TTY / Serial driver updates for 5.3-rc1

Here is the "large" TTY and Serial driver update for 5.3-rc1.
 
 It's in the negative number of lines overall as we removed an obsolete
 serial driver that was causing problems for some people who were trying
 to clean up some apis (the mpsc.c driver, which only worked for some
 pre-production hardware that no one has anymore.)
 
 Other than that, lots of tiny changes, cleaning up small things along
 with some platform-specific serial driver updates.
 
 All of these have been in linux-next for a while now with no reported
 issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'tty-5.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

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

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

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

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

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

Documentation/admin-guide/devices.txt

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

Documentation/devicetree/bindings/serial/8250.txt

@@ -53,6 +53,9 @@ Optional properties:
   programmable TX FIFO thresholds.
 - resets : phandle + reset specifier pairs
 - overrun-throttle-ms : how long to pause uart rx when input overrun is encountered.
+- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD
+  line respectively. It will use specified GPIO instead of the peripheral
+  function pin for the UART feature. If unsure, don't specify this property.
 
 Note:
 * fsl,ns16550:
@@ -74,3 +77,19 @@ Example:
 		interrupts = <10>;
 		reg-shift = <2>;
 	};
+
+Example for OMAP UART using GPIO-based modem control signals:
+
+	uart4: serial@49042000 {
+		compatible = "ti,omap3-uart";
+		reg = <0x49042000 0x400>;
+		interrupts = <80>;
+		ti,hwmods = "uart4";
+		clock-frequency = <48000000>;
+		cts-gpios = <&gpio3 5 GPIO_ACTIVE_LOW>;
+		rts-gpios = <&gpio3 6 GPIO_ACTIVE_LOW>;
+		dtr-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
+		dsr-gpios = <&gpio1 13 GPIO_ACTIVE_LOW>;
+		dcd-gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;
+		rng-gpios = <&gpio1 15 GPIO_ACTIVE_LOW>;
+	};

arch/ia64/hp/sim/simserial.c

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

drivers/ipack/devices/ipoctal.h

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

drivers/tty/serial/8250/8250.h

@@ -11,6 +11,8 @@
 #include <linux/serial_reg.h>
 #include <linux/dmaengine.h>
 
+#include "../serial_mctrl_gpio.h"
+
 struct uart_8250_dma {
 	int (*tx_dma)(struct uart_8250_port *p);
 	int (*rx_dma)(struct uart_8250_port *p);
@@ -128,6 +130,24 @@ static inline void serial_dl_write(struct uart_8250_port *up, int value)
 	up->dl_write(up, value);
 }
 
+static inline bool serial8250_set_THRI(struct uart_8250_port *up)
+{
+	if (up->ier & UART_IER_THRI)
+		return false;
+	up->ier |= UART_IER_THRI;
+	serial_out(up, UART_IER, up->ier);
+	return true;
+}
+
+static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
+{
+	if (!(up->ier & UART_IER_THRI))
+		return false;
+	up->ier &= ~UART_IER_THRI;
+	serial_out(up, UART_IER, up->ier);
+	return true;
+}
+
 struct uart_8250_port *serial8250_get_port(int line);
 
 void serial8250_rpm_get(struct uart_8250_port *p);
@@ -139,14 +159,82 @@ void serial8250_rpm_put_tx(struct uart_8250_port *p);
 int serial8250_em485_init(struct uart_8250_port *p);
 void serial8250_em485_destroy(struct uart_8250_port *p);
 
+/* MCR <-> TIOCM conversion */
+static inline int serial8250_TIOCM_to_MCR(int tiocm)
+{
+	int mcr = 0;
+
+	if (tiocm & TIOCM_RTS)
+		mcr |= UART_MCR_RTS;
+	if (tiocm & TIOCM_DTR)
+		mcr |= UART_MCR_DTR;
+	if (tiocm & TIOCM_OUT1)
+		mcr |= UART_MCR_OUT1;
+	if (tiocm & TIOCM_OUT2)
+		mcr |= UART_MCR_OUT2;
+	if (tiocm & TIOCM_LOOP)
+		mcr |= UART_MCR_LOOP;
+
+	return mcr;
+}
+
+static inline int serial8250_MCR_to_TIOCM(int mcr)
+{
+	int tiocm = 0;
+
+	if (mcr & UART_MCR_RTS)
+		tiocm |= TIOCM_RTS;
+	if (mcr & UART_MCR_DTR)
+		tiocm |= TIOCM_DTR;
+	if (mcr & UART_MCR_OUT1)
+		tiocm |= TIOCM_OUT1;
+	if (mcr & UART_MCR_OUT2)
+		tiocm |= TIOCM_OUT2;
+	if (mcr & UART_MCR_LOOP)
+		tiocm |= TIOCM_LOOP;
+
+	return tiocm;
+}
+
+/* MSR <-> TIOCM conversion */
+static inline int serial8250_MSR_to_TIOCM(int msr)
+{
+	int tiocm = 0;
+
+	if (msr & UART_MSR_DCD)
+		tiocm |= TIOCM_CAR;
+	if (msr & UART_MSR_RI)
+		tiocm |= TIOCM_RNG;
+	if (msr & UART_MSR_DSR)
+		tiocm |= TIOCM_DSR;
+	if (msr & UART_MSR_CTS)
+		tiocm |= TIOCM_CTS;
+
+	return tiocm;
+}
+
 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
 {
 	serial_out(up, UART_MCR, value);
+
+	if (up->gpios)
+		mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
 }
 
 static inline int serial8250_in_MCR(struct uart_8250_port *up)
 {
-	return serial_in(up, UART_MCR);
+	int mctrl;
+
+	mctrl = serial_in(up, UART_MCR);
+
+	if (up->gpios) {
+		unsigned int mctrl_gpio = 0;
+
+		mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
+		mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
+	}
+
+	return mctrl;
 }
 
 #if defined(__alpha__) && !defined(CONFIG_PCI)

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

@@ -14,6 +14,7 @@
  *	      serial8250_register_8250_port() ports
  */
 
+#include <linux/acpi.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/ioport.h>
@@ -982,6 +983,8 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 
 	uart = serial8250_find_match_or_unused(&up->port);
 	if (uart && uart->port.type != PORT_8250_CIR) {
+		struct mctrl_gpios *gpios;
+
 		if (uart->port.dev)
 			uart_remove_one_port(&serial8250_reg, &uart->port);
 
@@ -1016,6 +1019,22 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		if (up->port.flags & UPF_FIXED_TYPE)
 			uart->port.type = up->port.type;
 
+		/*
+		 * Only call mctrl_gpio_init(), if the device has no ACPI
+		 * companion device
+		 */
+		if (!has_acpi_companion(uart->port.dev)) {
+			gpios = mctrl_gpio_init(&uart->port, 0);
+			if (IS_ERR(gpios)) {
+				if (PTR_ERR(gpios) != -ENOSYS) {
+					ret = PTR_ERR(gpios);
+					goto out_unlock;
+				}
+			} else {
+				uart->gpios = gpios;
+			}
+		}
+
 		serial8250_set_defaults(uart);
 
 		/* Possibly override default I/O functions.  */
@@ -1082,6 +1101,7 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		}
 	}
 
+out_unlock:
 	mutex_unlock(&serial_mutex);
 
 	return ret;

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

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

drivers/tty/serial/8250/8250_mtk.c

@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
+#include <linux/pinctrl/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/serial_8250.h>
@@ -47,7 +48,6 @@
 #define MTK_UART_DMA_EN_RX	0x5
 
 #define MTK_UART_ESCAPE_CHAR	0x77	/* Escape char added under sw fc */
-#define MTK_UART_TX_SIZE	UART_XMIT_SIZE
 #define MTK_UART_RX_SIZE	0x8000
 #define MTK_UART_TX_TRIGGER	1
 #define MTK_UART_RX_TRIGGER	MTK_UART_RX_SIZE
@@ -70,6 +70,7 @@ struct mtk8250_data {
 #ifdef CONFIG_SERIAL_8250_DMA
 	enum dma_rx_status	rx_status;
 #endif
+	int			rx_wakeup_irq;
 };
 
 /* flow control mode */
@@ -89,28 +90,30 @@ static void mtk8250_dma_rx_complete(void *param)
 	struct mtk8250_data *data = up->port.private_data;
 	struct tty_port *tty_port = &up->port.state->port;
 	struct dma_tx_state state;
+	int copied, total, cnt;
 	unsigned char *ptr;
-	int copied;
-
-	dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr,
-				dma->rx_size, DMA_FROM_DEVICE);
-
-	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
 
 	if (data->rx_status == DMA_RX_SHUTDOWN)
 		return;
 
-	if ((data->rx_pos + state.residue) <= dma->rx_size) {
-		ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
-		copied = tty_insert_flip_string(tty_port, ptr, state.residue);
-	} else {
-		ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
-		copied = tty_insert_flip_string(tty_port, ptr,
-						dma->rx_size - data->rx_pos);
+	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
+	total = dma->rx_size - state.residue;
+	cnt = total;
+
+	if ((data->rx_pos + cnt) > dma->rx_size)
+		cnt = dma->rx_size - data->rx_pos;
+
+	ptr = (unsigned char *)(data->rx_pos + dma->rx_buf);
+	copied = tty_insert_flip_string(tty_port, ptr, cnt);
+	data->rx_pos += cnt;
+
+	if (total > cnt) {
 		ptr = (unsigned char *)(dma->rx_buf);
-		copied += tty_insert_flip_string(tty_port, ptr,
-				data->rx_pos + state.residue - dma->rx_size);
+		cnt = total - cnt;
+		copied += tty_insert_flip_string(tty_port, ptr, cnt);
+		data->rx_pos = cnt;
 	}
+
 	up->port.icount.rx += copied;
 
 	tty_flip_buffer_push(tty_port);
@@ -121,9 +124,7 @@ static void mtk8250_dma_rx_complete(void *param)
 static void mtk8250_rx_dma(struct uart_8250_port *up)
 {
 	struct uart_8250_dma *dma = up->dma;
-	struct mtk8250_data *data = up->port.private_data;
 	struct dma_async_tx_descriptor	*desc;
-	struct dma_tx_state	 state;
 
 	desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr,
 					   dma->rx_size, DMA_DEV_TO_MEM,
@@ -138,12 +139,6 @@ static void mtk8250_rx_dma(struct uart_8250_port *up)
 
 	dma->rx_cookie = dmaengine_submit(desc);
 
-	dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
-	data->rx_pos = state.residue;
-
-	dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr,
-				   dma->rx_size, DMA_FROM_DEVICE);
-
 	dma_async_issue_pending(dma->rxchan);
 }
 
@@ -156,13 +151,11 @@ static void mtk8250_dma_enable(struct uart_8250_port *up)
 	if (data->rx_status != DMA_RX_START)
 		return;
 
-	dma->rxconf.direction		= DMA_DEV_TO_MEM;
-	dma->rxconf.src_addr_width	= dma->rx_size / 1024;
-	dma->rxconf.src_addr		= dma->rx_addr;
+	dma->rxconf.src_port_window_size	= dma->rx_size;
+	dma->rxconf.src_addr				= dma->rx_addr;
 
-	dma->txconf.direction		= DMA_MEM_TO_DEV;
-	dma->txconf.dst_addr_width	= MTK_UART_TX_SIZE / 1024;
-	dma->txconf.dst_addr		= dma->tx_addr;
+	dma->txconf.dst_port_window_size	= UART_XMIT_SIZE;
+	dma->txconf.dst_addr				= dma->tx_addr;
 
 	serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR |
 		UART_FCR_CLEAR_XMIT);
@@ -551,6 +544,8 @@ static int mtk8250_probe(struct platform_device *pdev)
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 
+	data->rx_wakeup_irq = platform_get_irq(pdev, 1);
+
 	return 0;
 }
 
@@ -572,15 +567,35 @@ static int mtk8250_remove(struct platform_device *pdev)
 static int __maybe_unused mtk8250_suspend(struct device *dev)
 {
 	struct mtk8250_data *data = dev_get_drvdata(dev);
+	int irq = data->rx_wakeup_irq;
+	int err;
 
 	serial8250_suspend_port(data->line);
 
+	pinctrl_pm_select_sleep_state(dev);
+	if (irq >= 0) {
+		err = enable_irq_wake(irq);
+		if (err) {
+			dev_err(dev,
+				"failed to enable irq wake on IRQ %d: %d\n",
+				irq, err);
+			pinctrl_pm_select_default_state(dev);
+			serial8250_resume_port(data->line);
+			return err;
+		}
+	}
+
 	return 0;
 }
 
 static int __maybe_unused mtk8250_resume(struct device *dev)
 {
 	struct mtk8250_data *data = dev_get_drvdata(dev);
+	int irq = data->rx_wakeup_irq;
+
+	if (irq >= 0)
+		disable_irq_wake(irq);
+	pinctrl_pm_select_default_state(dev);
 
 	serial8250_resume_port(data->line);
 

drivers/tty/serial/8250/8250_of.c

@@ -70,9 +70,10 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 		/* Get clk rate through clk driver if present */
 		info->clk = devm_clk_get(&ofdev->dev, NULL);
 		if (IS_ERR(info->clk)) {
-			dev_warn(&ofdev->dev,
-				"clk or clock-frequency not defined\n");
 			ret = PTR_ERR(info->clk);
+			if (ret != -EPROBE_DEFER)
+				dev_warn(&ofdev->dev,
+					 "failed to get clock: %d\n", ret);
 			goto err_pmruntime;
 		}
 
