Merge tag 'tty-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel…

…/git/gregkh/tty

Pull tty/serial updates from Greg KH:
 "Here is the big tty and serial pull request for 4.20-rc1

  Lots of little things here, including a merge from the SPI tree in
  order to keep things simpler for everyone to sync around for one
  platform.

  Major stuff is:

   - tty buffer clearing after use

   - atmel_serial fixes and additions

   - xilinx uart driver updates

  and of course, lots of tiny fixes and additions to individual serial
  drivers.

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

* tag 'tty-4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (66 commits)
  of: base: Change logic in of_alias_get_alias_list()
  of: base: Fix english spelling in of_alias_get_alias_list()
  serial: sh-sci: do not warn if DMA transfers are not supported
  serial: uartps: Do not allow use aliases >= MAX_UART_INSTANCES
  tty: check name length in tty_find_polling_driver()
  serial: sh-sci: Add r8a77990 support
  tty: wipe buffer if not echoing data
  tty: wipe buffer.
  serial: fsl_lpuart: Remove the alias node dependence
  TTY: sn_console: Replace spin_is_locked() with spin_trylock()
  Revert "serial:serial_core: Allow use of CTS for PPS line discipline"
  serial: 8250_uniphier: add auto-flow-control support
  serial: 8250_uniphier: flatten probe function
  serial: 8250_uniphier: remove unused "fifo-size" property
  dt-bindings: serial: sh-sci: Document r8a7744 bindings
  serial: uartps: Fix missing unlock on error in cdns_get_id()
  tty/serial: atmel: add ISO7816 support
  tty/serial_core: add ISO7816 infrastructure
  serial:serial_core: Allow use of CTS for PPS line discipline
  serial: docs: Fix filename for serial reference implementation
  ...

Documentation/devicetree/bindings/serial/renesas,sci-serial.txt

@@ -14,6 +14,10 @@ Required properties:
     - "renesas,scifa-r8a7743" for R8A7743 (RZ/G1M) SCIFA compatible UART.
     - "renesas,scifb-r8a7743" for R8A7743 (RZ/G1M) SCIFB compatible UART.
     - "renesas,hscif-r8a7743" for R8A7743 (RZ/G1M) HSCIF compatible UART.
+    - "renesas,scif-r8a7744" for R8A7744 (RZ/G1N) SCIF compatible UART.
+    - "renesas,scifa-r8a7744" for R8A7744 (RZ/G1N) SCIFA compatible UART.
+    - "renesas,scifb-r8a7744" for R8A7744 (RZ/G1N) SCIFB compatible UART.
+    - "renesas,hscif-r8a7744" for R8A7744 (RZ/G1N) HSCIF compatible UART.
     - "renesas,scif-r8a7745" for R8A7745 (RZ/G1E) SCIF compatible UART.
     - "renesas,scifa-r8a7745" for R8A7745 (RZ/G1E) SCIFA compatible UART.
     - "renesas,scifb-r8a7745" for R8A7745 (RZ/G1E) SCIFB compatible UART.
@@ -50,6 +54,8 @@ Required properties:
     - "renesas,hscif-r8a77970" for R8A77970 (R-Car V3M) HSCIF compatible UART.
     - "renesas,scif-r8a77980" for R8A77980 (R-Car V3H) SCIF compatible UART.
     - "renesas,hscif-r8a77980" for R8A77980 (R-Car V3H) HSCIF compatible UART.
+    - "renesas,scif-r8a77990" for R8A77990 (R-Car E3) SCIF compatible UART.
+    - "renesas,hscif-r8a77990" for R8A77990 (R-Car E3) HSCIF compatible UART.
     - "renesas,scif-r8a77995" for R8A77995 (R-Car D3) SCIF compatible UART.
     - "renesas,hscif-r8a77995" for R8A77995 (R-Car D3) HSCIF compatible UART.
     - "renesas,scifa-sh73a0" for SH73A0 (SH-Mobile AG5) SCIFA compatible UART.

