL);
+	if (!efm_port) {
+		dev_dbg(&pdev->dev, "failed to allocate private data\n");
+		return -ENOMEM;
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		ret = -ENODEV;
+		dev_dbg(&pdev->dev, "failed to determine base address\n");
+		goto err_get_base;
+	}
+
+	if (resource_size(res) < 60) {
+		ret = -EINVAL;
+		dev_dbg(&pdev->dev, "memory resource too small\n");
+		goto err_too_small;
+	}
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret <= 0) {
+		dev_dbg(&pdev->dev, "failed to get rx irq\n");
+		goto err_get_rxirq;
+	}
+
+	efm_port->port.irq = ret;
+
+	ret = platform_get_irq(pdev, 1);
+	if (ret <= 0)
+		ret = efm_port->port.irq + 1;
+
+	efm_port->txirq = ret;
+
+	efm_port->port.dev = &pdev->dev;
+	efm_port->port.mapbase = res->start;
+	efm_port->port.type = PORT_EFMUART;
+	efm_port->port.iotype = UPIO_MEM32;
+	efm_port->port.fifosize = 2;
+	efm_port->port.ops = &efm32_uart_pops;
+	efm_port->port.flags = UPF_BOOT_AUTOCONF;
+
+	ret = efm32_uart_probe_dt(pdev, efm_port);
+	if (ret > 0)
+		/* not created by device tree */
+		efm_port->port.line = pdev->id;
+
+	if (efm_port->port.line >= 0 &&
+			efm_port->port.line < ARRAY_SIZE(efm32_uart_ports))
+		efm32_uart_ports[efm_port->port.line] = efm_port;
+
+	ret = uart_add_one_port(&efm32_uart_reg, &efm_port->port);
+	if (ret) {
+		dev_dbg(&pdev->dev, "failed to add port: %d\n", ret);
+
+		if (pdev->id >= 0 && pdev->id < ARRAY_SIZE(efm32_uart_ports))
+			efm32_uart_ports[pdev->id] = NULL;
+err_get_rxirq:
+err_too_small:
+err_get_base:
+		kfree(efm_port);
+	} else {
+		platform_set_drvdata(pdev, efm_port);
+		dev_dbg(&pdev->dev, "\\o/\n");
+	}
+
+	return ret;
+}
+
+static int __devexit efm32_uart_remove(struct platform_device *pdev)
+{
+	struct efm32_uart_port *efm_port = platform_get_drvdata(pdev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	uart_remove_one_port(&efm32_uart_reg, &efm_port->port);
+
+	if (pdev->id >= 0 && pdev->id < ARRAY_SIZE(efm32_uart_ports))
+		efm32_uart_ports[pdev->id] = NULL;
+
+	kfree(efm_port);
+
+	return 0;
+}
+
+static struct of_device_id efm32_uart_dt_ids[] = {
+	{
+		.compatible = "efm32,uart",
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, efm32_uart_dt_ids);
+
+static struct platform_driver efm32_uart_driver = {
+	.probe = efm32_uart_probe,
+	.remove = __devexit_p(efm32_uart_remove),
+
+	.driver = {
+		.name = DRIVER_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = efm32_uart_dt_ids,
+	},
+};
+
+static int __init efm32_uart_init(void)
+{
+	int ret;
+
+	ret = uart_register_driver(&efm32_uart_reg);
+	if (ret)
+		return ret;
+
+	ret = platform_driver_register(&efm32_uart_driver);
+	if (ret)
+		uart_unregister_driver(&efm32_uart_reg);
+
+	pr_info("EFM32 UART/USART driver\n");
+
+	return ret;
+}
+module_init(efm32_uart_init);
+
+static void __exit efm32_uart_exit(void)
+{
+	platform_driver_unregister(&efm32_uart_driver);
+	uart_unregister_driver(&efm32_uart_reg);
+}
+
+MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
+MODULE_DESCRIPTION("EFM32 UART/USART driver");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRIVER_NAME);
diff --git a/drivers/tty/serial/m32r_sio.c b/drivers/tty/serial/m32r_sio.c
index 94a6792..e465dda 100644
--- a/drivers/tty/serial/m32r_sio.c
+++ b/drivers/tty/serial/m32r_sio.c
@@ -70,13 +70,6 @@
 