@@ -205,18 +206,16 @@ err_pmruntime:
 /*
  * Try to register a serial port
  */
-static const struct of_device_id of_platform_serial_table[];
 static int of_platform_serial_probe(struct platform_device *ofdev)
 {
-	const struct of_device_id *match;
 	struct of_serial_info *info;
 	struct uart_8250_port port8250;
+	unsigned int port_type;
 	u32 tx_threshold;
-	int port_type;
 	int ret;
 
-	match = of_match_device(of_platform_serial_table, &ofdev->dev);
-	if (!match)
+	port_type = (unsigned long)of_device_get_match_data(&ofdev->dev);
+	if (port_type == PORT_UNKNOWN)
 		return -EINVAL;
 
 	if (of_property_read_bool(ofdev->dev.of_node, "used-by-rtas"))
@@ -226,7 +225,6 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
 	if (info == NULL)
 		return -ENOMEM;
 
-	port_type = (unsigned long)match->data;
 	memset(&port8250, 0, sizeof(port8250));
 	ret = of_platform_serial_setup(ofdev, port_type, &port8250.port, info);
 	if (ret)

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

@@ -141,18 +141,20 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
 
 	serial8250_do_set_mctrl(port, mctrl);
 
-	/*
-	 * Turn off autoRTS if RTS is lowered and restore autoRTS setting
-	 * if RTS is raised
-	 */
-	lcr = serial_in(up, UART_LCR);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
-		priv->efr |= UART_EFR_RTS;
-	else
-		priv->efr &= ~UART_EFR_RTS;
-	serial_out(up, UART_EFR, priv->efr);
-	serial_out(up, UART_LCR, lcr);
+	if (!up->gpios) {
+		/*
+		 * Turn off autoRTS if RTS is lowered and restore autoRTS
+		 * setting if RTS is raised
+		 */
+		lcr = serial_in(up, UART_LCR);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
+			priv->efr |= UART_EFR_RTS;
+		else
+			priv->efr &= ~UART_EFR_RTS;
+		serial_out(up, UART_EFR, priv->efr);
+		serial_out(up, UART_LCR, lcr);
+	}
 }
 
 /*
@@ -453,7 +455,8 @@ static void omap_8250_set_termios(struct uart_port *port,
 	priv->efr = 0;
 	up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
 
-	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
+	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW &&
+	    !up->gpios) {
 		/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
 		up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
 		priv->efr |= UART_EFR_CTS;
@@ -923,15 +926,13 @@ static void omap_8250_dma_tx_complete(void *param)
 		ret = omap_8250_tx_dma(p);
 		if (ret)
 			en_thri = true;
-
 	} else if (p->capabilities & UART_CAP_RPM) {
 		en_thri = true;
 	}
 
 	if (en_thri) {
 		dma->tx_err = 1;
-		p->ier |= UART_IER_THRI;
-		serial_port_out(&p->port, UART_IER, p->ier);
+		serial8250_set_THRI(p);
 	}
 
 	spin_unlock_irqrestore(&p->port.lock, flags);
@@ -959,10 +960,7 @@ static int omap_8250_tx_dma(struct uart_8250_port *p)
 			ret = -EBUSY;
 			goto err;
 		}
-		if (p->ier & UART_IER_THRI) {
-			p->ier &= ~UART_IER_THRI;
-			serial_out(p, UART_IER, p->ier);
-		}
+		serial8250_clear_THRI(p);
 		return 0;
 	}
 
@@ -1020,10 +1018,7 @@ static int omap_8250_tx_dma(struct uart_8250_port *p)
 	if (dma->tx_err)
 		dma->tx_err = 0;
 
-	if (p->ier & UART_IER_THRI) {
-		p->ier &= ~UART_IER_THRI;
-		serial_out(p, UART_IER, p->ier);
-	}
+	serial8250_clear_THRI(p);
 	if (skip_byte)
 		serial_out(p, UART_TX, xmit->buf[xmit->tail]);
 	return 0;

drivers/tty/serial/8250/8250_pci.c

@@ -1326,13 +1326,66 @@ static int pci_default_setup(struct serial_private *priv,
 
 	return setup_port(priv, port, bar, offset, board->reg_shift);
 }
+static void
+pericom_do_set_divisor(struct uart_port *port, unsigned int baud,
+			       unsigned int quot, unsigned int quot_frac)
+{
+	int scr;
+	int lcr;
+	int actual_baud;
+	int tolerance;
 
+	for (scr = 5 ; scr <= 15 ; scr++) {
+		actual_baud = 921600 * 16 / scr;
+		tolerance = actual_baud / 50;
+
+		if ((baud < actual_baud + tolerance) &&
+			(baud > actual_baud - tolerance)) {
+
+			lcr = serial_port_in(port, UART_LCR);
+			serial_port_out(port, UART_LCR, lcr | 0x80);
+
+			serial_port_out(port, UART_DLL, 1);
+			serial_port_out(port, UART_DLM, 0);
+			serial_port_out(port, 2, 16 - scr);
+			serial_port_out(port, UART_LCR, lcr);
+			return;
+		} else if (baud > actual_baud) {
+			break;
+		}
+	}
+	serial8250_do_set_divisor(port, baud, quot, quot_frac);
+}
 static int pci_pericom_setup(struct serial_private *priv,
 		  const struct pciserial_board *board,
 		  struct uart_8250_port *port, int idx)
 {
 	unsigned int bar, offset = board->first_offset, maxnr;
 
+	bar = FL_GET_BASE(board->flags);
+	if (board->flags & FL_BASE_BARS)
+		bar += idx;
+	else
+		offset += idx * board->uart_offset;
+
+
+	maxnr = (pci_resource_len(priv->dev, bar) - board->first_offset) >>
+		(board->reg_shift + 3);
+
+	if (board->flags & FL_REGION_SZ_CAP && idx >= maxnr)
+		return 1;
+
+	port->port.set_divisor = pericom_do_set_divisor;
+
+	return setup_port(priv, port, bar, offset, board->reg_shift);
+}
+
+static int pci_pericom_setup_four_at_eight(struct serial_private *priv,
+		  const struct pciserial_board *board,
+		  struct uart_8250_port *port, int idx)
+{
+	unsigned int bar, offset = board->first_offset, maxnr;
+
 	bar = FL_GET_BASE(board->flags);
 	if (board->flags & FL_BASE_BARS)
 		bar += idx;
@@ -1348,6 +1401,8 @@ static int pci_pericom_setup(struct serial_private *priv,
 	if (board->flags & FL_REGION_SZ_CAP && idx >= maxnr)
 		return 1;
 
+	port->port.set_divisor = pericom_do_set_divisor;
+
 	return setup_port(priv, port, bar, offset, board->reg_shift);
 }
 
@@ -1995,7 +2050,7 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
 		.device		= PCI_DEVICE_ID_PERICOM_PI7C9X7954,
 		.subvendor	= PCI_ANY_ID,
 		.subdevice	= PCI_ANY_ID,
-		.setup		= pci_pericom_setup,
+		.setup		= pci_pericom_setup_four_at_eight,
 	},
 	/*
 	 * PLX
@@ -2032,107 +2087,113 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
 		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SDB,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4S,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4DB,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_COM232_4,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SMDB,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_COM_4SM,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_ICM422_4,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_ICM485_4,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4S,
 		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_ICM232_4,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_MPCIE_ICM232_4,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM422_4,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM485_4,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM232_4,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_COM_4SM,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
 	{
 		.vendor     = PCI_VENDOR_ID_ACCESIO,
 		.device     = PCI_DEVICE_ID_ACCESIO_PCIE_ICM_4SM,
 		.subvendor  = PCI_ANY_ID,
 		.subdevice  = PCI_ANY_ID,
-		.setup      = pci_pericom_setup,
+		.setup      = pci_pericom_setup_four_at_eight,
 	},
-	/*
+	{
+		.vendor     = PCI_VENDOR_ID_ACCESIO,
+		.device     = PCI_ANY_ID,
+		.subvendor  = PCI_ANY_ID,
+		.subdevice  = PCI_ANY_ID,
+		.setup      = pci_pericom_setup,
+	},	/*
 	 * SBS Technologies, Inc., PMC-OCTALPRO 232
 	 */
 	{

drivers/tty/serial/8250/8250_pnp.c

@@ -462,8 +462,8 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 		return -ENODEV;
 
 	dev_dbg(&dev->dev,
-		 "Setup PNP port: port %lx, mem %pa, irq %d, type %d\n",
-		 uart.port.iobase, &uart.port.mapbase,
+		 "Setup PNP port: port %#lx, mem %#llx, irq %u, type %u\n",
+		 uart.port.iobase, (unsigned long long)uart.port.mapbase,
 		 uart.port.irq, uart.port.iotype);
 
 	if (flags & CIR_PORT) {

drivers/tty/serial/8250/8250_port.c

@@ -1502,11 +1502,8 @@ static void __stop_tx_rs485(struct uart_8250_port *p)
 
 static inline void __do_stop_tx(struct uart_8250_port *p)
 {
-	if (p->ier & UART_IER_THRI) {
-		p->ier &= ~UART_IER_THRI;
-		serial_out(p, UART_IER, p->ier);
+	if (serial8250_clear_THRI(p))
 		serial8250_rpm_put_tx(p);
-	}
 }
 
 static inline void __stop_tx(struct uart_8250_port *p)
@@ -1555,10 +1552,7 @@ static inline void __start_tx(struct uart_port *port)
 	if (up->dma && !up->dma->tx_dma(up))
 		return;
 
-	if (!(up->ier & UART_IER_THRI)) {
-		up->ier |= UART_IER_THRI;
-		serial_port_out(port, UART_IER, up->ier);
-
+	if (serial8250_set_THRI(up)) {
 		if (up->bugs & UART_BUG_TXEN) {
 			unsigned char lsr;
 
@@ -1662,6 +1656,8 @@ static void serial8250_disable_ms(struct uart_port *port)
 	if (up->bugs & UART_BUG_NOMSR)
 		return;
 
+	mctrl_gpio_disable_ms(up->gpios);
+
 	up->ier &= ~UART_IER_MSI;
 	serial_port_out(port, UART_IER, up->ier);
 }
@@ -1674,6 +1670,8 @@ static void serial8250_enable_ms(struct uart_port *port)
 	if (up->bugs & UART_BUG_NOMSR)
 		return;
 
+	mctrl_gpio_enable_ms(up->gpios);
+
 	up->ier |= UART_IER_MSI;
 
 	serial8250_rpm_get(up);
@@ -1869,13 +1867,13 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
 
 	status = serial_port_in(port, UART_LSR);
 
-	if (status & (UART_LSR_DR | UART_LSR_BI) &&
-	    iir & UART_IIR_RDI) {
+	if (status & (UART_LSR_DR | UART_LSR_BI)) {
 		if (!up->dma || handle_rx_dma(up, iir))
 			status = serial8250_rx_chars(up, status);
 	}
 	serial8250_modem_status(up);
-	if ((!up->dma || up->dma->tx_err) && (status & UART_LSR_THRE))
+	if ((!up->dma || up->dma->tx_err) && (status & UART_LSR_THRE) &&
+		(up->ier & UART_IER_THRI))
 		serial8250_tx_chars(up);
 
 	uart_unlock_and_check_sysrq(port, flags);
@@ -1944,22 +1942,17 @@ unsigned int serial8250_do_get_mctrl(struct uart_port *port)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
 	unsigned int status;
-	unsigned int ret;
+	unsigned int val;
 
 	serial8250_rpm_get(up);
 	status = serial8250_modem_status(up);
 	serial8250_rpm_put(up);
 
-	ret = 0;
-	if (status & UART_MSR_DCD)
-		ret |= TIOCM_CAR;
-	if (status & UART_MSR_RI)
-		ret |= TIOCM_RNG;
-	if (status & UART_MSR_DSR)
-		ret |= TIOCM_DSR;
-	if (status & UART_MSR_CTS)
-		ret |= TIOCM_CTS;
-	return ret;
+	val = serial8250_MSR_to_TIOCM(status);
+	if (up->gpios)
+		return mctrl_gpio_get(up->gpios, &val);
+
+	return val;
 }
 EXPORT_SYMBOL_GPL(serial8250_do_get_mctrl);
 
@@ -1973,18 +1966,9 @@ static unsigned int serial8250_get_mctrl(struct uart_port *port)
 void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
 	struct uart_8250_port *up = up_to_u8250p(port);
-	unsigned char mcr = 0;
+	unsigned char mcr;
 
-	if (mctrl & TIOCM_RTS)
-		mcr |= UART_MCR_RTS;
-	if (mctrl & TIOCM_DTR)
-		mcr |= UART_MCR_DTR;
-	if (mctrl & TIOCM_OUT1)
-		mcr |= UART_MCR_OUT1;
-	if (mctrl & TIOCM_OUT2)
-		mcr |= UART_MCR_OUT2;
-	if (mctrl & TIOCM_LOOP)
-		mcr |= UART_MCR_LOOP;
+	mcr = serial8250_TIOCM_to_MCR(mctrl);
 
 	mcr = (mcr & up->mcr_mask) | up->mcr_force | up->mcr;
 

drivers/tty/serial/8250/Kconfig

@@ -8,6 +8,7 @@ config SERIAL_8250
 	tristate "8250/16550 and compatible serial support"
 	depends on !S390
 	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
 	---help---
 	  This selects whether you want to include the driver for the standard
 	  serial ports.  The standard answer is Y.  People who might say N

drivers/tty/serial/Kconfig

@@ -457,20 +457,6 @@ config SERIAL_21285_CONSOLE
 	  your boot loader (lilo or loadlin) about how to pass options to the
 	  kernel at boot time.)
 