Documentation/devicetree/bindings/serial/uniphier-uart.txt

@@ -7,7 +7,7 @@ Required properties:
 - clocks: phandle to the input clock.
 
 Optional properties:
-- fifo-size: the RX/TX FIFO size.  Defaults to 64 if not specified.
+-auto-flow-control: enable automatic flow control support.
 
 Example:
 	aliases {
@@ -19,5 +19,4 @@ Example:
 		reg = <0x54006800 0x40>;
 		interrupts = <0 33 4>;
 		clocks = <&uart_clk>;
-		fifo-size = <64>;
 	};

Documentation/serial/driver

@@ -7,7 +7,7 @@ This document is meant as a brief overview of some aspects of the new serial
 driver.  It is not complete, any questions you have should be directed to
 <[email protected]>
 
-The reference implementation is contained within amba_pl011.c.
+The reference implementation is contained within amba-pl011.c.
 
 
 

Documentation/serial/serial-iso7816.txt

@@ -0,0 +1,83 @@
+                        ISO7816 SERIAL COMMUNICATIONS
+
+1. INTRODUCTION
+
+  ISO/IEC7816 is a series of standards specifying integrated circuit cards (ICC)
+  also known as smart cards.
+
+2. HARDWARE-RELATED CONSIDERATIONS
+
+  Some CPUs/UARTs (e.g., Microchip AT91) contain a built-in mode capable of
+  handling communication with a smart card.
+
+  For these microcontrollers, the Linux driver should be made capable of
+  working in both modes, and proper ioctls (see later) should be made
+  available at user-level to allow switching from one mode to the other, and
+  vice versa.
+
+3. DATA STRUCTURES ALREADY AVAILABLE IN THE KERNEL
+
+  The Linux kernel provides the serial_iso7816 structure (see [1]) to handle
+  ISO7816 communications. This data structure is used to set and configure
+  ISO7816 parameters in ioctls.
+
+  Any driver for devices capable of working both as RS232 and ISO7816 should
+  implement the iso7816_config callback in the uart_port structure. The
+  serial_core calls iso7816_config to do the device specific part in response
+  to TIOCGISO7816 and TIOCSISO7816 ioctls (see below). The iso7816_config
+  callback receives a pointer to struct serial_iso7816.
+
+4. USAGE FROM USER-LEVEL
+
+  From user-level, ISO7816 configuration can be get/set using the previous
+  ioctls. For instance, to set ISO7816 you can use the following code:
+
+	#include <linux/serial.h>
+
+	/* Include definition for ISO7816 ioctls: TIOCSISO7816 and TIOCGISO7816 */
+	#include <sys/ioctl.h>
+
+	/* Open your specific device (e.g., /dev/mydevice): */
+	int fd = open ("/dev/mydevice", O_RDWR);
+	if (fd < 0) {
+		/* Error handling. See errno. */
+	}
+
+	struct serial_iso7816 iso7816conf;
+
+	/* Reserved fields as to be zeroed */
+	memset(&iso7816conf, 0, sizeof(iso7816conf));
+
+	/* Enable ISO7816 mode: */
+	iso7816conf.flags |= SER_ISO7816_ENABLED;
+
+	/* Select the protocol: */
+	/* T=0 */
+	iso7816conf.flags |= SER_ISO7816_T(0);
+	/* or T=1 */
+	iso7816conf.flags |= SER_ISO7816_T(1);
+
+	/* Set the guard time: */
+	iso7816conf.tg = 2;
+
+	/* Set the clock frequency*/
+	iso7816conf.clk = 3571200;
+
+	/* Set transmission factors: */
+	iso7816conf.sc_fi = 372;
+	iso7816conf.sc_di = 1;
+
+	if (ioctl(fd_usart, TIOCSISO7816, &iso7816conf) < 0) {
+		/* Error handling. See errno. */
+	}
+
+	/* Use read() and write() syscalls here... */
+
+	/* Close the device when finished: */
+	if (close (fd) < 0) {
+		/* Error handling. See errno. */
+	}
+
+5. REFERENCES
+
+ [1]    include/uapi/linux/serial.h

