Merge tag 'tty-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty

Pull tty / serial updates from Greg KH:
 "Here is the "big" set of tty/serial driver patches for 5.15-rc1

  Nothing major in here at all, just some driver updates and more
  cleanups on old tty apis and code that needed it that includes:

   - tty.h cleanup of things that didn't belong in it

   - other tty cleanups by Jiri

   - driver cleanups

   - rs485 support added to amba-pl011 driver

   - dts updates

   - stm32 serial driver updates

   - other minor fixes and driver updates

  All have been in linux-next for a while with no reported problems"

* tag 'tty-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (83 commits)
  tty: serial: uartlite: Use read_poll_timeout for a polling loop
  tty: serial: uartlite: Use constants in early_uartlite_putc
  tty: Fix data race between tiocsti() and flush_to_ldisc()
  serial: vt8500: Use of_device_get_match_data
  serial: tegra: Use of_device_get_match_data
  serial: 8250_ingenic: Use of_device_get_match_data
  tty: serial: linflexuart: Remove redundant check to simplify the code
  tty: serial: fsl_lpuart: do software reset for imx7ulp and imx8qxp
  tty: serial: fsl_lpuart: enable two stop bits for lpuart32
  tty: serial: fsl_lpuart: fix the wrong mapbase value
  mxser: use semi-colons instead of commas
  tty: moxa: use semi-colons instead of commas
  tty: serial: fsl_lpuart: check dma_tx_in_progress in tx dma callback
  tty: replace in_irq() with in_hardirq()
  serial: sh-sci: fix break handling for sysrq
  serial: stm32: use devm_platform_get_and_ioremap_resource()
  serial: stm32: use the defined variable to simplify code
  Revert "arm pl011 serial: support multi-irq request"
  tty: serial: samsung: Add Exynos850 SoC data
  tty: serial: samsung: Fix driver data macros style
  ...

1 files changed, 59 insertions, 0 deletions

diff --git a/include/linux/tty_buffer.h b/include/linux/tty_buffer.h
new file mode 100644
index 000000000000..3b9d77604291
--- /dev/null
+++ b/include/linux/tty_buffer.h
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_TTY_BUFFER_H
+#define _LINUX_TTY_BUFFER_H
+
+#include <linux/atomic.h>
+#include <linux/llist.h>
+#include <linux/mutex.h>
+#include <linux/workqueue.h>
+
+struct tty_buffer {
+	union {
+		struct tty_buffer *next;
+		struct llist_node free;
+	};
+	int used;
+	int size;
+	int commit;
+	int read;
+	int flags;
+	/* Data points here */
+	unsigned long data[];
+};
+
+/* Values for .flags field of tty_buffer */
+#define TTYB_NORMAL	1	/* buffer has no flags buffer */
+
+static inline unsigned char *char_buf_ptr(struct tty_buffer *b, int ofs)
+{
+	return ((unsigned char *)b->data) + ofs;
+}
+
+static inline char *flag_buf_ptr(struct tty_buffer *b, int ofs)
+{
+	return (char *)char_buf_ptr(b, ofs) + b->size;
+}
+
+struct tty_bufhead {
+	struct tty_buffer *head;	/* Queue head */
+	struct work_struct work;
+	struct mutex	   lock;
+	atomic_t	   priority;
+	struct tty_buffer sentinel;
+	struct llist_head free;		/* Free queue head */
+	atomic_t	   mem_used;    /* In-use buffers excluding free list */
+	int		   mem_limit;
+	struct tty_buffer *tail;	/* Active buffer */
+};
+
+/*
+ * When a break, frame error, or parity error happens, these codes are
+ * stuffed into the flags buffer.
+ */
+#define TTY_NORMAL	0
+#define TTY_BREAK	1
+#define TTY_FRAME	2
+#define TTY_PARITY	3
+#define TTY_OVERRUN	4
+
+#endif