-config SERIAL_MPSC
-	bool "Marvell MPSC serial port support"
-	depends on MV64X60
-	select SERIAL_CORE
-	help
-	  Say Y here if you want to use the Marvell MPSC serial controller.
-
-config SERIAL_MPSC_CONSOLE
-	bool "Support for console on Marvell MPSC serial port"
-	depends on SERIAL_MPSC
-	select SERIAL_CORE_CONSOLE
-	help
-	  Say Y here if you want to support a serial console on a Marvell MPSC.
-
 config SERIAL_PXA
 	bool "PXA serial port support (DEPRECATED)"
 	depends on ARCH_PXA || ARCH_MMP

drivers/tty/serial/Makefile

@@ -46,7 +46,6 @@ obj-$(CONFIG_SERIAL_CPM) += cpm_uart/
 obj-$(CONFIG_SERIAL_IMX) += imx.o
 obj-$(CONFIG_SERIAL_MPC52xx) += mpc52xx_uart.o
 obj-$(CONFIG_SERIAL_ICOM) += icom.o
-obj-$(CONFIG_SERIAL_MPSC) += mpsc.o
 obj-$(CONFIG_SERIAL_MESON) += meson_uart.o
 obj-$(CONFIG_SERIAL_SB1250_DUART) += sb1250-duart.o
 obj-$(CONFIG_SERIAL_SCCNXP) += sccnxp.o

drivers/tty/serial/amba-pl011.c

@@ -1717,7 +1717,7 @@ static int pl011_allocate_irq(struct uart_amba_port *uap)
 {
 	pl011_write(uap->im, uap, REG_IMSC);
 
-	return request_irq(uap->port.irq, pl011_int, 0, "uart-pl011", uap);
+	return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap);
 }
 
 /*

drivers/tty/serial/cpm_uart/cpm_uart_core.c

@@ -407,7 +407,16 @@ static int cpm_uart_startup(struct uart_port *port)
 			clrbits16(&pinfo->sccp->scc_sccm, UART_SCCM_RX);
 		}
 		cpm_uart_initbd(pinfo);
-		cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
+		if (IS_SMC(pinfo)) {
+			out_be32(&pinfo->smcup->smc_rstate, 0);
+			out_be32(&pinfo->smcup->smc_tstate, 0);
+			out_be16(&pinfo->smcup->smc_rbptr,
+				 in_be16(&pinfo->smcup->smc_rbase));
+			out_be16(&pinfo->smcup->smc_tbptr,
+				 in_be16(&pinfo->smcup->smc_tbase));
+		} else {
+			cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
+		}
 	}
 	/* Install interrupt handler. */
 	retval = request_irq(port->irq, cpm_uart_int, 0, "cpm_uart", port);
@@ -567,8 +576,6 @@ static void cpm_uart_set_termios(struct uart_port *port,
 	/*
 	 * Set up parity check flag
 	 */
-#define RELEVANT_IFLAG(iflag) (iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))
-
 	port->read_status_mask = (BD_SC_EMPTY | BD_SC_OV);
 	if (termios->c_iflag & INPCK)
 		port->read_status_mask |= BD_SC_FR | BD_SC_PR;
@@ -861,16 +868,14 @@ static void cpm_uart_init_smc(struct uart_cpm_port *pinfo)
 	         (u8 __iomem *)pinfo->tx_bd_base - DPRAM_BASE);
 
 /*
- *  In case SMC1 is being relocated...
+ *  In case SMC is being relocated...
  */
-#if defined (CONFIG_I2C_SPI_SMC1_UCODE_PATCH)
 	out_be16(&up->smc_rbptr, in_be16(&pinfo->smcup->smc_rbase));
 	out_be16(&up->smc_tbptr, in_be16(&pinfo->smcup->smc_tbase));
 	out_be32(&up->smc_rstate, 0);
 	out_be32(&up->smc_tstate, 0);
 	out_be16(&up->smc_brkcr, 1);              /* number of break chars */
 	out_be16(&up->smc_brkec, 0);
-#endif
 
 	/* Set up the uart parameters in the
 	 * parameter ram.
@@ -884,8 +889,6 @@ static void cpm_uart_init_smc(struct uart_cpm_port *pinfo)
 	out_be16(&up->smc_brkec, 0);
 	out_be16(&up->smc_brkcr, 1);
 
-	cpm_line_cr_cmd(pinfo, CPM_CR_INIT_TRX);
-
 	/* Set UART mode, 8 bit, no parity, one stop.
 	 * Enable receive and transmit.
 	 */

drivers/tty/serial/digicolor-usart.c

@@ -541,7 +541,11 @@ static int __init digicolor_uart_init(void)
 	if (ret)
 		return ret;
 
-	return platform_driver_register(&digicolor_uart_platform);
+	ret = platform_driver_register(&digicolor_uart_platform);
+	if (ret)
+		uart_unregister_driver(&digicolor_uart);
+
+	return ret;
 }
 module_init(digicolor_uart_init);
 

drivers/tty/serial/fsl_lpuart.c

@@ -234,9 +234,18 @@
 
 static DEFINE_IDA(fsl_lpuart_ida);
 
+enum lpuart_type {
+	VF610_LPUART,
+	LS1021A_LPUART,
+	IMX7ULP_LPUART,
+	IMX8QXP_LPUART,
+};
+
 struct lpuart_port {
 	struct uart_port	port;
-	struct clk		*clk;
+	enum lpuart_type	devtype;
+	struct clk		*ipg_clk;
+	struct clk		*baud_clk;
 	unsigned int		txfifo_size;
 	unsigned int		rxfifo_size;
 
@@ -261,19 +270,29 @@ struct lpuart_port {
 };
 
 struct lpuart_soc_data {
-	char	iotype;
-	u8	reg_off;
+	enum lpuart_type devtype;
+	char iotype;
+	u8 reg_off;
 };
 
 static const struct lpuart_soc_data vf_data = {
+	.devtype = VF610_LPUART,
 	.iotype = UPIO_MEM,
 };
 
 static const struct lpuart_soc_data ls_data = {
+	.devtype = LS1021A_LPUART,
 	.iotype = UPIO_MEM32BE,
 };
 
-static struct lpuart_soc_data imx_data = {
+static struct lpuart_soc_data imx7ulp_data = {
+	.devtype = IMX7ULP_LPUART,
+	.iotype = UPIO_MEM32,
+	.reg_off = IMX_REG_OFF,
+};
+
+static struct lpuart_soc_data imx8qxp_data = {
+	.devtype = IMX8QXP_LPUART,
 	.iotype = UPIO_MEM32,
 	.reg_off = IMX_REG_OFF,
 };
@@ -281,7 +300,8 @@ static struct lpuart_soc_data imx_data = {
 static const struct of_device_id lpuart_dt_ids[] = {
 	{ .compatible = "fsl,vf610-lpuart",	.data = &vf_data, },
 	{ .compatible = "fsl,ls1021a-lpuart",	.data = &ls_data, },
-	{ .compatible = "fsl,imx7ulp-lpuart",	.data = &imx_data, },
+	{ .compatible = "fsl,imx7ulp-lpuart",	.data = &imx7ulp_data, },
+	{ .compatible = "fsl,imx8qxp-lpuart",	.data = &imx8qxp_data, },
 	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
@@ -289,6 +309,11 @@ MODULE_DEVICE_TABLE(of, lpuart_dt_ids);
 /* Forward declare this for the dma callbacks*/
 static void lpuart_dma_tx_complete(void *arg);
 
+static inline bool is_imx8qxp_lpuart(struct lpuart_port *sport)
+{
+	return sport->devtype == IMX8QXP_LPUART;
+}
+
 static inline u32 lpuart32_read(struct uart_port *port, u32 off)
 {
 	switch (port->iotype) {
@@ -314,6 +339,39 @@ static inline void lpuart32_write(struct uart_port *port, u32 val,
 	}
 }
 
+static int __lpuart_enable_clks(struct lpuart_port *sport, bool is_en)
+{
+	int ret = 0;
+
+	if (is_en) {
+		ret = clk_prepare_enable(sport->ipg_clk);
+		if (ret)
+			return ret;
+
+		ret = clk_prepare_enable(sport->baud_clk);
+		if (ret) {
+			clk_disable_unprepare(sport->ipg_clk);
+			return ret;
+		}
+	} else {
+		clk_disable_unprepare(sport->baud_clk);
+		clk_disable_unprepare(sport->ipg_clk);
+	}
+
+	return 0;
+}
+
+static unsigned int lpuart_get_baud_clk_rate(struct lpuart_port *sport)
+{
+	if (is_imx8qxp_lpuart(sport))
+		return clk_get_rate(sport->baud_clk);
+
+	return clk_get_rate(sport->ipg_clk);
+}
+
+#define lpuart_enable_clks(x)	__lpuart_enable_clks(x, true)
+#define lpuart_disable_clks(x)	__lpuart_enable_clks(x, false)
+
 static void lpuart_stop_tx(struct uart_port *port)
 {
 	unsigned char temp;
@@ -1040,10 +1098,8 @@ static inline int lpuart_start_rx_dma(struct lpuart_port *sport)
 		sport->rx_dma_rng_buf_len = 16;
 
 	ring->buf = kmalloc(sport->rx_dma_rng_buf_len, GFP_ATOMIC);
-	if (!ring->buf) {
-		dev_err(sport->port.dev, "Ring buf alloc failed\n");
+	if (!ring->buf)
 		return -ENOMEM;
-	}
 
 	sg_init_one(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len);
 	sg_set_buf(&sport->rx_sgl, ring->buf, sport->rx_dma_rng_buf_len);
@@ -2071,14 +2127,14 @@ lpuart_console_get_options(struct lpuart_port *sport, int *baud,
 	brfa = readb(sport->port.membase + UARTCR4);
 	brfa &= UARTCR4_BRFA_MASK;
 
-	uartclk = clk_get_rate(sport->clk);
+	uartclk = lpuart_get_baud_clk_rate(sport);
 	/*
 	 * baud = mod_clk/(16*(sbr[13]+(brfa)/32)
 	 */
 	baud_raw = uartclk / (16 * (sbr + brfa / 32));
 
 	if (*baud != baud_raw)
-		printk(KERN_INFO "Serial: Console lpuart rounded baud rate"
+		dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate"
 				"from %d to %d\n", baud_raw, *baud);
 }
 
@@ -2114,14 +2170,14 @@ lpuart32_console_get_options(struct lpuart_port *sport, int *baud,
 	bd = lpuart32_read(&sport->port, UARTBAUD);
 	bd &= UARTBAUD_SBR_MASK;
 	sbr = bd;
-	uartclk = clk_get_rate(sport->clk);
+	uartclk = lpuart_get_baud_clk_rate(sport);
 	/*
 	 * baud = mod_clk/(16*(sbr[13]+(brfa)/32)
 	 */
 	baud_raw = uartclk / (16 * sbr);
 
 	if (*baud != baud_raw)
-		printk(KERN_INFO "Serial: Console lpuart rounded baud rate"
+		dev_info(sport->port.dev, "Serial: Console lpuart rounded baud rate"
 				"from %d to %d\n", baud_raw, *baud);
 }
 
@@ -2288,6 +2344,7 @@ static int lpuart_probe(struct platform_device *pdev)
 	sport->port.mapbase = res->start;
 	sport->port.dev = &pdev->dev;
 	sport->port.type = PORT_LPUART;
+	sport->devtype = sdata->devtype;
 	ret = platform_get_irq(pdev, 0);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "cannot obtain irq\n");
@@ -2303,20 +2360,27 @@ static int lpuart_probe(struct platform_device *pdev)
 
 	sport->port.rs485_config = lpuart_config_rs485;
 