arch/alpha/include/uapi/asm/ioctls.h

@@ -102,6 +102,8 @@
 #define TIOCGPTLCK	_IOR('T', 0x39, int) /* Get Pty lock state */
 #define TIOCGEXCL	_IOR('T', 0x40, int) /* Get exclusive mode state */
 #define TIOCGPTPEER	_IO('T', 0x41) /* Safely open the slave */
+#define TIOCGISO7816	_IOR('T', 0x42, struct serial_iso7816)
+#define TIOCSISO7816	_IOWR('T', 0x43, struct serial_iso7816)
 
 #define TIOCSERCONFIG	0x5453
 #define TIOCSERGWILD	0x5454

arch/mips/include/uapi/asm/ioctls.h

@@ -93,6 +93,8 @@
 #define TIOCGPTLCK	_IOR('T', 0x39, int) /* Get Pty lock state */
 #define TIOCGEXCL	_IOR('T', 0x40, int) /* Get exclusive mode state */
 #define TIOCGPTPEER	_IO('T', 0x41) /* Safely open the slave */
+#define TIOCGISO7816	_IOR('T', 0x42, struct serial_iso7816)
+#define TIOCSISO7816	_IOWR('T', 0x43, struct serial_iso7816)
 
 /* I hope the range from 0x5480 on is free ... */
 #define TIOCSCTTY	0x5480		/* become controlling tty */

arch/parisc/include/uapi/asm/ioctls.h

@@ -62,6 +62,8 @@
 #define TIOCGPTLCK	_IOR('T', 0x39, int) /* Get Pty lock state */
 #define TIOCGEXCL	_IOR('T', 0x40, int) /* Get exclusive mode state */
 #define TIOCGPTPEER	_IO('T', 0x41) /* Safely open the slave */
+#define TIOCGISO7816	_IOR('T', 0x42, struct serial_iso7816)
+#define TIOCSISO7816	_IOWR('T', 0x43, struct serial_iso7816)
 
 #define FIONCLEX	0x5450  /* these numbers need to be adjusted. */
 #define FIOCLEX		0x5451

arch/powerpc/include/uapi/asm/ioctls.h

@@ -102,6 +102,8 @@
 #define TIOCGPTLCK	_IOR('T', 0x39, int) /* Get Pty lock state */
 #define TIOCGEXCL	_IOR('T', 0x40, int) /* Get exclusive mode state */
 #define TIOCGPTPEER	_IO('T', 0x41) /* Safely open the slave */
+#define TIOCGISO7816	_IOR('T', 0x42, struct serial_iso7816)
+#define TIOCSISO7816	_IOWR('T', 0x43, struct serial_iso7816)
 
 #define TIOCSERCONFIG	0x5453
 #define TIOCSERGWILD	0x5454

arch/sh/include/uapi/asm/ioctls.h

@@ -95,6 +95,8 @@
 #define TIOCGPTLCK	_IOR('T', 0x39, int) /* Get Pty lock state */
 #define TIOCGEXCL	_IOR('T', 0x40, int) /* Get exclusive mode state */
 #define TIOCGPTPEER	_IO('T', 0x41) /* Safely open the slave */
+#define TIOCGISO7816	_IOR('T', 0x42, struct serial_iso7816)
+#define TIOCSISO7816	_IOWR('T', 0x43, struct serial_iso7816)
 
 #define TIOCSERCONFIG	_IO('T', 83) /* 0x5453 */
 #define TIOCSERGWILD	_IOR('T', 84,  int) /* 0x5454 */

arch/sparc/include/uapi/asm/ioctls.h

@@ -27,6 +27,8 @@
 #define TIOCGEXCL	_IOR('T', 0x40, int) /* Get exclusive mode state */
 #define TIOCGRS485	_IOR('T', 0x41, struct serial_rs485)
 #define TIOCSRS485	_IOWR('T', 0x42, struct serial_rs485)
+#define TIOCGISO7816	_IOR('T', 0x43, struct serial_iso7816)
+#define TIOCSISO7816	_IOWR('T', 0x44, struct serial_iso7816)
 