 #define PASS_LIMIT	256
 
-/*
- * We default to IRQ0 for the "no irq" hack.   Some
- * machine types want others as well - they're free
- * to redefine this in their header file.
- */
-#define is_real_interrupt(irq)	((irq) != 0)
-
 #define BASE_BAUD	115200
 
 /* Standard COM flags */
@@ -640,7 +633,7 @@ static int m32r_sio_startup(struct uart_port *port)
 	 * hardware interrupt, we use a timer-based system.  The original
 	 * driver used to do this with IRQ0.
 	 */
-	if (!is_real_interrupt(up->port.irq)) {
+	if (!up->port.irq) {
 		unsigned int timeout = up->port.timeout;
 
 		timeout = timeout > 6 ? (timeout / 2 - 2) : 1;
@@ -687,7 +680,7 @@ static void m32r_sio_shutdown(struct uart_port *port)
 
 	sio_init();
 
-	if (!is_real_interrupt(up->port.irq))
+	if (!up->port.irq)
 		del_timer_sync(&up->timer);
 	else
 		serial_unlink_irq_chain(up);
diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c
index 1093a88..e9a770d 100644
--- a/drivers/tty/serial/mpc52xx_uart.c
+++ b/drivers/tty/serial/mpc52xx_uart.c
@@ -507,7 +507,7 @@ static int __init mpc512x_psc_fifoc_init(void)
 
 	psc_fifoc_irq = irq_of_parse_and_map(np, 0);
 	of_node_put(np);
-	if (psc_fifoc_irq == NO_IRQ) {
+	if (psc_fifoc_irq == 0) {
 		pr_err("%s: Can't get FIFOC irq\n", __func__);
 		iounmap(psc_fifoc);
 		return -ENODEV;
@@ -1354,7 +1354,7 @@ static int __devinit mpc52xx_uart_of_probe(struct platform_device *op)
 	}
 
 	psc_ops->get_irq(port, op->dev.of_node);
-	if (port->irq == NO_IRQ) {
+	if (port->irq == 0) {
 		dev_dbg(&op->dev, "Could not get irq\n");
 		return -EINVAL;
 	}
diff --git a/drivers/tty/serial/mux.c b/drivers/tty/serial/mux.c
index 06f6aef..c61d950 100644
--- a/drivers/tty/serial/mux.c
+++ b/drivers/tty/serial/mux.c
@@ -499,7 +499,7 @@ static int __init mux_probe(struct parisc_device *dev)
 		port->membase	= ioremap_nocache(port->mapbase, MUX_LINE_OFFSET);
 		port->iotype	= UPIO_MEM;
 		port->type	= PORT_MUX;
-		port->irq	= NO_IRQ;
+		port->irq	= 0;
 		port->uartclk	= 0;
 		port->fifosize	= MUX_FIFO_SIZE;
 		port->ops	= &mux_pops;
diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 17ae657..aa4d07b 100644
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -29,6 +29,7 @@
 #include <linux/nmi.h>
 #include <linux/delay.h>
 
+#include <linux/debugfs.h>
 #include <linux/dmaengine.h>
 #include <linux/pch_dma.h>
 
@@ -144,6 +145,8 @@ enum {
 #define PCH_UART_DLL		0x00
 #define PCH_UART_DLM		0x01
 
+#define PCH_UART_BRCSR		0x0E
+
 #define PCH_UART_IID_RLS	(PCH_UART_IIR_REI)
 #define PCH_UART_IID_RDR	(PCH_UART_IIR_RRI)
 #define PCH_UART_IID_RDR_TO	(PCH_UART_IIR_RRI | PCH_UART_IIR_TOI)
@@ -243,6 +246,8 @@ struct eg20t_port {
 	int				tx_dma_use;
 	void				*rx_buf_virt;
 	dma_addr_t			rx_buf_dma;
+
+	struct dentry	*debugfs;
 };
 
 /**
@@ -292,23 +297,73 @@ static const int trigger_level_64[4] = { 1, 16, 32, 56 };
 static const int trigger_level_16[4] = { 1, 4, 8, 14 };
 static const int trigger_level_1[4] = { 1, 1, 1, 1 };
 
-static void pch_uart_hal_request(struct pci_dev *pdev, int fifosize,
-				 int base_baud)
-{
-	struct eg20t_port *priv = pci_get_drvdata(pdev);
+#ifdef CONFIG_DEBUG_FS
 
