Merge tag 'tty-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the big tty/serial driver update for 4.18-rc1.

  There's nothing major here, just lots of serial driver updates. Full
  details are in the shortlog, nothing anything specific to call out
  here.

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

* tag 'tty-4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (55 commits)
  vt: Perform safe console erase only once
  serial: imx: disable UCR4_OREN on shutdown
  serial: imx: drop CTS/RTS handling from shutdown
  tty: fix typo in ASYNCB_FOURPORT comment
  serial: samsung: check DMA engine capabilities before using DMA mode
  tty: Fix data race in tty_insert_flip_string_fixed_flag
  tty: serial: msm_geni_serial: Fix TX infinite loop
  serial: 8250_dw: Fix runtime PM handling
  serial: 8250: omap: Fix idling of clocks for unused uarts
  tty: serial: drop ATH79 specific SoC symbols
  serial: 8250: Add missing rxtrig_bytes on Altera 16550 UART
  serial/aspeed-vuart: fix a couple mod_timer() calls
  serial: sh-sci: Use spin_{try}lock_irqsave instead of open coding version
  serial: 8250_of: Add IO space support
  tty/serial: atmel: use port->name as name in request_irq()
  serial: imx: dma_unmap_sg buffers on shutdown
  serial: imx: cleanup imx_uart_disable_dma()
  tty: serial: qcom_geni_serial: Add early console support
  tty: serial: qcom_geni_serial: Return IRQ_NONE for spurious interrupts
  tty: serial: qcom_geni_serial: Use iowrite32_rep to write to FIFO
  ...

21 files changed, 617 insertions, 230 deletions

diff --git a/drivers/tty/serial/8250/8250_aspeed_vuart.c b/drivers/tty/serial/8250/8250_aspeed_vuart.c
index 74a408d9db24..435bec40dee6 100644
--- a/drivers/tty/serial/8250/8250_aspeed_vuart.c
+++ b/drivers/tty/serial/8250/8250_aspeed_vuart.c
@@ -10,6 +10,8 @@
 #include <linux/of_address.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
 #include <linux/clk.h>
 
 #include "8250.h"
@@ -28,9 +30,18 @@ struct aspeed_vuart {
 	void __iomem		*regs;
 	struct clk		*clk;
 	int			line;
+	struct timer_list	unthrottle_timer;
+	struct uart_8250_port	*port;
 };
 
 /*
+ * If we fill the tty flip buffers, we throttle the data ready interrupt
+ * to prevent dropped characters. This timeout defines how long we wait
+ * to (conditionally, depending on buffer state) unthrottle.
+ */
+static const int unthrottle_timeout = HZ/10;
+
+/*
  * 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.
@@ -179,6 +190,114 @@ static void aspeed_vuart_shutdown(struct uart_port *uart_port)
 	serial8250_do_shutdown(uart_port);
 }
 