 /* Note that all the ioctls that are not available in Linux have a
  * double underscore on the front to: a) avoid some programs to

arch/xtensa/include/uapi/asm/ioctls.h

@@ -107,6 +107,8 @@
 #define TIOCGPTLCK	_IOR('T', 0x39, int) /* Get Pty lock state */
 #define TIOCGEXCL	_IOR('T', 0x40, int) /* Get exclusive mode state */
 #define TIOCGPTPEER	_IO('T', 0x41) /* Safely open the slave */
+#define TIOCGISO7816	_IOR('T', 0x42, struct serial_iso7816)
+#define TIOCSISO7816	_IOWR('T', 0x43, struct serial_iso7816)
 
 #define TIOCSERCONFIG	_IO('T', 83)
 #define TIOCSERGWILD	_IOR('T', 84,  int)

drivers/of/base.c

@@ -16,6 +16,7 @@
 
 #define pr_fmt(fmt)	"OF: " fmt
 
+#include <linux/bitmap.h>
 #include <linux/console.h>
 #include <linux/ctype.h>
 #include <linux/cpu.h>
@@ -1985,6 +1986,59 @@ int of_alias_get_id(struct device_node *np, const char *stem)
 }
 EXPORT_SYMBOL_GPL(of_alias_get_id);
 
+/**
+ * of_alias_get_alias_list - Get alias list for the given device driver
+ * @matches:	Array of OF device match structures to search in
+ * @stem:	Alias stem of the given device_node
+ * @bitmap:	Bitmap field pointer
+ * @nbits:	Maximum number of alias IDs which can be recorded in bitmap
+ *
+ * The function travels the lookup table to record alias ids for the given
+ * device match structures and alias stem.
+ *
+ * Return:	0 or -ENOSYS when !CONFIG_OF or
+ *		-EOVERFLOW if alias ID is greater then allocated nbits
+ */
+int of_alias_get_alias_list(const struct of_device_id *matches,
+			     const char *stem, unsigned long *bitmap,
+			     unsigned int nbits)
+{
+	struct alias_prop *app;
+	int ret = 0;
+
+	/* Zero bitmap field to make sure that all the time it is clean */
+	bitmap_zero(bitmap, nbits);
+
+	mutex_lock(&of_mutex);
+	pr_debug("%s: Looking for stem: %s\n", __func__, stem);
+	list_for_each_entry(app, &aliases_lookup, link) {
+		pr_debug("%s: stem: %s, id: %d\n",
+			 __func__, app->stem, app->id);
+
+		if (strcmp(app->stem, stem) != 0) {
+			pr_debug("%s: stem comparison didn't pass %s\n",
+				 __func__, app->stem);
+			continue;
+		}
+
+		if (of_match_node(matches, app->np)) {
+			pr_debug("%s: Allocated ID %d\n", __func__, app->id);
+
+			if (app->id >= nbits) {
+				pr_warn("%s: ID %d >= than bitmap field %d\n",
+					__func__, app->id, nbits);
+				ret = -EOVERFLOW;
+			} else {
+				set_bit(app->id, bitmap);
+			}
+		}
+	}
+	mutex_unlock(&of_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(of_alias_get_alias_list);
+
 /**
  * of_alias_get_highest_id - Get highest alias id for the given stem
  * @stem:	Alias stem to be examined

drivers/tty/ehv_bytechan.c

@@ -128,8 +128,8 @@ static int find_console_handle(void)
 	 */
 	iprop = of_get_property(np, "hv-handle", NULL);
 	if (!iprop) {
-		pr_err("ehv-bc: no 'hv-handle' property in %s node\n",
-		       np->name);
+		pr_err("ehv-bc: no 'hv-handle' property in %pOFn node\n",
+		       np);
 		return 0;
 	}
 	stdout_bc = be32_to_cpu(*iprop);
@@ -661,8 +661,8 @@ static int ehv_bc_tty_probe(struct platform_device *pdev)
 
 	iprop = of_get_property(np, "hv-handle", NULL);
 	if (!iprop) {
-		dev_err(&pdev->dev, "no 'hv-handle' property in %s node\n",
-			np->name);
+		dev_err(&pdev->dev, "no 'hv-handle' property in %pOFn node\n",
+			np);
 		return -ENODEV;
 	}
 