-	priv->trigger_level = 1;
-	priv->fcr = 0;
+#define PCH_REGS_BUFSIZE	1024
+static int pch_show_regs_open(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
 }
 
-static unsigned int get_msr(struct eg20t_port *priv, void __iomem *base)
+static ssize_t port_show_regs(struct file *file, char __user *user_buf,
+				size_t count, loff_t *ppos)
 {
-	unsigned int msr = ioread8(base + UART_MSR);
-	priv->dmsr |= msr & PCH_UART_MSR_DELTA;
+	struct eg20t_port *priv = file->private_data;
+	char *buf;
+	u32 len = 0;
+	ssize_t ret;
+	unsigned char lcr;
+
+	buf = kzalloc(PCH_REGS_BUFSIZE, GFP_KERNEL);
+	if (!buf)
+		return 0;
+
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"PCH EG20T port[%d] regs:\n", priv->port.line);
+
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"=================================\n");
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"IER: \t0x%02x\n", ioread8(priv->membase + UART_IER));
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"IIR: \t0x%02x\n", ioread8(priv->membase + UART_IIR));
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"LCR: \t0x%02x\n", ioread8(priv->membase + UART_LCR));
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"MCR: \t0x%02x\n", ioread8(priv->membase + UART_MCR));
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"LSR: \t0x%02x\n", ioread8(priv->membase + UART_LSR));
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"MSR: \t0x%02x\n", ioread8(priv->membase + UART_MSR));
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"BRCSR: \t0x%02x\n",
+			ioread8(priv->membase + PCH_UART_BRCSR));
 
-	return msr;
+	lcr = ioread8(priv->membase + UART_LCR);
+	iowrite8(PCH_UART_LCR_DLAB, priv->membase + UART_LCR);
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"DLL: \t0x%02x\n", ioread8(priv->membase + UART_DLL));
+	len += snprintf(buf + len, PCH_REGS_BUFSIZE - len,
+			"DLM: \t0x%02x\n", ioread8(priv->membase + UART_DLM));
+	iowrite8(lcr, priv->membase + UART_LCR);
+
+	if (len > PCH_REGS_BUFSIZE)
+		len = PCH_REGS_BUFSIZE;
+
+	ret =  simple_read_from_buffer(user_buf, count, ppos, buf, len);
+	kfree(buf);
+	return ret;
 }
 
+static const struct file_operations port_regs_ops = {
+	.owner		= THIS_MODULE,
+	.open		= pch_show_regs_open,
+	.read		= port_show_regs,
+	.llseek		= default_llseek,
+};
+#endif	/* CONFIG_DEBUG_FS */
+
 static void pch_uart_hal_enable_interrupt(struct eg20t_port *priv,
 					  unsigned int flag)
 {
@@ -442,8 +497,9 @@ static int pch_uart_hal_set_fifo(struct eg20t_port *priv,
 
 static u8 pch_uart_hal_get_modem(struct eg20t_port *priv)
 {
-	priv->dmsr = 0;
-	return get_msr(priv, priv->membase);
+	unsigned int msr = ioread8(priv->membase + UART_MSR);
+	priv->dmsr = msr & PCH_UART_MSR_DELTA;
+	return (u8)msr;
 }
 
 static void pch_uart_hal_write(struct eg20t_port *priv,
@@ -524,7 +580,7 @@ static int push_rx(struct eg20t_port *priv, const unsigned char *buf,
 
 static int pop_tx_x(struct eg20t_port *priv, unsigned char *buf)
 {
-	int ret;
+	int ret = 0;
 	struct uart_port *port = &priv->port;
 
 	if (port->x_char) {
@@ -533,8 +589,6 @@ static int pop_tx_x(struct eg20t_port *priv, unsigned char *buf)
 		buf[0] = port->x_char;
 		port->x_char = 0;
 		ret = 1;
-	} else {
-		ret = 0;
 	}
 
 	return ret;
@@ -1032,14 +1086,12 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id)
 static unsigned int pch_uart_tx_empty(struct uart_port *port)
 {
 	struct eg20t_port *priv;
-	int ret;
+
 	priv = container_of(port, struct eg20t_port, port);
 	if (priv->tx_empty)
-		ret = TIOCSER_TEMT;
+		return TIOCSER_TEMT;
 	else
-		ret = 0;
-
-	return ret;
+		return 0;
 }
 
