Merge tag 'tty-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty/serial driver updates from Greg KH:
 "Here is the big set of tty/serial driver changes for 5.12-rc1.

  Nothing huge, just lots of good cleanups and additions:

   - n_tty line discipline cleanups

   - vt core cleanups and reworks to make the code more "modern"

   - stm32 driver additions

   - tty led support added to the tty core and led layer

   - minor serial driver fixups and additions

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

* tag 'tty-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (54 commits)
  serial: core: Remove BUG_ON(in_interrupt()) check
  vt_ioctl: Remove in_interrupt() check
  dt-bindings: serial: imx: Switch to my personal address
  vt: keyboard, use new API for keyboard_tasklet
  serial: stm32: improve platform_get_irq condition handling in init_port
  serial: ifx6x60: Remove driver for deprecated platform
  tty: fix up iterate_tty_read() EOVERFLOW handling
  tty: fix up hung_up_tty_read() conversion
  tty: fix up hung_up_tty_write() conversion
  tty: teach the n_tty ICANON case about the new "cookie continuations" too
  tty: teach n_tty line discipline about the new "cookie continuations"
  tty: clean up legacy leftovers from n_tty line discipline
  tty: implement read_iter
  tty: convert tty_ldisc_ops 'read()' function to take a kernel pointer
  serial: remove sirf prima/atlas driver
  serial: mxs-auart: Remove <asm/cacheflush.h>
  serial: mxs-auart: Remove serial_mxs_probe_dt()
  serial: fsl_lpuart: Use of_device_get_match_data()
  dt-bindings: serial: renesas,hscif: Add r8a779a0 support
  tty: serial: Drop unused efm32 serial driver
  ...

70 files changed, 958 insertions, 5187 deletions

diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-tty b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
new file mode 100644
index 000000000000..2bf6b24e781b
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-led-trigger-tty
@@ -0,0 +1,6 @@
+What:		/sys/class/leds/<led>/ttyname
+Date:		Dec 2020
+KernelVersion:	5.10
+Contact:	linux-leds@vger.kernel.org
+Description:
+		Specifies the tty device name of the triggering tty
diff --git a/Documentation/devicetree/bindings/serial/fsl-imx-uart.yaml b/Documentation/devicetree/bindings/serial/fsl-imx-uart.yaml
index 9702c07a6b6c..2b06c6ce4a75 100644
--- a/Documentation/devicetree/bindings/serial/fsl-imx-uart.yaml
+++ b/Documentation/devicetree/bindings/serial/fsl-imx-uart.yaml
@@ -7,7 +7,7 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 title: Freescale i.MX Universal Asynchronous Receiver/Transmitter (UART)
 
 maintainers:
-  - Fabio Estevam <fabio.estevam@nxp.com>
+  - Fabio Estevam <festevam@gmail.com>
 
 allOf:
   - $ref: "serial.yaml"
diff --git a/Documentation/devicetree/bindings/serial/fsl-mxs-auart.yaml b/Documentation/devicetree/bindings/serial/fsl-mxs-auart.yaml
index ce1d89496342..14c7594c88c6 100644
--- a/Documentation/devicetree/bindings/serial/fsl-mxs-auart.yaml
+++ b/Documentation/devicetree/bindings/serial/fsl-mxs-auart.yaml
@@ -7,7 +7,7 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 title: Freescale MXS Application UART (AUART)
 
 maintainers:
-  - Fabio Estevam <fabio.estevam@nxp.com>
+  - Fabio Estevam <festevam@gmail.com>
 