-	sport->clk = devm_clk_get(&pdev->dev, "ipg");
-	if (IS_ERR(sport->clk)) {
-		ret = PTR_ERR(sport->clk);
-		dev_err(&pdev->dev, "failed to get uart clk: %d\n", ret);
+	sport->ipg_clk = devm_clk_get(&pdev->dev, "ipg");
+	if (IS_ERR(sport->ipg_clk)) {
+		ret = PTR_ERR(sport->ipg_clk);
+		dev_err(&pdev->dev, "failed to get uart ipg clk: %d\n", ret);
 		return ret;
 	}
 
-	ret = clk_prepare_enable(sport->clk);
-	if (ret) {
-		dev_err(&pdev->dev, "failed to enable uart clk: %d\n", ret);
-		return ret;
+	sport->baud_clk = NULL;
+	if (is_imx8qxp_lpuart(sport)) {
+		sport->baud_clk = devm_clk_get(&pdev->dev, "baud");
+		if (IS_ERR(sport->baud_clk)) {
+			ret = PTR_ERR(sport->baud_clk);
+			dev_err(&pdev->dev, "failed to get uart baud clk: %d\n", ret);
+			return ret;
+		}
 	}
 
-	sport->port.uartclk = clk_get_rate(sport->clk);
+	ret = lpuart_enable_clks(sport);
+	if (ret)
+		return ret;
+	sport->port.uartclk = lpuart_get_baud_clk_rate(sport);
 
 	lpuart_ports[sport->port.line] = sport;
 
@@ -2364,7 +2428,7 @@ static int lpuart_probe(struct platform_device *pdev)
 
 failed_attach_port:
 failed_irq_request:
-	clk_disable_unprepare(sport->clk);
+	lpuart_disable_clks(sport);
 	return ret;
 }
 
@@ -2376,7 +2440,7 @@ static int lpuart_remove(struct platform_device *pdev)
 
 	ida_simple_remove(&fsl_lpuart_ida, sport->port.line);
 
-	clk_disable_unprepare(sport->clk);
+	lpuart_disable_clks(sport);
 
 	if (sport->dma_tx_chan)
 		dma_release_channel(sport->dma_tx_chan);
@@ -2441,7 +2505,7 @@ static int lpuart_suspend(struct device *dev)
 	}
 
 	if (sport->port.suspended && !irq_wake)
-		clk_disable_unprepare(sport->clk);
+		lpuart_disable_clks(sport);
 
 	return 0;
 }
@@ -2453,7 +2517,7 @@ static int lpuart_resume(struct device *dev)
 	unsigned long temp;
 
 	if (sport->port.suspended && !irq_wake)
-		clk_prepare_enable(sport->clk);
+		lpuart_enable_clks(sport);
 
 	if (lpuart_is_32(sport)) {
 		lpuart32_setup_watermark(sport);

drivers/tty/serial/imx.c

@@ -383,6 +383,7 @@ static void imx_uart_ucrs_restore(struct imx_port *sport,
 }
 #endif
 
+/* called with port.lock taken and irqs caller dependent */
 static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
 {
 	*ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
@@ -391,6 +392,7 @@ static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
 	mctrl_gpio_set(sport->gpios, sport->port.mctrl);
 }
 
+/* called with port.lock taken and irqs caller dependent */
 static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
 {
 	*ucr2 &= ~UCR2_CTSC;
@@ -400,6 +402,7 @@ static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
 	mctrl_gpio_set(sport->gpios, sport->port.mctrl);
 }
 
+/* called with port.lock taken and irqs caller dependent */
 static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)
 {
 	*ucr2 |= UCR2_CTSC;
@@ -1549,49 +1552,6 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 		old_csize = CS8;
 	}
 
-	if ((termios->c_cflag & CSIZE) == CS8)
-		ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
-	else
-		ucr2 = UCR2_SRST | UCR2_IRTS;
-
-	if (termios->c_cflag & CRTSCTS) {
-		if (sport->have_rtscts) {
-			ucr2 &= ~UCR2_IRTS;
-
-			if (port->rs485.flags & SER_RS485_ENABLED) {
-				/*
-				 * RTS is mandatory for rs485 operation, so keep
-				 * it under manual control and keep transmitter
-				 * disabled.
-				 */
-				if (port->rs485.flags &
-				    SER_RS485_RTS_AFTER_SEND)
-					imx_uart_rts_active(sport, &ucr2);
-				else
-					imx_uart_rts_inactive(sport, &ucr2);
-			} else {
-				imx_uart_rts_auto(sport, &ucr2);
-			}
-		} else {
-			termios->c_cflag &= ~CRTSCTS;
-		}
-	} else if (port->rs485.flags & SER_RS485_ENABLED) {
-		/* disable transmitter */
-		if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
-			imx_uart_rts_active(sport, &ucr2);
-		else
-			imx_uart_rts_inactive(sport, &ucr2);
-	}
-
-
-	if (termios->c_cflag & CSTOPB)
-		ucr2 |= UCR2_STPB;
-	if (termios->c_cflag & PARENB) {
-		ucr2 |= UCR2_PREN;
-		if (termios->c_cflag & PARODD)
-			ucr2 |= UCR2_PROE;
-	}
-
 	del_timer_sync(&sport->timer);
 
 	/*
@@ -1602,6 +1562,45 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	spin_lock_irqsave(&sport->port.lock, flags);
 
+	/*
+	 * Read current UCR2 and save it for future use, then clear all the bits
+	 * except those we will or may need to preserve.
+	 */
+	old_ucr2 = imx_uart_readl(sport, UCR2);
+	ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
+
+	ucr2 |= UCR2_SRST | UCR2_IRTS;
+	if ((termios->c_cflag & CSIZE) == CS8)
+		ucr2 |= UCR2_WS;
+
+	if (!sport->have_rtscts)
+		termios->c_cflag &= ~CRTSCTS;
+
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		/*
+		 * RTS is mandatory for rs485 operation, so keep
+		 * it under manual control and keep transmitter
+		 * disabled.
+		 */
+		if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
+			imx_uart_rts_active(sport, &ucr2);
+		else
+			imx_uart_rts_inactive(sport, &ucr2);
+
+	} else if (termios->c_cflag & CRTSCTS)
+		imx_uart_rts_auto(sport, &ucr2);
+
+	if (termios->c_cflag & CRTSCTS)
+		ucr2 &= ~UCR2_IRTS;
+
+	if (termios->c_cflag & CSTOPB)
+		ucr2 |= UCR2_STPB;
+	if (termios->c_cflag & PARENB) {
+		ucr2 |= UCR2_PREN;
+		if (termios->c_cflag & PARODD)
+			ucr2 |= UCR2_PROE;
+	}
+
 	sport->port.read_status_mask = 0;
 	if (termios->c_iflag & INPCK)
 		sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
@@ -1639,7 +1638,6 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 	imx_uart_writel(sport,
 			old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
 			UCR1);
-	old_ucr2 = imx_uart_readl(sport, UCR2);
 	imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2);
 
 	while (!(imx_uart_readl(sport, USR2) & USR2_TXDC))
@@ -1647,7 +1645,6 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	/* then, disable everything */
 	imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2);
-	old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
 
 	/* custom-baudrate handling */
 	div = sport->port.uartclk / (baud * 16);
@@ -1685,8 +1682,7 @@ imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	imx_uart_writel(sport, old_ucr1, UCR1);
 
-	/* set the parity, stop bits and data size */
-	imx_uart_writel(sport, ucr2 | old_ucr2, UCR2);
+	imx_uart_writel(sport, ucr2, UCR2);
 
 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
 		imx_uart_enable_ms(&sport->port);
@@ -2015,7 +2011,7 @@ imx_uart_console_get_options(struct imx_port *sport, int *baud,
 		}
 
 		if (*baud != baud_raw)
-			pr_info("Console IMX rounded baud rate from %d to %d\n",
+			dev_info(sport->port.dev, "Console IMX rounded baud rate from %d to %d\n",
 				baud_raw, *baud);
 	}
 }

drivers/tty/serial/max310x.c

@@ -258,12 +258,17 @@ struct max310x_one {
 	struct work_struct	tx_work;
 	struct work_struct	md_work;
 	struct work_struct	rs_work;
+
+	u8 wr_header;
+	u8 rd_header;
+	u8 rx_buf[MAX310X_FIFO_SIZE];
 };
+#define to_max310x_port(_port) \
+	container_of(_port, struct max310x_one, port)
 
 struct max310x_port {
 	struct max310x_devtype	*devtype;
 	struct regmap		*regmap;
-	struct mutex		mutex;
 	struct clk		*clk;
 #ifdef CONFIG_GPIOLIB
 	struct gpio_chip	gpio;
@@ -496,37 +501,48 @@ static bool max310x_reg_precious(struct device *dev, unsigned int reg)
 
 static int max310x_set_baud(struct uart_port *port, int baud)
 {
-	unsigned int mode = 0, clk = port->uartclk, div = clk / baud;
+	unsigned int mode = 0, div = 0, frac = 0, c = 0, F = 0;
 
-	/* Check for minimal value for divider */
-	if (div < 16)
-		div = 16;
-
-	if (clk % baud && (div / 16) < 0x8000) {
+	/*
+	 * Calculate the integer divisor first. Select a proper mode
+	 * in case if the requested baud is too high for the pre-defined
+	 * clocks frequency.
+	 */
+	div = port->uartclk / baud;
+	if (div < 8) {
+		/* Mode x4 */
+		c = 4;
+		mode = MAX310X_BRGCFG_4XMODE_BIT;
+	} else if (div < 16) {
 		/* Mode x2 */
+		c = 8;
 		mode = MAX310X_BRGCFG_2XMODE_BIT;
-		clk = port->uartclk * 2;
-		div = clk / baud;
-
-		if (clk % baud && (div / 16) < 0x8000) {
-			/* Mode x4 */
-			mode = MAX310X_BRGCFG_4XMODE_BIT;
-			clk = port->uartclk * 4;
-			div = clk / baud;
-		}
+	} else {
+		c = 16;
 	}
 
-	max310x_port_write(port, MAX310X_BRGDIVMSB_REG, (div / 16) >> 8);
-	max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div / 16);
-	max310x_port_write(port, MAX310X_BRGCFG_REG, (div % 16) | mode);
+	/* Calculate the divisor in accordance with the fraction coefficient */
+	div /= c;
+	F = c*baud;
 
-	return DIV_ROUND_CLOSEST(clk, div);
+	/* Calculate the baud rate fraction */
+	if (div > 0)
+		frac = (16*(port->uartclk % F)) / F;
+	else
+		div = 1;
+
+	max310x_port_write(port, MAX310X_BRGDIVMSB_REG, div >> 8);
+	max310x_port_write(port, MAX310X_BRGDIVLSB_REG, div);
+	max310x_port_write(port, MAX310X_BRGCFG_REG, frac | mode);
+
+	/* Return the actual baud rate we just programmed */
+	return (16*port->uartclk) / (c*(16*div + frac));
 }
 
 static int max310x_update_best_err(unsigned long f, long *besterr)
 {
 	/* Use baudrate 115200 for calculate error */
-	long err = f % (115200 * 16);
+	long err = f % (460800 * 16);
 
 	if ((*besterr < 0) || (*besterr > err)) {
 		*besterr = err;
@@ -607,11 +623,11 @@ static int max310x_set_ref_clk(struct device *dev, struct max310x_port *s,
 
 static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int len)
 {
-	u8 header[] = { (port->iobase + MAX310X_THR_REG) | MAX310X_WRITE_BIT };
+	struct max310x_one *one = to_max310x_port(port);
 	struct spi_transfer xfer[] = {
 		{
-			.tx_buf = &header,
-			.len = sizeof(header),
+			.tx_buf = &one->wr_header,
+			.len = sizeof(one->wr_header),
 		}, {
 			.tx_buf = txbuf,
 			.len = len,
@@ -622,11 +638,11 @@ static void max310x_batch_write(struct uart_port *port, u8 *txbuf, unsigned int
 
 static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int len)
 {
-	u8 header[] = { port->iobase + MAX310X_RHR_REG };
+	struct max310x_one *one = to_max310x_port(port);
 	struct spi_transfer xfer[] = {
 		{
-			.tx_buf = &header,
-			.len = sizeof(header),
+			.tx_buf = &one->rd_header,
+			.len = sizeof(one->rd_header),
 		}, {
 			.rx_buf = rxbuf,
 			.len = len,
@@ -637,8 +653,8 @@ static void max310x_batch_read(struct uart_port *port, u8 *rxbuf, unsigned int l
 
 static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
 {
+	struct max310x_one *one = to_max310x_port(port);
 	unsigned int sts, ch, flag, i;
-	u8 buf[MAX310X_FIFO_SIZE];
 
 	if (port->read_status_mask == MAX310X_LSR_RXOVR_BIT) {
 		/* We are just reading, happily ignoring any error conditions.
@@ -653,7 +669,7 @@ static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
 		 * */
 
 		sts = max310x_port_read(port, MAX310X_LSR_IRQSTS_REG);
-		max310x_batch_read(port, buf, rxlen);
+		max310x_batch_read(port, one->rx_buf, rxlen);
 
 		port->icount.rx += rxlen;
 		flag = TTY_NORMAL;
@@ -664,9 +680,16 @@ static void max310x_handle_rx(struct uart_port *port, unsigned int rxlen)
 			port->icount.overrun++;
 		}
 