 /* Returns the current state of modem control inputs. */
@@ -1273,9 +1325,8 @@ static void pch_uart_set_termios(struct uart_port *port,
 		else
 			parity = PCH_UART_HAL_PARITY_EVEN;
 
-	} else {
+	} else
 		parity = PCH_UART_HAL_PARITY_NONE;
-	}
 
 	/* Only UART0 has auto hardware flow function */
 	if ((termios->c_cflag & CRTSCTS) && (priv->fifo_size == 256))
@@ -1447,7 +1498,6 @@ static void
 pch_console_write(struct console *co, const char *s, unsigned int count)
 {
 	struct eg20t_port *priv;
-
 	unsigned long flags;
 	u8 ier;
 	int locked = 1;
@@ -1554,6 +1604,7 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
 	int port_type;
 	struct pch_uart_driver_data *board;
 	const char *board_name;
+	char name[32];	/* for debugfs file name */
 
 	board = &drv_dat[id->driver_data];
 	port_type = board->port_type;
@@ -1614,7 +1665,8 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
 	spin_lock_init(&priv->port.lock);
 
 	pci_set_drvdata(pdev, priv);
-	pch_uart_hal_request(pdev, fifosize, base_baud);
+	priv->trigger_level = 1;
+	priv->fcr = 0;
 
 #ifdef CONFIG_SERIAL_PCH_UART_CONSOLE
 	pch_uart_ports[board->line_no] = priv;
@@ -1623,6 +1675,12 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
 	if (ret < 0)
 		goto init_port_hal_free;
 
+#ifdef CONFIG_DEBUG_FS
+	snprintf(name, sizeof(name), "uart%d_regs", board->line_no);
+	priv->debugfs = debugfs_create_file(name, S_IFREG | S_IRUGO,
+				NULL, priv, &port_regs_ops);
+#endif
+
 	return priv;
 
 init_port_hal_free:
@@ -1639,6 +1697,11 @@ init_port_alloc_err:
 
 static void pch_uart_exit_port(struct eg20t_port *priv)
 {
+
+#ifdef CONFIG_DEBUG_FS
+	if (priv->debugfs)
+		debugfs_remove(priv->debugfs);
+#endif
 	uart_remove_one_port(&pch_uart_driver, &priv->port);
 	pci_set_drvdata(priv->pdev, NULL);
 	free_page((unsigned long)priv->rxbuf.buf);
@@ -1646,9 +1709,7 @@ static void pch_uart_exit_port(struct eg20t_port *priv)
 
 static void pch_uart_pci_remove(struct pci_dev *pdev)
 {
-	struct eg20t_port *priv;
-
-	priv = (struct eg20t_port *)pci_get_drvdata(pdev);
+	struct eg20t_port *priv = pci_get_drvdata(pdev);
 
 	pci_disable_msi(pdev);
 
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c
index e9c2dfe4..08ebe90 100644
--- a/drivers/tty/serial/pmac_zilog.c
+++ b/drivers/tty/serial/pmac_zilog.c
@@ -1506,7 +1506,7 @@ no_dma:
 	 * fixed up interrupt info, but we use the device-tree directly
 	 * here due to early probing so we need the fixup too.
 	 */
-	if (uap->port.irq == NO_IRQ &&
+	if (uap->port.irq == 0 &&
 	    np->parent && np->parent->parent &&
 	    of_device_is_compatible(np->parent->parent, "gatwick")) {
 		/* IRQs on gatwick are offset by 64 */
diff --git a/drivers/tty/serial/sunzilog.c b/drivers/tty/serial/sunzilog.c
index 8e916e7..5a47d1b 100644
--- a/drivers/tty/serial/sunzilog.c
+++ b/drivers/tty/serial/sunzilog.c
@@ -1397,7 +1397,7 @@ static void __devinit sunzilog_init_hw(struct uart_sunzilog_port *up)
 #endif
 }
 
-static int zilog_irq = -1;
+static int zilog_irq;
 
 static int __devinit zs_probe(struct platform_device *op)
 {
@@ -1425,7 +1425,7 @@ static int __devinit zs_probe(struct platform_device *op)
 
 	rp = sunzilog_chip_regs[inst];
 