+static void __aspeed_vuart_set_throttle(struct uart_8250_port *up,
+		bool throttle)
+{
+	unsigned char irqs = UART_IER_RLSI | UART_IER_RDI;
+
+	up->ier &= ~irqs;
+	if (!throttle)
+		up->ier |= irqs;
+	serial_out(up, UART_IER, up->ier);
+}
+static void aspeed_vuart_set_throttle(struct uart_port *port, bool throttle)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned long flags;
+
+	spin_lock_irqsave(&port->lock, flags);
+	__aspeed_vuart_set_throttle(up, throttle);
+	spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void aspeed_vuart_throttle(struct uart_port *port)
+{
+	aspeed_vuart_set_throttle(port, true);
+}
+
+static void aspeed_vuart_unthrottle(struct uart_port *port)
+{
+	aspeed_vuart_set_throttle(port, false);
+}
+
+static void aspeed_vuart_unthrottle_exp(struct timer_list *timer)
+{
+	struct aspeed_vuart *vuart = from_timer(vuart, timer, unthrottle_timer);
+	struct uart_8250_port *up = vuart->port;
+
+	if (!tty_buffer_space_avail(&up->port.state->port)) {
+		mod_timer(&vuart->unthrottle_timer,
+			  jiffies + unthrottle_timeout);
+		return;
+	}
+
+	aspeed_vuart_unthrottle(&up->port);
+}
+
+/*
+ * Custom interrupt handler to manage finer-grained flow control. Although we
+ * have throttle/unthrottle callbacks, we've seen that the VUART device can
+ * deliver characters faster than the ldisc has a chance to check buffer space
+ * against the throttle threshold. This results in dropped characters before
+ * the throttle.
+ *
+ * We do this by checking for flip buffer space before RX. If we have no space,
+ * throttle now and schedule an unthrottle for later, once the ldisc has had
+ * a chance to drain the buffers.
+ */
+static int aspeed_vuart_handle_irq(struct uart_port *port)
+{
+	struct uart_8250_port *up = up_to_u8250p(port);
+	unsigned int iir, lsr;
+	unsigned long flags;
+	int space, count;
+
+	iir = serial_port_in(port, UART_IIR);
+
+	if (iir & UART_IIR_NO_INT)
+		return 0;
+
+	spin_lock_irqsave(&port->lock, flags);
+
+	lsr = serial_port_in(port, UART_LSR);
+
+	if (lsr & (UART_LSR_DR | UART_LSR_BI)) {
+		space = tty_buffer_space_avail(&port->state->port);
+
+		if (!space) {
+			/* throttle and schedule an unthrottle later */
+			struct aspeed_vuart *vuart = port->private_data;
+			__aspeed_vuart_set_throttle(up, true);
+
+			if (!timer_pending(&vuart->unthrottle_timer)) {
+				vuart->port = up;
+				mod_timer(&vuart->unthrottle_timer,
+					  jiffies + unthrottle_timeout);
+			}
+
+		} else {
+			count = min(space, 256);
+
+			do {
+				serial8250_read_char(up, lsr);
+				lsr = serial_in(up, UART_LSR);
+				if (--count == 0)
+					break;
+			} while (lsr & (UART_LSR_DR | UART_LSR_BI));
+
+			tty_flip_buffer_push(&port->state->port);
+		}
+	}
+
+	serial8250_modem_status(up);
+	if (lsr & UART_LSR_THRE)
+		serial8250_tx_chars(up);
+
+	spin_unlock_irqrestore(&port->lock, flags);
+
+	return 1;
+}
+
 static int aspeed_vuart_probe(struct platform_device *pdev)
 {
 	struct uart_8250_port port;
@@ -195,6 +314,7 @@ static int aspeed_vuart_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	vuart->dev = &pdev->dev;
+	timer_setup(&vuart->unthrottle_timer, aspeed_vuart_unthrottle_exp, 0);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	vuart->regs = devm_ioremap_resource(&pdev->dev, res);
@@ -208,6 +328,9 @@ static int aspeed_vuart_probe(struct platform_device *pdev)
 	port.port.mapsize = resource_size(res);
 	port.port.startup = aspeed_vuart_startup;
 	port.port.shutdown = aspeed_vuart_shutdown;
+	port.port.throttle = aspeed_vuart_throttle;
+	port.port.unthrottle = aspeed_vuart_unthrottle;
+	port.port.status = UPSTAT_SYNC_FIFO;
 	port.port.dev = &pdev->dev;
 
 	rc = sysfs_create_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
@@ -253,6 +376,7 @@ static int aspeed_vuart_probe(struct platform_device *pdev)
 
 	port.port.irq = irq_of_parse_and_map(np, 0);
 	port.port.irqflags = IRQF_SHARED;
+	port.port.handle_irq = aspeed_vuart_handle_irq;
 	port.port.iotype = UPIO_MEM;
 	port.port.type = PORT_16550A;
 	port.port.uartclk = clk;
@@ -292,6 +416,7 @@ static int aspeed_vuart_remove(struct platform_device *pdev)
 {
 	struct aspeed_vuart *vuart = platform_get_drvdata(pdev);
 
+	del_timer_sync(&vuart->unthrottle_timer);
 	aspeed_vuart_set_enabled(vuart, false);
 	serial8250_unregister_port(vuart->line);
 	sysfs_remove_group(&vuart->dev->kobj, &aspeed_vuart_attr_group);
diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 6fcdb90f616a..aff04f1de3a5 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -121,25 +121,44 @@ static void dw8250_check_lcr(struct uart_port *p, int value)
 }
 