@@ -682,8 +682,8 @@ static int ehv_bc_tty_probe(struct platform_device *pdev)
 	bc->rx_irq = irq_of_parse_and_map(np, 0);
 	bc->tx_irq = irq_of_parse_and_map(np, 1);
 	if ((bc->rx_irq == NO_IRQ) || (bc->tx_irq == NO_IRQ)) {
-		dev_err(&pdev->dev, "no 'interrupts' property in %s node\n",
-			np->name);
+		dev_err(&pdev->dev, "no 'interrupts' property in %pOFn node\n",
+			np);
 		ret = -ENODEV;
 		goto error;
 	}

drivers/tty/n_tty.c

@@ -152,17 +152,28 @@ static inline unsigned char *echo_buf_addr(struct n_tty_data *ldata, size_t i)
 	return &ldata->echo_buf[i & (N_TTY_BUF_SIZE - 1)];
 }
 
+/* If we are not echoing the data, perhaps this is a secret so erase it */
+static void zero_buffer(struct tty_struct *tty, u8 *buffer, int size)
+{
+	bool icanon = !!L_ICANON(tty);
+	bool no_echo = !L_ECHO(tty);
+
+	if (icanon && no_echo)
+		memset(buffer, 0x00, size);
+}
+
 static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
 			    size_t tail, size_t n)
 {
 	struct n_tty_data *ldata = tty->disc_data;
 	size_t size = N_TTY_BUF_SIZE - tail;
-	const void *from = read_buf_addr(ldata, tail);
+	void *from = read_buf_addr(ldata, tail);
 	int uncopied;
 
 	if (n > size) {
 		tty_audit_add_data(tty, from, size);
 		uncopied = copy_to_user(to, from, size);
+		zero_buffer(tty, from, size - uncopied);
 		if (uncopied)
 			return uncopied;
 		to += size;
@@ -171,7 +182,9 @@ static int tty_copy_to_user(struct tty_struct *tty, void __user *to,
 	}
 
 	tty_audit_add_data(tty, from, n);
-	return copy_to_user(to, from, n);
+	uncopied = copy_to_user(to, from, n);
+	zero_buffer(tty, from, n - uncopied);
+	return uncopied;
 }
 
 /**
@@ -1960,11 +1973,12 @@ static int copy_from_read_buf(struct tty_struct *tty,
 	n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);
 	n = min(*nr, n);
 	if (n) {
-		const unsigned char *from = read_buf_addr(ldata, tail);
+		unsigned char *from = read_buf_addr(ldata, tail);
 		retval = copy_to_user(*b, from, n);
 		n -= retval;
 		is_eof = n == 1 && *from == EOF_CHAR(tty);
 		tty_audit_add_data(tty, from, n);
+		zero_buffer(tty, from, n);
 		smp_store_release(&ldata->read_tail, ldata->read_tail + n);
 		/* Turn single EOF into zero-length read */
 		if (L_EXTPROC(tty) && ldata->icanon && is_eof &&

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

@@ -130,12 +130,8 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
 
 		l = l->next;
 
-		if (l == i->head && pass_counter++ > PASS_LIMIT) {
-			/* If we hit this, we're dead. */
-			printk_ratelimited(KERN_ERR
-				"serial8250: too much work for irq%d\n", irq);
+		if (l == i->head && pass_counter++ > PASS_LIMIT)
 			break;
-		}
 	} while (l != end);
 
 	spin_unlock(&i->lock);