 allOf:
   - $ref: "serial.yaml"
diff --git a/Documentation/devicetree/bindings/serial/renesas,hscif.yaml b/Documentation/devicetree/bindings/serial/renesas,hscif.yaml
index c139c5edb93e..512a84942f78 100644
--- a/Documentation/devicetree/bindings/serial/renesas,hscif.yaml
+++ b/Documentation/devicetree/bindings/serial/renesas,hscif.yaml
@@ -51,6 +51,7 @@ properties:
               - renesas,hscif-r8a77980     # R-Car V3H
               - renesas,hscif-r8a77990     # R-Car E3
               - renesas,hscif-r8a77995     # R-Car D3
+              - renesas,hscif-r8a779a0     # R-Car V3U
           - const: renesas,rcar-gen3-hscif # R-Car Gen3 and RZ/G2
           - const: renesas,hscif           # generic HSCIF compatible UART
 
diff --git a/Documentation/devicetree/bindings/serial/sirf-uart.txt b/Documentation/devicetree/bindings/serial/sirf-uart.txt
deleted file mode 100644
index 1e48bbbeecc6..000000000000
--- a/Documentation/devicetree/bindings/serial/sirf-uart.txt
+++ /dev/null
@@ -1,34 +0,0 @@
-* CSR SiRFprimaII/atlasVI Universal Synchronous Asynchronous Receiver/Transmitter *
-
-Required properties:
-- compatible : Should be "sirf,prima2-uart", "sirf, prima2-usp-uart",
-		"sirf,atlas7-uart" or "sirf,atlas7-usp-uart".
-- reg : Offset and length of the register set for the device
-- interrupts : Should contain uart interrupt
-- fifosize : Should define hardware rx/tx fifo size
-- clocks : Should contain uart clock number
-
-Optional properties:
-- uart-has-rtscts: we have hardware flow controller pins in hardware
-- rts-gpios: RTS pin for USP-based UART if uart-has-rtscts is true
-- cts-gpios: CTS pin for USP-based UART if uart-has-rtscts is true
-
-Example:
-
-uart0: uart@b0050000 {
-	cell-index = <0>;
-	compatible = "sirf,prima2-uart";
-	reg = <0xb0050000 0x1000>;
-	interrupts = <17>;
-	fifosize = <128>;
-	clocks = <&clks 13>;
-};
-
-On the board-specific dts, we can put rts-gpios and cts-gpios like
-
-usp@b0090000 {
-	compatible = "sirf,prima2-usp-uart";
-	uart-has-rtscts;
-	rts-gpios = <&gpio 15 0>;
-	cts-gpios = <&gpio 46 0>;
-};
diff --git a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
index 06d5f251ec88..8631678283f9 100644
--- a/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
+++ b/Documentation/devicetree/bindings/serial/st,stm32-uart.yaml
@@ -50,11 +50,14 @@ properties:
     minItems: 1
     maxItems: 2
 
-  cts-gpios:
-    maxItems: 1
-
-  rts-gpios:
-    maxItems: 1
+# cts-gpios and rts-gpios properties can be used instead of 'uart-has-rtscts'
+# or 'st,hw-flow-ctrl' (deprecated) for making use of any gpio pins for flow
+# control instead of dedicated pins.
+#
+# It should be noted that both cts-gpios/rts-gpios and 'uart-has-rtscts' or
+# 'st,hw-flow-ctrl' (deprecated) properties cannot co-exist in a design.
+  cts-gpios: true
+  rts-gpios: true
 
   wakeup-source: true
 
diff --git a/Documentation/networking/caif/caif.rst b/Documentation/networking/caif/caif.rst
index a07213030ccf..81a14373d780 100644
--- a/Documentation/networking/caif/caif.rst
+++ b/Documentation/networking/caif/caif.rst
@@ -68,7 +68,6 @@ There are debugfs parameters provided for serial communication.
 * tty_status: Prints the bit-mask tty status information
 
   - 0x01 - tty->warned is on.
-  - 0x02 - tty->low_latency is on.
   - 0x04 - tty->packed is on.
   - 0x08 - tty->flow_stopped is on.
   - 0x10 - tty->hw_stopped is on.
diff --git a/drivers/accessibility/speakup/spk_ttyio.c b/drivers/accessibility/speakup/spk_ttyio.c
index 6284aff434a1..835d17455fcd 100644
--- a/drivers/accessibility/speakup/spk_ttyio.c
+++ b/drivers/accessibility/speakup/spk_ttyio.c
@@ -152,7 +152,7 @@ static int spk_ttyio_initialise_ldisc(struct spk_synth *synth)
 	if (ret)
 		return ret;
 