 /* Returns once the transmitter is empty or we run out of retries */
-static void dw8250_tx_wait_empty(struct uart_port *p, int tries)
+static void dw8250_tx_wait_empty(struct uart_port *p)
 {
+	unsigned int tries = 20000;
+	unsigned int delay_threshold = tries - 1000;
 	unsigned int lsr;
 
 	while (tries--) {
 		lsr = readb (p->membase + (UART_LSR << p->regshift));
 		if (lsr & UART_LSR_TEMT)
 			break;
-		udelay (10);
+
+		/* The device is first given a chance to empty without delay,
+		 * to avoid slowdowns at high bitrates. If after 1000 tries
+		 * the buffer has still not emptied, allow more time for low-
+		 * speed links. */
+		if (tries < delay_threshold)
+			udelay (1);
 	}
 }
 
-static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
 {
 	struct dw8250_data *d = p->private_data;
 
 	/* Allow the TX to drain before we reconfigure */
 	if (offset == UART_LCR)
-		dw8250_tx_wait_empty(p, 1000);
+		dw8250_tx_wait_empty(p);
+
+	writeb(value, p->membase + (offset << p->regshift));
+
+	if (offset == UART_LCR && !d->uart_16550_compatible)
+		dw8250_check_lcr(p, value);
+}
+
+
+static void dw8250_serial_out(struct uart_port *p, int offset, int value)
+{
+	struct dw8250_data *d = p->private_data;
 
 	writeb(value, p->membase + (offset << p->regshift));
 
@@ -357,6 +376,9 @@ static void dw8250_quirks(struct uart_port *p, struct dw8250_data *data)
 			p->serial_in = dw8250_serial_in32be;
 			p->serial_out = dw8250_serial_out32be;
 		}
+		if (of_device_is_compatible(np, "marvell,armada-38x-uart"))
+			p->serial_out = dw8250_serial_out38x;
+
 	} else if (acpi_dev_present("APMC0D08", NULL, -1)) {
 		p->iotype = UPIO_MEM32;
 		p->regshift = 2;
@@ -554,6 +576,10 @@ static int dw8250_probe(struct platform_device *pdev)
 	if (!data->skip_autocfg)
 		dw8250_setup_port(p);
 
+#ifdef CONFIG_PM
+	uart.capabilities |= UART_CAP_RPM;
+#endif
+
 	/* If we have a valid fifosize, try hooking up DMA */
 	if (p->fifosize) {
 		data->dma.rxconf.src_maxburst = p->fifosize / 4;
@@ -666,6 +692,7 @@ static const struct dev_pm_ops dw8250_pm_ops = {
 static const struct of_device_id dw8250_of_match[] = {
 	{ .compatible = "snps,dw-apb-uart" },
 	{ .compatible = "cavium,octeon-3860-uart" },
+	{ .compatible = "marvell,armada-38x-uart" },
 	{ /* Sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, dw8250_of_match);
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
index ae6a256524d8..5cd8c36c8fcc 100644
--- a/drivers/tty/serial/8250/8250_early.c
+++ b/drivers/tty/serial/8250/8250_early.c
@@ -122,7 +122,7 @@ static void __init init_port(struct earlycon_device *device)
 	serial8250_early_out(port, UART_FCR, 0);	/* no fifo */
 	serial8250_early_out(port, UART_MCR, 0x3);	/* DTR + RTS */
 
-	if (port->uartclk && device->baud) {
+	if (port->uartclk) {
 		divisor = DIV_ROUND_CLOSEST(port->uartclk, 16 * device->baud);
 		c = serial8250_early_in(port, UART_LCR);
 		serial8250_early_out(port, UART_LCR, c | UART_LCR_DLAB);
diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 9835b1c1cbe1..bfb37f0be22f 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -92,13 +92,43 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 		goto err_unprepare;
 	}
 
+	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT |
+				  UPF_FIXED_TYPE;
 	spin_lock_init(&port->lock);
-	port->mapbase = resource.start;
-	port->mapsize = resource_size(&resource);
 