-	if (zilog_irq == -1)
+	if (!zilog_irq)
 		zilog_irq = op->archdata.irqs[0];
 
 	up = &sunzilog_port_table[inst * 2];
@@ -1580,7 +1580,7 @@ static int __init sunzilog_init(void)
 	if (err)
 		goto out_unregister_uart;
 
-	if (zilog_irq != -1) {
+	if (!zilog_irq) {
 		struct uart_sunzilog_port *up = sunzilog_irq_chain;
 		err = request_irq(zilog_irq, sunzilog_interrupt, IRQF_SHARED,
 				  "zs", sunzilog_irq_chain);
@@ -1621,7 +1621,7 @@ static void __exit sunzilog_exit(void)
 {
 	platform_driver_unregister(&zs_driver);
 
-	if (zilog_irq != -1) {
+	if (!zilog_irq) {
 		struct uart_sunzilog_port *up = sunzilog_irq_chain;
 
 		/* Disable Interrupts */
@@ -1637,7 +1637,7 @@ static void __exit sunzilog_exit(void)
 		}
 
 		free_irq(zilog_irq, sunzilog_irq_chain);
-		zilog_irq = -1;
+		zilog_irq = 0;
 	}
 
 	if (sunzilog_reg.nr) {
diff --git a/drivers/tty/serial/ucc_uart.c b/drivers/tty/serial/ucc_uart.c
index 2ebe606..f99b0c9 100644
--- a/drivers/tty/serial/ucc_uart.c
+++ b/drivers/tty/serial/ucc_uart.c
@@ -1360,7 +1360,7 @@ static int ucc_uart_probe(struct platform_device *ofdev)
 	}
 
 	qe_port->port.irq = irq_of_parse_and_map(np, 0);
-	if (qe_port->port.irq == NO_IRQ) {
+	if (qe_port->port.irq == 0) {
 		dev_err(&ofdev->dev, "could not map IRQ for UCC%u\n",
 		       qe_port->ucc_num + 1);
 		ret = -EINVAL;
diff --git a/drivers/tty/serial/vr41xx_siu.c b/drivers/tty/serial/vr41xx_siu.c
index 83148e7..cf0d948 100644
--- a/drivers/tty/serial/vr41xx_siu.c
+++ b/drivers/tty/serial/vr41xx_siu.c
@@ -61,7 +61,7 @@
 static struct uart_port siu_uart_ports[SIU_PORTS_MAX] = {
 	[0 ... SIU_PORTS_MAX-1] = {
 		.lock	= __SPIN_LOCK_UNLOCKED(siu_uart_ports->lock),
-		.irq	= -1,
+		.irq	= 0,
 	},
 };
 
@@ -171,7 +171,7 @@ static inline unsigned int siu_check_type(struct uart_port *port)
 {
 	if (port->line == 0)
 		return PORT_VR41XX_SIU;
-	if (port->line == 1 && port->irq != -1)
+	if (port->line == 1 && port->irq)
 		return PORT_VR41XX_DSIU;
 
 	return PORT_UNKNOWN;
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 7867b7c..8db9125 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -322,11 +322,16 @@ static void send_sig_all(int sig)
 {
 	struct task_struct *p;
 
+	read_lock(&tasklist_lock);
 	for_each_process(p) {
-		if (p->mm && !is_global_init(p))
-			/* Not swapper, init nor kernel thread */
-			force_sig(sig, p);
+		if (p->flags & PF_KTHREAD)
+			continue;
+		if (is_global_init(p))
+			continue;
+
+		force_sig(sig, p);
 	}
+	read_unlock(&tasklist_lock);
 }
 
 static void sysrq_handle_term(int key)
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index e41b9bb..ea7ebe2 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1271,6 +1271,19 @@ int tty_init_termios(struct tty_struct *tty)
 }
 EXPORT_SYMBOL_GPL(tty_init_termios);
 
