TTY/Serial patches for 4.20-rc1

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.
 
 Signed-off-by: Greg Kroah-Hartman <[email protected]>
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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
  ...

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