-	/* Check for shifted address mapping */
-	if (of_property_read_u32(np, "reg-offset", &prop) == 0)
-		port->mapbase += prop;
+	if (resource_type(&resource) == IORESOURCE_IO) {
+		port->iotype = UPIO_PORT;
+		port->iobase = resource.start;
+	} else {
+		port->mapbase = resource.start;
+		port->mapsize = resource_size(&resource);
+
+		/* Check for shifted address mapping */
+		if (of_property_read_u32(np, "reg-offset", &prop) == 0)
+			port->mapbase += prop;
+
+		port->iotype = UPIO_MEM;
+		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
+			switch (prop) {
+			case 1:
+				port->iotype = UPIO_MEM;
+				break;
+			case 2:
+				port->iotype = UPIO_MEM16;
+				break;
+			case 4:
+				port->iotype = of_device_is_big_endian(np) ?
+					       UPIO_MEM32BE : UPIO_MEM32;
+				break;
+			default:
+				dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
+					 prop);
+				ret = -EINVAL;
+				goto err_dispose;
+			}
+		}
+		port->flags |= UPF_IOREMAP;
+	}
 
 	/* Check for registers offset within the devices address range */
 	if (of_property_read_u32(np, "reg-shift", &prop) == 0)
@@ -114,26 +144,6 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 		port->line = ret;
 
 	port->irq = irq_of_parse_and_map(np, 0);
-	port->iotype = UPIO_MEM;
-	if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
-		switch (prop) {
-		case 1:
-			port->iotype = UPIO_MEM;
-			break;
-		case 2:
-			port->iotype = UPIO_MEM16;
-			break;
-		case 4:
-			port->iotype = of_device_is_big_endian(np) ?
-				       UPIO_MEM32BE : UPIO_MEM32;
-			break;
-		default:
-			dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
-				 prop);
-			ret = -EINVAL;
-			goto err_dispose;
-		}
-	}
 
 	info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
 	if (IS_ERR(info->rst)) {
@@ -147,8 +157,7 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 
 	port->type = type;
 	port->uartclk = clk;
-	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
-		| UPF_FIXED_PORT | UPF_FIXED_TYPE;
+	port->irqflags |= IRQF_SHARED;
 
 	if (of_property_read_bool(np, "no-loopback-test"))
 		port->flags |= UPF_SKIP_TEST;
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index 624b501fd253..1b337fee07ed 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -1110,13 +1110,14 @@ static int omap8250_no_handle_irq(struct uart_port *port)
 	return 0;
 }
 
+static const u8 omap4_habit = UART_ERRATA_CLOCK_DISABLE;
 static const u8 am3352_habit = OMAP_DMA_TX_KICK | UART_ERRATA_CLOCK_DISABLE;
 static const u8 dra742_habit = UART_ERRATA_CLOCK_DISABLE;
 
 static const struct of_device_id omap8250_dt_ids[] = {
 	{ .compatible = "ti,omap2-uart" },
 	{ .compatible = "ti,omap3-uart" },
-	{ .compatible = "ti,omap4-uart" },
+	{ .compatible = "ti,omap4-uart", .data = &omap4_habit, },
 	{ .compatible = "ti,am3352-uart", .data = &am3352_habit, },
 	{ .compatible = "ti,am4372-uart", .data = &am3352_habit, },
 	{ .compatible = "ti,dra742-uart", .data = &dra742_habit, },
@@ -1310,8 +1311,17 @@ static void omap8250_complete(struct device *dev)
 static int omap8250_suspend(struct device *dev)
 {
 	struct omap8250_priv *priv = dev_get_drvdata(dev);
+	struct uart_8250_port *up = serial8250_get_port(priv->line);
 
 	serial8250_suspend_port(priv->line);
+
+	pm_runtime_get_sync(dev);
+	if (!device_may_wakeup(dev))
+		priv->wer = 0;
+	serial_out(up, UART_OMAP_WER, priv->wer);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
 	flush_work(&priv->qos_work);
 	return 0;
 }
@@ -1353,6 +1363,19 @@ static int omap8250_soft_reset(struct device *dev)
 	int sysc;
 	int syss;
 