-		for (i = 0; i < rxlen; ++i) {
-			uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT, buf[i], flag);
-		}
+		for (i = 0; i < (rxlen - 1); ++i)
+			uart_insert_char(port, sts, 0, one->rx_buf[i], flag);
+
+		/*
+		 * Handle the overrun case for the last character only, since
+		 * the RxFIFO overflow happens after it is pushed to the FIFO
+		 * tail.
+		 */
+		uart_insert_char(port, sts, MAX310X_LSR_RXOVR_BIT,
+				 one->rx_buf[rxlen], flag);
 
 	} else {
 		if (unlikely(rxlen >= port->fifosize)) {
@@ -766,10 +789,9 @@ static void max310x_handle_tx(struct uart_port *port)
 
 static void max310x_start_tx(struct uart_port *port)
 {
-	struct max310x_one *one = container_of(port, struct max310x_one, port);
+	struct max310x_one *one = to_max310x_port(port);
 
-	if (!work_pending(&one->tx_work))
-		schedule_work(&one->tx_work);
+	schedule_work(&one->tx_work);
 }
 
 static irqreturn_t max310x_port_irq(struct max310x_port *s, int portno)
@@ -826,14 +848,11 @@ static irqreturn_t max310x_ist(int irq, void *dev_id)
 	return IRQ_RETVAL(handled);
 }
 
-static void max310x_wq_proc(struct work_struct *ws)
+static void max310x_tx_proc(struct work_struct *ws)
 {
 	struct max310x_one *one = container_of(ws, struct max310x_one, tx_work);
-	struct max310x_port *s = dev_get_drvdata(one->port.dev);
 
-	mutex_lock(&s->mutex);
 	max310x_handle_tx(&one->port);
-	mutex_unlock(&s->mutex);
 }
 
 static unsigned int max310x_tx_empty(struct uart_port *port)
@@ -863,7 +882,7 @@ static void max310x_md_proc(struct work_struct *ws)
 
 static void max310x_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
-	struct max310x_one *one = container_of(port, struct max310x_one, port);
+	struct max310x_one *one = to_max310x_port(port);
 
 	schedule_work(&one->md_work);
 }
@@ -962,37 +981,36 @@ static void max310x_set_termios(struct uart_port *port,
 static void max310x_rs_proc(struct work_struct *ws)
 {
 	struct max310x_one *one = container_of(ws, struct max310x_one, rs_work);
-	unsigned int val;
+	unsigned int delay, mode1 = 0, mode2 = 0;
 
-	val = (one->port.rs485.delay_rts_before_send << 4) |
+	delay = (one->port.rs485.delay_rts_before_send << 4) |
 		one->port.rs485.delay_rts_after_send;
-	max310x_port_write(&one->port, MAX310X_HDPIXDELAY_REG, val);
+	max310x_port_write(&one->port, MAX310X_HDPIXDELAY_REG, delay);
 
 	if (one->port.rs485.flags & SER_RS485_ENABLED) {
-		max310x_port_update(&one->port, MAX310X_MODE1_REG,
-				MAX310X_MODE1_TRNSCVCTRL_BIT,
-				MAX310X_MODE1_TRNSCVCTRL_BIT);
-		max310x_port_update(&one->port, MAX310X_MODE2_REG,
-				MAX310X_MODE2_ECHOSUPR_BIT,
-				MAX310X_MODE2_ECHOSUPR_BIT);
-	} else {
-		max310x_port_update(&one->port, MAX310X_MODE1_REG,
-				MAX310X_MODE1_TRNSCVCTRL_BIT, 0);
-		max310x_port_update(&one->port, MAX310X_MODE2_REG,
-				MAX310X_MODE2_ECHOSUPR_BIT, 0);
+		mode1 = MAX310X_MODE1_TRNSCVCTRL_BIT;
+
+		if (!(one->port.rs485.flags & SER_RS485_RX_DURING_TX))
+			mode2 = MAX310X_MODE2_ECHOSUPR_BIT;
 	}
+
+	max310x_port_update(&one->port, MAX310X_MODE1_REG,
+			MAX310X_MODE1_TRNSCVCTRL_BIT, mode1);
+	max310x_port_update(&one->port, MAX310X_MODE2_REG,
+			MAX310X_MODE2_ECHOSUPR_BIT, mode2);
 }
 
 static int max310x_rs485_config(struct uart_port *port,
 				struct serial_rs485 *rs485)
 {
-	struct max310x_one *one = container_of(port, struct max310x_one, port);
+	struct max310x_one *one = to_max310x_port(port);
 
 	if ((rs485->delay_rts_before_send > 0x0f) ||
 	    (rs485->delay_rts_after_send > 0x0f))
 		return -ERANGE;
 
-	rs485->flags &= SER_RS485_RTS_ON_SEND | SER_RS485_ENABLED;
+	rs485->flags &= SER_RS485_RTS_ON_SEND | SER_RS485_RX_DURING_TX |
+			SER_RS485_ENABLED;
 	memset(rs485->padding, 0, sizeof(rs485->padding));
 	port->rs485 = *rs485;
 
@@ -1018,6 +1036,22 @@ static int max310x_startup(struct uart_port *port)
 	max310x_port_update(port, MAX310X_MODE2_REG,
 			    MAX310X_MODE2_FIFORST_BIT, 0);
 
+	/* Configure mode1/mode2 to have rs485/rs232 enabled at startup */
+	val = (clamp(port->rs485.delay_rts_before_send, 0U, 15U) << 4) |
+		clamp(port->rs485.delay_rts_after_send, 0U, 15U);
+	max310x_port_write(port, MAX310X_HDPIXDELAY_REG, val);
+
+	if (port->rs485.flags & SER_RS485_ENABLED) {
+		max310x_port_update(port, MAX310X_MODE1_REG,
+				    MAX310X_MODE1_TRNSCVCTRL_BIT,
+				    MAX310X_MODE1_TRNSCVCTRL_BIT);
+
+		if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
+			max310x_port_update(port, MAX310X_MODE2_REG,
+					    MAX310X_MODE2_ECHOSUPR_BIT,
+					    MAX310X_MODE2_ECHOSUPR_BIT);
+	}
+
 	/* Configure flow control levels */
 	/* Flow control halt level 96, resume level 48 */
 	max310x_port_write(port, MAX310X_FLOWLVL_REG,
@@ -1269,8 +1303,6 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 	uartclk = max310x_set_ref_clk(dev, s, freq, xtal);
 	dev_dbg(dev, "Reference clock set to %i Hz\n", uartclk);
 
-	mutex_init(&s->mutex);
-
 	for (i = 0; i < devtype->nr; i++) {
 		unsigned int line;
 
@@ -1298,11 +1330,15 @@ static int max310x_probe(struct device *dev, struct max310x_devtype *devtype,
 		/* Clear IRQ status register */
 		max310x_port_read(&s->p[i].port, MAX310X_IRQSTS_REG);
 		/* Initialize queue for start TX */
-		INIT_WORK(&s->p[i].tx_work, max310x_wq_proc);
+		INIT_WORK(&s->p[i].tx_work, max310x_tx_proc);
 		/* Initialize queue for changing LOOPBACK mode */
 		INIT_WORK(&s->p[i].md_work, max310x_md_proc);
 		/* Initialize queue for changing RS485 mode */
 		INIT_WORK(&s->p[i].rs_work, max310x_rs_proc);
+		/* Initialize SPI-transfer buffers */
+		s->p[i].wr_header = (s->p[i].port.iobase + MAX310X_THR_REG) |
+				    MAX310X_WRITE_BIT;
+		s->p[i].rd_header = (s->p[i].port.iobase + MAX310X_RHR_REG);
 
 		/* Register port */
 		ret = uart_add_one_port(&max310x_uart, &s->p[i].port);
@@ -1350,8 +1386,6 @@ out_uart:
 		}
 	}
 
-	mutex_destroy(&s->mutex);
-
 out_clk:
 	clk_disable_unprepare(s->clk);
 
@@ -1372,7 +1406,6 @@ static int max310x_remove(struct device *dev)
 		s->devtype->power(&s->p[i].port, 0);
 	}
 
-	mutex_destroy(&s->mutex);
 	clk_disable_unprepare(s->clk);
 
 	return 0;

drivers/tty/serial/msm_serial.c

@@ -383,10 +383,14 @@ no_rx:
 
 static inline void msm_wait_for_xmitr(struct uart_port *port)
 {
+	unsigned int timeout = 500000;
+
 	while (!(msm_read(port, UART_SR) & UART_SR_TX_EMPTY)) {
 		if (msm_read(port, UART_ISR) & UART_ISR_TX_READY)
 			break;
 		udelay(1);
+		if (!timeout--)
+			break;
 	}
 	msm_write(port, UART_CR_CMD_RESET_TX_READY, UART_CR);
 }

drivers/tty/serial/serial_core.c

@@ -1777,6 +1777,7 @@ static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
 {
 	struct uart_state *state = container_of(port, struct uart_state, port);
 	struct uart_port *uport;
+	int ret;
 
 	uport = uart_port_check(state);
 	if (!uport || uport->flags & UPF_DEAD)
@@ -1787,7 +1788,11 @@ static int uart_port_activate(struct tty_port *port, struct tty_struct *tty)
 	/*
 	 * Start up the serial port.
 	 */
-	return uart_startup(tty, state, 0);
+	ret = uart_startup(tty, state, 0);
+	if (ret > 0)
+		tty_port_set_active(port, 1);
+
+	return ret;
 }
 
 static const char *uart_type(struct uart_port *port)

drivers/tty/serial/serial_mctrl_gpio.c

@@ -12,6 +12,7 @@
 #include <linux/termios.h>
 #include <linux/serial_core.h>
 #include <linux/module.h>
+#include <linux/property.h>
 
 #include "serial_mctrl_gpio.h"
 
@@ -116,6 +117,19 @@ struct mctrl_gpios *mctrl_gpio_init_noauto(struct device *dev, unsigned int idx)
 
 	for (i = 0; i < UART_GPIO_MAX; i++) {
 		enum gpiod_flags flags;
+		char *gpio_str;
+		bool present;
+
+		/* Check if GPIO property exists and continue if not */
+		gpio_str = kasprintf(GFP_KERNEL, "%s-gpios",
+				     mctrl_gpios_desc[i].name);
+		if (!gpio_str)
+			continue;
+
+		present = device_property_present(dev, gpio_str);
+		kfree(gpio_str);
+		if (!present)
+			continue;
 
 		if (mctrl_gpios_desc[i].dir_out)
 			flags = GPIOD_OUT_LOW;

drivers/tty/serial/sh-sci.c

@@ -1398,6 +1398,7 @@ static void sci_dma_tx_work_fn(struct work_struct *work)
 	struct circ_buf *xmit = &port->state->xmit;
 	unsigned long flags;
 	dma_addr_t buf;
+	int head, tail;
 
 	/*
 	 * DMA is idle now.
@@ -1407,16 +1408,23 @@ static void sci_dma_tx_work_fn(struct work_struct *work)
 	 * consistent xmit buffer state.
 	 */
 	spin_lock_irq(&port->lock);
-	buf = s->tx_dma_addr + (xmit->tail & (UART_XMIT_SIZE - 1));
+	head = xmit->head;
+	tail = xmit->tail;
+	buf = s->tx_dma_addr + (tail & (UART_XMIT_SIZE - 1));
 	s->tx_dma_len = min_t(unsigned int,
-		CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
-		CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
-	spin_unlock_irq(&port->lock);
+		CIRC_CNT(head, tail, UART_XMIT_SIZE),
+		CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE));
+	if (!s->tx_dma_len) {
+		/* Transmit buffer has been flushed */
+		spin_unlock_irq(&port->lock);
+		return;
+	}
 
 	desc = dmaengine_prep_slave_single(chan, buf, s->tx_dma_len,
 					   DMA_MEM_TO_DEV,
 					   DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc) {
+		spin_unlock_irq(&port->lock);
 		dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n");
 		goto switch_to_pio;
 	}
@@ -1424,18 +1432,18 @@ static void sci_dma_tx_work_fn(struct work_struct *work)
 	dma_sync_single_for_device(chan->device->dev, buf, s->tx_dma_len,
 				   DMA_TO_DEVICE);
 