+int tty_standard_install(struct tty_driver *driver, struct tty_struct *tty)
+{
+	int ret = tty_init_termios(tty);
+	if (ret)
+		return ret;
+
+	tty_driver_kref_get(driver);
+	tty->count++;
+	driver->ttys[tty->index] = tty;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(tty_standard_install);
+
 /**
  *	tty_driver_install_tty() - install a tty entry in the driver
  *	@driver: the driver for the tty
@@ -1286,21 +1299,8 @@ EXPORT_SYMBOL_GPL(tty_init_termios);
 static int tty_driver_install_tty(struct tty_driver *driver,
 						struct tty_struct *tty)
 {
-	int idx = tty->index;
-	int ret;
-
-	if (driver->ops->install) {
-		ret = driver->ops->install(driver, tty);
-		return ret;
-	}
-
-	if (tty_init_termios(tty) == 0) {
-		tty_driver_kref_get(driver);
-		tty->count++;
-		driver->ttys[idx] = tty;
-		return 0;
-	}
-	return -ENOMEM;
+	return driver->ops->install ? driver->ops->install(driver, tty) :
+		tty_standard_install(driver, tty);
 }
 
 /**
@@ -1365,7 +1365,6 @@ static int tty_reopen(struct tty_struct *tty)
  *	@driver: tty driver we are opening a device on
  *	@idx: device index
  *	@ret_tty: returned tty structure
- *	@first_ok: ok to open a new device (used by ptmx)
  *
  *	Prepare a tty device. This may not be a "new" clean device but
  *	could also be an active device. The pty drivers require special
@@ -1385,18 +1384,11 @@ static int tty_reopen(struct tty_struct *tty)
  * relaxed for the (most common) case of reopening a tty.
  */
 
-struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
-								int first_ok)
+struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx)
 {
 	struct tty_struct *tty;
 	int retval;
 
-	/* Check if pty master is being opened multiple times */
-	if (driver->subtype == PTY_TYPE_MASTER &&
-		(driver->flags & TTY_DRIVER_DEVPTS_MEM) && !first_ok) {
-		return ERR_PTR(-EIO);
-	}
-
 	/*
 	 * First time open is complex, especially for PTY devices.
 	 * This code guarantees that either everything succeeds and the
@@ -1797,11 +1789,11 @@ int tty_release(struct inode *inode, struct file *filp)
 	 * the slots and preserving the termios structure.
 	 */
 	release_tty(tty, idx);
+	tty_unlock();
 
 	/* Make this pty number available for reallocation */
 	if (devpts)
 		devpts_kill_index(inode, idx);
-	tty_unlock();
 	return 0;
 }
 
@@ -1950,7 +1942,7 @@ retry_open:
 		if (retval)
 			tty = ERR_PTR(retval);
 	} else
-		tty = tty_init_dev(driver, index, 0);
+		tty = tty_init_dev(driver, index);
 
 	mutex_unlock(&tty_mutex);
 	if (driver)
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 611b206..1e30cc9 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -214,15 +214,14 @@ static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
 	if (!try_module_get(serial->type->driver.owner))
 		goto error_module_get;
 
-	/* perform the standard setup */
-	retval = tty_init_termios(tty);
-	if (retval)
-		goto error_init_termios;
-
 	retval = usb_autopm_get_interface(serial->interface);
 	if (retval)
 		goto error_get_interface;
 
+	retval = tty_standard_install(driver, tty);
+	if (retval)
+		goto error_init_termios;
+
 	mutex_unlock(&serial->disc_mutex);
 
 	/* allow the driver to update the settings */
@@ -231,14 +230,11 @@ static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
 
 	tty->driver_data = port;
 
-	/* Final install (we use the default method) */
-	tty_driver_kref_get(driver);
-	tty->count++;
-	driver->ttys[idx] = tty;
 	return retval;
 
- error_get_interface:
  error_init_termios:
+	usb_autopm_put_interface(serial->interface);
+ error_get_interface:
 	module_put(serial->type->driver.owner);
  error_module_get:
  error_no_port:
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index c4e2a58..1c6f908 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -36,7 +36,61 @@
 #define DEVPTS_DEFAULT_PTMX_MODE 0000
 #define PTMX_MINOR	2
 