+	/*
+	 * At least on omap4, unused uarts may not idle after reset without
+	 * a basic scr dma configuration even with no dma in use. The
+	 * module clkctrl status bits will be 1 instead of 3 blocking idle
+	 * for the whole clockdomain. The softreset below will clear scr,
+	 * and we restore it on resume so this is safe to do on all SoCs
+	 * needing omap8250_soft_reset() quirk. Do it in two writes as
+	 * recommended in the comment for omap8250_update_scr().
+	 */
+	serial_out(up, UART_OMAP_SCR, OMAP_UART_SCR_DMAMODE_1);
+	serial_out(up, UART_OMAP_SCR,
+		   OMAP_UART_SCR_DMAMODE_1 | OMAP_UART_SCR_DMAMODE_CTL);
+
 	sysc = serial_in(up, UART_OMAP_SYSC);
 
 	/* softreset the UART */
@@ -1403,6 +1426,8 @@ static int omap8250_runtime_suspend(struct device *dev)
 
 		/* Restore to UART mode after reset (for wakeup) */
 		omap8250_update_mdr1(up, priv);
+		/* Restore wakeup enable register */
+		serial_out(up, UART_OMAP_WER, priv->wer);
 	}
 
 	if (up->dma && up->dma->rxchan)
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 95833cbc4338..cf541aab2bd0 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -243,6 +243,7 @@ static const struct serial8250_config uart_config[] = {
 		.fifo_size	= 32,
 		.tx_loadsz	= 32,
 		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 8, 16, 30},
 		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
 	},
 	[PORT_ALTR_16550_F64] = {
@@ -250,6 +251,7 @@ static const struct serial8250_config uart_config[] = {
 		.fifo_size	= 64,
 		.tx_loadsz	= 64,
 		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 16, 32, 62},
 		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
 	},
 	[PORT_ALTR_16550_F128] = {
@@ -257,6 +259,7 @@ static const struct serial8250_config uart_config[] = {
 		.fifo_size	= 128,
 		.tx_loadsz	= 128,
 		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
+		.rxtrig_bytes	= {1, 32, 64, 126},
 		.flags		= UART_CAP_FIFO | UART_CAP_AFE,
 	},
 	/*
@@ -1680,7 +1683,7 @@ static void serial8250_enable_ms(struct uart_port *port)
 	serial8250_rpm_put(up);
 }
 
-static void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
+void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
 {
 	struct uart_port *port = &up->port;
 	unsigned char ch;
@@ -1740,6 +1743,7 @@ static void serial8250_read_char(struct uart_8250_port *up, unsigned char lsr)
 
 	uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
 }
+EXPORT_SYMBOL_GPL(serial8250_read_char);
 
 /*
  * serial8250_rx_chars: processes according to the passed in LSR
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 0f058df0b070..df8bd0c7b97d 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -115,7 +115,6 @@ config SERIAL_SB1250_DUART_CONSOLE
 
 config SERIAL_ATMEL
 	bool "AT91 on-chip serial port support"
-	depends on HAS_DMA
 	depends on ARCH_AT91 || COMPILE_TEST
 	select SERIAL_CORE
 	select SERIAL_MCTRL_GPIO if GPIOLIB
@@ -500,7 +499,6 @@ config SERIAL_SA1100_CONSOLE
 
 config SERIAL_IMX
 	tristate "IMX serial port support"
-	depends on HAS_DMA
 	depends on ARCH_MXC || COMPILE_TEST
 	select SERIAL_CORE
 	select RATIONAL
@@ -676,6 +674,8 @@ config SERIAL_SH_SCI
 
 config SERIAL_SH_SCI_NR_UARTS
 	int "Maximum number of SCI(F) serial ports" if EXPERT
+	range 1 64 if 64BIT
+	range 1 32 if !64BIT
 	depends on SERIAL_SH_SCI
 	default "3" if H8300
 	default "10" if SUPERH
@@ -1262,7 +1262,6 @@ config SERIAL_PCH_UART_CONSOLE
 
