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
  ...

2 files changed, 84 insertions, 1 deletions

diff --git a/Documentation/serial/driver b/Documentation/serial/driver
index da193e092fc3..86e47c19a924 100644
--- a/Documentation/serial/driver
+++ b/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
 <rmk@arm.linux.org.uk>
 
-The reference implementation is contained within amba_pl011.c.
+The reference implementation is contained within amba-pl011.c.
 
 
 
diff --git a/Documentation/serial/serial-iso7816.txt b/Documentation/serial/serial-iso7816.txt
new file mode 100644
index 000000000000..3193d24a2b0f
--- /dev/null
+++ b/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