-extern int pty_limit;			/* Config limit on Unix98 ptys */
+/*
+ * sysctl support for setting limits on the number of Unix98 ptys allocated.
+ * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly.
+ */
+static int pty_limit = NR_UNIX98_PTY_DEFAULT;
+static int pty_reserve = NR_UNIX98_PTY_RESERVE;
+static int pty_limit_min;
+static int pty_limit_max = INT_MAX;
+static int pty_count;
+
+static struct ctl_table pty_table[] = {
+	{
+		.procname	= "max",
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.data		= &pty_limit,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &pty_limit_min,
+		.extra2		= &pty_limit_max,
+	}, {
+		.procname	= "reserve",
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.data		= &pty_reserve,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &pty_limit_min,
+		.extra2		= &pty_limit_max,
+	}, {
+		.procname	= "nr",
+		.maxlen		= sizeof(int),
+		.mode		= 0444,
+		.data		= &pty_count,
+		.proc_handler	= proc_dointvec,
+	},
+	{}
+};
+
+static struct ctl_table pty_kern_table[] = {
+	{
+		.procname	= "pty",
+		.mode		= 0555,
+		.child		= pty_table,
+	},
+	{}
+};
+
+static struct ctl_table pty_root_table[] = {
+	{
+		.procname	= "kernel",
+		.mode		= 0555,
+		.child		= pty_kern_table,
+	},
+	{}
+};
+
 static DEFINE_MUTEX(allocated_ptys_lock);
 
 static struct vfsmount *devpts_mnt;
@@ -49,10 +103,11 @@ struct pts_mount_opts {
 	umode_t mode;
 	umode_t ptmxmode;
 	int newinstance;
+	int max;
 };
 
 enum {
-	Opt_uid, Opt_gid, Opt_mode, Opt_ptmxmode, Opt_newinstance,
+	Opt_uid, Opt_gid, Opt_mode, Opt_ptmxmode, Opt_newinstance,  Opt_max,
 	Opt_err
 };
 
@@ -63,6 +118,7 @@ static const match_table_t tokens = {
 #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES
 	{Opt_ptmxmode, "ptmxmode=%o"},
 	{Opt_newinstance, "newinstance"},
+	{Opt_max, "max=%d"},
 #endif
 	{Opt_err, NULL}
 };
@@ -109,6 +165,7 @@ static int parse_mount_options(char *data, int op, struct pts_mount_opts *opts)
 	opts->gid     = 0;
 	opts->mode    = DEVPTS_DEFAULT_MODE;
 	opts->ptmxmode = DEVPTS_DEFAULT_PTMX_MODE;
+	opts->max     = NR_UNIX98_PTY_MAX;
 
 	/* newinstance makes sense only on initial mount */
 	if (op == PARSE_MOUNT)
@@ -152,6 +209,12 @@ static int parse_mount_options(char *data, int op, struct pts_mount_opts *opts)
 			if (op == PARSE_MOUNT)
 				opts->newinstance = 1;
 			break;
+		case Opt_max:
+			if (match_int(&args[0], &option) ||
+			    option < 0 || option > NR_UNIX98_PTY_MAX)
+				return -EINVAL;
+			opts->max = option;
+			break;
 #endif
 		default:
 			printk(KERN_ERR "devpts: called with bogus options\n");
@@ -258,6 +321,8 @@ static int devpts_show_options(struct seq_file *seq, struct dentry *root)
 	seq_printf(seq, ",mode=%03o", opts->mode);
 #ifdef CONFIG_DEVPTS_MULTIPLE_INSTANCES
 	seq_printf(seq, ",ptmxmode=%03o", opts->ptmxmode);
+	if (opts->max < NR_UNIX98_PTY_MAX)
+		seq_printf(seq, ",max=%d", opts->max);
 #endif
 
 	return 0;
@@ -438,6 +503,12 @@ retry:
 		return -ENOMEM;
 
 	mutex_lock(&allocated_ptys_lock);
+	if (pty_count >= pty_limit -
+			(fsi->mount_opts.newinstance ? pty_reserve : 0)) {
+		mutex_unlock(&allocated_ptys_lock);
+		return -ENOSPC;
+	}
+
 	ida_ret = ida_get_new(&fsi->allocated_ptys, &index);
 	if (ida_ret < 0) {
 		mutex_unlock(&allocated_ptys_lock);
@@ -446,11 +517,12 @@ retry:
 		return -EIO;
 	}
 