 config SERIAL_MXS_AUART
 	tristate "MXS AUART support"
-	depends on HAS_DMA
 	depends on ARCH_MXS || MACH_ASM9260 || COMPILE_TEST
 	select SERIAL_CORE
 	select SERIAL_MCTRL_GPIO if GPIOLIB
@@ -1295,7 +1294,7 @@ config SERIAL_XILINX_PS_UART_CONSOLE
 
 config SERIAL_AR933X
 	tristate "AR933X serial port support"
-	depends on HAVE_CLK && SOC_AR933X
+	depends on HAVE_CLK && ATH79
 	select SERIAL_CORE
 	help
 	  If you have an Atheros AR933X SOC based board and want to use the
@@ -1473,7 +1472,6 @@ config SERIAL_SPRD_CONSOLE
 config SERIAL_STM32
 	tristate "STMicroelectronics STM32 serial port support"
 	select SERIAL_CORE
-	depends on HAS_DMA
 	depends on ARCH_STM32 || COMPILE_TEST
 	help
 	  This driver is for the on-chip Serial Controller on
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
index 4b40a5b449ee..ebd33c0232e6 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -1727,10 +1727,26 @@ static int pl011_allocate_irq(struct uart_amba_port *uap)
  */
 static void pl011_enable_interrupts(struct uart_amba_port *uap)
 {
+	unsigned int i;
+
 	spin_lock_irq(&uap->port.lock);
 
 	/* Clear out any spuriously appearing RX interrupts */
 	pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR);
+
+	/*
+	 * RXIS is asserted only when the RX FIFO transitions from below
+	 * to above the trigger threshold.  If the RX FIFO is already
+	 * full to the threshold this can't happen and RXIS will now be
+	 * stuck off.  Drain the RX FIFO explicitly to fix this:
+	 */
+	for (i = 0; i < uap->fifosize * 2; ++i) {
+		if (pl011_read(uap, REG_FR) & UART01x_FR_RXFE)
+			break;
+
+		pl011_read(uap, REG_DR);
+	}
+
 	uap->im = UART011_RTIM;
 	if (!pl011_dma_rx_running(uap))
 		uap->im |= UART011_RXIM;
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index e287fe8f10fc..55b3eff148b1 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -1757,7 +1757,6 @@ static int atmel_startup(struct uart_port *port)
 {
 	struct platform_device *pdev = to_platform_device(port->dev);
 	struct atmel_uart_port *atmel_port = to_atmel_uart_port(port);
-	struct tty_struct *tty = port->state->port.tty;
 	int retval;
 
 	/*
@@ -1772,8 +1771,8 @@ static int atmel_startup(struct uart_port *port)
 	 * Allocate the IRQ
 	 */
 	retval = request_irq(port->irq, atmel_interrupt,
-			IRQF_SHARED | IRQF_COND_SUSPEND,
-			tty ? tty->name : "atmel_serial", port);
+			     IRQF_SHARED | IRQF_COND_SUSPEND,
+			     dev_name(&pdev->dev), port);
 	if (retval) {
 		dev_err(port->dev, "atmel_startup - Can't get irq\n");
 		return retval;
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 22683393a0f2..c14873b67803 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -246,7 +246,6 @@ int __init of_setup_earlycon(const struct earlycon_id *match,
 		return -ENXIO;
 	}
 	port->mapbase = addr;
-	port->uartclk = BASE_BAUD * 16;
 
 	val = of_get_flat_dt_prop(node, "reg-offset", NULL);
 	if (val)
@@ -281,6 +280,10 @@ int __init of_setup_earlycon(const struct earlycon_id *match,
 	if (val)
 		early_console_dev.baud = be32_to_cpu(*val);
 
+	val = of_get_flat_dt_prop(node, "clock-frequency", NULL);
+	if (val)
+		port->uartclk = be32_to_cpu(*val);
+
 	if (options) {
 		early_console_dev.baud = simple_strtoul(options, NULL, 0);
 		strlcpy(early_console_dev.options, options,
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index c2fc6bef7a6f..4e853570ea80 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1291,18 +1291,13 @@ static void imx_uart_enable_dma(struct imx_port *sport)
 
 static void imx_uart_disable_dma(struct imx_port *sport)
 {
-	u32 ucr1, ucr2;
+	u32 ucr1;
 