-	tty = tty_kopen(dev);
+	tty = tty_kopen_exclusive(dev);
 	if (IS_ERR(tty))
 		return PTR_ERR(tty);
 
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 8be4d807d137..637c5b8c2aa1 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -801,7 +801,8 @@ static int hci_uart_tty_ioctl(struct tty_struct *tty, struct file *file,
  * We don't provide read/write/poll interface for user space.
  */
 static ssize_t hci_uart_tty_read(struct tty_struct *tty, struct file *file,
-				 unsigned char __user *buf, size_t nr)
+				 unsigned char *buf, size_t nr,
+				 void **cookie, unsigned long offset)
 {
 	return 0;
 }
@@ -818,29 +819,28 @@ static __poll_t hci_uart_tty_poll(struct tty_struct *tty,
 	return 0;
 }
 
+static struct tty_ldisc_ops hci_uart_ldisc = {
+	.owner		= THIS_MODULE,
+	.magic		= TTY_LDISC_MAGIC,
+	.name		= "n_hci",
+	.open		= hci_uart_tty_open,
+	.close		= hci_uart_tty_close,
+	.read		= hci_uart_tty_read,
+	.write		= hci_uart_tty_write,
+	.ioctl		= hci_uart_tty_ioctl,
+	.compat_ioctl	= hci_uart_tty_ioctl,
+	.poll		= hci_uart_tty_poll,
+	.receive_buf	= hci_uart_tty_receive,
+	.write_wakeup	= hci_uart_tty_wakeup,
+};
+
 static int __init hci_uart_init(void)
 {
-	static struct tty_ldisc_ops hci_uart_ldisc;
 	int err;
 
 	BT_INFO("HCI UART driver ver %s", VERSION);
 
 	/* Register the tty discipline */
-
-	memset(&hci_uart_ldisc, 0, sizeof(hci_uart_ldisc));
-	hci_uart_ldisc.magic		= TTY_LDISC_MAGIC;
-	hci_uart_ldisc.name		= "n_hci";
-	hci_uart_ldisc.open		= hci_uart_tty_open;
-	hci_uart_ldisc.close		= hci_uart_tty_close;
-	hci_uart_ldisc.read		= hci_uart_tty_read;
-	hci_uart_ldisc.write		= hci_uart_tty_write;
-	hci_uart_ldisc.ioctl		= hci_uart_tty_ioctl;
-	hci_uart_ldisc.compat_ioctl	= hci_uart_tty_ioctl;
-	hci_uart_ldisc.poll		= hci_uart_tty_poll;
-	hci_uart_ldisc.receive_buf	= hci_uart_tty_receive;
-	hci_uart_ldisc.write_wakeup	= hci_uart_tty_wakeup;
-	hci_uart_ldisc.owner		= THIS_MODULE;
-
 	err = tty_register_ldisc(N_HCI, &hci_uart_ldisc);
 	if (err) {
 		BT_ERR("HCI line discipline registration failed. (%d)", err);
diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index e342daa73d1b..2be8d9a8eec5 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -2494,8 +2494,6 @@ static int mgslpc_open(struct tty_struct *tty, struct file * filp)
 		printk("%s(%d):mgslpc_open(%s), old ref count = %d\n",
 			 __FILE__, __LINE__, tty->driver->name, port->count);
 
-	port->low_latency = (port->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
-
 	spin_lock_irqsave(&info->netlock, flags);
 	if (info->netcount) {
 		retval = -EBUSY;
diff --git a/drivers/input/serio/serport.c b/drivers/input/serio/serport.c
index 8ac970a423de..33e9d9bfd036 100644
--- a/drivers/input/serio/serport.c
+++ b/drivers/input/serio/serport.c
@@ -156,7 +156,9 @@ out:
  * returning 0 characters.
  */
 