-	spin_lock_irq(&port->lock);
 	desc->callback = sci_dma_tx_complete;
 	desc->callback_param = s;
-	spin_unlock_irq(&port->lock);
 	s->cookie_tx = dmaengine_submit(desc);
 	if (dma_submit_error(s->cookie_tx)) {
+		spin_unlock_irq(&port->lock);
 		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");
 		goto switch_to_pio;
 	}
 
+	spin_unlock_irq(&port->lock);
 	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n",
-		__func__, xmit->buf, xmit->tail, xmit->head, s->cookie_tx);
+		__func__, xmit->buf, tail, head, s->cookie_tx);
 
 	dma_async_issue_pending(chan);
 	return;
@@ -1648,11 +1656,18 @@ static void sci_free_dma(struct uart_port *port)
 
 static void sci_flush_buffer(struct uart_port *port)
 {
+	struct sci_port *s = to_sci_port(port);
+
 	/*
 	 * In uart_flush_buffer(), the xmit circular buffer has just been
-	 * cleared, so we have to reset tx_dma_len accordingly.
+	 * cleared, so we have to reset tx_dma_len accordingly, and stop any
+	 * pending transfers
 	 */
-	to_sci_port(port)->tx_dma_len = 0;
+	s->tx_dma_len = 0;
+	if (s->chan_tx) {
+		dmaengine_terminate_async(s->chan_tx);
+		s->cookie_tx = -EINVAL;
+	}
 }
 #else /* !CONFIG_SERIAL_SH_SCI_DMA */
 static inline void sci_request_dma(struct uart_port *port)

drivers/tty/serial/stm32-usart.c

@@ -105,9 +105,7 @@ static int stm32_config_rs485(struct uart_port *port,
 	struct stm32_usart_config *cfg = &stm32_port->info->cfg;
 	u32 usartdiv, baud, cr1, cr3;
 	bool over8;
-	unsigned long flags;
 
-	spin_lock_irqsave(&port->lock, flags);
 	stm32_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
 
 	port->rs485 = *rs485conf;
@@ -147,7 +145,6 @@ static int stm32_config_rs485(struct uart_port *port,
 	}
 
 	stm32_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
-	spin_unlock_irqrestore(&port->lock, flags);
 
 	return 0;
 }
@@ -194,8 +191,8 @@ static int stm32_pending_rx(struct uart_port *port, u32 *sr, int *last_res,
 	return 0;
 }
 
-static unsigned long
-stm32_get_char(struct uart_port *port, u32 *sr, int *last_res)
+static unsigned long stm32_get_char(struct uart_port *port, u32 *sr,
+				    int *last_res)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -205,10 +202,13 @@ stm32_get_char(struct uart_port *port, u32 *sr, int *last_res)
 		c = stm32_port->rx_buf[RX_BUF_L - (*last_res)--];
 		if ((*last_res) == 0)
 			*last_res = RX_BUF_L;
-		return c;
 	} else {
-		return readl_relaxed(port->membase + ofs->rdr);
+		c = readl_relaxed(port->membase + ofs->rdr);
+		/* apply RDR data mask */
+		c &= stm32_port->rdr_mask;
 	}
+
+	return c;
 }
 
 static void stm32_receive_chars(struct uart_port *port, bool threaded)
@@ -225,35 +225,51 @@ static void stm32_receive_chars(struct uart_port *port, bool threaded)
 
 	while (stm32_pending_rx(port, &sr, &stm32_port->last_res, threaded)) {
 		sr |= USART_SR_DUMMY_RX;
-		c = stm32_get_char(port, &sr, &stm32_port->last_res);
 		flag = TTY_NORMAL;
-		port->icount.rx++;
 
+		/*
+		 * Status bits has to be cleared before reading the RDR:
+		 * In FIFO mode, reading the RDR will pop the next data
+		 * (if any) along with its status bits into the SR.
+		 * Not doing so leads to misalignement between RDR and SR,
+		 * and clear status bits of the next rx data.
+		 *
+		 * Clear errors flags for stm32f7 and stm32h7 compatible
+		 * devices. On stm32f4 compatible devices, the error bit is
+		 * cleared by the sequence [read SR - read DR].
+		 */
+		if ((sr & USART_SR_ERR_MASK) && ofs->icr != UNDEF_REG)
+			stm32_clr_bits(port, ofs->icr, USART_ICR_ORECF |
+				       USART_ICR_PECF | USART_ICR_FECF);
+
+		c = stm32_get_char(port, &sr, &stm32_port->last_res);
+		port->icount.rx++;
 		if (sr & USART_SR_ERR_MASK) {
-			if (sr & USART_SR_LBD) {
-				port->icount.brk++;
-				if (uart_handle_break(port))
-					continue;
-			} else if (sr & USART_SR_ORE) {
-				if (ofs->icr != UNDEF_REG)
-					writel_relaxed(USART_ICR_ORECF,
-						       port->membase +
-						       ofs->icr);
+			if (sr & USART_SR_ORE) {
 				port->icount.overrun++;
 			} else if (sr & USART_SR_PE) {
 				port->icount.parity++;
 			} else if (sr & USART_SR_FE) {
-				port->icount.frame++;
+				/* Break detection if character is null */
+				if (!c) {
+					port->icount.brk++;
+					if (uart_handle_break(port))
+						continue;
+				} else {
+					port->icount.frame++;
+				}
 			}
 
 			sr &= port->read_status_mask;
 
-			if (sr & USART_SR_LBD)
-				flag = TTY_BREAK;
-			else if (sr & USART_SR_PE)
+			if (sr & USART_SR_PE) {
 				flag = TTY_PARITY;
-			else if (sr & USART_SR_FE)
-				flag = TTY_FRAME;
+			} else if (sr & USART_SR_FE) {
+				if (!c)
+					flag = TTY_BREAK;
+				else
+					flag = TTY_FRAME;
+			}
 		}
 
 		if (uart_handle_sysrq_char(port, c))
@@ -271,21 +287,6 @@ static void stm32_tx_dma_complete(void *arg)
 	struct uart_port *port = arg;
 	struct stm32_port *stm32port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32port->info->ofs;
-	unsigned int isr;
-	int ret;
-
-	ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr,
-						isr,
-						(isr & USART_SR_TC),
-						10, 100000);
-
-	if (ret)
-		dev_err(port->dev, "terminal count not set\n");
-
-	if (ofs->icr == UNDEF_REG)
-		stm32_clr_bits(port, ofs->isr, USART_SR_TC);
-	else
-		stm32_set_bits(port, ofs->icr, USART_CR_TC);
 
 	stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
 	stm32port->tx_dma_busy = false;
@@ -294,32 +295,57 @@ static void stm32_tx_dma_complete(void *arg)
 	stm32_transmit_chars(port);
 }
 
+static void stm32_tx_interrupt_enable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	/*
+	 * Enables TX FIFO threashold irq when FIFO is enabled,
+	 * or TX empty irq when FIFO is disabled
+	 */
+	if (stm32_port->fifoen)
+		stm32_set_bits(port, ofs->cr3, USART_CR3_TXFTIE);
+	else
+		stm32_set_bits(port, ofs->cr1, USART_CR1_TXEIE);
+}
+
+static void stm32_tx_interrupt_disable(struct uart_port *port)
+{
+	struct stm32_port *stm32_port = to_stm32_port(port);
+	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
+
+	if (stm32_port->fifoen)
+		stm32_clr_bits(port, ofs->cr3, USART_CR3_TXFTIE);
+	else
+		stm32_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
+}
+
 static void stm32_transmit_chars_pio(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	struct circ_buf *xmit = &port->state->xmit;
-	unsigned int isr;
-	int ret;
 
 	if (stm32_port->tx_dma_busy) {
 		stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAT);
 		stm32_port->tx_dma_busy = false;
 	}
 
-	ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr,
-						isr,
-						(isr & USART_SR_TXE),
-						10, 100000);
+	while (!uart_circ_empty(xmit)) {
+		/* Check that TDR is empty before filling FIFO */
+		if (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_TXE))
+			break;
+		writel_relaxed(xmit->buf[xmit->tail], port->membase + ofs->tdr);
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		port->icount.tx++;
+	}
 
-	if (ret)
-		dev_err(port->dev, "tx empty not set\n");
-
-	stm32_set_bits(port, ofs->cr1, USART_CR1_TXEIE);
-
-	writel_relaxed(xmit->buf[xmit->tail], port->membase + ofs->tdr);
-	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
-	port->icount.tx++;
+	/* rely on TXE irq (mask or unmask) for sending remaining data */
+	if (uart_circ_empty(xmit))
+		stm32_tx_interrupt_disable(port);
+	else
+		stm32_tx_interrupt_enable(port);
 }
 
 static void stm32_transmit_chars_dma(struct uart_port *port)
@@ -377,7 +403,6 @@ static void stm32_transmit_chars_dma(struct uart_port *port)
 	/* Issue pending DMA TX requests */
 	dma_async_issue_pending(stm32port->tx_ch);
 
-	stm32_clr_bits(port, ofs->isr, USART_SR_TC);
 	stm32_set_bits(port, ofs->cr3, USART_CR3_DMAT);
 
 	xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
@@ -401,15 +426,15 @@ static void stm32_transmit_chars(struct uart_port *port)
 		return;
 	}
 
-	if (uart_tx_stopped(port)) {
-		stm32_stop_tx(port);
+	if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
+		stm32_tx_interrupt_disable(port);
 		return;
 	}
 
-	if (uart_circ_empty(xmit)) {
-		stm32_stop_tx(port);
-		return;
-	}
+	if (ofs->icr == UNDEF_REG)
+		stm32_clr_bits(port, ofs->isr, USART_SR_TC);
+	else
+		stm32_set_bits(port, ofs->icr, USART_ICR_TCCF);
 
 	if (stm32_port->tx_ch)
 		stm32_transmit_chars_dma(port);
@@ -420,7 +445,7 @@ static void stm32_transmit_chars(struct uart_port *port)
 		uart_write_wakeup(port);
 
 	if (uart_circ_empty(xmit))
-		stm32_stop_tx(port);
+		stm32_tx_interrupt_disable(port);
 }
 
 static irqreturn_t stm32_interrupt(int irq, void *ptr)
@@ -434,6 +459,10 @@ static irqreturn_t stm32_interrupt(int irq, void *ptr)
 
 	sr = readl_relaxed(port->membase + ofs->isr);
 
+	if ((sr & USART_SR_RTOF) && ofs->icr != UNDEF_REG)
+		writel_relaxed(USART_ICR_RTOCF,
+			       port->membase + ofs->icr);
+
 	if ((sr & USART_SR_WUF) && (ofs->icr != UNDEF_REG))
 		writel_relaxed(USART_ICR_WUCF,
 			       port->membase + ofs->icr);
@@ -495,10 +524,7 @@ static unsigned int stm32_get_mctrl(struct uart_port *port)
 /* Transmit stop */
 static void stm32_stop_tx(struct uart_port *port)
 {
-	struct stm32_port *stm32_port = to_stm32_port(port);
-	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
-
-	stm32_clr_bits(port, ofs->cr1, USART_CR1_TXEIE);
+	stm32_tx_interrupt_disable(port);
 }
 
 /* There are probably characters waiting to be transmitted. */
@@ -520,7 +546,10 @@ static void stm32_throttle(struct uart_port *port)
 	unsigned long flags;
 
 	spin_lock_irqsave(&port->lock, flags);
-	stm32_clr_bits(port, ofs->cr1, USART_CR1_RXNEIE);
+	stm32_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
+	if (stm32_port->cr3_irq)
+		stm32_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
+
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
@@ -532,7 +561,10 @@ static void stm32_unthrottle(struct uart_port *port)
 	unsigned long flags;
 
 	spin_lock_irqsave(&port->lock, flags);
-	stm32_set_bits(port, ofs->cr1, USART_CR1_RXNEIE);
+	stm32_set_bits(port, ofs->cr1, stm32_port->cr1_irq);
+	if (stm32_port->cr3_irq)
+		stm32_set_bits(port, ofs->cr3, stm32_port->cr3_irq);
+
 	spin_unlock_irqrestore(&port->lock, flags);
 }
 
@@ -542,7 +574,10 @@ static void stm32_stop_rx(struct uart_port *port)
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 
-	stm32_clr_bits(port, ofs->cr1, USART_CR1_RXNEIE);
+	stm32_clr_bits(port, ofs->cr1, stm32_port->cr1_irq);
+	if (stm32_port->cr3_irq)
+		stm32_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
+
 }
 
 /* Handle breaks - ignored by us */
@@ -554,7 +589,6 @@ static int stm32_startup(struct uart_port *port)
 {
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
-	struct stm32_usart_config *cfg = &stm32_port->info->cfg;
 	const char *name = to_platform_device(port->dev)->name;
 	u32 val;
 	int ret;
@@ -565,16 +599,21 @@ static int stm32_startup(struct uart_port *port)
 	if (ret)
 		return ret;
 