 	/* clear UCR1 */
 	ucr1 = imx_uart_readl(sport, UCR1);
 	ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
 	imx_uart_writel(sport, ucr1, UCR1);
 
-	/* clear UCR2 */
-	ucr2 = imx_uart_readl(sport, UCR2);
-	ucr2 &= ~(UCR2_CTSC | UCR2_CTS | UCR2_ATEN);
-	imx_uart_writel(sport, ucr2, UCR2);
-
 	imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
 
 	sport->dma_is_enabled = 0;
@@ -1427,13 +1422,21 @@ static void imx_uart_shutdown(struct uart_port *port)
 {
 	struct imx_port *sport = (struct imx_port *)port;
 	unsigned long flags;
-	u32 ucr1, ucr2;
+	u32 ucr1, ucr2, ucr4;
 
 	if (sport->dma_is_enabled) {
-		sport->dma_is_rxing = 0;
-		sport->dma_is_txing = 0;
 		dmaengine_terminate_sync(sport->dma_chan_tx);
+		if (sport->dma_is_txing) {
+			dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
+				     sport->dma_tx_nents, DMA_TO_DEVICE);
+			sport->dma_is_txing = 0;
+		}
 		dmaengine_terminate_sync(sport->dma_chan_rx);
+		if (sport->dma_is_rxing) {
+			dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
+				     1, DMA_FROM_DEVICE);
+			sport->dma_is_rxing = 0;
+		}
 
 		spin_lock_irqsave(&sport->port.lock, flags);
 		imx_uart_stop_tx(port);
@@ -1449,6 +1452,10 @@ static void imx_uart_shutdown(struct uart_port *port)
 	ucr2 = imx_uart_readl(sport, UCR2);
 	ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
 	imx_uart_writel(sport, ucr2, UCR2);
+
+	ucr4 = imx_uart_readl(sport, UCR4);
+	ucr4 &= ~UCR4_OREN;
+	imx_uart_writel(sport, ucr4, UCR4);
 	spin_unlock_irqrestore(&sport->port.lock, flags);
 
 	/*
@@ -2425,8 +2432,7 @@ static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
 
 static int imx_uart_suspend_noirq(struct device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct imx_port *sport = platform_get_drvdata(pdev);
+	struct imx_port *sport = dev_get_drvdata(dev);
 
 	imx_uart_save_context(sport);
 
@@ -2437,8 +2443,7 @@ static int imx_uart_suspend_noirq(struct device *dev)
 
 static int imx_uart_resume_noirq(struct device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct imx_port *sport = platform_get_drvdata(pdev);
+	struct imx_port *sport = dev_get_drvdata(dev);
 	int ret;
 
 	ret = clk_enable(sport->clk_ipg);
@@ -2452,8 +2457,7 @@ static int imx_uart_resume_noirq(struct device *dev)
 
 static int imx_uart_suspend(struct device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct imx_port *sport = platform_get_drvdata(pdev);
+	struct imx_port *sport = dev_get_drvdata(dev);
 	int ret;
 
 	uart_suspend_port(&imx_uart_uart_driver, &sport->port);
@@ -2471,8 +2475,7 @@ static int imx_uart_suspend(struct device *dev)
 
 static int imx_uart_resume(struct device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct imx_port *sport = platform_get_drvdata(pdev);
+	struct imx_port *sport = dev_get_drvdata(dev);
 
 	/* disable wakeup from i.MX UART */
 	imx_uart_enable_wakeup(sport, false);
@@ -2487,8 +2490,7 @@ static int imx_uart_resume(struct device *dev)
 
 static int imx_uart_freeze(struct device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct imx_port *sport = platform_get_drvdata(pdev);
+	struct imx_port *sport = dev_get_drvdata(dev);
 
 	uart_suspend_port(&imx_uart_uart_driver, &sport->port);
 