-static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file, unsigned char __user * buf, size_t nr)
+static ssize_t serport_ldisc_read(struct tty_struct * tty, struct file * file,
+				  unsigned char *kbuf, size_t nr,
+				  void **cookie, unsigned long offset)
 {
 	struct serport *serport = (struct serport*) tty->disc_data;
 	struct serio *serio;
diff --git a/drivers/leds/trigger/Kconfig b/drivers/leds/trigger/Kconfig
index ce9429ca6dde..b77a01bd27f4 100644
--- a/drivers/leds/trigger/Kconfig
+++ b/drivers/leds/trigger/Kconfig
@@ -144,4 +144,13 @@ config LEDS_TRIGGER_AUDIO
 	  the audio mute and mic-mute changes.
 	  If unsure, say N
 
+config LEDS_TRIGGER_TTY
+	tristate "LED Trigger for TTY devices"
+	depends on TTY
+	help
+	  This allows LEDs to be controlled by activity on ttys which includes
+	  serial devices like /dev/ttyS0.
+
+	  When build as a module this driver will be called ledtrig-tty.
+
 endif # LEDS_TRIGGERS
diff --git a/drivers/leds/trigger/Makefile b/drivers/leds/trigger/Makefile
index 733a83e2a718..25c4db97cdd4 100644
--- a/drivers/leds/trigger/Makefile
+++ b/drivers/leds/trigger/Makefile
@@ -15,3 +15,4 @@ obj-$(CONFIG_LEDS_TRIGGER_PANIC)	+= ledtrig-panic.o
 obj-$(CONFIG_LEDS_TRIGGER_NETDEV)	+= ledtrig-netdev.o
 obj-$(CONFIG_LEDS_TRIGGER_PATTERN)	+= ledtrig-pattern.o
 obj-$(CONFIG_LEDS_TRIGGER_AUDIO)	+= ledtrig-audio.o
+obj-$(CONFIG_LEDS_TRIGGER_TTY)		+= ledtrig-tty.o
diff --git a/drivers/leds/trigger/ledtrig-tty.c b/drivers/leds/trigger/ledtrig-tty.c
new file mode 100644
index 000000000000..d2ab6ab080ac
--- /dev/null
+++ b/drivers/leds/trigger/ledtrig-tty.c
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/delay.h>
+#include <linux/leds.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/tty.h>
+#include <uapi/linux/serial.h>
+
+struct ledtrig_tty_data {
+	struct led_classdev *led_cdev;
+	struct delayed_work dwork;
+	struct mutex mutex;
+	const char *ttyname;
+	struct tty_struct *tty;
+	int rx, tx;
+};
+
+static void ledtrig_tty_restart(struct ledtrig_tty_data *trigger_data)
+{
+	schedule_delayed_work(&trigger_data->dwork, 0);
+}
+
+static ssize_t ttyname_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
+	ssize_t len = 0;
+
+	mutex_lock(&trigger_data->mutex);
+
+	if (trigger_data->ttyname)
+		len = sprintf(buf, "%s\n", trigger_data->ttyname);
+
+	mutex_unlock(&trigger_data->mutex);
+
+	return len;
+}
+
+static ssize_t ttyname_store(struct device *dev,
+			     struct device_attribute *attr, const char *buf,
+			     size_t size)
+{
+	struct ledtrig_tty_data *trigger_data = led_trigger_get_drvdata(dev);
+	char *ttyname;
+	ssize_t ret = size;
+	bool running;
+
+	if (size > 0 && buf[size - 1] == '\n')
+		size -= 1;
+
+	if (size) {
+		ttyname = kmemdup_nul(buf, size, GFP_KERNEL);
+		if (!ttyname) {
+			ret = -ENOMEM;
+			goto out_unlock;
+		}
+	} else {
+		ttyname = NULL;
+	}
+
+	mutex_lock(&trigger_data->mutex);
+
+	running = trigger_data->ttyname != NULL;
+
+	kfree(trigger_data->ttyname);