-	if (cfg->has_wakeup && stm32_port->wakeirq >= 0) {
-		ret = dev_pm_set_dedicated_wake_irq(port->dev,
-						    stm32_port->wakeirq);
-		if (ret) {
-			free_irq(port->irq, port);
-			return ret;
-		}
+	/* RX FIFO Flush */
+	if (ofs->rqr != UNDEF_REG)
+		stm32_set_bits(port, ofs->rqr, USART_RQR_RXFRQ);
+
+	/* Tx and RX FIFO configuration */
+	if (stm32_port->fifoen) {
+		val = readl_relaxed(port->membase + ofs->cr3);
+		val &= ~(USART_CR3_TXFTCFG_MASK | USART_CR3_RXFTCFG_MASK);
+		val |= USART_CR3_TXFTCFG_HALF << USART_CR3_TXFTCFG_SHIFT;
+		val |= USART_CR3_RXFTCFG_HALF << USART_CR3_RXFTCFG_SHIFT;
+		writel_relaxed(val, port->membase + ofs->cr3);
 	}
 
-	val = USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
+	/* RX FIFO enabling */
+	val = stm32_port->cr1_irq | USART_CR1_RE;
 	if (stm32_port->fifoen)
 		val |= USART_CR1_FIFOEN;
 	stm32_set_bits(port, ofs->cr1, val);
@@ -587,18 +626,57 @@ static void stm32_shutdown(struct uart_port *port)
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	struct stm32_usart_config *cfg = &stm32_port->info->cfg;
-	u32 val;
+	u32 val, isr;
+	int ret;
 
-	val = USART_CR1_TXEIE | USART_CR1_RXNEIE | USART_CR1_TE | USART_CR1_RE;
+	val = USART_CR1_TXEIE | USART_CR1_TE;
+	val |= stm32_port->cr1_irq | USART_CR1_RE;
 	val |= BIT(cfg->uart_enable_bit);
 	if (stm32_port->fifoen)
 		val |= USART_CR1_FIFOEN;
+
+	ret = readl_relaxed_poll_timeout(port->membase + ofs->isr,
+					 isr, (isr & USART_SR_TC),
+					 10, 100000);
+
+	if (ret)
+		dev_err(port->dev, "transmission complete not set\n");
+
 	stm32_clr_bits(port, ofs->cr1, val);
 
-	dev_pm_clear_wake_irq(port->dev);
 	free_irq(port->irq, port);
 }
 
+static unsigned int stm32_get_databits(struct ktermios *termios)
+{
+	unsigned int bits;
+
+	tcflag_t cflag = termios->c_cflag;
+
+	switch (cflag & CSIZE) {
+	/*
+	 * CSIZE settings are not necessarily supported in hardware.
+	 * CSIZE unsupported configurations are handled here to set word length
+	 * to 8 bits word as default configuration and to print debug message.
+	 */
+	case CS5:
+		bits = 5;
+		break;
+	case CS6:
+		bits = 6;
+		break;
+	case CS7:
+		bits = 7;
+		break;
+	/* default including CS8 */
+	default:
+		bits = 8;
+		break;
+	}
+
+	return bits;
+}
+
 static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 			    struct ktermios *old)
 {
@@ -606,7 +684,7 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
 	struct stm32_usart_config *cfg = &stm32_port->info->cfg;
 	struct serial_rs485 *rs485conf = &port->rs485;
-	unsigned int baud;
+	unsigned int baud, bits;
 	u32 usartdiv, mantissa, fraction, oversampling;
 	tcflag_t cflag = termios->c_cflag;
 	u32 cr1, cr2, cr3;
@@ -622,26 +700,64 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 	/* Stop serial port and reset value */
 	writel_relaxed(0, port->membase + ofs->cr1);
 
-	cr1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_RXNEIE;
+	/* flush RX & TX FIFO */
+	if (ofs->rqr != UNDEF_REG)
+		stm32_set_bits(port, ofs->rqr,
+			       USART_RQR_TXFRQ | USART_RQR_RXFRQ);
 
+	cr1 = USART_CR1_TE | USART_CR1_RE;
 	if (stm32_port->fifoen)
 		cr1 |= USART_CR1_FIFOEN;
 	cr2 = 0;
-	cr3 = 0;
+	cr3 = readl_relaxed(port->membase + ofs->cr3);
+	cr3 &= USART_CR3_TXFTIE | USART_CR3_RXFTCFG_MASK | USART_CR3_RXFTIE
+		| USART_CR3_TXFTCFG_MASK;
 
 	if (cflag & CSTOPB)
 		cr2 |= USART_CR2_STOP_2B;
 
+	bits = stm32_get_databits(termios);
+	stm32_port->rdr_mask = (BIT(bits) - 1);
+
 	if (cflag & PARENB) {
+		bits++;
 		cr1 |= USART_CR1_PCE;
-		if ((cflag & CSIZE) == CS8) {
-			if (cfg->has_7bits_data)
-				cr1 |= USART_CR1_M0;
-			else
-				cr1 |= USART_CR1_M;
-		}
 	}
 
+	/*
+	 * Word length configuration:
+	 * CS8 + parity, 9 bits word aka [M1:M0] = 0b01
+	 * CS7 or (CS6 + parity), 7 bits word aka [M1:M0] = 0b10
+	 * CS8 or (CS7 + parity), 8 bits word aka [M1:M0] = 0b00
+	 * M0 and M1 already cleared by cr1 initialization.
+	 */
+	if (bits == 9)
+		cr1 |= USART_CR1_M0;
+	else if ((bits == 7) && cfg->has_7bits_data)
+		cr1 |= USART_CR1_M1;
+	else if (bits != 8)
+		dev_dbg(port->dev, "Unsupported data bits config: %u bits\n"
+			, bits);
+
+	if (ofs->rtor != UNDEF_REG && (stm32_port->rx_ch ||
+				       stm32_port->fifoen)) {
+		if (cflag & CSTOPB)
+			bits = bits + 3; /* 1 start bit + 2 stop bits */
+		else
+			bits = bits + 2; /* 1 start bit + 1 stop bit */
+
+		/* RX timeout irq to occur after last stop bit + bits */
+		stm32_port->cr1_irq = USART_CR1_RTOIE;
+		writel_relaxed(bits, port->membase + ofs->rtor);
+		cr2 |= USART_CR2_RTOEN;
+		/* Not using dma, enable fifo threshold irq */
+		if (!stm32_port->rx_ch)
+			stm32_port->cr3_irq =  USART_CR3_RXFTIE;
+	}
+
+	cr1 |= stm32_port->cr1_irq;
+	cr3 |= stm32_port->cr3_irq;
+
 	if (cflag & PARODD)
 		cr1 |= USART_CR1_PS;
 
@@ -679,14 +795,14 @@ static void stm32_set_termios(struct uart_port *port, struct ktermios *termios,
 	if (termios->c_iflag & INPCK)
 		port->read_status_mask |= USART_SR_PE | USART_SR_FE;
 	if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
-		port->read_status_mask |= USART_SR_LBD;
+		port->read_status_mask |= USART_SR_FE;
 
 	/* Characters to ignore */
 	port->ignore_status_mask = 0;
 	if (termios->c_iflag & IGNPAR)
 		port->ignore_status_mask = USART_SR_PE | USART_SR_FE;
 	if (termios->c_iflag & IGNBRK) {
-		port->ignore_status_mask |= USART_SR_LBD;
+		port->ignore_status_mask |= USART_SR_FE;
 		/*
 		 * If we're ignoring parity and break indicators,
 		 * ignore overruns too (for real raw support).
@@ -808,12 +924,32 @@ static int stm32_init_port(struct stm32_port *stm32port,
 	port->flags	= UPF_BOOT_AUTOCONF;
 	port->ops	= &stm32_uart_ops;
 	port->dev	= &pdev->dev;
-	port->irq	= platform_get_irq(pdev, 0);
+	port->fifosize	= stm32port->info->cfg.fifosize;
+
+	ret = platform_get_irq(pdev, 0);
+	if (ret <= 0) {
+		if (ret != -EPROBE_DEFER)
+			dev_err(&pdev->dev, "Can't get event IRQ: %d\n", ret);
+		return ret ? ret : -ENODEV;
+	}
+	port->irq = ret;
+
 	port->rs485_config = stm32_config_rs485;
 
 	stm32_init_rs485(port, pdev);
 
-	stm32port->wakeirq = platform_get_irq(pdev, 1);
+	if (stm32port->info->cfg.has_wakeup) {
+		stm32port->wakeirq = platform_get_irq(pdev, 1);
+		if (stm32port->wakeirq <= 0 && stm32port->wakeirq != -ENXIO) {
+			if (stm32port->wakeirq != -EPROBE_DEFER)
+				dev_err(&pdev->dev,
+					"Can't get event wake IRQ: %d\n",
+					stm32port->wakeirq);
+			return stm32port->wakeirq ? stm32port->wakeirq :
+				-ENODEV;
+		}
+	}
+
 	stm32port->fifoen = stm32port->info->cfg.has_fifo;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -862,6 +998,8 @@ static struct stm32_port *stm32_of_get_stm32_port(struct platform_device *pdev)
 	stm32_ports[id].hw_flow_control = of_property_read_bool(np,
 							"st,hw-flow-ctrl");
 	stm32_ports[id].port.line = id;
+	stm32_ports[id].cr1_irq = USART_CR1_RXNEIE;
+	stm32_ports[id].cr3_irq = 0;
 	stm32_ports[id].last_res = RX_BUF_L;
 	return &stm32_ports[id];
 }
@@ -1020,15 +1158,22 @@ static int stm32_serial_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	if (stm32port->info->cfg.has_wakeup && stm32port->wakeirq >= 0) {
+	if (stm32port->wakeirq > 0) {
 		ret = device_init_wakeup(&pdev->dev, true);
 		if (ret)
 			goto err_uninit;
+
+		ret = dev_pm_set_dedicated_wake_irq(&pdev->dev,
+						    stm32port->wakeirq);
+		if (ret)
+			goto err_nowup;
+
+		device_set_wakeup_enable(&pdev->dev, false);
 	}
 
 	ret = uart_add_one_port(&stm32_usart_driver, &stm32port->port);
 	if (ret)
-		goto err_nowup;
+		goto err_wirq;
 
 	ret = stm32_of_dma_rx_probe(stm32port, pdev);
 	if (ret)
@@ -1042,8 +1187,12 @@ static int stm32_serial_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_wirq:
+	if (stm32port->wakeirq > 0)
+		dev_pm_clear_wake_irq(&pdev->dev);
+
 err_nowup:
-	if (stm32port->info->cfg.has_wakeup && stm32port->wakeirq >= 0)
+	if (stm32port->wakeirq > 0)
 		device_init_wakeup(&pdev->dev, false);
 
 err_uninit:
@@ -1057,7 +1206,6 @@ static int stm32_serial_remove(struct platform_device *pdev)
 	struct uart_port *port = platform_get_drvdata(pdev);
 	struct stm32_port *stm32_port = to_stm32_port(port);
 	struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
-	struct stm32_usart_config *cfg = &stm32_port->info->cfg;
 
 	stm32_clr_bits(port, ofs->cr3, USART_CR3_DMAR);
 
@@ -1079,8 +1227,10 @@ static int stm32_serial_remove(struct platform_device *pdev)
 				  TX_BUF_L, stm32_port->tx_buf,
 				  stm32_port->tx_dma_buf);
 
-	if (cfg->has_wakeup && stm32_port->wakeirq >= 0)
+	if (stm32_port->wakeirq > 0) {
+		dev_pm_clear_wake_irq(&pdev->dev);
 		device_init_wakeup(&pdev->dev, false);
+	}
 
 	clk_disable_unprepare(stm32_port->clk);
 
@@ -1195,7 +1345,7 @@ static void stm32_serial_enable_wakeup(struct uart_port *port, bool enable)
 	struct stm32_usart_config *cfg = &stm32_port->info->cfg;
 	u32 val;
 
-	if (!cfg->has_wakeup || stm32_port->wakeirq < 0)
+	if (stm32_port->wakeirq <= 0)
 		return;
 
 	if (enable) {

drivers/tty/serial/stm32-usart.h

@@ -27,6 +27,7 @@ struct stm32_usart_config {
 	bool has_7bits_data;
 	bool has_wakeup;
 	bool has_fifo;
+	int fifosize;
 };
 
 struct stm32_usart_info {
@@ -54,6 +55,7 @@ struct stm32_usart_info stm32f4_info = {
 	.cfg = {
 		.uart_enable_bit = 13,
 		.has_7bits_data = false,
+		.fifosize = 1,
 	}
 };
 
@@ -74,6 +76,7 @@ struct stm32_usart_info stm32f7_info = {
 	.cfg = {
 		.uart_enable_bit = 0,
 		.has_7bits_data = true,
+		.fifosize = 1,
 	}
 };
 
@@ -96,6 +99,7 @@ struct stm32_usart_info stm32h7_info = {
 		.has_7bits_data = true,
 		.has_wakeup = true,
 		.has_fifo = true,
+		.fifosize = 16,
 	}
 };
 