@@ -2497,8 +2499,7 @@ static int imx_uart_freeze(struct device *dev)
 
 static int imx_uart_thaw(struct device *dev)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct imx_port *sport = platform_get_drvdata(pdev);
+	struct imx_port *sport = dev_get_drvdata(dev);
 
 	uart_resume_port(&imx_uart_uart_driver, &sport->port);
 
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c
index ee96cf0d0057..736b74fd6623 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -1812,11 +1812,34 @@ static const struct of_device_id msm_match_table[] = {
 };
 MODULE_DEVICE_TABLE(of, msm_match_table);
 
+static int __maybe_unused msm_serial_suspend(struct device *dev)
+{
+	struct msm_port *port = dev_get_drvdata(dev);
+
+	uart_suspend_port(&msm_uart_driver, &port->uart);
+
+	return 0;
+}
+
+static int __maybe_unused msm_serial_resume(struct device *dev)
+{
+	struct msm_port *port = dev_get_drvdata(dev);
+
+	uart_resume_port(&msm_uart_driver, &port->uart);
+
+	return 0;
+}
+
+static const struct dev_pm_ops msm_serial_dev_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume)
+};
+
 static struct platform_driver msm_platform_driver = {
 	.remove = msm_serial_remove,
 	.probe = msm_serial_probe,
 	.driver = {
 		.name = "msm_serial",
+		.pm = &msm_serial_dev_pm_ops,
 		.of_match_table = msm_match_table,
 	},
 };
diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
index f503fab1e268..d04b5eeea3c6 100644
--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -71,6 +71,8 @@
 #define UART_BRDV		0x10
 #define  BRDV_BAUD_MASK         0x3FF
 
+#define UART_OSAMP		0x14
+
 #define MVEBU_NR_UARTS		2
 
 #define MVEBU_UART_TYPE		"mvebu-uart"
@@ -108,6 +110,17 @@ struct mvebu_uart_driver_data {
 	struct uart_flags flags;
 };
 
+/* Saved registers during suspend */
+struct mvebu_uart_pm_regs {
+	unsigned int rbr;
+	unsigned int tsh;
+	unsigned int ctrl;
+	unsigned int intr;
+	unsigned int stat;
+	unsigned int brdv;
+	unsigned int osamp;
+};
+
 /* MVEBU UART driver structure */
 struct mvebu_uart {
 	struct uart_port *port;
@@ -115,6 +128,9 @@ struct mvebu_uart {
 	int irq[UART_IRQ_COUNT];
 	unsigned char __iomem *nb;
 	struct mvebu_uart_driver_data *data;
+#if defined(CONFIG_PM)
+	struct mvebu_uart_pm_regs pm_regs;
+#endif /* CONFIG_PM */
 };
 
 static struct mvebu_uart *to_mvuart(struct uart_port *port)
@@ -718,6 +734,51 @@ static struct uart_driver mvebu_uart_driver = {
 #endif
 };
 
+#if defined(CONFIG_PM)
+static int mvebu_uart_suspend(struct device *dev)
+{
+	struct mvebu_uart *mvuart = dev_get_drvdata(dev);
+	struct uart_port *port = mvuart->port;
+
+	uart_suspend_port(&mvebu_uart_driver, port);
+
+	mvuart->pm_regs.rbr = readl(port->membase + UART_RBR(port));
+	mvuart->pm_regs.tsh = readl(port->membase + UART_TSH(port));
+	mvuart->pm_regs.ctrl = readl(port->membase + UART_CTRL(port));
+	mvuart->pm_regs.intr = readl(port->membase + UART_INTR(port));
+	mvuart->pm_regs.stat = readl(port->membase + UART_STAT);
+	mvuart->pm_regs.brdv = readl(port->membase + UART_BRDV);
+	mvuart->pm_regs.osamp = readl(port->membase + UART_OSAMP);
+
+	device_set_wakeup_enable(dev, true);
+
+	return 0;
+}
+
+static int mvebu_uart_resume(struct device *dev)
+{
+	struct mvebu_uart *mvuart = dev_get_drvdata(dev);
+	struct uart_port *port = mvuart->port;
+
+	writel(mvuart->pm_regs.rbr, port->membase + UART_RBR(port));
+	writel(mvuart->pm_regs.tsh, port->memb