-	if (index >= pty_limit) {
+	if (index >= fsi->mount_opts.max) {
 		ida_remove(&fsi->allocated_ptys, index);
 		mutex_unlock(&allocated_ptys_lock);
-		return -EIO;
+		return -ENOSPC;
 	}
+	pty_count++;
 	mutex_unlock(&allocated_ptys_lock);
 	return index;
 }
@@ -462,6 +534,7 @@ void devpts_kill_index(struct inode *ptmx_inode, int idx)
 
 	mutex_lock(&allocated_ptys_lock);
 	ida_remove(&fsi->allocated_ptys, idx);
+	pty_count--;
 	mutex_unlock(&allocated_ptys_lock);
 }
 
@@ -558,11 +631,15 @@ void devpts_pty_kill(struct tty_struct *tty)
 static int __init init_devpts_fs(void)
 {
 	int err = register_filesystem(&devpts_fs_type);
+	struct ctl_table_header *table;
+
 	if (!err) {
+		table = register_sysctl_table(pty_root_table);
 		devpts_mnt = kern_mount(&devpts_fs_type);
 		if (IS_ERR(devpts_mnt)) {
 			err = PTR_ERR(devpts_mnt);
 			unregister_filesystem(&devpts_fs_type);
+			unregister_sysctl_table(table);
 		}
 	}
 	return err;
diff --git a/include/linux/altera_uart.h b/include/linux/altera_uart.h
index a10a907..c022c82 100644
--- a/include/linux/altera_uart.h
+++ b/include/linux/altera_uart.h
@@ -5,8 +5,6 @@
 #ifndef	__ALTUART_H
 #define	__ALTUART_H
 
-#include <linux/init.h>
-
 struct altera_uart_platform_uart {
 	unsigned long mapbase;	/* Physical address base */
 	unsigned int irq;	/* Interrupt vector */
@@ -14,6 +12,4 @@ struct altera_uart_platform_uart {
 	unsigned int bus_shift;	/* Bus shift (address stride) */
 };
 
-int __init early_altera_uart_setup(struct altera_uart_platform_uart *platp);
-
 #endif /* __ALTUART_H */
diff --git a/include/linux/platform_data/efm32-uart.h b/include/linux/platform_data/efm32-uart.h
new file mode 100644
index 0000000..ed0e975
--- /dev/null
+++ b/include/linux/platform_data/efm32-uart.h
@@ -0,0 +1,18 @@
+/*
+ *
+ *
+ */
+#ifndef __LINUX_PLATFORM_DATA_EFM32_UART_H__
+#define __LINUX_PLATFORM_DATA_EFM32_UART_H__
+
+#include <linux/types.h>
+
+/**
+ * struct efm32_uart_pdata
+ * @location: pinmux location for the I/O pins (to be written to the ROUTE
+ * 	register)
+ */
+struct efm32_uart_pdata {
+	u8 location;
+};
+#endif /* ifndef __LINUX_PLATFORM_DATA_EFM32_UART_H__ */
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index c91ace7..585bfd0 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -210,6 +210,8 @@
 /* Atheros AR933X SoC */
 #define PORT_AR933X	99
 
+/* Energy Micro efm32 SoC */
+#define PORT_EFMUART   100
 
 #ifdef __KERNEL__
 
diff --git a/include/linux/tty.h b/include/linux/tty.h
index 5dbb3cb..a91ff40 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -52,6 +52,7 @@
  * hardcoded at present.)
  */
 #define NR_UNIX98_PTY_DEFAULT	4096      /* Default maximum for Unix98 ptys */
+#define NR_UNIX98_PTY_RESERVE	1024	  /* Default reserve for main devpts */
 #define NR_UNIX98_PTY_MAX	(1 << MINORBITS) /* Absolute limit */
 
 /*
@@ -480,10 +481,11 @@ extern void free_tty_struct(struct tty_struct *tty);
 extern void initialize_tty_struct(struct tty_struct *tty,
 		struct tty_driver *driver, int idx);
 extern void deinitialize_tty_struct(struct tty_struct *tty);
-extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx,
-								int first_ok);
+extern struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx);
 extern int tty_release(struct inode *inode, struct file *filp);
 extern int tty_init_termios(struct tty_struct *tty);
+extern int tty_standard_install(struct tty_driver *driver,
+		struct tty_struct *tty);
 
 extern struct tty_struct *tty_pair_get_tty(struct tty_struct *tty);
 extern struct tty_struct *tty_pair_get_pty(struct tty_struct *tty);