+	tty_kref_put(trigger_data->tty);
+	trigger_data->tty = NULL;
+
+	trigger_data->ttyname = ttyname;
+
+out_unlock:
+	mutex_unlock(&trigger_data->mutex);
+
+	if (ttyname && !running)
+		ledtrig_tty_restart(trigger_data);
+
+	return ret;
+}
+static DEVICE_ATTR_RW(ttyname);
+
+static void ledtrig_tty_work(struct work_struct *work)
+{
+	struct ledtrig_tty_data *trigger_data =
+		container_of(work, struct ledtrig_tty_data, dwork.work);
+	struct serial_icounter_struct icount;
+	int ret;
+
+	mutex_lock(&trigger_data->mutex);
+
+	if (!trigger_data->ttyname) {
+		/* exit without rescheduling */
+		mutex_unlock(&trigger_data->mutex);
+		return;
+	}
+
+	/* try to get the tty corresponding to $ttyname */
+	if (!trigger_data->tty) {
+		dev_t devno;
+		struct tty_struct *tty;
+		int ret;
+
+		ret = tty_dev_name_to_number(trigger_data->ttyname, &devno);
+		if (ret < 0)
+			/*
+			 * A device with this name might appear later, so keep
+			 * retrying.
+			 */
+			goto out;
+
+		tty = tty_kopen_shared(devno);
+		if (IS_ERR(tty) || !tty)
+			/* What to do? retry or abort */
+			goto out;
+
+		trigger_data->tty = tty;
+	}
+
+	ret = tty_get_icount(trigger_data->tty, &icount);
+	if (ret) {
+		dev_info(trigger_data->tty->dev, "Failed to get icount, stopped polling\n");
+		mutex_unlock(&trigger_data->mutex);
+		return;
+	}
+
+	if (icount.rx != trigger_data->rx ||
+	    icount.tx != trigger_data->tx) {
+		led_set_brightness(trigger_data->led_cdev, LED_ON);
+
+		trigger_data->rx = icount.rx;
+		trigger_data->tx = icount.tx;
+	} else {
+		led_set_brightness(trigger_data->led_cdev, LED_OFF);
+	}
+
+out:
+	mutex_unlock(&trigger_data->mutex);
+	schedule_delayed_work(&trigger_data->dwork, msecs_to_jiffies(100));
+}
+
+static struct attribute *ledtrig_tty_attrs[] = {
+	&dev_attr_ttyname.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(ledtrig_tty);
+
+static int ledtrig_tty_activate(struct led_classdev *led_cdev)
+{
+	struct ledtrig_tty_data *trigger_data;
+
+	trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
+	if (!trigger_data)
+		return -ENOMEM;
+
+	led_set_trigger_data(led_cdev, trigger_data);
+
+	INIT_DELAYED_WORK(&trigger_data->dwork, ledtrig_tty_work);
+	trigger_data->led_cdev = led_cdev;
+	mutex_init(&trigger_data->mutex);
+
+	return 0;
+}
+
+static void ledtrig_tty_deactivate(struct led_classdev *led_cdev)
+{
+	struct ledtrig_tty_data *trigger_data = led_get_trigger_data(led_cdev);
+
+	cancel_delayed_work_sync(&trigger_data->dwork);
+
+	kfree(trigger_data);
+}
+
+static struct led_trigger ledtrig_tty = {
+	.name = "tty",
+	.activate = ledtrig_tty_activate,
+	.deactivate = ledtrig_tty_deactivate,
+	.groups = ledtrig_tty_groups,
+};
+module_led_trigger(ledtrig_tty);
+
+MODULE_AUTHOR("Uwe Kleine-König <u.kleine-koenig@pengutronix.de>");
+MODULE_DESCRIPTION("UART LED trigger");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c
index bcc14c5875bf..8215cd77301f 100644
--- a/drivers/net/caif/caif_serial.c
+++ b/drive