@@ -108,7 +112,6 @@ struct stm32_usart_info stm32h7_info = {
 #define USART_SR_RXNE		BIT(5)
 #define USART_SR_TC		BIT(6)
 #define USART_SR_TXE		BIT(7)
-#define USART_SR_LBD		BIT(8)
 #define USART_SR_CTSIF		BIT(9)
 #define USART_SR_CTS		BIT(10)		/* F7 */
 #define USART_SR_RTOF		BIT(11)		/* F7 */
@@ -120,8 +123,7 @@ struct stm32_usart_info stm32h7_info = {
 #define USART_SR_SBKF		BIT(18)		/* F7 */
 #define USART_SR_WUF		BIT(20)		/* H7 */
 #define USART_SR_TEACK		BIT(21)		/* F7 */
-#define USART_SR_ERR_MASK	(USART_SR_LBD | USART_SR_ORE | \
-				 USART_SR_FE | USART_SR_PE)
+#define USART_SR_ERR_MASK	(USART_SR_ORE | USART_SR_FE | USART_SR_PE)
 /* Dummy bits */
 #define USART_SR_DUMMY_RX	BIT(16)
 
@@ -151,8 +153,7 @@ struct stm32_usart_info stm32h7_info = {
 #define USART_CR1_PS		BIT(9)
 #define USART_CR1_PCE		BIT(10)
 #define USART_CR1_WAKE		BIT(11)
-#define USART_CR1_M		BIT(12)
-#define USART_CR1_M0		BIT(12)		/* F7 */
+#define USART_CR1_M0		BIT(12)		/* F7 (CR1_M for F4) */
 #define USART_CR1_MME		BIT(13)		/* F7 */
 #define USART_CR1_CMIE		BIT(14)		/* F7 */
 #define USART_CR1_OVER8		BIT(15)
@@ -169,8 +170,6 @@ struct stm32_usart_info stm32h7_info = {
 /* USART_CR2 */
 #define USART_CR2_ADD_MASK	GENMASK(3, 0)	/* F4 */
 #define USART_CR2_ADDM7		BIT(4)		/* F7 */
-#define USART_CR2_LBDL		BIT(5)
-#define USART_CR2_LBDIE		BIT(6)
 #define USART_CR2_LBCL		BIT(8)
 #define USART_CR2_CPHA		BIT(9)
 #define USART_CR2_CPOL		BIT(10)
@@ -209,6 +208,19 @@ struct stm32_usart_info stm32h7_info = {
 #define USART_CR3_WUS_MASK	GENMASK(21, 20)	/* H7 */
 #define USART_CR3_WUS_START_BIT	BIT(21)		/* H7 */
 #define USART_CR3_WUFIE		BIT(22)		/* H7 */
+#define USART_CR3_TXFTIE	BIT(23)		/* H7 */
+#define USART_CR3_TCBGTIE	BIT(24)		/* H7 */
+#define USART_CR3_RXFTCFG_MASK	GENMASK(27, 25)	/* H7 */
+#define USART_CR3_RXFTCFG_SHIFT	25		/* H7 */
+#define USART_CR3_RXFTIE	BIT(28)		/* H7 */
+#define USART_CR3_TXFTCFG_MASK	GENMASK(31, 29)	/* H7 */
+#define USART_CR3_TXFTCFG_SHIFT	29		/* H7 */
+
+/* TX FIFO threashold set to half of its depth */
+#define USART_CR3_TXFTCFG_HALF	0x2
+
+/* RX FIFO threashold set to half of its depth */
+#define USART_CR3_RXFTCFG_HALF	0x2
 
 /* USART_GTPR */
 #define USART_GTPR_PSC_MASK	GENMASK(7, 0)
@@ -227,12 +239,10 @@ struct stm32_usart_info stm32h7_info = {
 
 /* USART_ICR */
 #define USART_ICR_PECF		BIT(0)		/* F7 */
-#define USART_ICR_FFECF		BIT(1)		/* F7 */
-#define USART_ICR_NCF		BIT(2)		/* F7 */
+#define USART_ICR_FECF		BIT(1)		/* F7 */
 #define USART_ICR_ORECF		BIT(3)		/* F7 */
 #define USART_ICR_IDLECF	BIT(4)		/* F7 */
 #define USART_ICR_TCCF		BIT(6)		/* F7 */
-#define USART_ICR_LBDCF		BIT(8)		/* F7 */
 #define USART_ICR_CTSCF		BIT(9)		/* F7 */
 #define USART_ICR_RTOCF		BIT(11)		/* F7 */
 #define USART_ICR_EOBCF		BIT(12)		/* F7 */
@@ -256,11 +266,14 @@ struct stm32_port {
 	struct dma_chan *tx_ch;  /* dma tx channel            */
 	dma_addr_t tx_dma_buf;   /* dma tx buffer bus address */
 	unsigned char *tx_buf;   /* dma tx buffer cpu address */
+	u32 cr1_irq;		 /* USART_CR1_RXNEIE or RTOIE */
+	u32 cr3_irq;		 /* USART_CR3_RXFTIE */
 	int last_res;
 	bool tx_dma_busy;	 /* dma tx busy               */
 	bool hw_flow_control;
 	bool fifoen;
 	int wakeirq;
+	int rdr_mask;		/* receive data register mask */
 };
 
 static struct stm32_port stm32_ports[STM32_MAX_PORTS];

drivers/tty/serial/xilinx_uartps.c

@@ -26,21 +26,23 @@
 #include <linux/of.h>
 #include <linux/module.h>
 #include <linux/pm_runtime.h>
+#include <linux/iopoll.h>
 
 #define CDNS_UART_TTY_NAME	"ttyPS"
 #define CDNS_UART_NAME		"xuartps"
-#define CDNS_UART_MAJOR		0	/* use dynamic node allocation */
 #define CDNS_UART_FIFO_SIZE	64	/* FIFO size */
 #define CDNS_UART_REGISTER_SPACE	0x1000
+#define TX_TIMEOUT		500000
 
 /* Rx Trigger level */
 static int rx_trigger_level = 56;
-module_param(rx_trigger_level, uint, S_IRUGO);
+static int uartps_major;
+module_param(rx_trigger_level, uint, 0444);
 MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes");
 
 /* Rx Timeout */
 static int rx_timeout = 10;
-module_param(rx_timeout, uint, S_IRUGO);
+module_param(rx_timeout, uint, 0444);
 MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
 
 /* Register offsets for the UART. */
@@ -199,7 +201,7 @@ struct cdns_platform_data {
 	u32 quirks;
 };
 #define to_cdns_uart(_nb) container_of(_nb, struct cdns_uart, \
-		clk_rate_change_nb);
+		clk_rate_change_nb)
 
 /**
  * cdns_uart_handle_rx - Handle the received bytes along with Rx errors.
@@ -312,15 +314,16 @@ static void cdns_uart_handle_tx(void *dev_id)
 	} else {
 		numbytes = port->fifosize;
 		while (numbytes && !uart_circ_empty(&port->state->xmit) &&
-		       !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) {
+		       !(readl(port->membase + CDNS_UART_SR) &
+						CDNS_UART_SR_TXFULL)) {
 			/*
 			 * Get the data from the UART circular buffer
 			 * and write it to the cdns_uart's TX_FIFO
 			 * register.
 			 */
 			writel(
-				port->state->xmit.buf[port->state->xmit.
-				tail], port->membase + CDNS_UART_FIFO);
+				port->state->xmit.buf[port->state->xmit.tail],
+					port->membase + CDNS_UART_FIFO);
 
 			port->icount.tx++;
 
@@ -684,18 +687,21 @@ static void cdns_uart_set_termios(struct uart_port *port,
 	unsigned int cval = 0;
 	unsigned int baud, minbaud, maxbaud;
 	unsigned long flags;
-	unsigned int ctrl_reg, mode_reg;
-
-	spin_lock_irqsave(&port->lock, flags);
+	unsigned int ctrl_reg, mode_reg, val;
+	int err;
 
 	/* Wait for the transmit FIFO to empty before making changes */
 	if (!(readl(port->membase + CDNS_UART_CR) &
 				CDNS_UART_CR_TX_DIS)) {
-		while (!(readl(port->membase + CDNS_UART_SR) &
-				CDNS_UART_SR_TXEMPTY)) {
-			cpu_relax();
+		err = readl_poll_timeout(port->membase + CDNS_UART_SR,
+					 val, (val & CDNS_UART_SR_TXEMPTY),
+					 1000, TX_TIMEOUT);
+		if (err) {
+			dev_err(port->dev, "timed out waiting for tx empty");
+			return;
 		}
 	}
+	spin_lock_irqsave(&port->lock, flags);
 
 	/* Disable the TX and RX to set baud rate */
 	ctrl_reg = readl(port->membase + CDNS_UART_CR);
@@ -1073,8 +1079,6 @@ static void cdns_uart_poll_put_char(struct uart_port *port, unsigned char c)
 		cpu_relax();
 
 	spin_unlock_irqrestore(&port->lock, flags);
-
-	return;
 }
 #endif
 
@@ -1517,7 +1521,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	cdns_uart_uart_driver->owner = THIS_MODULE;
 	cdns_uart_uart_driver->driver_name = driver_name;
 	cdns_uart_uart_driver->dev_name	= CDNS_UART_TTY_NAME;
-	cdns_uart_uart_driver->major = CDNS_UART_MAJOR;
+	cdns_uart_uart_driver->major = uartps_major;
 	cdns_uart_uart_driver->minor = cdns_uart_data->id;
 	cdns_uart_uart_driver->nr = 1;
 
@@ -1546,6 +1550,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
 		goto err_out_id;
 	}
 
+	uartps_major = cdns_uart_uart_driver->tty_driver->major;
 	cdns_uart_data->cdns_uart_driver = cdns_uart_uart_driver;
 
 	/*

drivers/tty/tty_io.c

@@ -1837,7 +1837,7 @@ static struct tty_struct *tty_open_current_tty(dev_t device, struct file *filp)
 static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
 		int *index)
 {
-	struct tty_driver *driver;
+	struct tty_driver *driver = NULL;
 
 	switch (device) {
 #ifdef CONFIG_VT
@@ -1858,6 +1858,8 @@ static struct tty_driver *tty_lookup_driver(dev_t device, struct file *filp,
 				break;
 			}
 		}
+		if (driver)
+			tty_driver_kref_put(driver);
 		return ERR_PTR(-ENODEV);
 	}
 	default:

include/linux/mv643xx.h

@@ -918,52 +918,6 @@
 
 extern void mv64340_irq_init(unsigned int base);
 
-/* MPSC Platform Device, Driver Data (Shared register regions) */
-#define	MPSC_SHARED_NAME		"mpsc_shared"
-
-#define	MPSC_ROUTING_BASE_ORDER		0
-#define	MPSC_SDMA_INTR_BASE_ORDER	1
-
-#define MPSC_ROUTING_REG_BLOCK_SIZE	0x000c
-#define MPSC_SDMA_INTR_REG_BLOCK_SIZE	0x0084
-
-struct mpsc_shared_pdata {
-	u32	mrr_val;
-	u32	rcrr_val;
-	u32	tcrr_val;
-	u32	intr_cause_val;
-	u32	intr_mask_val;
-};
-
-/* MPSC Platform Device, Driver Data */
-#define	MPSC_CTLR_NAME			"mpsc"
-
-#define	MPSC_BASE_ORDER			0
-#define	MPSC_SDMA_BASE_ORDER		1
-#define	MPSC_BRG_BASE_ORDER		2
-
-#define MPSC_REG_BLOCK_SIZE		0x0038
-#define MPSC_SDMA_REG_BLOCK_SIZE	0x0c18
-#define MPSC_BRG_REG_BLOCK_SIZE		0x0008
-
-struct mpsc_pdata {
-	u8	mirror_regs;
-	u8	cache_mgmt;
-	u8	max_idle;
-	int	default_baud;
-	int	default_bits;
-	int	default_parity;
-	int	default_flow;
-	u32	chr_1_val;
-	u32	chr_2_val;
-	u32	chr_10_val;
-	u32	mpcr_val;
-	u32	bcr_val;
-	u8	brg_can_tune;
-	u8	brg_clk_src;
-	u32	brg_clk_freq;
-};
-
 /* Watchdog Platform Device, Driver Data */
 #define	MV64x60_WDT_NAME			"mv64x60_wdt"
 

include/linux/serial_8250.h

@@ -110,6 +110,7 @@ struct uart_8250_port {
 						 *   if no_console_suspend
 						 */
 	unsigned char		probe;
+	struct mctrl_gpios	*gpios;
 #define UART_PROBE_RSA	(1 << 0)
 
 	/*

include/uapi/linux/serial_core.h

@@ -129,7 +129,7 @@
 /* Motorola i.MX SoC */
 #define PORT_IMX	62
 
-/* Marvell MPSC */
+/* Marvell MPSC (obsolete unused) */
 #define PORT_MPSC	63
 
 /* TXX9 type number */